Battery and method for manufacturing a battery

It is an object of the invention to provide a battery, which allows a gas generated inside of a flat wound electrode body, to be discharged just to the outside of the electrode body, and prevents an electrolyte solution (a stored electrolytic solution, of the flat wound electrode body by charging / discharging addition is pushed flows out directly to the outside of the flat wound electrode body, and a process to manufacture these battery. the battery is equipped with a flat wound electrode body, a collector element and a stored electrolyte solution. the flat , wound electrode body has an active material layer wound portion that is obtained by winding an electrode plate has a flat, oval cross-section and has a wound, an active material layer forming portion and an exposed Wound on portion having a wound exposed film portion. An exposed wound central portion is separated from at least one of the two exposed end portions of the wound, while a contact with an active material layer wound portion is retained, which is adjacent to the exposed wound central portion in the axial direction. The collector element is joined to the exposed wound central portion.