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 Ti3C2Tx nanosheets were selected as the multi-functional substrate for cooperating few-layered SnS2 nanosheets, constructing SnS2/Ti3C2Tx 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 SnS2 and Ti3C2Tx nanosheets, which hinders the agglomeration of SnS2 and the restack of Ti3C2Tx, endowing the hybrid material with robust nanostructure. Thus, the shortcomings of the SnS2 anode are muchly relieved. In this way, the as-prepared SnS2/Ti3C2Tx 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 SnS2 anode brought by the cooperation of Ti3C2Tx, and presenting a reliable strategy to improve the electrochemical performance of sulfide anodes. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

In this study, SnS2/Ti3C2Tx hetero-structural nanosheets were used as electrode material to improve potassium ion batteries performance. The formation of Ti-S bonds prevented the aggregation of SnS2 and Ti3C2Tx, resulting in a robust nanostructure of the electrode and enhancing the storage performance of K-ion batteries.