▎ 摘　　要

NOVELTY - Preparing composite material containing selenide comprises (a) using metal sulfate or nitrate, mixing carbon source with sodium stannate, adjusting pH to 8-10 after 0-3degrees Celsius to obtain metal hydroxide microsphere precursor, and obtaining metal oxide microspheres after the first calcining, (b) mixing selenium powder with reducing agent to obtain selenite-containing solution, and (c) mixing metal oxide micropheres with carbon source to form mixed solution, adding selenium-containing liquid to the mixed solution for hydrothermal reaction, and calcining to obtain selenate-containing composite material. USE - The composite material is useful in cathode material for sodium ion battery (claimed) preparation technology field, lithium battery in smart phone, notebook computer and energy vehicle. ADVANTAGE - The method provides high purity, excellent crystal form, complete controllable structure containing double-metal component of selenide, realizes the selenium-containing composite material structure by controlling the structure of the metal oxide micro-sphere. The method overcomes the one-step hydrothermal method to obtain selenium material structure is difficult to control, resulting in high performance multi-metal selenite composite structure difficult to prepare, so as to provide selenium-containing composite material and preparation method and application thereof. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for selenide-containing composite material prepared by the preparation method.