US 12,034,142 B2
Method of producing negative electrode plate for non-aqueous electrolyte secondary battery
Kazuhiro Sotome, Himeji (JP); Kaori Ishikawa, Nishinomiya (JP); Yuta Matsuo, Kobe (JP); Kentaro Takahashi, Kasai (JP); Daisuke Ikeda, Kakogawa (JP); Kunihiko Hayashi, Miki (JP); and Naoki Uchida, Kakogawa (JP)
Assigned to Prime Planet Energy & Solutions, Inc., Tokyo (JP)
Filed by PRIME PLANET ENERGY & SOLUTIONS, INC., Tokyo (JP)
Filed on Oct. 14, 2021, as Appl. No. 17/501,092.
Claims priority of application No. 2020-184992 (JP), filed on Nov. 5, 2020.
Prior Publication US 2022/0140310 A1, May 5, 2022
Int. Cl. H01M 4/04 (2006.01); H01M 4/02 (2006.01); H01M 4/36 (2006.01); H01M 4/583 (2010.01); H01M 4/62 (2006.01)
CPC H01M 4/0435 (2013.01) [H01M 4/366 (2013.01); H01M 4/583 (2013.01); H01M 4/622 (2013.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method of producing a negative electrode plate for a non-aqueous electrolyte secondary battery, the method comprising:
(A) applying a first negative electrode slurry to a surface of a negative electrode substrate to form a first layer;
(B) applying a second negative electrode slurry to a surface of the first layer to form a second layer; and
(C) compressing the first layer and the second layer to produce the negative electrode plate,
the first negative electrode slurry including a first negative electrode composite material,
the second negative electrode slurry including a second negative electrode composite material,
each of the first negative electrode composite material and the second negative electrode composite material including a negative electrode active material and a cellulose-based binder,
the negative electrode active material consisting essentially of a first graphite powder and a second graphite powder,
the first graphite powder having a circularity of 0.94 or more, and
a fraction of a D50 of the second graphite powder to a D50 of the first graphite powder being 29% to 54%,
in each of the first negative electrode composite material and the second negative electrode composite material,
the first graphite powder having a mass fraction of 88.1% to 93.6%, and
the second graphite powder having a mass fraction of 5% to 10%,
the first negative electrode composite material including the cellulose-based binder at a first mass fraction,
the second negative electrode composite material including the cellulose-based binder at a second mass fraction, and
a ratio of the first mass fraction to the second mass fraction being 0.40 to 0.56.