| 摘要 |
The invention discloses a square lithium ion battery, comprising a first pole slice, a first tab disposed on the first pole slice and a second pole slice. The square lithium ion battery is characterized in that the first pole slice and the second pole slice are rolled up to make an electrical core; the first pole slice includes a conductive foil positioned on the inner ring of the electrical core, wherein the conductive foil comprises an end portion and a linear portion; the first tab is arranged on the end portion; a first tab protective device covers the first tab; and the linear portion is provided with an auxiliary film. According to the invention, the linear portion of the conductive foil on the inner ring of the electrical core in the square battery is provided with the auxiliary film, and nonuniform distribution of the cell thickness is minimized by the thickness of the auxiliary film, so as to improve the distortion phenomenon of the cell appearance due to local expansion of the square battery during the cell charge and discharge process, reduce appearance fraction defective of the square battery, decrease cell production cost and raise product yield. |
