US 12,394,824 B2
Secondary battery
Takatoshi Munaoka, Kyoto (JP); Shinichi Katayama, Kyoto (JP); Atsushi Ouki, Kyoto (JP); Masaki Kuratsuka, Kyoto (JP); Takashige Fujikawa, Kyoto (JP); and Yousuke Shima, Kyoto (JP)
Assigned to Murata Manufacturing Co., Ltd., Kyoto (JP)
Filed by MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed on Dec. 29, 2022, as Appl. No. 18/090,947.
Application 18/090,947 is a continuation of application No. PCT/JP2021/033476, filed on Sep. 13, 2021.
Claims priority of application No. 2020-156447 (JP), filed on Sep. 17, 2020.
Prior Publication US 2023/0137208 A1, May 4, 2023
Int. Cl. H01M 10/0569 (2010.01); H01M 4/485 (2010.01); H01M 4/525 (2010.01); H01M 10/0525 (2010.01)
CPC H01M 10/0569 (2013.01) [H01M 4/485 (2013.01); H01M 4/525 (2013.01); H01M 10/0525 (2013.01); H01M 2300/0028 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A secondary battery comprising:
a positive electrode including a lithium-nickel composite oxide;
a negative electrode including a lithium-titanium composite oxide; and
an electrolytic solution including a carboxylic acid ester, wherein
the carboxylic acid ester includes at least one of ethyl acetate, propyl acetate, ethyl propionate, or propyl propionate,
a first oxygen spectrum and a second oxygen spectrum are detectable by a surface analysis of the positive electrode by X-ray photoelectron spectroscopy, the first oxygen spectrum having a peak within a range of binding energy that is greater than or equal to 528 electron volts and less than or equal to 531 electron volts, the second oxygen spectrum having a peak within a range of binding energy that is greater than 531 electron volts and less than or equal to 535 electron volts,
a ratio of an intensity of the first oxygen spectrum to an intensity of the second oxygen spectrum is greater than or equal to 0.30 and less than or equal to 0.80,
a third oxygen spectrum and a fourth oxygen spectrum are detectable by a surface analysis of the negative electrode by the X-ray photoelectron spectroscopy, the third oxygen spectrum having a peak within a range of binding energy that is greater than or equal to 528 electron volts and less than or equal to 531 electron volts, the fourth oxygen spectrum having a peak within a range of binding energy that is greater than 531 electron volts and less than or equal to 535 electron volts, and
a ratio of an intensity of the third oxygen spectrum to an intensity of the fourth oxygen spectrum is greater than or equal to 0.82 and less than or equal to 1.35.