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Mg-S Batteries
CHAPTER TWELVE
Mg-S Batteries According to Ref. [1], the metal magnesium (Mg) is a promising material for anodes in next-generation batteries, due to its nondendritic deposition and high capacity. However, the best cathode for the Mg accumulator was based on the MgxMo3S4 complex, with high molecular weight, which made the full link energetically uncompetitive. To increase the energy density, a highcapacity cathode material in the form of sulfur was proposed. However, until now only limited research has been done on the Mg/S system, and all of the studies are plagued by the weak reversibility attributed to the formation of electrochemically inactive forms of MgSx. A new strategy was developed, based on the use of the Li+ role in activating the MgSx form, for the combination of a nondendritic Mg anode with a reversible polysulfide cathode, and a truly reversible Mg-S battery with a capacity of up to 1000 mAh g 1 for more than 30 cycles. The cell showed two discharge plates at 1.75 and 1.0 V, which corresponds to an energy density of up to 874 Wh kg 1. It was shown that the Mg/S battery has a much better reversibility after the introduction of LiTFSI as an additive. It has been suggested that the reversibility results from chemical reactivation of MgSx (more specifically MgS and MgS2) with Li+. The diagram of Mg-S cell operation is shown in Fig. 51. Fig. 52A shows charging/discharging curves for a sulfur cathode in an electrolyte with 0.1 M Mg-HMDS + 1.0 M LiTFSI composition in three electrode cells with a current of 71 mAh g 1 at room temperature. Fig. 52B illustrates the stability of the cyclic Mg-S battery operation in the electrolyte with and without LiTFSI [1]. The mechanism of operation of the Mg-S battery with the addition of LiTFSI is shown in Fig. 53. According to Ref. [2], magnesium accumulators (Mg) have been proposed for electrochemical storage of energy, and for use in electric vehicles, due to the properties of Mg, such as prevalence of occurrence, work safety, and high volume capacity. Among the various anode materials of alkaline/ alkaline earth metals, magnesium (Mg) has the highest theoretical volumetric capacity (3832 mAh cm 3) and a high negative reduction potential of 2.356 V compared to a normal hydrogen electrode (NHE).
Next-generation Batteries with Sulfur Cathodes https://doi.org/10.1016/B978-0-12-816392-4.00012-8
© 2019 Elsevier Inc. All rights reserved.
175
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Next-generation Batteries with Sulfur Cathodes
Fig. 51 Diagram of the Mg-S cell [1].
Fig. 52 (A) Load/discharge curves for a sulfur cathode in an electrolyte composition 0.1 M Mg-HMDS + 1.0 M LiTFSI in three electrode cells for a current of 71 mAh g 1 at room temperature. The arrow shows the increasing capacity tendency for the ACC/S composite cathode because of slow electrolyte penetration. (B) Stability of the cyclic Mg-S battery in electrolyte with and without LiTFSI [1].
For comparison, graphite anodes currently used in lithium-ion batteries (LIB) have a volumetric efficiency of only 777 mAh cm 3 [3]. As an anode material, Mg can be considered a safer electrode in liquid electrolytes,
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177
Fig. 53 Mechanism of Mg/S battery operation with the addition of LiTFSI [1].
