Abstract: An energy storage device, includes a terminal; an electrode assembly having a body portion and a tab portion projecting from the body portion; and a current collector electrically connecting the terminal and the tab portion with each other. The current collector is configured such that a plate portion and a second plate portion which opposedly face each other are continuously formed with each other with curved portion interposed therebetween, and a thickness of the curved portion is set smaller than a thickness of the first plate portion and a thickness of the second plate portion.

Abstract: To realize the stabilization of an energy storage device while forming a current collector per se in a compact shape. An energy storage device 10 includes a terminal (negative electrode terminal 300), an electrode assembly 400 having a body portion 430 and tab portions 420 projecting from the body portion 430, and a current collector (negative electrode current collector 150) electrically connecting the terminal and the tab portions 420 with each other. The current collector is configured such that a first plate portion 1521 and a second plate portion 522 which opposedly face each other are continuously formed with each other with a curved portion 1513 interposed therebetween. A thickness t of the curved portion 1513 is set smaller than a thickness t2 of the first plate portion 1521 and a thickness t2 of the second plate portion 1522.

Abstract: The invention has purposes of increasing length of a wound body in a roll by efficiently using a space formed in a container and of improving strength as a unit by reducing the space. In a roll (1) in which a wound body (2) is wound around a specified axis for plural times, a spacer (3) is provided in a portion of a region between turns of the wound body (2).