As　the　energy　density　of　lithium-ion　batteries　(LIBs)　continues　to　increase,their　safety　has　become　a　great　concern　for　further　practical　large-scale　applications.One　of　the　ultimate　solution　of　the　safety　issue　is　to　develop　intrinsically　safe　battery　components,where　the　battery　separators　and　liquid　electrolytes　are　critical　for　the　battery　thermal　runaway　process.In　this　review,we　summarize　recent　progress　in　the　rational　materials　design　on　battery　separators　and　liquid　electrolyte　towards　the　goal　of　improving　the　safety　of　LIBs.Also,some　strategies　for　further　improving　safety　of　LIBs　are　also　briefly　outlooked.