because it does not form dendrites as compared to lithium [4]. Theoretical calculations show that Mg promotes the growth of smooth surfaces compared to Li and Na, due to its lower diffusion barriers and highercoordinated configurations [5]. Raw material for Mg is cheaper than for lithium, and its compounds are usually nontoxic. Sulfur (S) is a promising cathode battery material based on Mg, due to the high theoretical capacity (1671 mAh g 1 or 3459 mAh cm 3) and natural prevalence. The combination of the Mg anode and the sulfur cathode gives a theoretical energy density of 3200 Wh L 1, compared to 2800 Wh L 1 for lithium-sulfur batteries [3,6]. However, several problems must be solved for the Mg/S battery. The limits of development of Mg/S batteries result from the limited availability of suitable electrolytes with high ionic conductivity, in which Mg can be reassembled [7]. This is mainly due to the strong electrophilic nature of sulfur, which requires a nonnucleophilic electrolyte. We developed a nonnucleophilic electrolyte by adding AlCl3 to the THF solution of magnesium hexamethyldisilazide chloride and tested the Mg/S cell in
178
Next-generation Batteries with Sulfur Cathodes
two cycles with a discharging capacity of 1200 and 394 mAh g 1, respectively, at a discharging voltage of about 1 V [3]. Recently, information about a nonnucleophilic Mg/S battery electrolyte based on a nonnucleophilic magnesium-bis(hexamethyldisilazide) [(HMDS) 2Mg]-reacted with AICI3 as Lewis acid (1:2 molar ratio) was reported, and the reaction products were dissolved in other solvents, such as ether compounds [8]. Using these electrolytes, the potential of discharging the Mg/S battery was increased to 1.65 V, which is close to the thermodynamic voltage (1.7 V) [9]. According to Ref. [10] most simple magnesium salts tend to passivate the Mg metal surface too quickly to function as electrolytes for Mg batteries. To improve such situations, an electroactive salt [Mg(THF)6][AlCl4]2 was synthesized and structurally characterized. The Mg electrolyte based on this simple mononuclear salt showed a high Mg cycling efficiency, good anodic stability (2.5 V vs. Mg), and high ionic conductivity (8.5 mS cm 1). Magnesium/sulfur cells employing the as-prepared electrolyte exhibited good cycling performance over 20 cycles in the range of 0.3–2.6 V, thus indicating an electrochemically reversible conversion of S to MgS without severe passivation of the Mg metal electrode surface. According to Ref. [11], room temperature rechargeable magnesium (Mg) batteries were designed from Mg as a negative material, sulfurcontaining composite prepared from elemental sulfur and the bis(alkenyl) compound having a crown ether unit (BUMB18C6) or linear ether unit (UOEE) as a positive material and the simple electrolyte (0.7 mol dm 3 Mg[N(SO2CF3)2]2-triglyme (G3) solution). The reaction between molten S and the bis(alkenyl) compound (BUMB18C6 or UOEE) provided the sulfur-containing composite, S-BUMB18C6 or S-UOEE. Both sulfurcontaining composites were electrochemically active in the Mg salt-based electrolyte, acetonitrile- or G3-Mg[N(SO2CF3)2]2 electrolyte. The first discharge capacity of the test cells with the sulfur-containing composite was 460 Ah kg 1 with an S-BUMB18C6 electrode and 495 Ah kg 1 with the S-UOEE electrode. According to the continuous charge-discharge cycle tests (at the 10th cycle), the discharge capacity of the test cell with the S-BUMB18C6 electrode (68.1 Ah kg 1) was higher than that with the S-UOEE electrode (0.18 Ah kg 1). The crown ether units in the S-BUMB18C6 composite created ion-conducting paths in the cathode, preventing a rise in the internal resistance of the cathode, and providing better cycle performance with the test cells having the S-BUMB18C6 composite electrode than those with the S-UOEE electrode.
