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Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes
Please cite this article in press as: Yu and Manthiram, Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes, Joule (2017), https:// doi.org/10.1016/j.joule.2017.10.011
Perspective
Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes Xingwen Yu1 and Arumugam Manthiram1,*
This perspective presents a new battery concept with a ‘‘mediator-ion’’ solidstate electrolyte for the development of next-generation battery technologies to meet the growing needs of large-scale electrical energy storage. The uniqueness of this mediator-ion strategy is that the redox reactions at the anode and the cathode are sustained by a shuttling of a mediator ion between the anolyte and the catholyte through the solid-state electrolyte. The active anode and cathode materials can be in the form of solid, liquid, or gas. Use of a solid-electrolyte separator eliminates the common problem of chemical crossover between the anode and cathode, overcomes the dendrite problem when employing metal anodes, and offers the possibility of employing different liquid electrolytes at the anode and cathode. Based on these unique features, the mediator-ion battery concept offers a versatile approach for the development of a broad range of new battery systems. Introduction Energy is one of the most important societal topics.1,2 With the depletion of fossil fuels, we need to find alternative renewable energy resources that can provide low-cost, abundant, clean energy to support the 7 billion people presently living on the planet, and the expected 10-plus billion people by the end of this century.3–5 Renewable energy resources generally exist over geographically broad areas.6–8 International surveys of public opinion indicate that there is extremely strong support for promoting renewable sources of wind power and solar power.9–12 However, solar and wind energies are harvested intermittently and need efficient storage and utilization.13,14 Electrochemical energy storage, in the form of secondary (or rechargeable) batteries, is promising for these applications.15–23 Among the current battery technologies that either have been well developed or are being developed, low-temperature aqueous batteries always offer the most significant advantages for large-scale applications in terms of maintenance, safety, reliability, and cost.24–27 Conventionally, an aqueous battery is usually fabricated/ operated with a liquid electrolyte integrated porous separator. The liquid electrolyte provides an ionic path between the anode and the cathode. The separator is designed to electrically separate the two electrodes. In such a battery system, both the anode and the cathode must be in solid phase (e.g., Zn-MnO2 battery, Cd-NiOOH battery, MH-NiOOH battery, and lead-acid battery28–31), since the porous separator allows liquid or gaseous electrode materials to migrate from one electrode to the other. The electrode shuttle would induce undesired chemical reactions internally between the two electrodes. Furthermore, if any charge/discharge products (or intermediate products) are soluble in aqueous electrolyte, a chemical crossover between the two electrodes would occur and consequently result in self-discharge and a low efficiency of batteries.32–35 In case of employing a metal electrode, the formation of metal dendrite during cycling could lead to a
Context & Scale With the depletion of fossil fuels and growing environmental concerns, there is a pressing need for renewable energy resources that can provide abundant, clean, and low-cost energy to support our modern life. Wind and solar power are reliable, sustainable energy sources, but they are harvested intermittently. Therefore, proper storage technologies are needed to efficiently utilize the solar and wind energies. Electrochemical energy storage, in the form of rechargeable (or secondary) batteries, is one of the most promising technologies for storing renewable energies. In this perspective, a recently proposed and validated mediatorion battery concept is presented. It provides a novel strategy for the development of aqueous batteries with low-cost electrode materials to meet the growing needs of largescale electrochemical energy storage. The uniqueness of this battery-development strategy is that the redox reactions at the anode and cathode are ionically linked by a shuttling of a mediatorion through a solid-state electrolyte. Under the ‘‘mediatorion’’ operating principle, a broad range of new battery systems can be developed with a variety of lowcost, high-capacity, highelectromotive-force electrode materials in the forms of solid, liquid, or gas.
Joule 1, 1–10, November 15, 2017 ª 2017 Elsevier Inc.
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short-circuit in the battery since the metal dendrite could penetrate through the porous separator.36,37 From a fundamental point of view, it is known that many liquid-phase or gas-phase materials exhibit both high operating voltages and high electrochemical capacity, which are promising as electrodes for the development of high-energy, low-cost aqueous batteries.38–40 However, as discussed above, the traditional battery operating principle with a porous separator strictly limits the application of liquid or gaseous electrodes due to their tendency of shuttling through the porous separator along with the liquid electrolyte. With the use of a solid-electrolyte separator, it is possible to overcome such chemical-crossover problems of gaseous or liquid electrode materials. However, it is a challenge to develop aqueous batteries with low-cost anode chemistries, such as Zn, Fe, or Al, with a solid electrolyte, since solid electrolytes capable of transporting divalent or trivalent ions (e.g., Zn2+, Fe2+, or Al3+) are practically unavailable.41,42 In fact at present, cationic solid electrolytes at ambient temperatures are limited to alkali-metal ions (e.g., Li+ and Na+ ions), which only allow Li+ or Na+ ion transport. Given the above situation, a unique battery-development strategy has recently been pursued since 2013 by employing a mediator-ion solid-electrolyte separator.43–49 Over the last few years, a few aqueous battery systems have been successfully demonstrated with liquid or gaseous electrode materials.43–49 Herein, we introduce first the ‘‘mediator-ion’’ battery concept, followed by the history, progress, and future prospects of this novel development strategy. Battery Concept, Operating Principles, and Significance In a solid-electrolyte battery, the solid electrolyte acts as both an electrical separator and an ionic transport medium. Under the traditional battery operating principle, the battery systems demonstrated with lithium solid electrolytes (e.g., all-solid-state lithium-ion batteries50 and solid-electrolyte lithium-air batteries51) or sodium solid electrolytes (e.g., high-temperature Na-S batteries52 and high-temperature Na-NiCl2 batteries53) were all developed with the involvement of transporting ions (Li+ ion or Na+ ion) in the anode reactions. Therefore, it requires the use of Li-based or Na-based anode, limiting the adoption of aqueous anode chemistries since Li and Na cannot be used in aqueous environments.54–59 The mediator-ion strategy presented in this perspective aims at developing battery systems with all-aqueous battery chemistries. The mediator-ion, i.e., Li+-ion or Na+-ion, transport in the solid electrolyte acts as a ‘‘messenger’’ to balance the charge transfer at the anode and cathode, rather than being directly involved in the electrode reactions. The redox reactions at the cathode and anode in a cell are completely isolated by the solid electrolyte, but the electrochemical charge transfer at the cathode and anode are ‘‘ionically linked’’ by the shuttling of the mediator ion in the solid electrolyte, as schematically illustrated in Figure 1. Therefore, a variety of redox chemistries can be adopted in a cell under this operating principle. The significance of the presented mediator-ion strategy is that it provides an innovative battery-development platform for taking the best advantage of liquid-phase or gas-phase electrochemical energy materials to develop new low-cost, safe, aqueous battery systems. By properly managing the solid-state electrolyte (SSE), anolyte (the aqueous electrolyte at the anode), and catholyte (the aqueous electrolyte at the cathode), the mediator-ion battery concept will be a versatile approach for the development of a broad range of electrochemical energy storage systems.
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1Materials
Science & Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA *Correspondence: [email protected] https://doi.org/10.1016/j.joule.2017.10.011
Please cite this article in press as: Yu and Manthiram, Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes, Joule (2017), https:// doi.org/10.1016/j.joule.2017.10.011
Figure 1. Schematic of an Aqueous Electrochemical Energy Storage System Operated with a Mediator-Ion Solid Electrolyte
Mediator-Ion Batteries with Lithium-Ion Solid Electrolytes The mediator-ion aqueous batteries were first demonstrated with lithium-ion solidstate electrolytes (Li-SSE). In 2013, Chen et al. first presented an aqueous Zn-KMnO4 cell with a solid Zn anode and a liquid KMnO4 cathode.43 Under the traditional battery operating principle, KMnO4 is not supposed to be used as an active cathode due to its soluble nature in aqueous solution. In the study of Chen et al., a Li1+x+yAlxTi2-xSiyP3-yO12 (LATP) ceramic solid electrolyte was employed as an Li+-ion exchange membrane to separate an acidic cathode electrolyte and an alkaline anode electrolyte, as schematically illustrated in Figure 2A; the cell is annotated here as Zn(KOH/LiOH) k Li-SSE k KMnO4(H2SO4). Operating with an acidic-alkaline double electrolyte, a high-voltage Zn-KMnO4 cell (2.8 V) was successfully demonstrated. The Li+ ions migrate through the LATP membrane to support the redox reactions at the anode and cathode.43 In the next two years, Dong et al. (in 2014)44 and Zhang et al. (in 2015)45 respectively demonstrated Daniell-type batteries (with a zinc-copper [Zn-Cu] chemistry) with Li+-ion solid electrolytes. The traditional Daniell-type batteries are not rechargeable and pose serious self-discharge due to the crossover of Cu2+. The redesigned Daniell-type batteries demonstrated by Dong et al. and Zhang et al. employ a ceramic Li+-ion solid electrolyte to separate the Zn and Cu electrodes to prevent the Cu2+ crossover, as schematically illustrated in Figure 2B; the cell is annotated here as Zn(Zn(NO3)2) k Li-SSE k Cu(LiNO3). Thus, rechargeable Zn-Cu batteries without significant self-discharge characteristics were achieved. The Li+-ion in these studies was termed an ‘‘electrochemical messenger,’’ since it conducts ionic species (Li+-ion) rather than reacts with the two electrodes during battery operation.44,45 Since 2016, our group has demonstrated two aqueous battery systems (zinc-air and zinc-bromine batteries) based on an Li+-ion conductive solid electrolyte (LATP) and have termed this unique battery-development approach the mediator-ion strategy.46,47 By strategically separating an alkaline zinc anode and an acidic air cathode by an LATP solid-electrolyte separator as schematically illustrated in Figure 2C (the cell is annotated as Zn(LiOH) k Li-SSE k air (H3PO4/LiH2PO4)), the Zn-air battery we developed exhibited a higher cell voltage than conventional alkaline Zn-air batteries
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Figure 2. Schematic Illustrations of Mediator-Ion Batteries with Lithium-Ion Solid Electrolytes (A) Zn(KOH/LiOH) k Li-SSE k KMnO4 (H 2 SO 4 ) battery. (B) Zn(Zn(NO3 ) 2 ) k Li-SSE k Cu(LiNO 3 ) battery. (C) Zn(LiOH) k Li-SSE k air (H 3 PO4 /LiH2 PO4 ) battery. (D) Zn(LiOH) k Li-SSE k Br 2 (LiBr) battery. Reproduced with permission from Chen et al. 43 (copyright 2013, Royal Society of Chemistry), Don et al. 44 (copyright 2014, Nature Publishing Group), Li and Manthiram 47 (copyright 2016, John Wiley), and Yu et al. 46 (copyright 2017, John Wiley).
