| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electrochemical device capable of suppressing expansion of a power storage element at the time of abnormality and realizing a high capacity.SOLUTION: An electrochemical device includes a power storage element. The power storage element includes: a positive electrode including a positive electrode current collector having a front surface and a back surface, a first positive electrode layer 132 made of a positive electrode material and laminated on the front surface to have a first thickness D1, and a second positive electrode layer 133 made of the positive electrode material and laminated on the back surface to have a second thickness D2 that is thinner than the first thickness D1; a negative electrode; and a separator, wherein the first positive electrode layer 132 and the second positive electrode layer 133 are wound so that the first positive electrode layer 132 comes inside the second positive electrode layer 133, and when an initial thickness of the positive electrode is referred to as a thickness A and a thickness of the positive electrode after voltage application thereto is referred to as a thickness B, the first thickness and the second thickness have such a relation that a result of division of the first thickness by the second thickness is greater than a square of B/A.</p> |
