This utility model relates to the field of
battery cell cap technology, and discloses a high-safety cylindrical composite cap, including a top cover, an explosion-proof sheet, a sealing
assembly, a positive
electrode connecting piece, an insulating pad, and an insulating isolation plate and a buffer pad for preventing internal short circuits of the
battery cell. The top cover is located at the top, the explosion-proof sheet is located below the top cover and is fixedly connected to the top cover, and the sealing
assembly is located below the explosion-proof sheet and fits tightly with the outer shell of the cylindrical battery. This high-safety cylindrical composite cap uses a sealing
assembly including a rubber sealing ring and an elastic
metal sealing ring. The sealing ring is tightly fitted onto the top edge of the cylindrical battery shell, effectively filling the tiny gaps between the shell and the cap. The sealing ring is located above the sealing ring and fits tightly with the explosion-proof sheet. The elasticity of the
metal further enhances the sealing effect, effectively preventing external
moisture and impurities from entering the battery, avoiding performance degradation and shortened lifespan due to
contamination, and also preventing leakage of
electrolyte inside the battery.