To provide a lithium ion battery having a desired battery performance without requiring a current collecting lead.

A positive electrode plate 18, provided with a non-coated part 24 at one end of the width direction, is coated with a positive electrode active material 26. A negative electrode plate 20, provided with a non-coated part 28 at other end of the width direction, is coated with a negative electrode active material 30. The non-coated parts 24, 28 are projected opposing each other, and the positive electrode active material 26 and the negative electrode active material 30 are arranged opposing each other and approximately matching in the width direction.