Electrochemical Performance of SnS@Graphene Composites Prepared by Deep Eutectic Solvent Method

SnS material is considered as an attractive anode material to substitute commercial graphite anodes of lithium-ion batteries (LIBs) due to its large capacity, low cost, and environment-friendliness. However, the side reactions induced during charge/discharge processes significantly expand the volume of SnS material, limiting its development. Herein, a novel deep eutectic solvent is synthesized with polyethylene glycol and SnCl2 center dot 2H(2)O, and SnS@graphene composites are prepared using a one-step pyrolytic vulcanization method. The composite material is sandwich-shaped with graphene sheet layers interspersed with SnS particles. Tests after making them into button cells have shown that the composite electrodes have excellent electrochemical properties: an initial discharge capacity of 1346 mAh g(-1) at the current density of 100 mA g(-1); outstanding long-period performance under high current. In the case of 1 A g(-1), it still has 421.8 mAh g(-1) capacity after 1000 cycles. It also shows superior rate characteristics: under the current density of 5 A g(-1), its specific discharge capacity is 343 mAh g(-1); the specific discharge capacity increases rapidly to 798 mAh g(-1) when the current density returns to 1 A g(-1).