Mg-S Batteries
179
The first tests of the Mg/S battery pointed to the effects of polarization during charging, low stability of cyclic operation, disappearance of the initial capacity, and dissolution of polysulfides, analogous to the Li/S battery system [12,13]. In Li/S batteries, soluble polysulfides led to self-discharge and degradation of the cell [14,15]. The electrical insulation property of sulfur is another problem that gives low electronic transmission of the load to the current collectors. To solve some of these problems, it is necessary to design a nanodispersed active sulfur composite in a suitable carbon matrix host. The carbonaceous host material must have (a) a strong chemical anchoring of sulfur and then form polysulfides, (b) a high electrical conductivity, (c) a mechanically stable frame withstanding the load generated by sulfur volume changes during cyclic operation, (d) easy access of liquid electrolyte to active sulfur, and (e) small pores without large holes to contain polysulfides. Among the various types of carbon nanomaterials there are graphene-based nanostructures (G), which are preferred materials for energy storage applications, due to their unique properties, such as large surface area, high load mobility, excellent electronic and thermal conductivity, high mechanical strength, and good stability chemically [16–18]. According to Ref. [2], the magnesium Mg battery was produced using a graphene-sulfur nanocomposite as a cathode, a magnesium-carbon composite as an anode, and as an electrolyte a nonnucleophilic Mg-based complex in a tetraglyme solvent. The graphene-sulfur nanocomposite was prepared by combining thermal and chemical precipitation methods. The Mg-S cell provides a higher reversible capacity (448 mAh g 1), a longer cyclic capacity (236 mAh g 1 at the end of the 50th cycle), and a better ability to withstand rated currents than previous cells. The use of a cathode from a graphenesulfur composite with properties such as a large surface, porous morphology, very good electronic conductivity, the presence of functional oxygen groups, together with a nonnucleophilic magnesium electrolyte ensures greater efficiency of the battery. Fig. 54A shows the stability of the cyclic S-rGO nanocomposite for the first 50 cycles at a current density of 20 mA g 1. In turn, Fig. 54B shows the ability to withstand the nominal currents of the S-rGO electrode for current densities between 5 and 45 mA g 1. Fig. 55 shows the electrochemical mechanism of the nanocomposite S-rGO electrode inside the Mg/S cell. During the study described in Ref. [19], vanadium oxychloride was used as an electrode material in a Mg-based battery. The cell delivered just 45 mA h g 1 in the first cycle. The delivered capacity could be improved
180
Next-generation Batteries with Sulfur Cathodes
Fig. 54 (A) Stability of the cyclic S-rGO nanocomposite for the first 50 cycles at a current density of 20 mA g 1. (B) Ability to withstand the nominal currents of the S-rGO electrode for current density between 5 and 45 mA g 1 [2].
through preliminary cycling of the VOCl electrode with Li, as the VOCl can expand its interlayer spacing upon intercalation of ions or molecules within them. In fact, a VOCl electrode with expanded interlayer spacing should facilitate the intercalation of Mg2+, thus leading to higher specific capacities. The Li pretreatment was able to promote the specific capacity by a factor of four (170 mAh g 1) after the first discharge at 298 K. Over 130 mAh g 1 was retained at 5 mA g 1 after 70 cycles.
Mg-S Batteries
181
Fig. 55 Electrochemical mechanism of the nanocomposite S-rGO electrode inside the Mg/S cell [2].
REFERENCES [1] T. Gao, M. Noked, A.J. Pearse, E. Gillette, X. Fan, Y. Zhu, C. Luo, L. Suo, M.A. Schroeder, K. Xu, S.B. Lee, G.W. Rubloff, C. Wang, Enhancing the reversibility of Mg/S battery chemistry through Li+ mediation. J. Am. Chem. Soc. 137 (38) (2015) 12388–12393, https://doi.org/10.1021/jacs.5b07820. [2] B.P. Vinayan, Z. Zhao-Karger, T. Diemant, V.S.K. Chakravadhanula, N.I. Schwarzburger, M.A. Cambaz, R.J. Behm, C. K€ ubel, M. Fichtner, Performance study of magnesium–sulfur battery using a graphene based sulfur composite cathode electrode and a non-nucleophilic Mg electrolyte, Nanoscale 8 (2016) 3296–3306, https://doi. org/10.1039/C5NR04383B (Paper). [3] H.S. Kim, T.S. Arthur, G.D. Allred, J. Zajicek, J.G. Newman, A.E. Rodnyansky, A.G. Oliver, W.C. Boggess, J. Muldoon, Structure and compatibility of a magnesium electrolyte with a sulphur cathode, Nat. Commun. 2 (2011) 427. [4] T.D. Gregory, R.J. Hoffman, R.C. Winterton, Nonaqueous electrochemistry of magnesium applications to energy storage, J. Electrochem. Soc. 137 (1990) 775–780. [5] M. J€ackle, A. Groß, Microscopic properties of lithium, sodium, and magnesium battery anode materials related to possible dendrite growth, J. Chem. Phys. 141 (2014)174710. [6] X. Ji, K.T. Lee, L.F. Nazar, A highly ordered nanostructured carbon–sulphur cathode for lithium–sulphur batteries, Nat. Mater. 8 (2009) 500–506. [7] O. Tutusaus, R. Mohtadi, Paving the way towards highly stable and practical electrolytes for rechargeable magnesium batteries, ChemElectroChem 2 (2015) 51–57. [8] Z. Zhao-Karger, X. Zhao, O. Fuhr, M. Fichtner, Bisamide based non-nucleophilic electrolytes for rechargeable magnesium batteries, RSC Adv. 3 (2013) 16330–16335. [9] Z. Zhao-Karger, X. Zhao, D. Wang, T. Diemant, R.J. Behm, M. Fichtner, Performance improvement of magnesium sulfur batteries with modified non-nucleophilic electrolytes, Adv. Energy Mater. 5 (2014)1401155.
