| 摘要 |
[Problem] To prevent lithium from depositing in a portion where a positive electrode plate, a negative electrode plate, and a separator are bent. [Solution] A lithium-ion secondary battery has a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate has a positive electrode collector plate and a positive electrode active material layer formed on the surface of the positive electrode collector plate. The negative electrode plate has a negative electrode collector plate and a negative electrode active material layer formed on the surface of the negative electrode collector plate. The separator is disposed between the positive electrode plate and the negative electrode plate. The positive electrode plate, the negative electrode plate, and the separator are wound while being stacked on each other and each have a flat portion disposed along a plane and receiving an external loading and a bending portion on which bending work is performed. The positive electrode active material layer has a flat region corresponding to the flat portion and a bending region corresponding to the bending portion. The density of the positive electrode active material layer in at least a part of the bending region is higher than the density of the positive electrode active material layer in the flat region. |
