Wound electrochemical device and method of manufacturing same

摘要

A wound electrochemical device has a wound body 1 formed by winding a multilayer member 3 including a multilayer structure composed of a positive electrode 20, a separator 40, and a negative electrode 10; wherein each of the positive and negative electrodes 20, 10 includes a structure having an active material layer formed on both sides of a current collector; wherein the wound body 1 has a space at a center portion thereof; and wherein the smallest radius of curvature R of a curved part in an innermost circumferential portion of the wound body 1 satisfies the following expression (1): R=α×T1+2⁢T2
where R is the smallest radius of curvature of the curved part in the innermost circumferential portion of the wound body (unit: µm), α is a value within the range of 3.33 to 7.12, T1 is a thickness of the current collector of the electrode positioned at the innermost circumference of the wound body (unit: µm), and T2 is a thickness of the active material layer of the electrode positioned at the innermost circumference of the wound body (unit: µm), T2 being a value within the range of 8 to 30 (unit: µm).