Patent ID: 8658305
Filing Date: 2014-02-25
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
1. A lithium-ion battery comprising an electrode assembly obtained by superposing and winding together a negative electrode sheet having a negative active material layer on the surface of a long continuous sheet negative electrode collector, a positive electrode sheet having a positive active material layer on the surface of a long continuous sheet positive electrode collector, and a long continuous sheet separator interposed therebetween, wherein the negative active material layer is formed, with a band-shaped portion being left on at least one edge of the negative electrode collector along the lengthwise direction thereof; the negative electrode sheet is superposed on the positive electrode sheet so that the band-shaped portion sticks out beyond one edge of the positive electrode sheet along the lengthwise direction thereof; on the exterior surface of the negative active material layer, a porous inorganic layer is formed starting at the flat part of the active material layer, wrapping around the end thereof on the side of the band-shaped portion, and extending to the surface of the negative electrode collector; and porosity Pa [vol %] of the porous inorganic layer at the edge of the negative active material layer on the side of the band-shaped portion is lower than porosity Pb [vol %] of the inorganic layer at the width center of the active material layer.