NEGATIVE ACTIVE MATERICAL, PREPARATION METHOD THEREOF, SECONDARY BATTERYAND RELATED BATTERY MODULE, BATTERY PACK AND DEVICE

The present application discloses a negative active material, preparation process thereof and a secondary battery and the related battery module, battery pack and device. The negative active material comprises a core material and a modified polymer coating layer coated on at least a part of the outer surface of the core material, the core material comprises one or more of silicon-based materials and tin based materials, the coating layer comprises carbon element and nitrogen element, wherein the nitrogen element is present in the negative active material in a mass percentage of 0.1%˜0.66%, and the coating layer comprises a —C═N-linkage.