due to the higher potential of oxygen reduction reaction under acidic condition relative to that under alkaline condition. Operating the battery with an acidic air cathode also prevents the existence of a CO2 ingression problem in the conventional alkaline Zn-air batteries. In addition, the incorporation of a solid electrolyte circumvents the Zn-dendrite concerns.47 At ambient temperatures, bromine usually exists in a liquid phase. Therefore, it is difficult to utilize bromine as an electrode material to develop an aqueous battery with a traditional porous separator. A mediator-ion solid electrolyte can eliminate the chemical-crossover concern of liquid bromine. Figure 2D illustrates the mediator-ion Zn-Br2 battery developed by incorporating an LATP solid electrolyte (the cell is annotated as Zn(LiOH) k Li-SSE k Br2(LiBr)). With this battery system as an example, the charge-discharge mechanism of the mediator-ion battery concept is briefly described here. The discharge-charge mechanisms of the other mediatorion battery systems are similar to those of the Zn-Br2 battery system. The reaction occurring at the anode during discharge involves the oxidation of zinc-metal to form zinc ions (Zn2+). Under an alkaline condition, Zn2+ would combine with the OH to produce zincate ions (Zn(OH)42). The reduction of liquid Br2 at the cathode produces bromide ions (Br). Meanwhile, the Li+ ions in the anolyte transport through the LATP solid electrolyte to balance the ionic charge between the two electrodes. The processes are reversed during the charge process. At the anode, the Zn(OH)42 ions are reduced to Zn metal, which is deposited onto the anode current collector. The combination of the Li+ ions with OH ions forms soluble LiOH in the solution.
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Figure 3. Schematic Illustration of Mediator-Ion Batteries with Sodium-Ion Solid Electrolytes (A) Zn(NaOH) k Na-SSE k Br 2 (NaBr) battery. (B) Zn(NaOH) k Na-SSE k K3 Fe(CN) 6 (NaOH) battery. (C) Fe(NaOH) k Na-SSE k O2 (H3 PO4 /NaH 2 PO 4 ) battery. (D) Fe(NaOH) k Na-SSE k K3 Fe(CN) 6 (NaOH) battery. (E) Zn(NaOH) k Na-SSE k air (H 3 PO 4 /NaH 2 PO4 ) battery. (F) Zn(NaOH) k Na-SSE k Ce 4+(MSA/Na 2 SO4 ) battery. Reproduced with permission from Yu et al. 46 (copyright 2017, John Wiley), Yu and Manthiram 48 (copyright 2017, American Chemical Society), and Yu and Manthiram 49 (copyright 2017, John Wiley).
At the cathode, the Br is oxidized to Br2. To maintain an ionic charge balance, Li+ ions migrate backward from the cathode to the anode through the solid electrolyte. Mediator-Ion Batteries with Sodium-Ion Solid Electrolytes In addition to the Li+-ion solid electrolytes, room-temperature sodium-ion (Na+-ion) solid-state electrolytes (Na-SSE) are applicable to the development of mediator-ion batteries. Our group has recently demonstrated and validated a number of mediator-ion battery systems with two types of Na+-ion solid electrolytes, Na3.4Sc2(PO4)2.6(SiO4)0.4 (synthesized in our laboratory) and Na3Zr2Si2PO12 (NZSP, provided by the 421 Energy Corporation, South Korea).46,48,49 Figure 3 schematically illustrates these battery systems (the cell annotations are as described in the legend of Figure 3). The discharge-charge mechanisms of the mediator-ion batteries with the sodium-ion solid electrolytes are similar to those with the lithium-ion solid electrolytes. The Na+-ion shuttling through the solid electrolyte between the cathode and anode acts as an ionic mediator of charge transfer rather than being directly involved in the electrochemical reactions. The redox reactions at the cathode and anode are ionically linked by the sodium mediator ion. With the Fe(NaOH) k Na-SSE k O2(H3PO4/NaH2PO4) battery system as an example, the charge-discharge mechanism of the sodium-ion-mediated batteries is now briefly described. On discharge, the iron anode is oxidized to a mixture of Fe2+ and Fe3+ to form the mixed hydroxides Fe(OH)2 and Fe(OH)3, which can be expressed as Fe(OH)n.48 At the cathode side, the O2 is reduced to H2O. To maintain charge balance, the Na+ ions in the
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Figure 4. Polarization and Impedance Behaviors of the the Zn(NaOH) k Na-SSE k Br2(NaBr) and Zn(LiOH) k Li-SSE k Br2(LiBr) Cells (A) Voltage profiles of the Zn(NaOH) k Na-SSE k Br 2 (NaBr) and Zn(LiOH) k Li-SSE k Br 2 (LiBr) cells operated at 1.0 mA cm 2 . (B) Voltage profiles of the Zn(NaOH) k Na-SSE k Br 2 (NaBr) and Zn(LiOH) k Li-SSE k Br 2 (LiBr) cells operated at 3.0 mA cm 2 . (C) Nyquist plots of the electrochemical impedance spectroscopies of the Zn(NaOH) k Na-SSE k Br 2 (NaBr) and the Zn(LiOH) k Li-SSE k Br 2 (LiBr) cells. Reproduced with permission from Yu et al. 46 (copyright 2017, John Wiley).
anolyte migrate through the Na-SSE to the cathode side. These processes are reversed during charge. The Fe(OH)n is reduced to metallic Fe at the anode, while the H2O is oxidized to O2 at the cathode. Meanwhile Na+ ions migrate back to the anolyte through the Na-SSE to form NaOH. The discharge-charge mechanisms of the other sodium-ion-mediated battery systems are similar to the above descriptions. We have found that the sodium-ion solid electrolytes are a better option than the Li+-ion solid electrolytes for the development of mediator-ion batteries, especially with respect to the high abundance of sodium and the relatively high chemical/ electrochemical stability of sodium-ion solid electrolytes in aqueous environments.43–45,47 Moreover, sodium-ion solid electrolytes offer an exceptional advantage for their convenience in matching up with the liquid catholytes and anolytes to be used. This is because both the dissociation behavior and the solubility of Na salts (e.g., NaOH) are relatively higher than those of Li salts (e.g., LiOH).60 We have compared the cycling performances of two mediator-ion Zn-Br2 batteries with the same electrode chemistry but respectively prepared with Li+-ion and Na+-ion solid electrolytes. The anolytes and catholytes in these two batteries were accordingly adjusted to match, respectively, the lithium or the sodium mediator ion. The two cells are, respectively, termed Zn(NaOH) k Na-SSE k Br2(NaBr) cell and Zn(LiOH) k Li-SSE k Br2(LiBr). Figures 4A and 4B compare the discharge-charge voltages of the two cells at the current densities of, respectively, 1.0 mA cm2 and 3.0 mA cm2. It is observed that the Zn(LiOH) k Li-SSE k Br2(LiBr) cell shows relatively higher polarization behavior.46 Figure 4C compares the electrochemical impedance spectroscopy data obtained with the two cells. The Zn(NaOH) k Na-SSE k Br2(NaBr) cell exhibits relatively lower impedance than the Zn(LiOH) k Li-SSE k Br2(LiBr) cell.46 Conclusions, Challenges, and Outlook This perspective presents a recently validated mediator-ion battery concept that offers a new strategy for the development of aqueous batteries with alkali-metalion solid-electrolyte separators and inexpensive anodes such as Zn and Fe. The uniqueness of this mediator-ion approach is that the redox reactions at the anode and cathode are sustained by a shuttling of the mediator alkali-metal ion between the anode electrolyte (anolyte) and the cathode electrolyte (catholyte). The alkalimetal ion (lithium ion or sodium ion) in the solid electrolytes serves as an ionic mediator of charge transfer between the cathode and anode, rather than directly
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Table 1. Summary of the Aqueous Mediator-Ion Battery Systems that Have So Far Been Demonstrated: Specifications of the Anode, Anolyte, Solid Electrolyte, Catholyte, and Cathode Cell Annotation
Anode
Anolyte
Solid Electrolyte
Catholyte
Cathode
Reference
Zn(KOH/LiOH) k Li-SSE k KMnO4(H2SO4)
Zn
KOH/LiOH
Li1+x+yAlxTi2-xSiyP3-yO12
H2SO4/KMnO4
KMnO4
Chen et al.43
Zn(Zn(NO3)2) k Li-SSE k Cu(LiNO3)
Zn
Zn(NO3)2
Li1+x+yAlxTi2-xSiyP3-yO12
LiNO3
Cu
Dong et al.44
Zn(ZnSO4/Li2SO4) k Li-SSE k Cu(CuSO4/ Li2SO4)
Zn
ZnSO4/ Li2SO4
Li1+x+yAlxTi2-xSiyP3-yO12
CuSO4/Li2SO4
Cu
Zhang et al.45
Zn(LiOH) k Li-SSE k air (H3PO4/LiH2PO4)
Zn
LiOH
Li1+x+yAlxTi2-xSiyP3-yO12
H3PO4/LiH2PO4
O2-Pt/C-IrO2
Li et al.47
Zn(LiOH) k Li-SSE k Br2(LiBr)
Zn
LiOH
Li1+x+yAlxTi2-xSiyP3-yO12
Br2/LiBr
Br2
Yu et al.46
Zn(NaOH) k Na-SSE k Br2(NaBr)
Zn
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
Br2/NaBr
Br2
Yu et al.46
Zn(NaOH) k Na-SSE k air (H3PO4/NaH2PO4)
Zn
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
H3PO4/NaH2PO4
O2-Pt/C-IrO2
Yu et al.46
Zn(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
Zn
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
K3Fe(CN)6/NaOH
K3Fe(CN)6
Yu et al.46
Fe(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
Fe
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
K3Fe(CN)6/NaOH
K3Fe(CN)6
Yu et al.46
Fe(NaOH) k Na-SSE k O2(H3PO4/NaH2PO4)
Fe
NaOH
Na3Zr2Si2PO12
H3PO4/NaH2PO4
O2-Pt/C-IrO2
Yu et al.48
Zn
NaOH
Na3Zr2Si2PO12
Ce(SO4)2/CH4SO3/ H2SO4/Na2SO4
Ce(SO4)2
Yu et al.49
4+
Zn(NaOH) k Na-SSE k Ce (MSA/Na2SO4)