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Next-generation Batteries with Sulfur Cathodes
[10] W. Li, S. Cheng, J. Wang, Y. Qiu, Z. Zheng, H. Lin, S. Nanda, Q. Ma, Y. Xu, F. Ye, Synthesis, crystal structure, and electrochemical properties of a simple magnesium electrolyte for magnesium/sulfur batteries, Angew. Chem. Int. Ed. 55 (2016) 6406–6410, https://doi.org/10.1002/anie.201600256. [11] K. Itaoka, I.T. Kim, K. Yamabuki, N. Yoshimoto, H. Tsutsumi, Room temperature rechargeable magnesium batteries with sulfur-containing composite cathodes prepared from elemental sulfur and bis(alkenyl) compound having a cyclic or linear ether unit. J. Power Sources 297 (2015) 323–328, https://doi.org/10.1016/j.jpowsour. 2015.08.029. [12] P. Saha, M.K. Datta, O.I. Velikokhatnyi, A. Manivannan, D. Alman, P.N. Kumta, Rechargeable magnesium battery: current status and key challenges for the future, Prog. Mater. Sci. 66 (2014) 1–86. [13] A. Manthiram, Y. Fu, Y.-S. Su, Challenges and prospects of lithium–sulfur batteries, Acc. Chem. Res. 46 (2012) 1125–1134. [14] D. Moy, A. Manivannan, S.R. Narayanan, Direct measurement of polysulfide shuttle current: a window into understanding the performance of lithium-sulfur cells, J. Electrochem. Soc. 162 (2015) A1–A7. [15] Y.V. Mikhaylik, J.R. Akridge, Polysulfide shuttle study in the Li/S battery system, J. Electrochem. Soc. 151 (2004) A1969–A1976. [16] Y. Sun, Q. Wu, G. Shi, Graphene based new energy materials, Energy Environ. Sci. 4 (2011) 1113–1132. [17] J. Hou, Y. Shao, M.W. Ellis, R.B. Moore, B. Yi, Graphene-based electrochemical energy conversion and storage: fuel cells, supercapacitors and lithium ion batteries, Phys. Chem. Chem. Phys. 13 (2011) 15384–15402. [18] B.P. Vinayan, N.I. Schwarzburger, M. Fichtner, Synthesis of a nitrogen rich (2D–1D) hybrid carbon nanomaterial using a MnO2 nanorod template for high performance Li-ion battery applications, J. Mater. Chem. A 3 (2015) 6810–6818. [19] C.B. Minella, P. Gao, Z. Zhao-Karger, X. Mu, T. Diemant, M. Pfeifer, V.S.K. Chakravadhanula, R.J. Behm, M. Fichtner, Interlayer-expanded vanadium oxychloride as an electrode material for magnesium-based batteries, ChemElectroChem 4 (2017) 738.
