Improvement of the electrochemical performance of Li1.2Ni0.13Co0.13Mn0.54O2 cathode material by Al2O3 surface coating

Journal Pre-proof Improvement of the electrochemical performance of Li1.2Ni0.13Co0.13Mn0.54O2 cathode material by Al2O3 surface coating

Tong Zou, WeiJing Qi, XiaoShuo Liu, XiaoQin Wu, DingHuan Fan, ShouHui Guo, Li Wang PII:

S1572-6657(20)30028-X

DOI:

https://doi.org/10.1016/j.jelechem.2020.113845

Reference:

JEAC 113845

To appear in:

Journal of Electroanalytical Chemistry

Received date:

4 December 2019

Revised date:

3 January 2020

Accepted date:

9 January 2020

Please cite this article as: T. Zou, W. Qi, X. Liu, et al., Improvement of the electrochemical performance of Li1.2Ni0.13Co0.13Mn0.54O2 cathode material by Al2O3 surface coating, Journal of Electroanalytical Chemistry(2020), https://doi.org/10.1016/ j.jelechem.2020.113845

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© 2020 Published by Elsevier.

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Improvement of the Electrochemical Performance of Li1.2Ni0.13Co0.13Mn0.54O2 Cathode Material by Al2O3 Surface Coating

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Tong Zoua, WeiJing Qia, XiaoShuo Liua, XiaoQin Wua, DingHuan Fana,

Department of Physics, Nanchang University, Nanchang 330031, China

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ShouHui Guoa, Li Wanga,*

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*Corresponding Author.

Keywords:

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Tel:+ 86-791-3860108. E-mail address: [email protected].

surface

modified,

Al2O3

electrochemical properties

coating,

highest

rate

performance,

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ABSTRACT: The layered Li-rich Li1.2Ni0.13Co0.13Mn0.54O2 cathode materials have been synthesized by a facile approach and subsequently modified with different amount of Al2O3 nano layer. The microstructure and electrochemical performance of the pristine and Al2O3 coated samples were investigated systematically. It is found that the pristine particles are uniformly coated with Al2O3 layer. In particular, the 3 wt% Al2O3-coated cathode delivers the highest initial discharge capacity of 317.9 mAhg-1

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at 25 mAg-1 in the voltage window 2.0–4.8 V, and best rate performance (317.9

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mAhg-1 at 0.1 C, 105.6 mAhg-1 at 10 C), and best cyclability (discharge capacity of

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164 mAhg-1 at 2 C after 200 cycles with capacity retention of 86.3%), which is much

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better than that of the pristine cathode (discharge capacity of 124 mAhg-1 at 2 C after

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200 cycles with capacity retention of 73.3%). Electrochemical impedance

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spectroscopy (EIS) shows that the Al2O3 coating can reduce the charge transfer resistance during the cycle, which is attributed to the suppression of the side reactions

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and the stability of the surface structure of the active materials by Al2O3 oxide coating. These findings provide a research direction for solving serious defects such as large initial irreversible capacity loss and poor cycle stability of lithium-rich cathode materials for lithium ion batteries.

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1. Introduction Lithium-ion batteries (LIBs) have the advantages of high energy density, long cycle life and stability, and are widely used in portable electronic products, electric vehicles, large-scale energy storage facilities, aerospace and weaponry [1-4]. These days LIBs is the most important secondary power source and has been widely promoted [5]. However, most of the cathode materials for currently commercialized

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LIBs such as LiCoO2, spinel LiMn2O4, olivine LiFePO4 and α-NaFeO2 type structure

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LiNi1/3Mn1/3Co1/3O2 (NMC-111) or LiNi0.8Co0.15Al0.05O2 (NCA) only have the

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capacities around 120-200 mAhg-1, which cannot meet the requirements of high

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energy density, especially when used for electric vehicles and energy storage [6-8]. At

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recent, layered lithium-rich cathode materials xLiMO2•(1-x) Li2MnO3 (M = Ni, Co,