involving the electrode reactions. So far this novel battery concept has been demonstrated through the operation of a number of aqueous battery systems with various solid, liquid, or gaseous electrode materials, as well as different mediator-ion solid electrolytes, as summarized in Table 1. The electrochemical performances of these aqueous mediator-ion batteries in terms of cell voltage, cycle life, and power density are summarized in Table 2. The most significant contribution of this mediator-ion strategy is that it allows the use of active electrode (anode and cathode) materials in any physical form (either solid, liquid, or gas). Therefore, this novel battery strategy provides a versatile approach to making efficient use of gas-phase or liquid-phase electrochemical materials to develop inexpensive/affordable, safe, aqueous energy storage systems. The use of a solid-electrolyte separator completely eliminates the chemical-crossover problem of the liquid-phase or gas-phase electrode materials and circumvents the dendrite problem in the case of employing metal anodes. In addition, in such a battery system the anolyte and catholyte liquids can be completely different, offering great advantages for optimizing the cell components, voltage, energy density, and cost. In addition to the battery systems that have been demonstrated as listed in Table 1, this mediator-ion battery platform can be applied to a broad range of new redox couples. Although this battery concept has been demonstrated as a powerful platform for the development of future battery technologies, there are critical challenges that need to be considered. The first concern is the ionic conductivity of the currently available solid-electrolyte materials and the mechanical stability problems of the large-area solid-electrolyte separators. An optimistic note is that the research and development in the solid-electrolyte area is continuously progressing with concerted efforts by the SSE community. Both the mechanical property and ionic conductivity of solidelectrolyte materials are expected to be continuously improved in the future, which will benefit the technological platform of mediator-ion batteries. The second concern is the fabrication cost of solid electrolytes. At the current stage, the cost of technically viable solid electrolytes is chiefly contributed from the fabrication process. The material cost, especially for the sodium-ion solid electrolytes, is not a major concern. Therefore, the cost of solid electrolytes is actually not an
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Table 2. Electrochemical Performances of the Aqueous Mediator-Ion Battery Systems that Have So Far Been Demonstrated: Cell Voltage, Cycle Life, and Power Density Cell Annotation
Cell Voltage (V)
Cycle Life
Power Density
Reference
Zn(KOH/LiOH) k Li-SSE k KMnO4(H2SO4)
2.8
>100 hr
750 mW g1 KMnO4
Chen et al.43
Zn(Zn(NO3)2) k Li-SSE k Cu(LiNO3)
0.8
150 cycles
5.0 mW cm2
Dong et al.44
Zn(ZnSO4/Li2SO4) k Li-SSE k Cu(CuSO4/Li2SO4)
0.9
NA
6.0 mW cm2
Zhang et al.45
Zn(LiOH) k Li-SSE k air (H3PO4/LiH2PO4)
1.8
50 cycles
4.5 mW cm2
Li et al.47
Zn(LiOH) k Li-SSE k Br2(LiBr)
2.0
50 cycles
8.0 mW cm2
Yu et al.46
2
Yu et al.46
Zn(NaOH) k Na-SSE k Br2(NaBr)
2.2
50 cycles
14.0 mW cm
Zn(NaOH) k Na-SSE k air (H3PO4/NaH2PO4)
1.8
25 cycles
5.0 mW cm2
Yu et al.46
Zn(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
1.65
50 cycles
14.0 mW cm2
Yu et al.46
Fe(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
1.0
18 cycles
1.0 mW cm2
Yu et al.46
Fe(NaOH) k Na-SSE k O2(H3PO4/NaH2PO4)
1.5
50 cycles
2.0 mW cm2
Yu et al.48
Zn(NaOH) k Na-SSE k Ce4+(MSA/Na2SO4)
2.4
50 cycles
11.0 mW cm2
Yu et al.49
intrinsic issue. With the continuous advancements in the fabrication techniques, the SSEs are expected to become more affordable. The third concern is the long-term chemical stability of the ceramic electrolytes in aqueous solutions. Currently there is an urgent need to perform a rigorous and comprehensive study on the stability of both the Li-SSE and the Na-SSE materials in different aqueous solutions. From our preliminary experience, the LATP membrane exhibits good compatibility and stability with the alkaline anolyte and weakly acidic catholyte.47 According to the information provided by the supplier of the sodium solid electrolyte, Na3Zr2Si2PO12 used for the demonstration of the mediatorion batteries is basically stable under the cell operating conditions.48,49 The fourth major concern is that the capacity of the mediator-ion batteries is possibly affected by the requirement of a certain amount of mediator ions (M+) in the electrolyte (both the anolyte and the catholyte) to maintain an ionic charge balance between the anode and the cathode. The mediator-ion compounds exist as a supporting electrolyte and are electrochemically inactive, thus lowering the gravimetric (largely) and volumetric (slightly) energy densities of the battery system. However, since the mediator-ion approach offers multiple advantages in enhancing the cell voltage and optimizing the cell components, the negative impact from the supporting electrolytes can be compensated. On the other hand, for the impact from the use of supporting electrolytes to be minimized, additional efforts are needed to optimize the amount of mediator ions in the cell.
ACKNOWLEDGMENTS This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under award number DE-SC0005397.
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REFERENCES 1. Michelson, E.S. (2016). Which way for the world? A review of energy, economic growth, and geopolitical futures: eight long-range scenarios. Futures 78-79, 71–73. 2. Crowley, B. (2000). Statistical review of world energy. Hydrocarb. Process. 79, 23. 3. Gilland, B. (1995). World-population, economic-growth, and energy demand, 19902100—a review of projections. Popul. Dev. Rev. 21, 507–512. 4. Liu, W., and Ramirez, A. (2017). State of the art review of the environmental assessment and risks of underground geo-energy resources exploitation. Renew. Sust. Energ. Rev. 76, 628–644. 5. Tiewsoh, L.S., Sivek, M., and Jirasek, J. (2017). Traditional energy resources in India (coal, crude oil, natural gas): a review. Energ. Source Part B 12, 110–118. 6. Hepbasli, A. (2008). A key review on exergetic analysis and assessment of renewable energy resources for a sustainable future. Renew. Sust. Energ. Rev. 12, 593–661. 7. Izadyar, N., Ong, H.C., Chong, W.T., and Leong, K.Y. (2016). Resource assessment of the renewable energy potential for a remote area: a review. Renew. Sust. Energ. Rev. 62, 908–923. 8. Momoh, J.A., and Reddy, S.S. (2014). Review of optimization techniques for renewable energy resources. 2014 IEEE Symposium on Power Electronics and Machines for Wind and Water Applications. 14617982. 9. Kannan, N., and Vakeesan, D. (2016). Solar energy for future world: a review. Renew. Sust. Energ. Rev. 62, 1092–1105. 10. Al-Falahi, M.D.A., Jayasinghe, S.D.G., and Enshaei, H. (2017). A review on recent size optimization methodologies for standalone solar and wind hybrid renewable energy system. Energ. Convers. Manage. 143, 252–274. 11. Bird, L., Lew, D., Milligan, M., Carlini, E.M., Estanqueiro, A., Flynn, D., Gomez-Lazaro, E., Holttinen, H., Menemenlis, N., Orths, A., et al. (2016). Wind and solar energy curtailment: a review of international experience. Renew. Sust. Energ. Rev. 65, 577–586. 12. Lianos, P. (2017). Review of recent trends in photoelectrocatalytic conversion of solar energy to electricity and hydrogen. Appl. Catal. B 210, 235–254. 13. Abhinav, R., and Pindoriya, N.M. (2016). Grid integration of wind turbine and battery energy storage system: review and key challenges. 2016 IEEE 6th International Conference on Power Systems 16358802. 14. Gunter, N., and Marinopoulos, A. (2016). Energy storage for grid services and applications: classification, market review, metrics, and methodology for evaluation of deployment cases. J. Energy Storage 8, 226–234. 15. Wang, G.S., Konstantinou, G., Townsend, C.D., Pou, J., Vazquez, S., Demetriades, G.D., and Agelidis, V.G. (2016). A review of power electronics for grid connection of utility-scale
battery energy storage systems. IEEE Trans. Sustain. Energy 7, 1778–1790. 16. Dunn, B., Kamath, H., and Tarascon, J.M. (2011). Electrical energy storage for the grid: a battery of choices. Science 334, 928–935. 17. Yang, Z.G., Zhang, J., Kintner-Meyer, M.C., Lu, X., Choi, D., Lemmon, J.P., and Liu, J. (2011). Electrochemical energy storage for green grid. Chem. Rev. 111, 3577–3613. 18. Goodenough, J.B. (2013). Evolution of strategies for modern rechargeable batteries. Acc. Chem. Res. 46, 1053–1061. 19. Sun, T., Li, Z.J., Wang, H.G., Bao, D., Meng, F.L., and Zhang, X.B. (2016). A Biodegradable polydopamine-derived electrode material for high-capacity and long-life lithium-ion and sodium-ion batteries. Angew. Chem. Int. Ed. 55, 10662–10666. 20. Zhu, Y.H., Yuan, S., Bao, D., Yin, Y.B., Zhong, H.X., Zhang, X.B., Yan, J.M., and Jiang, Q. (2017). Decorating waste cloth via industrial wastewater for tube-type flexible and wearable sodium-ion batteries. Adv. Mater. 29, 1603719.