Mg-S Batteries According to Ref. [1], the metal magnesium (Mg) is a promising material for anodes in next-generation batteries, due to its nondendritic deposition and high capacity. However, the best cathode for the Mg accumulator was based on the MgxMo3S4 complex, with high molecular weight, which made the full link energetically uncompetitive. To increase the energy density, a highcapacity cathode material in the form of sulfur was proposed. However, until now only limited research has been done on the Mg/S system, and all of the studies are plagued by the weak reversibility attributed to the formation of electrochemically inactive forms of MgSx. A new strategy was developed, based on the use of the Li+ role in activating the MgSx form, for the combination of a nondendritic Mg anode with a reversible polysulfide cathode, and a truly reversible Mg-S battery with a capacity of up to 1000 mAh g 1 for more than 30 cycles. The cell showed two discharge plates at 1.75 and 1.0 V, which corresponds to an energy density of up to 874 Wh kg 1. It was shown that the Mg/S battery has a much better reversibility after the introduction of LiTFSI as an additive. It has been suggested that the reversibility results from chemical reactivation of MgSx (more specifically MgS and MgS2) with Li+. The diagram of Mg-S cell operation is shown in Fig. 51. Fig. 52A shows charging/discharging curves for a sulfur cathode in an electrolyte with 0.1 M Mg-HMDS + 1.0 M LiTFSI composition in three electrode cells with a current of 71 mAh g 1 at room temperature. Fig. 52B illustrates the stability of the cyclic Mg-S battery operation in the electrolyte with and without LiTFSI [1]. The mechanism of operation of the Mg-S battery with the addition of LiTFSI is shown in Fig. 53. According to Ref. [2], magnesium accumulators (Mg) have been proposed for electrochemical storage of energy, and for use in electric vehicles, due to the properties of Mg, such as prevalence of occurrence, work safety, and high volume capacity. Among the various anode materials of alkaline/ alkaline earth metals, magnesium (Mg) has the highest theoretical volumetric capacity (3832 mAh cm 3) and a high negative reduction potential of 2.356 V compared to a normal hydrogen electrode (NHE).
Next-generation Batteries with Sulfur Cathodes https://doi.org/10.1016/B978-0-12-816392-4.00012-8
© 2019 Elsevier Inc. All rights reserved.
175
176
Next-generation Batteries with Sulfur Cathodes
Fig. 51 Diagram of the Mg-S cell [1].
Fig. 52 (A) Load/discharge curves for a sulfur cathode in an electrolyte composition 0.1 M Mg-HMDS + 1.0 M LiTFSI in three electrode cells for a current of 71 mAh g 1 at room temperature. The arrow shows the increasing capacity tendency for the ACC/S composite cathode because of slow electrolyte penetration. (B) Stability of the cyclic Mg-S battery in electrolyte with and without LiTFSI [1].
For comparison, graphite anodes currently used in lithium-ion batteries (LIB) have a volumetric efficiency of only 777 mAh cm 3 [3]. As an anode material, Mg can be considered a safer electrode in liquid electrolytes,
Mg-S Batteries
177
Fig. 53 Mechanism of Mg/S battery operation with the addition of LiTFSI [1].
