▎ 摘　　要

NOVELTY - Preparing three-dimensional cross-linked tin selenide / three-dimensional reduced - graphene oxide composite material comprises (a) adding graphene oxide to deionized water, dispersing to obtain solution A, placing the mixed solution A into a polytetrafluoroethylene lining high pressure reaction kettle, placing the sealed reaction kettle into a homogeneous hydrothermal reactor, cooling to obtain cylindrical three-dimensional graphene hydrogel B, freeze-drying to obtain cylindrical three-dimensional graphene C, adding into ethylene glycol, stirring, dispersing, adding tin(ii) chloride dehydrate, stirring, adding surfactant to form solution D, adding selenium powder to reducing agent, stirring, mixing to obtain solution E, adding to solution D to form mixed solution F, stirring, mixing, adding homogeneously mixed solution F into polytetrafluoroethylene lining high pressure reaction kettle, hydrothermally reacting to obtain product G, collecting the samples and heating to obtain material. USE - The composite material is useful in cathode of potassium ion battery (claimed). ADVANTAGE - The method has mild reaction conditions; obtains simple experimental device and is easy to implement; ensures that the three-dimensional graphene provides space for the volume expansion of the tin selenide alloy at the electrode; suppress the volume expansion of alloy anode materials and improves the capacity of the battery. DETAILED DESCRIPTION - Preparing three-dimensional cross-linked tin selenide / three-dimensional reduced - graphene oxide composite material comprises (a) adding 80-120 mg graphene oxide to 20-50 ml deionized water, dispersing evenly to obtain solution A, (b) placing the mixed solution A into a polytetrafluoroethylene lining high pressure reaction kettle, placing the sealed reaction kettle into a homogeneous hydrothermal reactor, setting the temperature parameter to 100-200℃, and reaction time for 6-36 hours, cooling to obtain cylindrical three-dimensional graphene hydrogel B, (c) placing the cylindrical three-dimensional graphene hydrogel B into freeze-drying to obtain cylindrical three-dimensional graphene C, (d) adding cylindrical three-dimensional graphene C into 30-70 ml ethylene glycol, stirring, dispersing evenly, adding 0.04557-4.557 g tin(ii) chloride dehydrate, continuing stirring until the mixture was uniform, adding 0.046-0.46 g surfactant to form solution D, (e) adding 0.0158-1.58 g selenium powder to 3-5 ml reducing agent, stirring until dispersed, mixing to obtain solution E, where the ratio of tin(ii) chloride dehydrate and selenium powder is 1:1-5, (g) adding solution E drop wise to solution D to form mixed solution F, stirring, mixing evenly, adding homogeneously mixed solution F into a 100 ml polytetrafluoroethylene lining high pressure reaction kettle, hydrothermally reacting at 120-200℃ for 10-24 hours to obtain product G and (h) collecting the product G by centrifugation, collecting the samples after freeze-drying and placing in a reaction furnace under nitrogen protective gas and heating to 400-800℃ at a heating rate of 10℃/minute for 5-10 hours to obtain material. An INDEPENDENT CLAIM is also included for a three-dimensional cross-linked tin selenide / three-dimensional reduced - graphene oxide composite material, which is prepared by the above method.