Ni3S2/Co9S8 heterojunction decorated wheat straw cellulose carbon for lithium-ion battery anode material

Transition metal sulfides exhibit a high theoretical specific capacity and have great potential to be used as a negative electrode material for lithium-ion batteries, but they are prone to produce volume expansion during the cycle process, which leads to the disintegration of the electrode material structure and affects the battery performance. This paper reports the synthesis of high-performance electrode materials, Ni 3 S 2 /Co 9 S 8 /WSCC, a composite of Ni 3 S 2 /Co 9 S 8 nanocages, and wheat straw cellulose carbon (WSCC) by a simple hydrothermal method. This composite structure has the following advantages: (1) two metal sulfides, Ni 3 S 2 and Co 9 S 8 , are introduced simultaneously through the synthesis of nanocages, which can increase the defects and active sites at the interface. At the same time, the nanocage structure helps to buffer the volume change during ion insertion and detachment and promote ion diffusion. (2) The biomass carbon material as a substrate not only plays a supporting role, but also reduces the agglomeration of nanocages, making them have better dispersion. Using it as a lithium-ion battery anode, it has a specific capacity of 535.8 mAh g −1 after 300 cycles at 1 C.