Patent ID: 8486549
Filing Date: 2013-07-16
Classification: H01M,Y02E,Y02P

Abstract:
1. A lithium ion secondary battery comprising: a positive electrode current collector; a positive electrode active material layer that is provided in contact with said positive electrode current collector; a separator layer that is provided on a side of said positive electrode active material layer on which said positive electrode current collector is not provided; a negative electrode active material layer that comprises silicon or tin, is provided on a side of said separator layer on which said positive electrode active material layer is not provided and a portion of the negative electrode material layer facing said separator layer includes an opposing portion opposing said positive electrode active material layer and a non-opposing portion not opposing said positive electrode active material layer, said opposing portion and said non-opposing portion containing lithium; and a negative electrode current collector that is provided on a side of said negative electrode active material layer on which said separator layer is not provided, wherein an amount of lithium contained in said non-opposing portion is about the same or larger than an amount of lithium contained in said opposing portion in a discharged state.