Affiliation:
1. Institute of Advanced Battery Materials and Devices College of Materials Science and Engineering Beijing University of Technology Beijing 100124 P. R. China
2. Key Laboratory of Advanced Functional Materials Ministry of Education Beijing University of Technology Beijing 100124 P. R. China
3. State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 P. R. China
Abstract
AbstractManganese‐based lithium‐rich layered oxides (Mn‐LLOs) are promising candidate cathode materials for lithium‐ion batteries, however, the severe voltage decay during cycling is the most concern for their practical applications. Herein, an Mn‐based composite nanostructure constructed Li2MnO3 (LMO@Li2MnO3) is developed via an ultrathin amorphous functional oxide LixMnOy coating at the grain surface. Due to the thin and universal LMO amorphous surface layer etched from the lithiation process by the high‐concentration alkaline solution, the structural and interfacial stability of Li2MnO3 are enhanced apparently, showing the significantly improved voltage maintenance, cycle stability, and energy density. In particular, the LMO@Li2MnO3 cathode exhibits zero voltage decay over 200 cycles. Combining with ex situ spectroscopic and microscopic techniques, the Mn2+/4+ coexisted behavior of the amorphous LMO is revealed, which enables the stable electrochemistry of Li2MnO3. This work provides new possible routes for suppressing the voltage decay of Mn‐LLOs by modifying with the composite functional unit construction.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Natural Science Foundation of Beijing Municipality