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Mn, etc.), has been attracted considerable attentions as promising cathodes for LIBs, since it can display high capacity of more than 250 mAhg-1 within 2.0-4.8 V, high

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operating voltage, environmental benignity and low cost [9,10]. This lithium-rich material widely regarded as one of the best choices for cathode materials for next-generation lithium-ion batteries [11-13]. However, such materials currently have problems such as high irreversible capacity for the initial discharge, poor rate performance, voltage decay during cycling, etc, which restricts their large-scale commercial applications [14-16]. Many efforts have been devoted to solve the above drawbacks, such as surface modification, ion doping, optimized topography, and so on [17,18]. Among these modification methods, surface coating is an effective methods to improve the

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electrochemical performance of the layered lithium-rich cathode materials, because the surface coating can decrease the contact area between lithium-rich manganese-based materials and organic electrolytes to reduce the interface side effects and preserve the physical and chemical state of lattice defects after the first charge [19-21]. Materials commonly used for surface coating include metal oxides

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(MgO [22], ZnO [23], Al2O3 [24]), metal fluorides (FeF3 [25], AlF3 [26]), metal phosphates (FePO4 [27], Li3PO4[28]), and carbon [29]. According to previous reports,

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Al2O3 has been proved to be a good coating. Al2O3 is electrochemically inert as a

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conductive interlayer, it can reduce the contact between the electrolyte and the

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electrode, suppress the dissolution of metal ions, and at the same time effectively

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suppress the phase transition and improve the stability of the crystal structure [25].

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Chen et al [30] reported that the Li1.2Mn0.54Ni0.13Co0.13O2 cathode material was synthesized by the electrospinning method and then the Al2O3 has been coated, and

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thus shows high capacity retention of 97.6% after 90 cycles at 1 C. Zhou et al [31] used co-precipitation method obtained Li1.2Mn0.54Ni0.13Co0.13O2 active material and coated Al2O3 via sol-gel method and thus suppressed voltage decay during cycling. Seteni et al [17] reported that Li1.2Mn0.54Ni0.13Co0.13O2 material was synthesized by combustion method and then coated with nano-sized Al2O3 particles via a wet chemical process, and demonstrate the initial discharge capacity of 285 mAhg-1. However, in previous reports, the modified material has not been substantially improved in terms of high rate capacity, cycle stability, etc, which has greatly limited the commercial application of lithium ion batteries [32].

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In this work, we have obtained nanoplate lithium-rich manganese-based cathode materials of Li1.2Ni0.13Co0.13Mn0.54O2 (LNCM) by a simple approach. Subsequently, the surfaces of the materials were modified with different contents Al2O3 nanolayers. The structure, cycle properties, rate properties and other electrochemical properties of the Al2O3 coating were investigated in detail to evaluate the practical application

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potential of the Al2O3 coating. After the surface modification with Al2O3, the microstructures of the electrode materials remained unchanged, however, the

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2. Experiment

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long cycle, reaching 105.6 mAhg-1 at 10 C.

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electrochemical performance was remarkably improved, especially at a high rate and

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2.1. Synthesis of pristine LNCM material

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All the chemicals in this work were of analytical grade and used without further purification. In a typical synthesis, First, stoichiometric amounts of LiNO3 (25 mmol),

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Mn(CHCOO)2•4H2O (10.8 mmol), Ni(NO3)2•6H2O (2.6 mmol), Co(NO3)2•6H2O (2.6 mmol), citric acid (49.2 mmol), polyvinylpyrrolidone (PVP, 1 g) were dissolved in 25 ml ethylene glycol under stirring. Subsequently, the solution was stirred at 85 ℃ for 12 h until it turned brown gel and then dried in an oven at 120 ℃ for 12 h to obtain the brown solid. Thereafter, the solid was ground to fine powder. Finally, the powder was preheated at 450 ℃ for 5 h and then sintered at 900 ℃ for 12 h in air atmosphere to get LNCM material. 2.2 Preparation of Al2O3-coated LNCM material A certain amount of Al(NO3)3•9H2O was dissolved into 200 ml deionized water,

