The　Si　material　of　the　highest　theoretical　capacity　(4200　mAh.g(-1))　cannot　be　commercially　applied　in　real　life　owing　to　its　vast　volume　expansion　during　the　charge-discharge　process　and　low　electrical　conductivity.　Here,　we　introduce　a　Si@SnO2　material　with　a　coating　structure,　in　which　SnO2　is　coated　on　the　surface　of　the　silicon　material.　The　coating　structure　can　effectively　alleviate　the　volume　expansion　stress　of　the　silicon　material.　The　Sn　produced　by　the　reaction　of　SnO2　with　Li　during　the　first　cycle　has　good　conductivity,　thereby　improving　the　electrochemical　performance　of　the　silicon　material.　The　electrochemical　performance　of　the　material　is　excel-lent.　At　the　current　density　of　0.2A.g(-1),　the　first　coulombic　efficiency　of　the　battery　reaches　84.1%,　and　the　specific　discharge　capacity　of　the　battery　can　be　reached　at　1926mAh.g(-1)　after　200　cycles.