Effect of Mg Content on the Electrochemical Properties of (MgCoNiZnLi)O Based High Entropy Oxides for Li-Ion Batteries

Abstract

High entropy oxides (HEOs) are attractive as a negative electrode material for lithium-ion batteries because of the high specific capacities and cycling stabilities. Moreover, they offer a wide range of compositional variation to reach the desired electrochemical performances. In this study, we synthesized the Mgx(CoNiZnLi)100-xO high entropy oxides using conventional solid state reaction technique and examined their electrochemical properties in lithium-ion cells as anode material. The structural properties of as-synthesized Mg5(CoNiZnLi)95O and Mg35(CoNiZnLi)65O HEOs were investigated using X-ray diffraction (XRD) technique, which showed that all the oxides have single-phase rock-salt structure. When tested as anode material in lithium-ion cell, Mg5(CoNiZnLi)95O anode exhibits higher initial discharge capacity than Mg35(CoNiZnLi)65O electrode. However, the Mg35(CoNiZnLi)65O electrode shows the higher cycling stability than Mg5(CoNiZnLi)95O electrode at the further cycle period. This work offers an approach to control the electrochemical properties of HEO based anodes by tuning active and inactive cation contents in the structure.

Keywords

• Conversion type anode
• Li-ion battery
• High entropy oxide

References

1. Fang, S., Bresser, D., & Passerini, S. (2019). Transition metal oxide anodes for electrochemical energy storage in lithium- and sodium- ion batteries. Advanced Energy Materials, 10, 1902485.
2. Lökçü, E., Toparli, Ç., & Anik, M. (2020). Electrochemical performance of (MgCoNiZn)1-xLixO high-entropy oxides in lithium-ion batteries. ACS Applied Materials & Interfaces, 12, 23860-23866.
3. Lu, J., Chen, Z., Pan, F., Cui, Y., & Amine, K. (2018). High-performance anode materials for rechargeable lithium-ion batteries. Electrochemical Energy Reviews, 1, 35−53.
4. Puthusseri, D., Wahid, M., & Ogale, S. (2018). Conversion-type anode materials for alkali-ion batteries: State of the art and possible research directions. ACS Omega, 3, 4591−4601.
5. Rost, C. M., Sachet, E., Borman, T., Moballegh, A., Dickey, E. C., Hou, D., Jones, J. L., Curtarolo, S., & Maria, J.-P. (2015). Entropy-stabilized oxides. Nature Communications, 6, 1−8.
6. Sarkar, A., Velasco, L., Wang, D., Wang, Q., Talasila, G., de Biasi, L., Kübel, C., Brezesinski, T., Bhattacharya, S. S., Hahn, H., & Breitung, B. (2018). High entropy oxides for reversible energy storage. Nature Communications, 9(3400), 1-9.
7. Qiu, N., Chen, H., Yang, Z., Sun, S., Wang, Y., & Cui, Y. (2019). A high entropy oxide (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2O) with superior lithium storage performance. Journal of Alloys and Compounds, 777, 767−774.
8. Yuan, C., Wu, H. B., Xie, Y.;, & Lou, X. W. D. (2014). Mixed transition- metal oxides: Design, synthesis, and energy-related applications. Angewandte Chemie International Edition, 53, 1488−1504.