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and then the as-prepared nanoplate Li1.2Ni0.13Co0.13Mn0.54O2 powder dispersed in above solution. After an hour of ultrasound, the pH of the solution was adjusted to 12 by adding ammonia drop by drop and stirred for 3 h at room temperature, the filtered solids were then dried at 80 ℃ for 5 h. Finally the dried powder was sintered at 300 ℃ for 8 h to obtain the final product Al2O3 coated LNCM material. By changing the

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content of Al(NO3)•9H2O, we obtained coating materials with Al2O3 mass fraction of

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1 %, 3 %, and 5 %, and labeled them as LNCM-AO1, LNCM-AO3, LNCM-AO5.

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2.3 Material characterization

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The crystal structure and phase purity of all materials were analyzed by a Bruker

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D8 advanced X-ray diffraction with Cu kα radiation in the 2θ range from 10°-80°. Chemical composition of the samples were analyzed by inductively coupled plasma

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optical emission spectroscopy (ICP-OES, Optima 8000 DV, PerkinElmer Co, USA).

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morphology of the samples were examined by field emission scanning electron microscopy (SEM, Quanta FEG 200), and the energy dispersive spectrometer (EDS) test was used to observed elemental distribution of the materials. Transmission electron microscopy (TEM JEOL JEM-2100) was applied to determine the coating of the surface. The valence states of the metal elements were characterized by X-ray photoelectron spectroscopy (XPS, Thermo ESCALAB 250Xi). 2.4 Electrochemical Measurements Electrochemical measurements were performed using a CR2025 type coin cells assembled in an argon-filled glovebox. The working electrodes was consisted of 80

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wt%, active material, 10 wt% polyvinylidene fuoride (PVDF) binder and 10 wt% super-P conductive carbon mixed in N-methyl pyrrolidone (NMP). The cathode slurry was pasted on Al foil and dried at 60 ℃ in vacuum oven for overnight. The loading mass of the active substance was about 1-2 mg·cm-2, metal lithium sheet as counter electrode. 1 M LiPF6 dissolved in a mixture ethylene carbonate (EC)-dimethyl

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carbonate (DMC)-ethylmethyl carbonate (1:1:1 by volume) as the electrolyte and porous polypropylene based membrane (Celgard 2500) as the separator. The

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galvanostatic charge/discharge tests were performed in a voltage range of 2.0-4.8 V at

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25 ℃ using a Neware battery tester at a current density of 1 C = 250 mAg-1. Cyclic

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voltammetry (CV) was measured at a scan of 0.1 mV-1 on a electrochemical

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workstation (CorrTest CS350H). In addition, the electrochemical impedance

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spectroscopy (EIS) measurements were performed in a frequency range from 0.1 Hz to 100 KHz with an amplitude of 10 mV.

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3. Results and Discussion

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Fig. 1. XRD patterns of the pristine and Al2O3 coated materials.

Fig. 1 shows the XRD patterns of the pristine and Al2O3 coated Li1.2Ni0.13Co0.13 Mn0.54O2 cathode materials. In the XRD patterns, the sharp and well-defined reflection peaks suggest that all materials were highly crystallized. All of diffraction peaks can be well-indexed to the typical hexagonal α-NaFeO2 type structure with space group

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R-3m, except for a number of weak peaks between 20° and 25°, which can be attributed to the cation ordering of Li and Mn in the transition metal layers and the

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existence of monoclinic Li2MnO3 phase with a C2/m symmetry [33,34]. At all XRD

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diffraction peaks, significant splitting of the peaks was observed clearly between

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adjacent peaks of (006)/(102) and (018)/(110), indicating the existence of a typical

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layered structure [15,35]. For X-ray diffraction patterns of Al2O3 coated samples, no

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peak corresponding to the impurity phase was found may due to its low content and amorphous, indicating that the surface modification does not change the crystal

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structure of the pristine material. The atomic composition of the pristine and the Al2O3 surface modified samples were determined by ICP-OES and the results were listed in Table 1. It can be seen that the measured compositions of all samples were approximately the same as the theoretical values. Table 1. Chemical composition and ICP-AES analysis of pristine and Al2O3-coated samples.

