▎ 摘　　要

NOVELTY - Negative electrode material for potassium ion battery, comprises nano tin(IV) sulfide/graphene composite material in which tin(IV) sulfide occupies mass proportion of 30-90 wt.%, preferably 65-85 wt.% and tin(IV) sulfide has a particle size of 1-50 nanometer, preferably 1-25 nanometer. USE - Method for preparing negative electrode material for potassium ion battery. ADVANTAGE - The method enables to prepare negative electrode material for potassium ion battery in which graphene nanometre tin(IV) sulfide/ omposite electrode material can obtain 714 milliAmpere hour per gram high reversible specific capacity, excellent rate performance and cycle performance, cycling 50 cycles at current density of 500 milliAmpere per gram and , reversible capacity of 483 milliAmpere hour per gram and cycling 50 cycles at current density of 250 milliAmpere per gram and still keeps the reversible capacity of 464 milliAmpere hour per gram, which effectively solves bottleneck problem of low capacity of conventional potassium ion battery. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing negative electrode material for potassium ion battery, which involves dissolving graphene, tin source, sulfur source and an auxiliary agent in water, and producing potassium by low-temperature hydrothermal synthesis and heat treating to obtain desired product.