Double-shell Li-rich layered oxide hollow microspheres with sandwich-like carbon@spinel@layered@spinel@carbon shells as high-rate lithium ion battery cathode

• DOI: 10.1016/j.nanoen.2019.02.040
• Publication Date: 2019-02-16T11:10:53Z
• Authors: Yating Ma; Pengfei Liu; Qingshui Xie; Guobing Zhang; Hongfei Zheng; Yuxin Cai; Zhi Li; Laisen Wang; Zi-Zhong Zhu; Liqiang Mai; Dong-Liang Peng
• Keywords: Carbon fibers; Carbothermic reaction

Abstract Li-rich layered oxides (LRLO) with high specific capacity over 250 mA h g−1 are attractive cathode material candidates for the next-generation high performance lithium-ion batteries. However, LRLO always suffers from low initial Coulombic efficiency, poor cycling and rate properties. Herein, unique double-shell LRLO hollow microspheres with sandwich-like carbon@spinel@layered@spinel@carbon shells (LRLO-500@S@C) were successfully synthesized via a facile template-free method, followed by carbothermal reduction treatment. The fabricated LRLO-500@S@C cathode delivers a high initial charge capacity of 312.5 mA h g−1 with a large initial Coulombic efficiency of 89.7%. After cycling 200 times, large and stable discharge capacities of 228.3 mA h g−1 and 196.1 mA h g−1 can be obtained at 1.0 C and 5.0 C, respectively. Moreover, coin-type full cell with LRLO-500@S@C as cathode and Li4Ti5O12 as anode delivers outstanding lithium storage properties. The impressive electrochemical performances of LRLO-500@S@C cathode material can be attributed to its multiscale coordinated design based on hierarchical double-shell hollow construction, the special layered@spinel@carbon heterostructured shells and the introduced oxygen vacancies, which benefit to shorten Li-ion diffusion paths, strengthen structural stability and reduce side reactions.