Samples LNCM LNCM-AO1 LNCM-AO3 LNCM-AO5

Theoretical molar value of Li/Ni/Co/Mn Li1.2Ni0.13Co0.13Mn0.54 Li1.2Ni0.13Co0.13Mn0.54 Li1.2Ni0.13Co0.13Mn0.54 Li1.2Ni0.13Co0.13Mn0.54

Actual molar value of Li/Ni/Co/Mn (use Mn=0.54 for all samples) Li1.228Ni0.129Co0.127Mn0.54 Li1.185Ni0.128Co0.124Mn0.54 Li1.183Ni0.125Co0.121Mn0.54 Li1.170Ni0.121Co0.131Mn0.54

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Fig. 2. SEM images of (a) bare LNCM, (b) LNCM-AO1, (c) LNCM-AO3, (d) LNCM-AO5.

Fig. 3. EDS elemental maps of LNCM-AO3.

The morphologies of pristine materials and Al2O3 coated materials were shown

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in Fig. 2. The bare particles and coated particles were uniformly distributed with a smooth and clean surface. all the samples were composed of polygonal primary particles with a size distribution of 50-150 nm. After surface modification by Al2O3, the SEM images showed no significant difference in particle size and morphology. Moreover, the particle surface was still smooth and clean, which suggested that the

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Al2O3 layer should be uniform and thin on the surface of Li1.2Ni0.13Co0.13Mn0.54O2.

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Fig.4. XPS spectra of the (a) wide-scan spectrum (b) Al2p spectrum of LNCM-AO3.

In order to prove the existence of Al2O3 coating, EDS, XPS, TEM tests were applied. The elemental distribution of the Al2O3-coated sample was measured by EDS and the results were shown in Fig. 3, the EDS elemental maps clearly shows that the Al element was evenly distributed on the surface of the LNCM particles. The valence states of Al element was characterized by XPS. In Fig. 4(b), a peak appears near 73.8 eV, which corresponds to the Al 2p3/2 XPS spectrum, taking into account the peak of O1s [30]. We can infer that Al2O3 was successfully coated on the surface of the pristine material, which is in good agreement with the TEM results.

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Fig. 5. TEM images of LNCM (a, b, c) and LNCM-AO3 (d, e, f ).

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TEM measurements were performed to observe the microstructures of the

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pristine sample and the surface modified sample and confirm whether the Al2O3 layer was effectively coated on the surface of LNCM particles. For the pristine sample

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LNCM (Fig. 5 a, b, c), the interplanar spacing was measured to be approximately 0.47

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nm, which corresponds to the (003) interlayer spacing of the layered structure Li1.2Ni0.13Co0.13Mn0.54O2, and these stripes were very straight and clear, showing a good layered structure [36]. For the LNCM-AO3 sample (Fig. 5 d, e, f), It can be clearly seen that the amorphous Al2O3 layer with a thickness of about 4-6 nm uniformly covers the surface of the pristine material and the interlayer spacing was the same as the LNCM sample, indicating that the layered structure was maintained.

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Fig. 6. The initial charge-discharge curves of pristine and Al2O3 coated materials at 0.1 C between

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2.0 and 4.8 V.