technology for consumer and electric vehicle batteries—a review and up-date. J. Power Sources 65, 1–7. 31. Singh, A., and Karandikar, P.B. (2017). A broad review on desulfation of lead-acid battery for electric hybrid vehicle. Microsyst. Technol. 23, 2263–2273. 32. Yu, X.W., and Licht, S. (2007). Advances in Fe(VI) charge storage Part II. Reversible alkaline super-iron batteries and nonaqueous superiron batteries. J. Power Sources 171, 1010– 1022. 33. Yu, X.W., and Lich, S. (2007). Advances in Fe(VI) charge storage part I. primary alkaline superiron batteries. J. Power Sources 171, 966–980. 34. Manthiram, A., Fu, Y.Z., and Su, Y.S. (2013). Challenges and prospects of lithium-sulfur batteries. Acc. Chem. Res. 46, 1125–1134. 35. Manthiram, A., and Yu, X.W. (2015). Ambient temperature sodium-sulfur batteries. Small 11, 2108–2114.
21. Zhu, Y.H., Yin, Y.B., Yang, X., Sun, T., Wang, S., Jiang, Y.S., Yan, J.M., and Zhang, X.B. (2017). Transformation of rusty stainless-steel meshes into stable, low-cost, and binder-free cathodes for high-performance potassium-ion batteries. Angew. Chem. Int. Ed. 56, 7881–7885.
36. Song, Y.X., Hu, J., Tang, J., Gu, W., He, L., and Ji, X. (2016). Real-time X-ray imaging reveals interfacial growth, suppression, and dissolution of zinc dendrites dependent on anions of ionic liquid additives for rechargeable battery applications. ACS Appl. Mater. Interfaces 8, 32031–32040.
22. Xu, J.J., Chang, Z.W., Wang, Y., Liu, D.P., Zhang, Y., and Zhang, X.B. (2016). Cathode surface-induced, solvation-mediated, micrometer-sized Li2O2 cycling for Li-O2 batteries. Adv. Mater. 28, 9620–9628.
37. Wang, K.L., Pei, P.C., Ma, Z., Chen, H.C., Xu, H.C., Chen, D.F., and Wang, X.Z. (2015). Dendrite growth in the recharging process of zinc-air batteries. J Mater Chem A 3, 22648– 22655.
23. Yin, Y.B., Xu, J.J., Liu, Q.C., and Zhang, X.B. (2016). Macroporous interconnected hollow carbon nanofibers inspired by golden-toad eggs toward a binder-free, high-rate, and flexible electrode. Adv. Mater. 28, 7494–7500.
38. Kilner, J., Irvine, S., and Edwards, P. (2012). Functional Materials for Sustainable Energy Applications, First Edition (Woodhead Publishing).
24. Chen, A.X., and Sen, P.K. (2016). Advancement in battery technology: a state-of-the-art review. IEEE Industry Applications Society Annual Meeting, 16447436. 25. Malhotra, A., Battke, B., Beuse, M., Stephan, A., and Schmidt, T. (2016). Use cases for stationary battery technologies: a review of the literature and existing projects. Renew. Sust. Energy Rev. 56, 705–721. 26. Claus, D., and Besenhard, J. (2011). Handbook of Battery Materials, Second Edition (Wiley-VCH). 27. Crompton, T. (2000). Battery Reference Book, Third Edition (Butterworth-Heinemann). 28. Pan, H.L., Shao, Y.Y., Yan, P.F., Cheng, Y.W., Han, K.S., Nie, Z.M., Wang, C.M., Yang, J.H., Li, X.L., Bhattacharya, P., et al. (2016). Reversible aqueous zinc/manganese oxide energy storage from conversion reactions. Nat. Energy 1, 16039. 29. Pourabdollah, K. (2017). Development of electrolyte inhibitors in nickel cadmium batteries. Chem. Eng. Sci. 160, 304–312. 30. Dhar, S.K., Ovshinsky, S.R., Gifford, P.R., Corrigan, D.A., Fetcenko, M.A., and Venkatesan, S. (1997). Nickel metal hydride
39. Granqvist, C.G. (1995). Handbook of Inorganic Electrochromic Materials (Elsevier Science). 40. Bard, A.J. (2001). Electrochemical Methods: Fundamentals and Applications, Second Edition (John Wiley). 41. Kohler, J., Imanaka, N., and Adachi, G.Y. (1998). Multivalent cationic conduction in crystalline solids. Chem. Mater. 10, 3790–3812. 42. Ikeda, S., Kanbayashi, Y., Nomura, K., Kasai, A., and Ito, K. (1990). Solid electrolytes with multivalent cation conduction. Zinc ion conduction in Zn-Zr-PO4 system. Solid State Ionics 40-41, 79–82. 43. Chen, L., Guo, Z.Y., Xia, Y.Y., and Wang, Y.G. (2013). High-voltage aqueous battery approaching 3 V using an acidic-alkaline double electrolyte. Chem. Commun. (Camb.) 49, 2204–2206. 44. Dong, X.L., Wang, Y.G., and Xia, Y.G. (2014). Re-building Daniell cell with a Li-ion exchange film. Sci. Rep. 4, 6916. 45. Zhang, H.P., Yang, T., Wu, X., Zhou, Y., Yang, C., Zhu, T., and Dong, R. (2015). Using Li+ as the electrochemical messenger to fabricate battery. Chem. Commun. (Camb.) 51, 7294– 7297.
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Please cite this article in press as: Yu and Manthiram, Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes, Joule (2017), https:// doi.org/10.1016/j.joule.2017.10.011
46. Yu, X.W., Gross, M.M., Wang, S.F., and Manthiram, A. (2017). Aqueous electrochemical energy storage with a mediator-ion solid electrolyte. Adv. Energy Mater. 7, 1602454. 47. Li, L.J., and Manthiram, A. (2016). Long-life, high-voltage acidic Zn-air batteries. Adv. Energy Mater. 6, 1502054. 48. Yu, X.W., and Manthiram, A. (2017). A voltageenhanced, low-cost aqueous iron-air battery enabled with a mediator-ion solid electrolyte. ACS Energy Lett. 2, 1050–1055. 49. Yu, X.W., and Manthiram, A. (2017). A zinccerium cell for energy storage using a sodiumion exchange membrane. Adv. Sustain. Syst. 1, 1700082. 50. Kerman, K., Luntz, A., Viswanathan, V., Chiang, Y.M., and Chen, Z.B. (2017). Review—practical challenges hindering the development of solid state Li ion batteries. J. Electrochem. Soc. 164, A1731–A1744.
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Joule 1, 1–10, November 15, 2017
51. He, P., Zhang, T., Jiang, J., and Zhou, H.S. (2016). Lithium-air batteries with hybrid electrolytes. J. Phys. Chem. Lett. 7, 1267–1280.
56. Goodenough, J.B., Hong, H.Y.P., and Kafalas, J.A. (1976). Fast Na+-ion transport in skeleton structures. Mater. Res. Bull. 11, 203–220.
52. Gordon, R.S. (1974). Critical review of materials problems in sodium sulfur battery. Am. Ceram. Soc. Bull. 53, 616.
57. Hayashi, A., Noi, K., Tanibata, N., Nagao, M., and Tatsumisago, M. (2014). High sodium ion conductivity of glass ceramic electrolytes with cubic Na3PS4. J. Power Sources 258, 420–423.
53. Chang, H.J., Canfield, N.L., Jung, K., Sprenkle, V.L., and Li, G.S. (2017). Advanced Na-NiCl2 battery using nickel-coated graphite with core shell microarchitecture. ACS Appl. Mater. Interfaces 9, 11609–11614. 54. Goodenough, J.B., and Singh, P. (2015). Review—solid electrolytes in rechargeable electrochemical cells. J. Electrochem. Soc. 162, A2387–A2392. 55. Bachman, J.C., Muy, S., Grimaud, A., Chang, H.H., Pour, N., Lux, S.F., Paschos, O., Maglia, F., Lupart, S., Lamp, P., et al. (2016). Inorganic solid-state electrolytes for lithium batteries: mechanisms and properties governing ion conduction. Chem. Rev. 116, 140–162.
58. Kim, J.G., Son, B., Mukherjee, S., Schuppert, N., Bates, A., Kwon, O., Choi, M.J., Chung, H.Y., and Park, S. (2015). A review of lithium and non-lithium based solid state batteries. J. Power Sources 282, 299–322. 59. Kubota, K., and Komaba, S. (2015). Review— practical issues and future perspective for Naion batteries. J. Electrochem. Soc. 162, A2538– A2550. 60. Corti, H., Crovetto, R., and Fernandezprini, R. (1979). Aqueous-solutions of lithium hydroxide at various temperatures—conductivity and activity-coefficients. J. Solution Chem. 8, 897–908.
