US 12,424,622 B2
Secondary battery
Takamasa Ono, Kyoto (JP)
Assigned to Murata Manufacturing Co., Ltd., Kyoto (JP)
Filed by MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed on Sep. 22, 2022, as Appl. No. 17/950,343.
Application 17/950,343 is a continuation of application No. PCT/JP2020/042563, filed on Nov. 16, 2020.
Claims priority of application No. 2020-058204 (JP), filed on Mar. 27, 2020.
Prior Publication US 2023/0014480 A1, Jan. 19, 2023
Int. Cl. H01M 4/00 (2006.01); H01M 4/525 (2010.01); H01M 10/0525 (2010.01); H01M 10/0567 (2010.01); H01M 50/105 (2021.01); H01M 4/02 (2006.01)
CPC H01M 4/525 (2013.01) [H01M 10/0525 (2013.01); H01M 10/0567 (2013.01); H01M 50/105 (2021.01); H01M 2004/028 (2013.01); H01M 2300/0025 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A secondary battery comprising:
a positive electrode including a positive electrode active material;
a negative electrode; and
an electrolytic solution including a multi-nitrile compound, wherein
the positive electrode active material includes a lithium-nickel composite oxide and a boron compound, the lithium-nickel composite oxide having a layered rock-salt crystal structure represented by Formula (1) below,
the positive electrode active material has a crystallite size of a (104) plane that is greater than or equal to 40.0 nanometers and less than or equal to 74.5 nanometers, the crystallite size being calculated by X-ray diffractometry and Scherrer equation, and
the positive electrode active material has an element concentration ratio represented by Expression (2) below that is greater than or equal to 0.15 and less than or equal to 0.90, the element concentration ratio being calculated on a basis of a B1s spectrum, a Ni2p3/2 spectrum, a Co2p3/2 spectrum, a Mn2p1/2 spectrum, and an Al2s spectrum of the positive electrode active material detected by X-ray photoelectron spectroscopy,
LiaNi1-bMbOc  (1)
where
M is at least one of Co, Fe, Mn, Cu, Zn, Al, Cr, V, Ti, Mg, or Zr, and
a, b, and c satisfy 0.8<a<1.2, 0≤b≤0.5, and 0<c<3,
R=I2/I1  (2)
where
R is the element concentration ratio,
I1 is sum total of a Ni concentration in atomic percent, a Co concentration in atomic percent, a Mn concentration in atomic percent, and an Al concentration in atomic percent that are calculated on a basis of the Ni2p3/2 spectrum, the Co2p3/2 spectrum, the Mn2p1/2 spectrum, and the Al2s spectrum, respectively, and
I2 is a B concentration in atomic percent calculated on a basis of the B1s spectrum.