Abstract:

SnS₂ is considered as an attractive anode material to substitute commercial graphite anodes of lithium-ion batteries due to its high specific capacity of 645 mAh·g^-1 as well as low cost. Nevertheless, it suffers poor large volume expansion during the lithiation/delithiation processes, leading to the loss of electrical contact and rapid capacity fading. Herein, by using a facile one-step solvothermal method, SnS₂ nanoflower/graphene nanocomposites (SnS₂ NF/GNs) were prepared, where flower-like SnS₂ hierarchical nanostructures consisting of ultrathin nanoplates, are tightly enwrapped in graphene nanosheets. As anode materials for lithium-ion batteries, the SnS₂ NF/GNs electrode exhibit superior electrochemical performance, with a reversible capacity of 523 mAh·g^-1 after 200 charge-discharge cycles. The enhanced Li storage performance was attributed to the synergistic effect of SnS₂ and graphene. The SnS₂ NF can effectively accommodate the volume change and shorten Li⁺ diffusion distance, while graphene nanosheets can further alleviate the volume expansion of SnS₂ and improve the electronic conductivity.

Key words: Lithium-ion battery, Anode, SnS₂ nanoflower, Graphene