US 12,451,518 B2
Secondary battery having a film covering a negative active material layer
Tomomi Sakuma, Kyoto (JP); Masahiro Miyamoto, Kyoto (JP); and Raman Kukreja, Kyoto (JP)
Assigned to Murata Manufacturing Co., Ltd., Kyoto (JP)
Filed by MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed on Dec. 13, 2022, as Appl. No. 18/080,321.
Application 18/080,321 is a continuation of application No. PCT/JP2021/009519, filed on Mar. 10, 2021.
Claims priority of application No. 2020-103184 (JP), filed on Jun. 15, 2020.
Prior Publication US 2023/0114874 A1, Apr. 13, 2023
Int. Cl. H01M 10/0567 (2010.01); H01M 10/0525 (2010.01); H01M 10/0569 (2010.01)
CPC H01M 10/0567 (2013.01) [H01M 10/0525 (2013.01); H01M 10/0569 (2013.01); H01M 2300/0028 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A secondary battery comprising:
a positive electrode;
a negative electrode; and
an electrolytic solution, wherein
the negative electrode includes a film covering a negative electrode active material layer,
the electrolytic solution includes a chain carboxylic acid ester, and
according to an analysis of the film by inductively coupled plasma optical emission spectroscopy,
a content of boron in the film is greater than or equal to 10 micromoles per square meter and less than or equal to 30 micromoles per square meter,
a content of sulfur in the film is greater than or equal to 20 micromoles per square meter and less than or equal to 70 micromoles per square meter, and
a ratio of the content of sulfur to the content of boron is greater than or equal to 1.0 and less than or equal to 3.0.