Magnesium-lithium　hybrid　batteries　(MLHBs)　have　gained　increasing　attention　due　to　their　combined　advantages　of　rapid　ion　insertion/extraction　cathode　and　magnesium　metal　anode.　Herein,　SnS2-SPAN　hybrid　cathode　with　strong　C-Sn　bond　and　rich　defects　is　ingeniously　constructed　to　realize　Mg2+/Li+　co-intercalation.　The　physical　and　chemical　double-confinement　synergistic　engineering　of　sulfurized　polyacrylonitrile　can　suppress　the　agglomeration　of　SnS2　nanoparticles　and　the　volume　expansion,　simultaneously　promote　charge　transfer　and　enhance　structural　stability.　The　introduced　abundant　sulfur　vacancies　provide　more　active　sites　for　Mg2+/Li+　co-intercalation.　Meanwhile,　the　beneficial　effects　of　rich　sulfur　defects　and　C-Sn　bond　on　enhanced　electrochemical　properties　are　further　evidenced　by　density-functional　theory　(DFT)　calculations.　Therefore,　compared　with　pristine　SnS2,　SnS2-SPAN　cathode　displays　high　specific　capacity　(218　mAh　g−1　at　0.5　A　g−1　over　700　cycles)　and　ultra-long　cycling　life　(101　mAh　g−1　at　5　A　g−1　up　to　28,000　cycles).　And　a　high　energy　density　of　307　Wh　kg−1　can　be　realized　by　the　SnS2-SPAN//Mg　pouch　cell.　Such　elaborate　and　simple　design　supplies　a　reference　for　the　exploitation　of　advanced　cathode　materials　with　excellent　electrochemical　properties　for　MLHBs.　©　2024