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LNCM LNCM-AO1 LNCM-AO3 LNCM-AO5

Initial discharge capacity (mAh/g) 284.5 293.6 317.9 304.9

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Samples

Initial charge capacity (mAh/g) 380.8 366.2 387.4 389.9

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Table 2. Initial charge-discharge capacity of pristine sample and Al2O3 modified sample

Irreversible capacity (mAh/g)

Initial coulombic efficiency (%)

96.3 72.6 69.5 85.0

74.7 80.2 82.1 78.2

Fig. 6 shows the initial charge-discharge curves of pristine and Al2O3 coated materials at a constant current density of 0.1 C between 2 V and 4.8 V. Moreover, the specific charge and discharge capacity was listed in the table 2. Obviously, all electrodes have a similar initial charge-discharge curve and the initial charging process can be divided into two parts. The voltage gradually reaches 4.5 V, which corresponds to the lithium ion extraction from the electrochemically active LiMO2 (M=Ni, Co, Mn) phase, accompanied by an increase in the transition metal valence

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(1)

When the voltage reaches 4.5 V, the oxygen and lithium ions in Li2MnO3 are removed from the structure in the form of Li2O to form an electrochemically active MnO2, which was represented by a long voltage platform with the first charge curve of 4.5 V [8,37], shown as Eq. (2)

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xLi2MnO3·(1-x)MO2 → MnO2·(1-x)MO2+ xLi2O (2)

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Both the pristine material and the Al2O3 surface-coated material have large

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irreversible capacity loss and low Coulomb efficiency in the first charge-discharge

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process. This was because in the initial discharge process, only part of the lithium ions

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were embedded in the positive electrode material, a large amount of transition metal ions migrate from the surface to the bulk phase during the charging process,

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occupying the vacancies left after the Li+ and O were released, and partial Li+ cannot

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be re-embedded into the crystal lattice, resulting in the initial irreversible capacity loss and lower coulombic efficiency [15,38]. The first discharge capacity of the pristine, LNCM-AO1, LNCM-AO3 and LNCM-AO5 samples were 284.5, 293.6, 317.9 and 304.9 mAhg-1 respectively. Furthermore, comparing the pristine material with the Al2O3-coated material, it can be found that the irreversible capacity loss of the surface-modified material becomes smaller, and the corresponding coulombic efficiency was improved, which was attributed to the surface coating layer being effective in suppressing surface side reactions and stable material surface structure and provide a shorter lithium ion diffusion path [39,40].

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Fig. 7. (a) Rate capability of pristine and (1,3,5 wt.%) Al2O3 coated samples. (b) Cycle

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performance of pristine and (1,3,5 wt.%) Al2O3 coated samples at 2 C.

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The rate performance of the pristine and surface modified electrodes at different

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current densities changed from 0.1 C to 10 C was shown in Fig. 7(a). At all the current rates, the Al2O3 coated sample exhibits a higher rate capability than the

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pristine sample, especially in the high current rates. It can be observed that as the

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current density increases, the discharge capacity of all materials gradually decreases, and the discharge capacity gap between the pristine sample and the coated sample gradually increases. The discharge capacities are 32.6 mAhg-1 for the pristine sample, 45.6 mAhg-1 for the 1.0 wt% coated sample, 105.6 mAhg-1 for the 3.0 wt% coated sample and 88.1 mAhg-1 for the 5.0 wt% coated LNCM sample at a 10 C rate. Furthermore, the 3.0 wt% coated samples deliver a discharge capacity of 317.9, 272.7, 234.2, 199.1, 169.7 ,133.6, 105.6 mAhg-1 corresponding to 0.1, 0.2, 0.5, 1, 2, 5 and 10 C rates, respectively, and clearly gives the best rate capability among all the samples. When the content of Al2O3 coating increases to 5.0 wt%, the rate capability decreases compared with that of the 3.0 wt% samples, indicating that the Al2O3 coating was too

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thick to reduce the conductivity between the particles. To further illustrate surface modification can improve the cycle stability of materials, the long-term cycling performance of the pristine and Al2O3 modified LNCM cathode materials were carried out at 2 C between 2.0 and 4.8 V at 25 ℃. In Fig. 7(b), Al2O3 surface modified electrode material has higher discharge capacity and

