Single battery, power battery pack and electric vehicle

The invention discloses a single battery, a power battery pack and an electric vehicle, the single battery is a square battery, the single battery comprises a battery body, the battery body has a thickness D, and the thickness D of the battery body and the volume V of the battery body meet the formula: D/V = 0.0000065-0.00002 mm <-2 >. The power battery pack provided by the embodiment of the invention has the advantages of high space utilization rate, high energy density, high cruising ability and the like.