because it does not form dendrites as compared to lithium [4]. Theoretical calculations show that Mg promotes the growth of smooth surfaces compared to Li and Na, due to its lower diffusion barriers and highercoordinated configurations [5]. Raw material for Mg is cheaper than for lithium, and its compounds are usually nontoxic. Sulfur (S) is a promising cathode battery material based on Mg, due to the high theoretical capacity (1671 mAh g 1 or 3459 mAh cm 3) and natural prevalence. The combination of the Mg anode and the sulfur cathode gives a theoretical energy density of 3200 Wh L 1, compared to 2800 Wh L 1 for lithium-sulfur batteries [3,6]. However, several problems must be solved for the Mg/S battery. The limits of development of Mg/S batteries result from the limited availability of suitable electrolytes with high ionic conductivity, in which Mg can be reassembled [7]. This is mainly due to the strong electrophilic nature of sulfur, which requires a nonnucleophilic electrolyte. We developed a nonnucleophilic electrolyte by adding AlCl3 to the THF solution of magnesium hexamethyldisilazide chloride and tested the Mg/S cell in
178
Next-generation Batteries with Sulfur Cathodes
two cycles with a discharging capacity of 1200 and 394 mAh g 1, respectively, at a discharging voltage of about 1 V [3]. Recently, information about a nonnucleophilic Mg/S battery electrolyte based on a nonnucleophilic magnesium-bis(hexamethyldisilazide) [(HMDS) 2Mg]-reacted with AICI3 as Lewis acid (1:2 molar ratio) was reported, and the reaction products were dissolved in other solvents, such as ether compounds [8]. Using these electrolytes, the potential of discharging the Mg/S battery was increased to 1.65 V, which is close to the thermodynamic voltage (1.7 V) [9]. According to Ref. [10] most simple magnesium salts tend to passivate the Mg metal surface too quickly to function as electrolytes for Mg batteries. To improve such situations, an electroactive salt [Mg(THF)6][AlCl4]2 was synthesized and structurally characterized. The Mg electrolyte based on this simple mononuclear salt showed a high Mg cycling efficiency, good anodic stability (2.5 V vs. Mg), and high ionic conductivity (8.5 mS cm 1). Magnesium/sulfur cells employing the as-prepared electrolyte exhibited good cycling performance over 20 cycles in the range of 0.3–2.6 V, thus indicating an electrochemically reversible conversion of S to MgS without severe passivation of the Mg metal electrode surface. According to Ref. [11], room temperature rechargeable magnesium (Mg) batteries were designed from Mg as a negative material, sulfurcontaining composite prepared from elemental sulfur and the bis(alkenyl) compound having a crown ether unit (BUMB18C6) or linear ether unit (UOEE) as a positive material and the simple electrolyte (0.7 mol dm 3 Mg[N(SO2CF3)2]2-triglyme (G3) solution). The reaction between molten S and the bis(alkenyl) compound (BUMB18C6 or UOEE) provided the sulfur-containing composite, S-BUMB18C6 or S-UOEE. Both sulfurcontaining composites were electrochemically active in the Mg salt-based electrolyte, acetonitrile- or G3-Mg[N(SO2CF3)2]2 electrolyte. The first discharge capacity of the test cells with the sulfur-containing composite was 460 Ah kg 1 with an S-BUMB18C6 electrode and 495 Ah kg 1 with the S-UOEE electrode. According to the continuous charge-discharge cycle tests (at the 10th cycle), the discharge capacity of the test cell with the S-BUMB18C6 electrode (68.1 Ah kg 1) was higher than that with the S-UOEE electrode (0.18 Ah kg 1). The crown ether units in the S-BUMB18C6 composite created ion-conducting paths in the cathode, preventing a rise in the internal resistance of the cathode, and providing better cycle performance with the test cells having the S-BUMB18C6 composite electrode than those with the S-UOEE electrode.
