In situ growth of CoO nanosheets on a carbon fiber derived from corn cellulose as an advanced hybrid anode for lithium-ion batteries

Abstract

Owing to the abundant reserves, low cost and flexible processing, biomass carbon has been widely implemented as the anode for lithium-ion batteries (LIBs). However, they suffer from a low specific capacity. In this study, we propose a facile method to prepare a CoO/carbon fiber (CoO/CF) hybrid electrode by employing corn cellulose as the procurer. It is found that the CoO nanosheets perpendicularly grow on the CF, which promotes Li⁺ diffusion. Moreover, CF can alleviate the structural strain caused by CoO during the charge/discharge process. Further, the electrochemical measurements show that the active redox reaction enabled by Co²⁺/Co⁰ increases the specific capacity. Consequently, the optimized CoO/CF anode demonstrates a highly reversible specific capacity of 847 mA h g⁻¹ at 0.1 A g⁻¹ after 100 cycles. Remarkably, the Li⁺ storage mechanisms of CoO/CF are explored, indicating that the formation of metallic Co upon cycling is effective in enhancing the conductivity of the whole electrode and cycling stability.