Perspective
Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes Xingwen Yu1 and Arumugam Manthiram1,*
This perspective presents a new battery concept with a ‘‘mediator-ion’’ solidstate electrolyte for the development of next-generation battery technologies to meet the growing needs of large-scale electrical energy storage. The uniqueness of this mediator-ion strategy is that the redox reactions at the anode and the cathode are sustained by a shuttling of a mediator ion between the anolyte and the catholyte through the solid-state electrolyte. The active anode and cathode materials can be in the form of solid, liquid, or gas. Use of a solid-electrolyte separator eliminates the common problem of chemical crossover between the anode and cathode, overcomes the dendrite problem when employing metal anodes, and offers the possibility of employing different liquid electrolytes at the anode and cathode. Based on these unique features, the mediator-ion battery concept offers a versatile approach for the development of a broad range of new battery systems. Introduction Energy is one of the most important societal topics.1,2 With the depletion of fossil fuels, we need to find alternative renewable energy resources that can provide low-cost, abundant, clean energy to support the 7 billion people presently living on the planet, and the expected 10-plus billion people by the end of this century.3–5 Renewable energy resources generally exist over geographically broad areas.6–8 International surveys of public opinion indicate that there is extremely strong support for promoting renewable sources of wind power and solar power.9–12 However, solar and wind energies are harvested intermittently and need efficient storage and utilization.13,14 Electrochemical energy storage, in the form of secondary (or rechargeable) batteries, is promising for these applications.15–23 Among the current battery technologies that either have been well developed or are being developed, low-temperature aqueous batteries always offer the most significant advantages for large-scale applications in terms of maintenance, safety, reliability, and cost.24–27 Conventionally, an aqueous battery is usually fabricated/ operated with a liquid electrolyte integrated porous separator. The liquid electrolyte provides an ionic path between the anode and the cathode. The separator is designed to electrically separate the two electrodes. In such a battery system, both the anode and the cathode must be in solid phase (e.g., Zn-MnO2 battery, Cd-NiOOH battery, MH-NiOOH battery, and lead-acid battery28–31), since the porous separator allows liquid or gaseous electrode materials to migrate from one electrode to the other. The electrode shuttle would induce undesired chemical reactions internally between the two electrodes. Furthermore, if any charge/discharge products (or intermediate products) are soluble in aqueous electrolyte, a chemical crossover between the two electrodes would occur and consequently result in self-discharge and a low efficiency of batteries.32–35 In case of employing a metal electrode, the formation of metal dendrite during cycling could lead to a
Context & Scale With the depletion of fossil fuels and growing environmental concerns, there is a pressing need for renewable energy resources that can provide abundant, clean, and low-cost energy to support our modern life. Wind and solar power are reliable, sustainable energy sources, but they are harvested intermittently. Therefore, proper storage technologies are needed to efficiently utilize the solar and wind energies. Electrochemical energy storage, in the form of rechargeable (or secondary) batteries, is one of the most promising technologies for storing renewable energies. In this perspective, a recently proposed and validated mediatorion battery concept is presented. It provides a novel strategy for the development of aqueous batteries with low-cost electrode materials to meet the growing needs of largescale electrochemical energy storage. The uniqueness of this battery-development strategy is that the redox reactions at the anode and cathode are ionically linked by a shuttling of a mediatorion through a solid-state electrolyte. Under the ‘‘mediatorion’’ operating principle, a broad range of new battery systems can be developed with a variety of lowcost, high-capacity, highelectromotive-force electrode materials in the forms of solid, liquid, or gas.
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short-circuit in the battery since the metal dendrite could penetrate through the porous separator.36,37 From a fundamental point of view, it is known that many liquid-phase or gas-phase materials exhibit both high operating voltages and high electrochemical capacity, which are promising as electrodes for the development of high-energy, low-cost aqueous batteries.38–40 However, as discussed above, the traditional battery operating principle with a porous separator strictly limits the application of liquid or gaseous electrodes due to their tendency of shuttling through the porous separator along with the liquid electrolyte. With the use of a solid-electrolyte separator, it is possible to overcome such chemical-crossover problems of gaseous or liquid electrode materials. However, it is a challenge to develop aqueous batteries with low-cost anode chemistries, such as Zn, Fe, or Al, with a solid electrolyte, since solid electrolytes capable of transporting divalent or trivalent ions (e.g., Zn2+, Fe2+, or Al3+) are practically unavailable.41,42 In fact at present, cationic solid electrolytes at ambient temperatures are limited to alkali-metal ions (e.g., Li+ and Na+ ions), which only allow Li+ or Na+ ion transport. Given the above situation, a unique battery-development strategy has recently been pursued since 2013 by employing a mediator-ion solid-electrolyte separator.43–49 Over the last few years, a few aqueous battery systems have been successfully demonstrated with liquid or gaseous electrode materials.43–49 Herein, we introduce first the ‘‘mediator-ion’’ battery concept, followed by the history, progress, and future prospects of this novel development strategy. Battery Concept, Operating Principles, and Significance In a solid-electrolyte battery, the solid electrolyte acts as both an electrical separator and an ionic transport medium. Under the traditional battery operating principle, the battery systems demonstrated with lithium solid electrolytes (e.g., all-solid-state lithium-ion batteries50 and solid-electrolyte lithium-air batteries51) or sodium solid electrolytes (e.g., high-temperature Na-S batteries52 and high-temperature Na-NiCl2 batteries53) were all developed with the involvement of transporting ions (Li+ ion or Na+ ion) in the anode reactions. Therefore, it requires the use of Li-based or Na-based anode, limiting the adoption of aqueous anode chemistries since Li and Na cannot be used in aqueous environments.54–59 The mediator-ion strategy presented in this perspective aims at developing battery systems with all-aqueous battery chemistries. The mediator-ion, i.e., Li+-ion or Na+-ion, transport in the solid electrolyte acts as a ‘‘messenger’’ to balance the charge transfer at the anode and cathode, rather than being directly involved in the electrode reactions. The redox reactions at the cathode and anode in a cell are completely isolated by the solid electrolyte, but the electrochemical charge transfer at the cathode and anode are ‘‘ionically linked’’ by the shuttling of the mediator ion in the solid electrolyte, as schematically illustrated in Figure 1. Therefore, a variety of redox chemistries can be adopted in a cell under this operating principle. The significance of the presented mediator-ion strategy is that it provides an innovative battery-development platform for taking the best advantage of liquid-phase or gas-phase electrochemical energy materials to develop new low-cost, safe, aqueous battery systems. By properly managing the solid-state electrolyte (SSE), anolyte (the aqueous electrolyte at the anode), and catholyte (the aqueous electrolyte at the cathode), the mediator-ion battery concept will be a versatile approach for the development of a broad range of electrochemical energy storage systems.
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1Materials
Science & Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA *Correspondence: [email protected] https://doi.org/10.1016/j.joule.2017.10.011
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Figure 1. Schematic of an Aqueous Electrochemical Energy Storage System Operated with a Mediator-Ion Solid Electrolyte
Mediator-Ion Batteries with Lithium-Ion Solid Electrolytes The mediator-ion aqueous batteries were first demonstrated with lithium-ion solidstate electrolytes (Li-SSE). In 2013, Chen et al. first presented an aqueous Zn-KMnO4 cell with a solid Zn anode and a liquid KMnO4 cathode.43 Under the traditional battery operating principle, KMnO4 is not supposed to be used as an active cathode due to its soluble nature in aqueous solution. In the study of Chen et al., a Li1+x+yAlxTi2-xSiyP3-yO12 (LATP) ceramic solid electrolyte was employed as an Li+-ion exchange membrane to separate an acidic cathode electrolyte and an alkaline anode electrolyte, as schematically illustrated in Figure 2A; the cell is annotated here as Zn(KOH/LiOH) k Li-SSE k KMnO4(H2SO4). Operating with an acidic-alkaline double electrolyte, a high-voltage Zn-KMnO4 cell (2.8 V) was successfully demonstrated. The Li+ ions migrate through the LATP membrane to support the redox reactions at the anode and cathode.43 In the next two years, Dong et al. (in 2014)44 and Zhang et al. (in 2015)45 respectively demonstrated Daniell-type batteries (with a zinc-copper [Zn-Cu] chemistry) with Li+-ion solid electrolytes. The traditional Daniell-type batteries are not rechargeable and pose serious self-discharge due to the crossover of Cu2+. The redesigned Daniell-type batteries demonstrated by Dong et al. and Zhang et al. employ a ceramic Li+-ion solid electrolyte to separate the Zn and Cu electrodes to prevent the Cu2+ crossover, as schematically illustrated in Figure 2B; the cell is annotated here as Zn(Zn(NO3)2) k Li-SSE k Cu(LiNO3). Thus, rechargeable Zn-Cu batteries without significant self-discharge characteristics were achieved. The Li+-ion in these studies was termed an ‘‘electrochemical messenger,’’ since it conducts ionic species (Li+-ion) rather than reacts with the two electrodes during battery operation.44,45 Since 2016, our group has demonstrated two aqueous battery systems (zinc-air and zinc-bromine batteries) based on an Li+-ion conductive solid electrolyte (LATP) and have termed this unique battery-development approach the mediator-ion strategy.46,47 By strategically separating an alkaline zinc anode and an acidic air cathode by an LATP solid-electrolyte separator as schematically illustrated in Figure 2C (the cell is annotated as Zn(LiOH) k Li-SSE k air (H3PO4/LiH2PO4)), the Zn-air battery we developed exhibited a higher cell voltage than conventional alkaline Zn-air batteries
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Figure 2. Schematic Illustrations of Mediator-Ion Batteries with Lithium-Ion Solid Electrolytes (A) Zn(KOH/LiOH) k Li-SSE k KMnO4 (H 2 SO 4 ) battery. (B) Zn(Zn(NO3 ) 2 ) k Li-SSE k Cu(LiNO 3 ) battery. (C) Zn(LiOH) k Li-SSE k air (H 3 PO4 /LiH2 PO4 ) battery. (D) Zn(LiOH) k Li-SSE k Br 2 (LiBr) battery. Reproduced with permission from Chen et al. 43 (copyright 2013, Royal Society of Chemistry), Don et al. 44 (copyright 2014, Nature Publishing Group), Li and Manthiram 47 (copyright 2016, John Wiley), and Yu et al. 46 (copyright 2017, John Wiley).
