Enhancing lithium-ion storage performance of hollow CoS2/MoS2 nanospheres via N-doped carbon-coating

Transition metal sulfides (TMSs) have been considered as up-and-coming anode materials for lithium-ion batteries (LIBs) owing to their large theoretical capacity and good reversibility . However, obvious volume variation and sluggish kinetics greatly limit their practical application. To address this issue, we successfully design and fabricate hollow CoS 2 /MoS 2 nanospheres and effectively enhance their lithium storage performance via N-doped carbon-coating (CoS 2 /MoS 2 @N-C). The unique hollow structure provides shortened ion-diffusion path, while the N-doped carbon shells buffer the severe volume changes during cycling and improve the electronic conductivity of the electrode. When used as an anode material for LIBs, the CoS 2 /MoS 2 @N-C displays high specific capacity (1056.9 mA h g −1 at 100 mA g −1 ), excellent cycling stability (653.9 mA h g −1 after 250 cycles at 1000 mA g −1 ), and rate capability (685 mA h g −1 at 2000 mA g −1 ). The CoS 2 /MoS 2 @N-C||LiFePO 4 full-cell LIB is also assembled and exhibits remarkable performance. The remarkable electrochemical performance of CoS 2 /MoS 2 @N-C electrode could be assigned to the synergistic enhancement effect of the N-doped carbon coating and hollow structure, which efficiently shorten the ion diffusion path , boost the charge transfer rate, and alleviated the volume changes of the electrode upon cycling.