Dual conductive surface engineering of LiNi0.8Co0.1Mn0.1O2 cathode for high-energy density

Abstract

Ni-rich cathode materials have been considered as next-generation power lithium batteries due to their high energy density. However, some of the inherent properties have hindered Ni-rich cathode materials from further applications. Herein, a light weight and self-standing GPI-NCM811 electrode was obtained by filling polyvinylidene fluoride (PVDF) and acetylene black-coated LiNi0.8Co0.1Mn0.1O2 (NCM811) material into graphitized polyimide (GPI) with double conductive surface engineering, which can maintain the structural stability during cycling and ensure the rapid diffusion of electron/Li-ion. The initial specific capacity of GPI-NCM811electrode (210 mAh/g) is obviously higher than the NCM811 electrode (202 mAh/g) at 0.1C. The initial Coulombic efficiency (ICE) of GPI-NCM811electrode increased from 88.9 to 95.9% and its rate capacity is 127 mAh/g at 10 C, which is much higher than that of NCM811 electrode (104 mAh/g). It is because GPI has conductive network structure that can accommodate more electrolyte and fast electron conduction. The GPI-NCM811 electrode capacity remains 83.5% of initial specific capacity between 2.8–4.3 V at 1C after 500 times, while that of NCM811 electrode remains 61.8%. This is due to the synergistic effect of the mixed coating to inhibit the occurrence of side reactions and self-standing to reduce the shedding of electrode material from the fluid collector during long cycle.