Mg-S Batteries
179
The first tests of the Mg/S battery pointed to the effects of polarization during charging, low stability of cyclic operation, disappearance of the initial capacity, and dissolution of polysulfides, analogous to the Li/S battery system [12,13]. In Li/S batteries, soluble polysulfides led to self-discharge and degradation of the cell [14,15]. The electrical insulation property of sulfur is another problem that gives low electronic transmission of the load to the current collectors. To solve some of these problems, it is necessary to design a nanodispersed active sulfur composite in a suitable carbon matrix host. The carbonaceous host material must have (a) a strong chemical anchoring of sulfur and then form polysulfides, (b) a high electrical conductivity, (c) a mechanically stable frame withstanding the load generated by sulfur volume changes during cyclic operation, (d) easy access of liquid electrolyte to active sulfur, and (e) small pores without large holes to contain polysulfides. Among the various types of carbon nanomaterials there are graphene-based nanostructures (G), which are preferred materials for energy storage applications, due to their unique properties, such as large surface area, high load mobility, excellent electronic and thermal conductivity, high mechanical strength, and good stability chemically [16–18]. According to Ref. [2], the magnesium Mg battery was produced using a graphene-sulfur nanocomposite as a cathode, a magnesium-carbon composite as an anode, and as an electrolyte a nonnucleophilic Mg-based complex in a tetraglyme solvent. The graphene-sulfur nanocomposite was prepared by combining thermal and chemical precipitation methods. The Mg-S cell provides a higher reversible capacity (448 mAh g 1), a longer cyclic capacity (236 mAh g 1 at the end of the 50th cycle), and a better ability to withstand rated currents than previous cells. The use of a cathode from a graphenesulfur composite with properties such as a large surface, porous morphology, very good electronic conductivity, the presence of functional oxygen groups, together with a nonnucleophilic magnesium electrolyte ensures greater efficiency of the battery. Fig. 54A shows the stability of the cyclic S-rGO nanocomposite for the first 50 cycles at a current density of 20 mA g 1. In turn, Fig. 54B shows the ability to withstand the nominal currents of the S-rGO electrode for current densities between 5 and 45 mA g 1. Fig. 55 shows the electrochemical mechanism of the nanocomposite S-rGO electrode inside the Mg/S cell. During the study described in Ref. [19], vanadium oxychloride was used as an electrode material in a Mg-based battery. The cell delivered just 45 mA h g 1 in the first cycle. The delivered capacity could be improved
180
Next-generation Batteries with Sulfur Cathodes
Fig. 54 (A) Stability of the cyclic S-rGO nanocomposite for the first 50 cycles at a current density of 20 mA g 1. (B) Ability to withstand the nominal currents of the S-rGO electrode for current density between 5 and 45 mA g 1 [2].
through preliminary cycling of the VOCl electrode with Li, as the VOCl can expand its interlayer spacing upon intercalation of ions or molecules within them. In fact, a VOCl electrode with expanded interlayer spacing should facilitate the intercalation of Mg2+, thus leading to higher specific capacities. The Li pretreatment was able to promote the specific capacity by a factor of four (170 mAh g 1) after the first discharge at 298 K. Over 130 mAh g 1 was retained at 5 mA g 1 after 70 cycles.
Mg-S Batteries
181
Fig. 55 Electrochemical mechanism of the nanocomposite S-rGO electrode inside the Mg/S cell [2].
REFERENCES [1] T. Gao, M. Noked, A.J. Pearse, E. Gillette, X. Fan, Y. Zhu, C. Luo, L. Suo, M.A. Schroeder, K. Xu, S.B. Lee, G.W. Rubloff, C. Wang, Enhancing the reversibility of Mg/S battery chemistry through Li+ mediation. J. Am. Chem. Soc. 137 (38) (2015) 12388–12393, https://doi.org/10.1021/jacs.5b07820. [2] B.P. Vinayan, Z. Zhao-Karger, T. Diemant, V.S.K. Chakravadhanula, N.I. Schwarzburger, M.A. Cambaz, R.J. Behm, C. K€ ubel, M. Fichtner, Performance study of magnesium–sulfur battery using a graphene based sulfur composite cathode electrode and a non-nucleophilic Mg electrolyte, Nanoscale 8 (2016) 3296–3306, https://doi. org/10.1039/C5NR04383B (Paper). [3] H.S. Kim, T.S. Arthur, G.D. Allred, J. Zajicek, J.G. Newman, A.E. Rodnyansky, A.G. Oliver, W.C. Boggess, J. Muldoon, Structure and compatibility of a magnesium electrolyte with a sulphur cathode, Nat. Commun. 2 (2011) 427. [4] T.D. Gregory, R.J. Hoffman, R.C. Winterton, Nonaqueous electrochemistry of magnesium applications to energy storage, J. Electrochem. Soc. 137 (1990) 775–780. [5] M. J€ackle, A. Groß, Microscopic properties of lithium, sodium, and magnesium battery anode materials related to possible dendrite growth, J. Chem. Phys. 141 (2014)174710. [6] X. Ji, K.T. Lee, L.F. Nazar, A highly ordered nanostructured carbon–sulphur cathode for lithium–sulphur batteries, Nat. Mater. 8 (2009) 500–506. [7] O. Tutusaus, R. Mohtadi, Paving the way towards highly stable and practical electrolytes for rechargeable magnesium batteries, ChemElectroChem 2 (2015) 51–57. [8] Z. Zhao-Karger, X. Zhao, O. Fuhr, M. Fichtner, Bisamide based non-nucleophilic electrolytes for rechargeable magnesium batteries, RSC Adv. 3 (2013) 16330–16335. [9] Z. Zhao-Karger, X. Zhao, D. Wang, T. Diemant, R.J. Behm, M. Fichtner, Performance improvement of magnesium sulfur batteries with modified non-nucleophilic electrolytes, Adv. Energy Mater. 5 (2014)1401155.
