Three-dimensional SWCNT and MWCNT hybrid networks for extremely high-loading and high rate cathode materials

Abstract

Extremely high-loading LiNi_0.5Co_0.2Mn_0.3O₂ (NCM523) cathode materials (up to 99.5 wt%) were achieved through self-organization of a three-dimensional network of multi-walled and single-walled CNT hybrids. The full cell using the NCM523 cathode/graphite without any conventionally used insulating binder exhibited superior C-rate capability (105 mA h g⁻¹ at 10C) and remarkably improved cycling stability (94% capacity after 300 cycles at 1C). The hybridization of a small amount of single-walled CNTs enabled a fast lithiation/delithiation reaction with less polarization and prevented intergranular cracking in both the individual NCM523 secondary particles and NCM523 electrodes during cycling.