Heterostructure engineering of ultrathin SnS2/Ti3C2Tx nanosheets for high-performance potassium-ion batteries

Layered metal sulfides are considered as promising candidates for potassium ion batteries (KIBs) owing to the unique interlayer passages for ion diffusion. However, the insufficient electronic conductivity, inevitable volume expansion, and sulfur loss hinder the promotion of K-ion storage performance. Herein, few-layered Ti 3 C 2 T x nanosheets were selected as the multi-functional substrate for cooperating few-layered SnS 2 nanosheets, constructing SnS 2 /Ti 3 C 2 T x hetero-structural nanosheets (HNs) with the thickness as thin as about 5 nm. In this configuration, the formed Ti-S bonds provide robust interaction between SnS 2 and Ti 3 C 2 T x nanosheets, which hinders the agglomeration of SnS 2 and the restack of Ti 3 C 2 T x , endowing the hybrid material with robust nanostructure. Thus, the shortcomings of the SnS 2 anode are muchly relieved. In this way, the as-prepared SnS 2 /Ti 3 C 2 T x HNs electrode delivers reversible capacities of 462.1 mAh g −1 at 0.1 A g −1 and 166.1 mAh g −1 at 2.0 A g −1 , respectively, and a capacity of 85.5 mAh g −1 is remained even after 460 cycles at 2.0 A g −1 . These results are superior to those of the counterpart electrode, confirming aggressive promotion of K-ion storage performance of SnS 2 anode brought by the cooperation of Ti 3 C 2 T x , and presenting a reliable strategy to improve the electrochemical performance of sulfide anodes.