due to the higher potential of oxygen reduction reaction under acidic condition relative to that under alkaline condition. Operating the battery with an acidic air cathode also prevents the existence of a CO2 ingression problem in the conventional alkaline Zn-air batteries. In addition, the incorporation of a solid electrolyte circumvents the Zn-dendrite concerns.47 At ambient temperatures, bromine usually exists in a liquid phase. Therefore, it is difficult to utilize bromine as an electrode material to develop an aqueous battery with a traditional porous separator. A mediator-ion solid electrolyte can eliminate the chemical-crossover concern of liquid bromine. Figure 2D illustrates the mediator-ion Zn-Br2 battery developed by incorporating an LATP solid electrolyte (the cell is annotated as Zn(LiOH) k Li-SSE k Br2(LiBr)). With this battery system as an example, the charge-discharge mechanism of the mediator-ion battery concept is briefly described here. The discharge-charge mechanisms of the other mediatorion battery systems are similar to those of the Zn-Br2 battery system. The reaction occurring at the anode during discharge involves the oxidation of zinc-metal to form zinc ions (Zn2+). Under an alkaline condition, Zn2+ would combine with the OH to produce zincate ions (Zn(OH)42). The reduction of liquid Br2 at the cathode produces bromide ions (Br). Meanwhile, the Li+ ions in the anolyte transport through the LATP solid electrolyte to balance the ionic charge between the two electrodes. The processes are reversed during the charge process. At the anode, the Zn(OH)42 ions are reduced to Zn metal, which is deposited onto the anode current collector. The combination of the Li+ ions with OH ions forms soluble LiOH in the solution.
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Figure 3. Schematic Illustration of Mediator-Ion Batteries with Sodium-Ion Solid Electrolytes (A) Zn(NaOH) k Na-SSE k Br 2 (NaBr) battery. (B) Zn(NaOH) k Na-SSE k K3 Fe(CN) 6 (NaOH) battery. (C) Fe(NaOH) k Na-SSE k O2 (H3 PO4 /NaH 2 PO 4 ) battery. (D) Fe(NaOH) k Na-SSE k K3 Fe(CN) 6 (NaOH) battery. (E) Zn(NaOH) k Na-SSE k air (H 3 PO 4 /NaH 2 PO4 ) battery. (F) Zn(NaOH) k Na-SSE k Ce 4+(MSA/Na 2 SO4 ) battery. Reproduced with permission from Yu et al. 46 (copyright 2017, John Wiley), Yu and Manthiram 48 (copyright 2017, American Chemical Society), and Yu and Manthiram 49 (copyright 2017, John Wiley).
At the cathode, the Br is oxidized to Br2. To maintain an ionic charge balance, Li+ ions migrate backward from the cathode to the anode through the solid electrolyte. Mediator-Ion Batteries with Sodium-Ion Solid Electrolytes In addition to the Li+-ion solid electrolytes, room-temperature sodium-ion (Na+-ion) solid-state electrolytes (Na-SSE) are applicable to the development of mediator-ion batteries. Our group has recently demonstrated and validated a number of mediator-ion battery systems with two types of Na+-ion solid electrolytes, Na3.4Sc2(PO4)2.6(SiO4)0.4 (synthesized in our laboratory) and Na3Zr2Si2PO12 (NZSP, provided by the 421 Energy Corporation, South Korea).46,48,49 Figure 3 schematically illustrates these battery systems (the cell annotations are as described in the legend of Figure 3). The discharge-charge mechanisms of the mediator-ion batteries with the sodium-ion solid electrolytes are similar to those with the lithium-ion solid electrolytes. The Na+-ion shuttling through the solid electrolyte between the cathode and anode acts as an ionic mediator of charge transfer rather than being directly involved in the electrochemical reactions. The redox reactions at the cathode and anode are ionically linked by the sodium mediator ion. With the Fe(NaOH) k Na-SSE k O2(H3PO4/NaH2PO4) battery system as an example, the charge-discharge mechanism of the sodium-ion-mediated batteries is now briefly described. On discharge, the iron anode is oxidized to a mixture of Fe2+ and Fe3+ to form the mixed hydroxides Fe(OH)2 and Fe(OH)3, which can be expressed as Fe(OH)n.48 At the cathode side, the O2 is reduced to H2O. To maintain charge balance, the Na+ ions in the
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Figure 4. Polarization and Impedance Behaviors of the the Zn(NaOH) k Na-SSE k Br2(NaBr) and Zn(LiOH) k Li-SSE k Br2(LiBr) Cells (A) Voltage profiles of the Zn(NaOH) k Na-SSE k Br 2 (NaBr) and Zn(LiOH) k Li-SSE k Br 2 (LiBr) cells operated at 1.0 mA cm 2 . (B) Voltage profiles of the Zn(NaOH) k Na-SSE k Br 2 (NaBr) and Zn(LiOH) k Li-SSE k Br 2 (LiBr) cells operated at 3.0 mA cm 2 . (C) Nyquist plots of the electrochemical impedance spectroscopies of the Zn(NaOH) k Na-SSE k Br 2 (NaBr) and the Zn(LiOH) k Li-SSE k Br 2 (LiBr) cells. Reproduced with permission from Yu et al. 46 (copyright 2017, John Wiley).
anolyte migrate through the Na-SSE to the cathode side. These processes are reversed during charge. The Fe(OH)n is reduced to metallic Fe at the anode, while the H2O is oxidized to O2 at the cathode. Meanwhile Na+ ions migrate back to the anolyte through the Na-SSE to form NaOH. The discharge-charge mechanisms of the other sodium-ion-mediated battery systems are similar to the above descriptions. We have found that the sodium-ion solid electrolytes are a better option than the Li+-ion solid electrolytes for the development of mediator-ion batteries, especially with respect to the high abundance of sodium and the relatively high chemical/ electrochemical stability of sodium-ion solid electrolytes in aqueous environments.43–45,47 Moreover, sodium-ion solid electrolytes offer an exceptional advantage for their convenience in matching up with the liquid catholytes and anolytes to be used. This is because both the dissociation behavior and the solubility of Na salts (e.g., NaOH) are relatively higher than those of Li salts (e.g., LiOH).60 We have compared the cycling performances of two mediator-ion Zn-Br2 batteries with the same electrode chemistry but respectively prepared with Li+-ion and Na+-ion solid electrolytes. The anolytes and catholytes in these two batteries were accordingly adjusted to match, respectively, the lithium or the sodium mediator ion. The two cells are, respectively, termed Zn(NaOH) k Na-SSE k Br2(NaBr) cell and Zn(LiOH) k Li-SSE k Br2(LiBr). Figures 4A and 4B compare the discharge-charge voltages of the two cells at the current densities of, respectively, 1.0 mA cm2 and 3.0 mA cm2. It is observed that the Zn(LiOH) k Li-SSE k Br2(LiBr) cell shows relatively higher polarization behavior.46 Figure 4C compares the electrochemical impedance spectroscopy data obtained with the two cells. The Zn(NaOH) k Na-SSE k Br2(NaBr) cell exhibits relatively lower impedance than the Zn(LiOH) k Li-SSE k Br2(LiBr) cell.46 Conclusions, Challenges, and Outlook This perspective presents a recently validated mediator-ion battery concept that offers a new strategy for the development of aqueous batteries with alkali-metalion solid-electrolyte separators and inexpensive anodes such as Zn and Fe. The uniqueness of this mediator-ion approach is that the redox reactions at the anode and cathode are sustained by a shuttling of the mediator alkali-metal ion between the anode electrolyte (anolyte) and the cathode electrolyte (catholyte). The alkalimetal ion (lithium ion or sodium ion) in the solid electrolytes serves as an ionic mediator of charge transfer between the cathode and anode, rather than directly
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Table 1. Summary of the Aqueous Mediator-Ion Battery Systems that Have So Far Been Demonstrated: Specifications of the Anode, Anolyte, Solid Electrolyte, Catholyte, and Cathode Cell Annotation
Anode
Anolyte
Solid Electrolyte
Catholyte
Cathode
Reference
Zn(KOH/LiOH) k Li-SSE k KMnO4(H2SO4)
Zn
KOH/LiOH
Li1+x+yAlxTi2-xSiyP3-yO12
H2SO4/KMnO4
KMnO4
Chen et al.43
Zn(Zn(NO3)2) k Li-SSE k Cu(LiNO3)
Zn
Zn(NO3)2
Li1+x+yAlxTi2-xSiyP3-yO12
LiNO3
Cu
Dong et al.44
Zn(ZnSO4/Li2SO4) k Li-SSE k Cu(CuSO4/ Li2SO4)
Zn
ZnSO4/ Li2SO4
Li1+x+yAlxTi2-xSiyP3-yO12
CuSO4/Li2SO4
Cu
Zhang et al.45
Zn(LiOH) k Li-SSE k air (H3PO4/LiH2PO4)
Zn
LiOH
Li1+x+yAlxTi2-xSiyP3-yO12
H3PO4/LiH2PO4
O2-Pt/C-IrO2
Li et al.47
Zn(LiOH) k Li-SSE k Br2(LiBr)
Zn
LiOH
Li1+x+yAlxTi2-xSiyP3-yO12
Br2/LiBr
Br2
Yu et al.46
Zn(NaOH) k Na-SSE k Br2(NaBr)
Zn
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
Br2/NaBr
Br2
Yu et al.46
Zn(NaOH) k Na-SSE k air (H3PO4/NaH2PO4)
Zn
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
H3PO4/NaH2PO4
O2-Pt/C-IrO2
Yu et al.46
Zn(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
Zn
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
K3Fe(CN)6/NaOH
K3Fe(CN)6
Yu et al.46
Fe(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
Fe
NaOH
Na3.4Sc2(PO4)2.6(SiO4)0.4
K3Fe(CN)6/NaOH
K3Fe(CN)6
Yu et al.46
Fe(NaOH) k Na-SSE k O2(H3PO4/NaH2PO4)
Fe
NaOH
Na3Zr2Si2PO12
H3PO4/NaH2PO4
O2-Pt/C-IrO2
Yu et al.48
Zn
NaOH
Na3Zr2Si2PO12
Ce(SO4)2/CH4SO3/ H2SO4/Na2SO4
Ce(SO4)2
Yu et al.49
4+
Zn(NaOH) k Na-SSE k Ce (MSA/Na2SO4)
