A biomass-derived biochar-supported NiS/C anode material for lithium-ion batteries

Nickel sulfides are perfect anode materials for high-capacity and low-cost lithium-ion batteries (LIBs); however, with the shortcoming of polysulfide intermediate dissolution, volume expansion exceeding the limit during cycling also restricts their development. Herein, NiS/C composite materials are successfully anchored on chestnut shell fluff (CSF)-derived biochar by a glucose-auxiliary hydrothermal method along with an annealing treatment. The CSF biochar acts as an effective electron transmission channel for the rapid lithiation/delithiation of NiS and as a fixed sulfur carrier for inhibiting the dissolution of polysulfide. Glucose restrains the accumulation of NiS particles and then transforms into uniform amorphous carbon during annealing, which is more effective in buffering for rapid volume variation. Moreover, the CSF-NiS/C electrode exhibits a remarkable specific capacity of 1522.8 mAh g-1 (0.1 A g-1) and distinguished rate performance with 295 mAh g-1 capacity (3 A g-1), which are better than those of the pure NiS/C anode material displays. Researchers may be inspired by both of these reasonable design and synthesis strategies that are beneficial for the development of high-performance nickel-based sulfide anode materials for LIBs.