Promoting Surface Electric Conductivity for High-Rate LiCoO2 |
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Authors: | Shenyang Xu Xinghua Tan Wangyang Ding Wenju Ren Qi Zhao Weiyuan Huang Jiajie Liu Rui Qi Yongxin Zhang Jiachao Yang Changjian Zuo Haocheng Ji Hengyu Ren Bo Cao Haoyu Xue Zhihai Gao Haocong Yi Wenguang Zhao Yinguo Xiao Qinghe Zhao Mingjian Zhang Feng Pan |
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Institution: | 1. School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen, 518055 P. R. China;2. School of Advanced Manufacturing Engineering, Chongqing University of Posts and Telecommunications, Chongqing, 400065 China;3. Department of Materials, University of Oxford, 16 Parks Road, Hume-Rothery Building, Oxford, UK;4. School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004 China;5. School of Metallurgy and Environment, Central South University, Changsha, 410083 China;6. Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China |
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Abstract: | The cathode materials work as the host framework for both Li+ diffusion and electron transport in Li-ion batteries. The Li+ diffusion property is always the research focus, while the electron transport property is less studied. Herein, we propose a unique strategy to elevate the rate performance through promoting the surface electric conductivity. Specifically, a disordered rock-salt phase was coherently constructed at the surface of LiCoO2, promoting the surface electric conductivity by over one magnitude. It increased the effective voltage (Veff) imposed in the bulk, thus driving more Li+ extraction/insertion and making LiCoO2 exhibit superior rate capability (154 mAh g?1 at 10 C), and excellent cycling performance (93 % after 1000 cycles at 10 C). The universality of this strategy was confirmed by another surface design and a simulation. Our findings provide a new angle for developing high-rate cathode materials by tuning the surface electron transport property. |
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Keywords: | Effective Voltage Electric Conductivity High Rate LiCoO2 Surface Structure |
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