Research Area

The earliest developed LiCoO₂ layered oxide cathode material sparked the development of other layered cathode materials, dominating the positive electrode materials for lithium ion batteries. Within the practical operating conditions of today, the current generation layered oxide materials do not meet the future energy storage demands of 350 Wh kg^-1 per cell. This roughly translates to over 800 Wh kg^-1 at the positive electrode level. Li-excess materials have the potential to meet the high energy demands. Unlike the classical layered oxides, Li-excess materials exhibit capacities that go beyond conventional topotactic mechanistic theoretical values because of reversible and stable anionic redox.

In the past five years, our research group has made great progress on developing advanced characterization techniques (including coherent X-ray imaging, neutron pair distribution function, and resonant inelastic X-ray scattering) coupled with atomic scale modeling to properly characterize the dynamic phenomena that govern the anionic redox related performance limitations of Li-excess materials. Furthermore, our efforts have improved the material synthesis and surface modification to improve capacity retention. It is through the in-depth understanding of these anionic redox based cathode materials at atomistic and molecular level and their dynamic changes during the operation of batteries; we can successfully formulate strategies to optimize this class of cathode materials.

Highlighted Publications:

1. M. Zhang, B. Qiu, J. M. Gallardo-Amores, M. Olguin, H. Liu, Y. Li, C. Yin, S. Jiang, W. Yao, M. Elena Arroyo-de Dompablo, Z. Liu and Y. S. Meng, “High Pressure Effect on Structural and Electrochemical Properties of Anionic Redox- Based Lithium Transition Metal Oxides“, Matter, 2020, ASAP

2. A. Singer, M. Zhang, S. Hy, D. Cela, C. Fang, T. A. Wynn, B. Qiu, Y. Xia, Z. Liu, A. Ulvestad, N. Hua, J. Wingert, H. Liu, M. Sprung, A. V. Zozulya, E. Maxey, R. Harder, Y. S. Meng, and O. G. Shpyrko,”Nucleation of Dislocations and Their Dynamics in Layered Oxide Cathode Materials During Battery Charging‘ ,Nature Energy, 2018, 3, 641

3. B. Qiu, M. Zhang, L. Wu, J. Wang, Y. Xia, D. Qian, H.D. Liu, S. Hy, Y. Chen, K. An, Y. Zhu, Z. Liu, Y. S. Meng, “Gas–solid interfacial modification of oxygen activity in layered oxide cathodes for lithium-ion batteries“, Nature Communication 2016, 7,12108

4. Sunny Hy, H.D. Liu, M. Zhang, D. Qian, B.-J. Hwang, Y. S. Meng, “Performance and design considerations for lithium excess layered oxide positive electrode materials for lithium ion batteries“, Energy & Environmental Science, 2016, 9, 1931