Nitrogen-Doped Graphene-Supported Straw-Like CoSe<sub>2</sub> for Rapid and Stable Sodium-Ion Storage
Chong Xu, Kaiyi Chen, Guang Ma, Ye Wang, Sujian Wu, Sai Che, Yongpeng Cui, Wang Yang, Yongfeng Li
Abstract
Cobalt diselenide (CoSe 2 ) materials exhibit significant potential in sodium-ion batteries (SIBs) owing to their high theoretical specific capacity and excellent cycling stability. However, the conductivity and volume expansion of CoSe 2 limit its rate performance and cycling stability. Herein, a nitrogen-doped reduced graphene oxide (N-rGO) supported straw-like CoSe 2 anode material (CoSe 2 /N-rGO) is synthesized via a hydrothermal method. Experimental results show that nitrogen doping improves the conductivity and structural stability of CoSe 2 /N-rGO, enabling excellent rate performance (311.75 mAh g –1 at 10 A g –1 ) and high cycling stability (356.78 mAh g –1 after 1000 cycles at 1 A g –1 ). Notably, the CoSe 2 /N-rGO||NVP full cell exhibits a capacity of 117.4 mAh g –1 at 0.1 C, approaching 98.7% of the calculated maximum for NVP (118 mAh g –1 ). This approach offers new insights and valuable guidance for the structure of efficient electrode materials for energy storage systems.