SECONDARY BATTERY AND BATTERY MODULE, BATTERY PACK AND ELECTRICAL DEVICE CONTAINING THE SAME

The present application provides a secondary battery and a battery module, battery pack and electrical device containing the same. The secondary battery comprises a positive electrode plate and an non-aqueous electrolytic solution, wherein the positive electrode plate comprises a positive electrode active material with a core-shell structure, said positive electrode active material comprising an core and a shell covering said core, said core has a chemical formula of LiMnAPRO; said shell comprises a first cladding layer covering said core, a second cladding layer covering said first cladding layer and a third cladding layer covering said second cladding layer, said non-aqueous electrolytic solution comprises a first additive, said first additive comprises one or more of compounds as shown by Formula 1, Formula 2 and Formula 3.