As　the　energy　density　of　battery　increases　rapidly,lithium-ion　batteries(LIBs)are　facing　serious　safety　issue　with　thermal　runaway,which　largely　limits　the　large-scale　applications　of　high-energy-density　LIBs.It　is　generally　agreed　that　the　chemical　crosstalk　between　the　cathode　and　anode　leads　to　thermal　runaway　of　LIBs.Herein,a　multifunctional　high　safety　electrolyte　is　designed　with　synergistic　construc-tion　of　cathode　electrolyte　interphase　and　capture　of　reactive　free　radicals　to　limit　the　intrinsic　pathway　of　thermal　runaway.The　cathode　electrolyte　interphase　not　only　resists　the　gas　attack　from　the　anode　but　suppresses　the　parasitic　side　reactions　induced　by　electrolyte.And　the　function　of　free　radical　capture　has　the　ability　of　reducing　heat　release　from　thermal　runaway　of　battery.The　dual　strategy　improves　the　intrinsic　safety　of　battery　prominently　that　the　triggering　temperature　of　thermal　runaway　is　increased　by　24.4　℃　and　the　maximum　temperature　is　reduced　by　177.7　℃.Simultaneously,the　thermal　runaway　propagation　in　module　can　be　self-quenched.Moreover,the　electrolyte　design　balances　the　trade-off　of　electrochemical　and　safety　performance　of　high-energy　batteries.The　capacity　retention　of　LiNi0.8Co0.1Mn0.1O2|graphite　pouch　cell　has　been　significantly　increased　from　53.85％to　97.05％with　higher　coulombic　efficiency　of　99.94％at　operating　voltage　extended　up　to　4.5　V　for　200　cycles.Therefore,this　work　suggests　a　feasible　strategy　to　mitigate　the　safety　risk　of　high-energy-density　LIBs　without　sacrificing　electrochemical　performances.