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Next-generation Batteries with Sulfur Cathodes
[10] W. Li, S. Cheng, J. Wang, Y. Qiu, Z. Zheng, H. Lin, S. Nanda, Q. Ma, Y. Xu, F. Ye, Synthesis, crystal structure, and electrochemical properties of a simple magnesium electrolyte for magnesium/sulfur batteries, Angew. Chem. Int. Ed. 55 (2016) 6406–6410, https://doi.org/10.1002/anie.201600256. [11] K. Itaoka, I.T. Kim, K. Yamabuki, N. Yoshimoto, H. Tsutsumi, Room temperature rechargeable magnesium batteries with sulfur-containing composite cathodes prepared from elemental sulfur and bis(alkenyl) compound having a cyclic or linear ether unit. J. Power Sources 297 (2015) 323–328, https://doi.org/10.1016/j.jpowsour. 2015.08.029. [12] P. Saha, M.K. Datta, O.I. Velikokhatnyi, A. Manivannan, D. Alman, P.N. Kumta, Rechargeable magnesium battery: current status and key challenges for the future, Prog. Mater. Sci. 66 (2014) 1–86. [13] A. Manthiram, Y. Fu, Y.-S. Su, Challenges and prospects of lithium–sulfur batteries, Acc. Chem. Res. 46 (2012) 1125–1134. [14] D. Moy, A. Manivannan, S.R. Narayanan, Direct measurement of polysulfide shuttle current: a window into understanding the performance of lithium-sulfur cells, J. Electrochem. Soc. 162 (2015) A1–A7. [15] Y.V. Mikhaylik, J.R. Akridge, Polysulfide shuttle study in the Li/S battery system, J. Electrochem. Soc. 151 (2004) A1969–A1976. [16] Y. Sun, Q. Wu, G. Shi, Graphene based new energy materials, Energy Environ. Sci. 4 (2011) 1113–1132. [17] J. Hou, Y. Shao, M.W. Ellis, R.B. Moore, B. Yi, Graphene-based electrochemical energy conversion and storage: fuel cells, supercapacitors and lithium ion batteries, Phys. Chem. Chem. Phys. 13 (2011) 15384–15402. [18] B.P. Vinayan, N.I. Schwarzburger, M. Fichtner, Synthesis of a nitrogen rich (2D–1D) hybrid carbon nanomaterial using a MnO2 nanorod template for high performance Li-ion battery applications, J. Mater. Chem. A 3 (2015) 6810–6818. [19] C.B. Minella, P. Gao, Z. Zhao-Karger, X. Mu, T. Diemant, M. Pfeifer, V.S.K. Chakravadhanula, R.J. Behm, M. Fichtner, Interlayer-expanded vanadium oxychloride as an electrode material for magnesium-based batteries, ChemElectroChem 4 (2017) 738.