involving the electrode reactions. So far this novel battery concept has been demonstrated through the operation of a number of aqueous battery systems with various solid, liquid, or gaseous electrode materials, as well as different mediator-ion solid electrolytes, as summarized in Table 1. The electrochemical performances of these aqueous mediator-ion batteries in terms of cell voltage, cycle life, and power density are summarized in Table 2. The most significant contribution of this mediator-ion strategy is that it allows the use of active electrode (anode and cathode) materials in any physical form (either solid, liquid, or gas). Therefore, this novel battery strategy provides a versatile approach to making efficient use of gas-phase or liquid-phase electrochemical materials to develop inexpensive/affordable, safe, aqueous energy storage systems. The use of a solid-electrolyte separator completely eliminates the chemical-crossover problem of the liquid-phase or gas-phase electrode materials and circumvents the dendrite problem in the case of employing metal anodes. In addition, in such a battery system the anolyte and catholyte liquids can be completely different, offering great advantages for optimizing the cell components, voltage, energy density, and cost. In addition to the battery systems that have been demonstrated as listed in Table 1, this mediator-ion battery platform can be applied to a broad range of new redox couples. Although this battery concept has been demonstrated as a powerful platform for the development of future battery technologies, there are critical challenges that need to be considered. The first concern is the ionic conductivity of the currently available solid-electrolyte materials and the mechanical stability problems of the large-area solid-electrolyte separators. An optimistic note is that the research and development in the solid-electrolyte area is continuously progressing with concerted efforts by the SSE community. Both the mechanical property and ionic conductivity of solidelectrolyte materials are expected to be continuously improved in the future, which will benefit the technological platform of mediator-ion batteries. The second concern is the fabrication cost of solid electrolytes. At the current stage, the cost of technically viable solid electrolytes is chiefly contributed from the fabrication process. The material cost, especially for the sodium-ion solid electrolytes, is not a major concern. Therefore, the cost of solid electrolytes is actually not an
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Table 2. Electrochemical Performances of the Aqueous Mediator-Ion Battery Systems that Have So Far Been Demonstrated: Cell Voltage, Cycle Life, and Power Density Cell Annotation
Cell Voltage (V)
Cycle Life
Power Density
Reference
Zn(KOH/LiOH) k Li-SSE k KMnO4(H2SO4)
2.8
>100 hr
750 mW g1 KMnO4
Chen et al.43
Zn(Zn(NO3)2) k Li-SSE k Cu(LiNO3)
0.8
150 cycles
5.0 mW cm2
Dong et al.44
Zn(ZnSO4/Li2SO4) k Li-SSE k Cu(CuSO4/Li2SO4)
0.9
NA
6.0 mW cm2
Zhang et al.45
Zn(LiOH) k Li-SSE k air (H3PO4/LiH2PO4)
1.8
50 cycles
4.5 mW cm2
Li et al.47
Zn(LiOH) k Li-SSE k Br2(LiBr)
2.0
50 cycles
8.0 mW cm2
Yu et al.46
2
Yu et al.46
Zn(NaOH) k Na-SSE k Br2(NaBr)
2.2
50 cycles
14.0 mW cm
Zn(NaOH) k Na-SSE k air (H3PO4/NaH2PO4)
1.8
25 cycles
5.0 mW cm2
Yu et al.46
Zn(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
1.65
50 cycles
14.0 mW cm2
Yu et al.46
Fe(NaOH) k Na-SSE k K3Fe(CN)6(NaOH)
1.0
18 cycles
1.0 mW cm2
Yu et al.46
Fe(NaOH) k Na-SSE k O2(H3PO4/NaH2PO4)
1.5
50 cycles
2.0 mW cm2
Yu et al.48
Zn(NaOH) k Na-SSE k Ce4+(MSA/Na2SO4)
2.4
50 cycles
11.0 mW cm2
Yu et al.49
intrinsic issue. With the continuous advancements in the fabrication techniques, the SSEs are expected to become more affordable. The third concern is the long-term chemical stability of the ceramic electrolytes in aqueous solutions. Currently there is an urgent need to perform a rigorous and comprehensive study on the stability of both the Li-SSE and the Na-SSE materials in different aqueous solutions. From our preliminary experience, the LATP membrane exhibits good compatibility and stability with the alkaline anolyte and weakly acidic catholyte.47 According to the information provided by the supplier of the sodium solid electrolyte, Na3Zr2Si2PO12 used for the demonstration of the mediatorion batteries is basically stable under the cell operating conditions.48,49 The fourth major concern is that the capacity of the mediator-ion batteries is possibly affected by the requirement of a certain amount of mediator ions (M+) in the electrolyte (both the anolyte and the catholyte) to maintain an ionic charge balance between the anode and the cathode. The mediator-ion compounds exist as a supporting electrolyte and are electrochemically inactive, thus lowering the gravimetric (largely) and volumetric (slightly) energy densities of the battery system. However, since the mediator-ion approach offers multiple advantages in enhancing the cell voltage and optimizing the cell components, the negative impact from the supporting electrolytes can be compensated. On the other hand, for the impact from the use of supporting electrolytes to be minimized, additional efforts are needed to optimize the amount of mediator ions in the cell.
ACKNOWLEDGMENTS This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under award number DE-SC0005397.
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REFERENCES 1. Michelson, E.S. (2016). Which way for the world? A review of energy, economic growth, and geopolitical futures: eight long-range scenarios. Futures 78-79, 71–73. 2. Crowley, B. (2000). Statistical review of world energy. Hydrocarb. Process. 79, 23. 3. Gilland, B. (1995). World-population, economic-growth, and energy demand, 19902100—a review of projections. Popul. Dev. Rev. 21, 507–512. 4. Liu, W., and Ramirez, A. (2017). State of the art review of the environmental assessment and risks of underground geo-energy resources exploitation. Renew. Sust. Energ. Rev. 76, 628–644. 5. Tiewsoh, L.S., Sivek, M., and Jirasek, J. (2017). Traditional energy resources in India (coal, crude oil, natural gas): a review. Energ. Source Part B 12, 110–118. 6. Hepbasli, A. (2008). A key review on exergetic analysis and assessment of renewable energy resources for a sustainable future. Renew. Sust. Energ. Rev. 12, 593–661. 7. Izadyar, N., Ong, H.C., Chong, W.T., and Leong, K.Y. (2016). Resource assessment of the renewable energy potential for a remote area: a review. Renew. Sust. Energ. Rev. 62, 908–923. 8. Momoh, J.A., and Reddy, S.S. (2014). Review of optimization techniques for renewable energy resources. 2014 IEEE Symposium on Power Electronics and Machines for Wind and Water Applications. 14617982. 9. Kannan, N., and Vakeesan, D. (2016). Solar energy for future world: a review. Renew. Sust. Energ. Rev. 62, 1092–1105. 10. Al-Falahi, M.D.A., Jayasinghe, S.D.G., and Enshaei, H. (2017). A review on recent size optimization methodologies for standalone solar and wind hybrid renewable energy system. Energ. Convers. Manage. 143, 252–274. 11. Bird, L., Lew, D., Milligan, M., Carlini, E.M., Estanqueiro, A., Flynn, D., Gomez-Lazaro, E., Holttinen, H., Menemenlis, N., Orths, A., et al. (2016). Wind and solar energy curtailment: a review of international experience. Renew. Sust. Energ. Rev. 65, 577–586. 12. Lianos, P. (2017). Review of recent trends in photoelectrocatalytic conversion of solar energy to electricity and hydrogen. Appl. Catal. B 210, 235–254. 13. Abhinav, R., and Pindoriya, N.M. (2016). Grid integration of wind turbine and battery energy storage system: review and key challenges. 2016 IEEE 6th International Conference on Power Systems 16358802. 14. Gunter, N., and Marinopoulos, A. (2016). Energy storage for grid services and applications: classification, market review, metrics, and methodology for evaluation of deployment cases. J. Energy Storage 8, 226–234. 15. Wang, G.S., Konstantinou, G., Townsend, C.D., Pou, J., Vazquez, S., Demetriades, G.D., and Agelidis, V.G. (2016). A review of power electronics for grid connection of utility-scale
battery energy storage systems. IEEE Trans. Sustain. Energy 7, 1778–1790. 16. Dunn, B., Kamath, H., and Tarascon, J.M. (2011). Electrical energy storage for the grid: a battery of choices. Science 334, 928–935. 17. Yang, Z.G., Zhang, J., Kintner-Meyer, M.C., Lu, X., Choi, D., Lemmon, J.P., and Liu, J. (2011). Electrochemical energy storage for green grid. Chem. Rev. 111, 3577–3613. 18. Goodenough, J.B. (2013). Evolution of strategies for modern rechargeable batteries. Acc. Chem. Res. 46, 1053–1061. 19. Sun, T., Li, Z.J., Wang, H.G., Bao, D., Meng, F.L., and Zhang, X.B. (2016). A Biodegradable polydopamine-derived electrode material for high-capacity and long-life lithium-ion and sodium-ion batteries. Angew. Chem. Int. Ed. 55, 10662–10666. 20. Zhu, Y.H., Yuan, S., Bao, D., Yin, Y.B., Zhong, H.X., Zhang, X.B., Yan, J.M., and Jiang, Q. (2017). Decorating waste cloth via industrial wastewater for tube-type flexible and wearable sodium-ion batteries. Adv. Mater. 29, 1603719.
