Presentation Title：Local-Structure Adjustment and Nb/Ta-Based Optimization of Lithium-Rich Cathode Materials

Abstract:

Owing to their noticeable advantages including high specific capacity, low cost, and environmental friendliness, lithium-rich manganese-based layered oxides (LLOs) are regarded as the most promising cathode materials for high-energy-density lithium batteries. However, LLOs still suffer from certain performance drawbacks. Therefore, the deeper understanding of the unique local structures and electrochemical mechanisms of LLOs is urgently necessary, which will promote the development of targeted and efficient optimization strategies. Based on our continuous studies on LLOs for 16 years, this report will present several key topics about local-structure adjustment and performance enhancement of LLOs, including (i) the identification and electrochemical effects of the LiMn₆ ring and the π-bonding ring as functional units; (ii) the quantitative and site-specific doping to adjust the LiMn₆ rings and π-bonding rings at the local-structure level for adjusting the electrochemical behavior; and (iii) the important roles of Nb and Ta in doping/coating modifications of LLOs for efficient performance enhancement.

Bio：

Prof. Haijun Yu is a level-2 professor in Beijing University of Technology, and the director of Institute of Gongda-Guochuang Advanced Battery Materials and Devices. He has been selected as a distinguished professor of Ministry of Education of China, and the chief scientist of National Key R&D Program of China. He has gained honors such as Beijing Youth May Fourth Medal and Second Prize of Beijing Natural Science Award.

Prof. Yu focuses on the studies of advanced battery materials and devices. He is in charge of more than 30 national/provincial-level programs such as National Key R&D Program of China and Major Program of the National Natural Science Foundation of China, which cover advanced battery materials, battery and system, and electric vehicle applications. He has made systematic and innovative research progresses in the key materials of lithium-ion batteries, solid-state batteries, and sodium/ aluminum-ion batteries, and proposed the academic concept of "crystalline domain battery materials". He has also realized the industrialization of lithium-rich manganese-based layered oxides (LLOs) as cathode materials for the next-generation high-energy lithium-ion batteries.