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capacity retention rate compared with the pristine electrode material and the LNCM-AO3 sample shows the best cycle performance. At the end of 200 cycles,

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LNCM-AO3 exhibited the highest discharge capacity of 164 mAhg-1 and the capacity

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retention rate was 86.3%, while the discharge capacity of the pristine sample

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decreased significantly with cycling, with a discharge capacity of 124 mAhg-1 and a

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capacity retention rate of 73.3%. When the content of the Al2O3 coating was 5 wt%,

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the discharge capacity was 148 mAhg-1, and the capacity retention rate was 80.5%. The above results show that the proper amount of Al2O3 coating layer can

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significantly improve the cycle stability of the material and hinder the rapid decay of the capacity, because the surface coating can effectively reduce the contact area between the electrode material and the organic electrolyte, and suppress the interface side reaction and reduce decay in Li+ transport [34,41,42].

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Fig. 8. voltage profiles vs cycles of pristine and (1,3,5 wt.%) Al2O3 coated cathodes.

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Fig. 8 shows the discharge profiles and cycle performance of all samples. It clearly shows that the capacity and voltage of all samples have been faded in the cycle.

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During the cycling process, the migration and rearrangement of transition metal

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cations might cause irreversible phase transitions and lattice collapse, resulting in voltage decay [31]. Obviously, the voltage decay of the pristine sample was particularly rapid. However, the capacity decay and voltage drop of the Al 2O3 surface modified sample were significantly slower than the pristine sample, especially the LNCM-AO3 sample. This result further demonstrates that the Al2O3 coating can suppress the phase transition of the crystal and slow down the voltage decay.

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Fig. 9. cyclic voltammetry curves of (a) LNCM and (b) LNCM-AO3.

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In order to further understand the effect of Al2O3 modification on

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electrochemical mechanism. The cyclic voltammetry test was carried out on the

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pristine and LNCM-AO3 samples at a scan rate of 0.1 mVs-1 in the voltage range of

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2.0-4.8 V at 25 ℃. As shown in Fig. 9, the two oxidation peaks of the pristine sample appear at 4 V and 4.6 V respectively in the initial curve. The oxidation peak near 4 V

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represents the removal of Li+ and the oxidation reaction of Ni2+ and Co3+, while the oxidation peak around 4.6 V corresponds to the activation of Li2MnO3 and the removal of Li2O to form MnO2 [43-45]. For subsequent cycles, the CV characteristics were significantly different from those in the first cycle, and the peak at 4.6 V disappears, indicating that the deoxygenation process was irreversible, which was consistent with the initial charge-discharge performance [46]. For the CVs of LNCM-AO3 sample, the curve shows all redox peaks similar to those of pristine, except maintained a weak peak around 2.9 V corresponding to Mn redox reactions [47], which further proves that the coating of Al2O3 does not change the main

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electrochemical behavior of Li-rich manganese-based materials. Table 3. Charge-transfer resistance (Rp, Ω) of pristine and 1.0, 3.0 and 5.0 wt% Al2O3-coated samples at various cycles.

The Initial cycle 118.4 79.2 44.9 64.2

The 100th cycle 206.2 128.8 72.8 108.2

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Samples LNCM LNCM-AO1 LNCM-AO3 LNCM-AO5

Fig. 10. EIS plots of (a) LNCM (b) LNCM-AO1 (c) LNCM-AO3 (d) LNCM-AO5.

