Battery pack

The invention discloses a battery pack. The battery pack comprises a box body and a battery module, the battery module comprises a shell and a plurality of single batteries, and an isolation structure is arranged between every two adjacent single batteries; a first main air duct is arranged between the bottom of the box body and the bottom of the battery module; a second main air duct is formed at the upper part of the box body; the two main air ducts are respectively used for air inlet or air outlet; branch air ducts communicated with the two main air ducts are formed between the adjacent single batteries through isolation structures. The two main air ducts used for air inlet and air outlet are arranged at the bottom and the top of the battery module of the battery pack, and the two main air ducts used for air inlet and air outlet are arranged at the top and the bottom of the battery module, so that the existing height space of the battery pack is fully utilized; and the space utilization rate of the battery