NONAQUEOUS LITHIUM TYPE POWER STORAGE ELEMENT

PROBLEM TO BE SOLVED: To provide a nonaqueous lithium type power storage element which is superior in high output property and durability.SOLUTION: A nonaqueous lithium type power storage element comprises: a laminate or wound body arranged by laminating or winding a positive electrode and a negative electrode with a separator interposed therebetween; and a nonaqueous electrolyte including lithium ions. The positive electrode includes a lithium compound at a concentration of 1-50 mass%. The positive electrode has a positive electrode current collector and a positive electrode active material layer including active carbon. The negative electrode has a negative electrode current collector, and a negative electrode active material layer including a negative electrode active material capable of occluding and releasing a lithium ion. The ratio of a lithium ion concentration at a center in top view of the negative electrode active material layer of the negative electrode in an outermost layer of the laminate, and a lithium ion concentration at a center in top view of the negative electrode active material layer of the negative electrode in an innermost layer of the laminate is a particular ratio. In the nonaqueous lithium type power storage element, a lithium ion concentration is higher in a center portion rather than a peripheral edge of the negative electrode active material layer. The average particle diameter of the lithium compound, and the average particle diameter of the positive electrode active material are in predetermined value ranges.SELECTED DRAWING: None 【課題】高出力特性及び耐久性に優れた非水系リチウム型蓄電素子の提供。【解決手段】正極と負極がセパレータを介して積層又は捲回された積層体又は捲回体並びにリチウムイオンを含む非水系電解液を含む非水系リチウム型蓄電素子であって、正極は１質量％以上５０質量％以下の濃度でリチウム化合物を含み、正極は正極集電体と活性炭からなる正極活物質層とを有し、負極は負極集電体とリチウムイオンを吸蔵・放出できる負極活物質を含有する負極活物質層とを有し、積層体の最外層における負極の負極活物質層を上面視した際の中心のリチウムイオン濃度と積層体の最内層における負極の負極活物質層を上面視した際の中心のリチウムイオン濃度が特定比にあり、負極活物質層の周縁部よりも中心部においてリチウムイオンの濃度が高く、リチウム化合物の平均粒子径と正極活物質の平均粒子径が所定の値にある前記非水系リチウム型蓄電素子。【選択図】なし