The invention provides a battery cover plate
assembly, a preparation method thereof, a single battery and a
battery pack. The battery cover plate
assembly comprises a cover plate, a hollow
rivet, an
electrode terminal, a sealing layer and an insulation part, wherein the sealing layer is arranged between the
electrode terminal and the insulation part, the material of the sealing layer comprises
polymer, the sealing layer and the insulation part are fused with each other; a microcellular structure is distributed on the contact surface of the
electrode terminal and the sealing layer. According to the battery cover plate
assembly, the electrode terminal by arranging the sealing layer between the electrode terminal and the insulation part, the possibility of the deformation of the
polymer insulation part caused by the various environment factors such as temperature can be reduced, especially, the influence on the sealing combination of the electrode terminal and the cover plate can be lowered, meanwhile, the
binding force of organic
metal and the cover plate assembly can be further enhanced, and the development demand on the existing battery can be met. The invention provides a single battery and a
battery pack which have stable performance.