technology for consumer and electric vehicle batteries—a review and up-date. J. Power Sources 65, 1–7. 31. Singh, A., and Karandikar, P.B. (2017). A broad review on desulfation of lead-acid battery for electric hybrid vehicle. Microsyst. Technol. 23, 2263–2273. 32. Yu, X.W., and Licht, S. (2007). Advances in Fe(VI) charge storage Part II. Reversible alkaline super-iron batteries and nonaqueous superiron batteries. J. Power Sources 171, 1010– 1022. 33. Yu, X.W., and Lich, S. (2007). Advances in Fe(VI) charge storage part I. primary alkaline superiron batteries. J. Power Sources 171, 966–980. 34. Manthiram, A., Fu, Y.Z., and Su, Y.S. (2013). Challenges and prospects of lithium-sulfur batteries. Acc. Chem. Res. 46, 1125–1134. 35. Manthiram, A., and Yu, X.W. (2015). Ambient temperature sodium-sulfur batteries. Small 11, 2108–2114.
21. Zhu, Y.H., Yin, Y.B., Yang, X., Sun, T., Wang, S., Jiang, Y.S., Yan, J.M., and Zhang, X.B. (2017). Transformation of rusty stainless-steel meshes into stable, low-cost, and binder-free cathodes for high-performance potassium-ion batteries. Angew. Chem. Int. Ed. 56, 7881–7885.
36. Song, Y.X., Hu, J., Tang, J., Gu, W., He, L., and Ji, X. (2016). Real-time X-ray imaging reveals interfacial growth, suppression, and dissolution of zinc dendrites dependent on anions of ionic liquid additives for rechargeable battery applications. ACS Appl. Mater. Interfaces 8, 32031–32040.
22. Xu, J.J., Chang, Z.W., Wang, Y., Liu, D.P., Zhang, Y., and Zhang, X.B. (2016). Cathode surface-induced, solvation-mediated, micrometer-sized Li2O2 cycling for Li-O2 batteries. Adv. Mater. 28, 9620–9628.
37. Wang, K.L., Pei, P.C., Ma, Z., Chen, H.C., Xu, H.C., Chen, D.F., and Wang, X.Z. (2015). Dendrite growth in the recharging process of zinc-air batteries. J Mater Chem A 3, 22648– 22655.
23. Yin, Y.B., Xu, J.J., Liu, Q.C., and Zhang, X.B. (2016). Macroporous interconnected hollow carbon nanofibers inspired by golden-toad eggs toward a binder-free, high-rate, and flexible electrode. Adv. Mater. 28, 7494–7500.
38. Kilner, J., Irvine, S., and Edwards, P. (2012). Functional Materials for Sustainable Energy Applications, First Edition (Woodhead Publishing).
24. Chen, A.X., and Sen, P.K. (2016). Advancement in battery technology: a state-of-the-art review. IEEE Industry Applications Society Annual Meeting, 16447436. 25. Malhotra, A., Battke, B., Beuse, M., Stephan, A., and Schmidt, T. (2016). Use cases for stationary battery technologies: a review of the literature and existing projects. Renew. Sust. Energy Rev. 56, 705–721. 26. Claus, D., and Besenhard, J. (2011). Handbook of Battery Materials, Second Edition (Wiley-VCH). 27. Crompton, T. (2000). Battery Reference Book, Third Edition (Butterworth-Heinemann). 28. Pan, H.L., Shao, Y.Y., Yan, P.F., Cheng, Y.W., Han, K.S., Nie, Z.M., Wang, C.M., Yang, J.H., Li, X.L., Bhattacharya, P., et al. (2016). Reversible aqueous zinc/manganese oxide energy storage from conversion reactions. Nat. Energy 1, 16039. 29. Pourabdollah, K. (2017). Development of electrolyte inhibitors in nickel cadmium batteries. Chem. Eng. Sci. 160, 304–312. 30. Dhar, S.K., Ovshinsky, S.R., Gifford, P.R., Corrigan, D.A., Fetcenko, M.A., and Venkatesan, S. (1997). Nickel metal hydride
39. Granqvist, C.G. (1995). Handbook of Inorganic Electrochromic Materials (Elsevier Science). 40. Bard, A.J. (2001). Electrochemical Methods: Fundamentals and Applications, Second Edition (John Wiley). 41. Kohler, J., Imanaka, N., and Adachi, G.Y. (1998). Multivalent cationic conduction in crystalline solids. Chem. Mater. 10, 3790–3812. 42. Ikeda, S., Kanbayashi, Y., Nomura, K., Kasai, A., and Ito, K. (1990). Solid electrolytes with multivalent cation conduction. Zinc ion conduction in Zn-Zr-PO4 system. Solid State Ionics 40-41, 79–82. 43. Chen, L., Guo, Z.Y., Xia, Y.Y., and Wang, Y.G. (2013). High-voltage aqueous battery approaching 3 V using an acidic-alkaline double electrolyte. Chem. Commun. (Camb.) 49, 2204–2206. 44. Dong, X.L., Wang, Y.G., and Xia, Y.G. (2014). Re-building Daniell cell with a Li-ion exchange film. Sci. Rep. 4, 6916. 45. Zhang, H.P., Yang, T., Wu, X., Zhou, Y., Yang, C., Zhu, T., and Dong, R. (2015). Using Li+ as the electrochemical messenger to fabricate battery. Chem. Commun. (Camb.) 51, 7294– 7297.
Joule 1, 1–10, November 15, 2017
9
Please cite this article in press as: Yu and Manthiram, Electrochemical Energy Storage with Mediator-Ion Solid Electrolytes, Joule (2017), https:// doi.org/10.1016/j.joule.2017.10.011
46. Yu, X.W., Gross, M.M., Wang, S.F., and Manthiram, A. (2017). Aqueous electrochemical energy storage with a mediator-ion solid electrolyte. Adv. Energy Mater. 7, 1602454. 47. Li, L.J., and Manthiram, A. (2016). Long-life, high-voltage acidic Zn-air batteries. Adv. Energy Mater. 6, 1502054. 48. Yu, X.W., and Manthiram, A. (2017). A voltageenhanced, low-cost aqueous iron-air battery enabled with a mediator-ion solid electrolyte. ACS Energy Lett. 2, 1050–1055. 49. Yu, X.W., and Manthiram, A. (2017). A zinccerium cell for energy storage using a sodiumion exchange membrane. Adv. Sustain. Syst. 1, 1700082. 50. Kerman, K., Luntz, A., Viswanathan, V., Chiang, Y.M., and Chen, Z.B. (2017). Review—practical challenges hindering the development of solid state Li ion batteries. J. Electrochem. Soc. 164, A1731–A1744.
10
Joule 1, 1–10, November 15, 2017
51. He, P., Zhang, T., Jiang, J., and Zhou, H.S. (2016). Lithium-air batteries with hybrid electrolytes. J. Phys. Chem. Lett. 7, 1267–1280.
56. Goodenough, J.B., Hong, H.Y.P., and Kafalas, J.A. (1976). Fast Na+-ion transport in skeleton structures. Mater. Res. Bull. 11, 203–220.
52. Gordon, R.S. (1974). Critical review of materials problems in sodium sulfur battery. Am. Ceram. Soc. Bull. 53, 616.
57. Hayashi, A., Noi, K., Tanibata, N., Nagao, M., and Tatsumisago, M. (2014). High sodium ion conductivity of glass ceramic electrolytes with cubic Na3PS4. J. Power Sources 258, 420–423.
53. Chang, H.J., Canfield, N.L., Jung, K., Sprenkle, V.L., and Li, G.S. (2017). Advanced Na-NiCl2 battery using nickel-coated graphite with core shell microarchitecture. ACS Appl. Mater. Interfaces 9, 11609–11614. 54. Goodenough, J.B., and Singh, P. (2015). Review—solid electrolytes in rechargeable electrochemical cells. J. Electrochem. Soc. 162, A2387–A2392. 55. Bachman, J.C., Muy, S., Grimaud, A., Chang, H.H., Pour, N., Lux, S.F., Paschos, O., Maglia, F., Lupart, S., Lamp, P., et al. (2016). Inorganic solid-state electrolytes for lithium batteries: mechanisms and properties governing ion conduction. Chem. Rev. 116, 140–162.
58. Kim, J.G., Son, B., Mukherjee, S., Schuppert, N., Bates, A., Kwon, O., Choi, M.J., Chung, H.Y., and Park, S. (2015). A review of lithium and non-lithium based solid state batteries. J. Power Sources 282, 299–322. 59. Kubota, K., and Komaba, S. (2015). Review— practical issues and future perspective for Naion batteries. J. Electrochem. Soc. 162, A2538– A2550. 60. Corti, H., Crovetto, R., and Fernandezprini, R. (1979). Aqueous-solutions of lithium hydroxide at various temperatures—conductivity and activity-coefficients. J. Solution Chem. 8, 897–908.