Potassium(K)ion batteries present their promising application for large-scale energy storage systems with cost-effective characteristic.Unfortunately,the large K ion radius results in sluggish K ion diffusion kinetics and volume expansion of the elec-trode during the K ion insertion/extraction process.It is a challenge to explore capable anode materials with remarkable K ion storage ability.Herein,we design and prepare SnS2 ultrathin nanosheets via a facile hydrothermal process.When severing as anode materials for K ion batteries with optimized electrolyte,SnS2 presents an im-proved capacity and rate ability.The capable electrochemical per-formance is ascribed to the reduced ion diffusion pathway and ca-pacitor-dominated K-ion storage process.In addition,the K ion stor-age mechanism of SnS2 is investigated by the ex-situ X-ray diffraction technique.