Accurate Control of Initial Coulombic Efficiency for Lithium-rich Manganese-based Layered Oxides by Surface Multicomponent Integration |
| |
| Authors: | Dr. Dong Luo Xiaokai Ding Dr. Jianming Fan Zuhao Zhang Dr. Peizhi Liu Dr. Xiaohua Yang Prof. Junjie Guo Prof. Shuhui Sun Prof. Zhan Lin |
| |
| Affiliation: | 1. Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006 China;2. Fujian Provincial Key Laboratory of Clean Energy Materials, College of Chemistry and Materials, Longyan University, Longyan, 364012 China;3. Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan, 030024 China;4. Institut National de la Recherche Scientifique-Center for Energy, Materials and Telecommunications, Varennes, Quebec, J3X 1S2 Canada |
| |
| Abstract: | Low initial Coulombic efficiency (ICE) is an obstacle for practical application of Li-rich Mn-based layered oxides (LLOs), which is closely related with the irreversible oxygen evolution owing to the overoxidized reaction of surface labile oxygen. Here we report a NH4F-assisted surface multicomponent integration technology to accurately control the ICE, by which oxygen vacancies, spinel-layered coherent structure, and F-doping are skillfully integrated on the surface of treated LLOs microspheres. Though the regulation on the removed amount of labile oxygen by surface integrated structure, the ICE of LLOs cathodes can adjust from starting value to 100 %. X-ray absorption spectroscopy, refined X-ray diffraction, and scanning transmission electron microscopy show that the removed labile oxygen mainly comes from Li2MnO3-like structure. Even operating at a high cut-off voltage of 5 V, the capacity retention of integrated sample at 200 mA g−1 is still larger than 98 % after 100 cycles. |
| |
| Keywords: | cathodes initial Coulombic efficiency Li-rich Mn-based layered oxides lithium-ion batteries surface modification |
|
|