The electrochemical impedance spectroscopy (EIS) has always been an important part of the charging and discharging process of lithium-ion batteries. This was an important analysis to further understand the role of Al2O3 coating in improving the electrochemical performance of lithium-rich manganese-based cathode materials. Fig. 10 shows Nyquist plots of the pristine and Al2O3 coated electrodes at a charge state of 4.5 V for the first and 100th cycle, respectively. From the EIS fitting map and the equivalent circuit model in Fig. 10, the intersection of the EIS fitting

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curve in the high frequency region and the real axis was related to the ohmic internal resistance (Rs); the semicircle in the intermediate frequency region represents the charge transfer resistance (Rp) at the electrolyte/electrode interface; while the quasi-straight line in the low frequency region corresponds to the Warburg impedance (W1) of lithium ion diffusion in the electrode [48,49]. All sample curves have similar

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patterns, but differentiate between data, the fitting impedance parameter values of the equivalent circuit are as shown in Table 3. After 100 cycles, the Rp value of the

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pristine sample increased sharply from 118.4 Ω to 206.2 Ω, while the Rp value of the

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Al2O3 coated sample changed slightly: for the LNCM-AO1 sample, from the initial

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79.2 Ω to the 50th cycle of 128.8 Ω, for the LNCM-AO3 sample, from 44.9 Ω to 72.8

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Ω, from 64.2 Ω to 108.2 Ω, for LNCM-AO5 sample. The above results indicate that a

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certain amount of Al2O3 coating can effectively suppress the side effects between the active material and the electrolyte, reduce the structural instability of the electrode,

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and improve the charge transport efficiency [25]. 4. Conclusions

Li-rich layered oxides Li1.2Ni0.13Co0.13Mn0.54O2 for Lithium ion batteries have been successfully synthesized via a facile approach and subsequently coated with different amount of Al2O3 layer. There is no significant difference in crystal structure compared to the pristine sample and the coated sample, presenting an ordered hexagonal α-NaFeO2 layered structure. From the TEM images, it can be observed that the surface of the electrode material particles uniformly covers the Al2O3 nano layer with a thickness of about 4-6 nm. The samples with proper amount of Al2O3 deliver a

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better electrochemical performance, the initial coulombic efficiency increased from 74.7% to 82.1% when the Al2O3-coating content was 3.0 wt% at the 0.1 C rate, the LNCM-AO3 sample exhibited a discharge capacity of 317.9 mAhg-1 at a current rate of 0.1 C and a discharge capacity of 105.6 mAhg-1 at a current of 10 C. The discharge capacity was maintained at 164 mAhg-1 after 200 cycles at 2 C, and the capacity

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retention rate was 86.3%. In addition, electrochemical impedance analysis shows that the coated sample has a lower charge transfer resistance than the pristine sample. Our

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results show that Al2O3 coating can effectively improve the electrochemical

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performance of layered Li1.2Ni0.13Co0.13Mn0.54O2 material and may become a

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candidate for practical applications of hybrid electric vehicles and energy storage

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Acknowledgments

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systems.

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This study was financially supported by Natural Science Foundation of China (Grant No. 11727902). L.W. acknowledges Jiangxi Provincial Innovation Talents of Science and Technology (20165BCB18003). References (1) Y. M. Chiang, Building a Better Battery. Science. 330 (2010) 1485-1486. (2) A. Manthiram, A. V. Murugan, A. Sarkar, T. Muraliganth, Nanostructured Electrode Materials for Electrochemical Energy Storage and Conversion. Energy Environ. Sci. 1 (2008) 621−638. (3) J. Kasnatscheew, R. Wagner, M. Winter, I. Cekic-Laskovic. Interfaces and

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Capacity and Coulombic Efficiency. Adv. Mater. 29 (2017) 1701294.

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Author contributions Tong

Zou ： Conceptualization,

Methodology,

Software,

Investigation，Writing - Original Draft. WeiJing Qi ： Resources, Writing - Review & Editing, Supervision,

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Data Curation. XiaoShuo Liu：Validation, Formal analysis, Visualization.

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XiaoQin Wu: Validation, Formal analysis, Visualization.

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DingHuan Fan: Resources, Visualization.

Wang:

Supervision,

Project

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Li

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ShouHui Guo: Resources, Validation, Visualization. administration,

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acquisition, Writing - Review & Editing

Funding

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Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence

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the work reported in this paper.