US 11,728,478 B2
Positive electrode active material including impurity elements in a crystal defect or a cavity
Yohei Momma, Kanagawa (JP); Takahiro Kawakami, Kanagawa (JP); Teruaki Ochiai, Kanagawa (JP); and Masahiro Takahashi, Kanagawa (JP)
Assigned to Semiconductor Energy Laboratory Co., Ltd., Atsugi (JP)
Filed by SEMICONDUCTOR ENERGY LABORATORY CO., LTD., Atsugi (JP)
Filed on Jun. 30, 2020, as Appl. No. 16/917,190.
Application 16/917,190 is a continuation of application No. 16/900,108, filed on Jun. 12, 2020.
Application 16/900,108 is a continuation of application No. 15/800,184, filed on Nov. 1, 2017, abandoned.
Claims priority of application No. 2016-225046 (JP), filed on Nov. 18, 2016.
Prior Publication US 2020/0373567 A1, Nov. 26, 2020
Int. Cl. H01M 4/52 (2010.01); H01M 4/46 (2006.01); H01M 4/1391 (2010.01); H01M 4/62 (2006.01); H01M 4/36 (2006.01); C01G 51/00 (2006.01); H01M 4/525 (2010.01); H01M 4/131 (2010.01); H01M 10/0525 (2010.01); G01N 23/2273 (2018.01); H01M 4/02 (2006.01)
CPC H01M 4/466 (2013.01) [C01G 51/42 (2013.01); H01M 4/131 (2013.01); H01M 4/1391 (2013.01); H01M 4/366 (2013.01); H01M 4/525 (2013.01); H01M 4/62 (2013.01); H01M 4/625 (2013.01); H01M 10/0525 (2013.01); C01P 2002/00 (2013.01); C01P 2002/85 (2013.01); C01P 2004/04 (2013.01); C01P 2006/40 (2013.01); G01N 23/2273 (2013.01); H01M 2004/028 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A lithium-ion secondary battery comprising:
a positive electrode comprising a positive electrode active material,
wherein the positive electrode active material comprises a first region, a second region, and a third region,
wherein the first region comprises a layered rock-salt crystal structure,
wherein the third region comprises a rock-salt crystal structure,
wherein the second region covers at least a part of the first region,
wherein the third region covers at least a part of the second region,
wherein at least the part of the second region covered by the third region comprises a layered rock-salt crystal structure,
wherein the first region comprises lithium cobaltate,
wherein the second region comprises aluminum and oxygen,
wherein the third region comprises magnesium and oxygen,
wherein a crystal orientation of the rock-salt crystal structure of the third region is substantially aligned with a crystal orientation of the layered rock-salt crystal structure of at least the part of the second region covered by the third region,
wherein the positive electrode active material includes a crystal defect in the positive electrode active material, the crystal defect being observable from a TEM image,
wherein the crystal defect includes magnesium, and
wherein a distribution of aluminum comprises a region existing deeper from a surface of the positive electrode active material than a distribution of magnesium, and
wherein the positive electrode active material is free of at least one of intentionally added nickel and manganese.