US 12,009,506 B2
Nonaqueous electrolyte secondary battery
Yuji Yamamoto, Toyota (JP); Momoko Procter, Seto (JP); Yoshinari Makimura, Nisshin (JP); Tetsutaro Hayashi, Niihama (JP); and Willy Shun Kai Bong, Niihama (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA AND, Toyota (JP); and SUMITOMO METAL MINING CO., LTD., Tokyo (JP)
Filed by Toyota Jidosha Kabushiki Kaisha, Toyota (JP); and Sumitomo Metal Mining Co., Ltd., Tokyo (JP)
Filed on Jul. 16, 2020, as Appl. No. 16/930,746.
Claims priority of application No. 2019-133135 (JP), filed on Jul. 18, 2019.
Prior Publication US 2021/0020925 A1, Jan. 21, 2021
Int. Cl. H01M 4/36 (2006.01); H01M 4/02 (2006.01); H01M 4/131 (2010.01); H01M 4/485 (2010.01); H01M 10/0525 (2010.01)
CPC H01M 4/366 (2013.01) [H01M 4/131 (2013.01); H01M 4/485 (2013.01); H01M 10/0525 (2013.01); H01M 2004/027 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A nonaqueous electrolyte secondary battery comprising a cathode, an anode, and a nonaqueous electrolyte,
the cathode including a cathode active material layer that contains a granular cathode active material;
the granular cathode active material including:
a core part that contains a lithium-transition metal composite oxide of a layered structure, a mean particle size of the core part is from 0.1 μm to 20 μm;
a tungsten-concentrated layer that is formed over a surface of the core part and has a higher tungsten concentration determined by a TEM-EDX analysis than the core part; and
a lithium-tungsten compound particle that adheres to at least part of a surface of the tungsten-concentrated layer and contains tungsten and lithium, the tungsten-concentrated layer is an amorphous structure, and the lithium-tungsten compound particle has a higher tungsten concentration than the tungsten-concentrated layer, and an atomic concentration of tungsten in the lithium-tungsten compound particle is 90 at % or more based on a total number of transition metal atoms.