Hierarchical CoS<sub>2</sub>/N-Doped Carbon@MoS<sub>2</sub> Nanosheets with Enhanced Sodium Storage Performance
Fengping Xiao, Xuming Yang, Hongkang Wang, Denis Y. W. Yu, Andrey L. Rogach
Abstract
We introduce a hierarchical nanostructure of CoS 2 /N-doped carbon@MoS 2 comprising two transition-metal sulfides CoS 2 and MoS 2, with enhanced sodium storage performance in sodium-ion batteries. A micron-sized Co metal–organic framework (MOF) is transformed into a CoS 2 /N-doped carbon composite, followed by a solvothermal growth of MoS 2 nanosheets on the surface. The resulting composite material offers several specific advantages for sodium storage: (i) accelerated sodium-ion diffusion kinetics due to its heterogeneous interface; (ii) shortened ion diffusion path and exposed active sites for sodium storage due to its hierarchical nanosheet architecture; and (iii) homogeneous nitrogen doping of the MOF-derived carbon, which is beneficial for electronic conductivity. Due to these merits, this composite exhibits excellent electrochemical performance with a specific capacity of 596 mAh g –1 after 100 cycles at 0.1 A g –1 and 395 mAh g –1 at 5.0 A g –1 .