公开(公告)号：US20170271713A1

公开(公告)日：2017-09-21

申请号：US15608439

申请日：2017-05-30

Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.

Inventor： Tomoya FUTAMUA ,  Tamae MORIWAKA ,  Takahiro KAWAKAMI ,  Junpei MOMO ,  Nobuhiro INOUE

IPC: H01M10/0525 ,  H01M4/66 ,  H01M4/36 ,  H01M4/13

CPC classification number: H01M10/0525 ,  C30B1/00 ,  H01M4/13 ,  H01M4/136 ,  H01M4/362 ,  H01M4/5825 ,  H01M4/665 ,  H01M4/668 ,  H01M2004/021 ,  H01M2004/028 ,  Y02E60/122 ,  Y02P70/54

Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer over the positive electrode current collector. The positive electrode active material layer includes a plurality of lithium-containing, composite oxides each of which is expressed by LiMPO4 (M is one or more of Fe (II), Mn (II), Co (II), and Ni (II)) that is a general formula. The lithium-containing composite oxide is a flat single crystal particle in which the length in the b-axis direction is shorter than each of the lengths in the a-axis direction and the c-axis direction. The lithium-containing composite oxide is provided over the positive electrode current collector so that the b-axis of the single crystal particle intersects with the surface of the positive electrode current collector.