US 11,677,075 B2
Cathode active material for lithium ion secondary battery, method for manufacturing cathode active material for lithium ion secondary battery, and lithium ion secondary
Shuichi Takano, Tokyo (JP); Akira Gunji, Tokyo (JP); Hisato Tokoro, Tokyo (JP); Genei Nakajima, Tokyo (JP); Tatsuya Toyama, Tokyo (JP); and Shin Takahashi, Tokyo (JP)
Assigned to PROTERIAL, LTD., Tokyo (JP)
Appl. No. 16/644,114
Filed by Proterial, Ltd., Tokyo (JP)
PCT Filed Dec. 26, 2018, PCT No. PCT/JP2018/047888
§ 371(c)(1), (2) Date Mar. 3, 2020,
PCT Pub. No. WO2019/131779, PCT Pub. Date Jul. 4, 2019.
Claims priority of application No. JP2017-252400 (JP), filed on Dec. 27, 2017.
Prior Publication US 2020/0251733 A1, Aug. 6, 2020
Int. Cl. H01M 4/525 (2010.01); H01M 10/0525 (2010.01); H01M 4/505 (2010.01); C01G 53/00 (2006.01); H01M 4/02 (2006.01); H01M 4/131 (2010.01); H01M 10/052 (2010.01)
CPC H01M 4/525 (2013.01) [C01G 53/50 (2013.01); H01M 4/505 (2013.01); H01M 10/0525 (2013.01); C01G 53/42 (2013.01); C01P 2002/52 (2013.01); C01P 2002/54 (2013.01); C01P 2004/03 (2013.01); C01P 2004/45 (2013.01); C01P 2004/50 (2013.01); C01P 2004/51 (2013.01); C01P 2004/54 (2013.01); C01P 2004/61 (2013.01); C01P 2004/62 (2013.01); C01P 2006/12 (2013.01); C01P 2006/14 (2013.01); C01P 2006/16 (2013.01); C01P 2006/40 (2013.01); H01M 4/131 (2013.01); H01M 10/052 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01); Y02E 60/10 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A cathode active material for a lithium ion secondary battery, comprising:
a primary particle of a lithium composite compound represented by the following formula (1); and
a secondary particle formed by an aggregation of primary particles of the lithium composite compound, wherein
a ratio (D1/D2) between an average particle size (D1) of the primary particles and an average particle size (D2) of secondary particles is from 0.006 to 0.25 both inclusive,
the cathode active material for a lithium ion secondary battery has a specific surface area from 0.2 m2/g to 1.0 m2/g both inclusive,
an amount of lithium carbonate is from 0.08% by mass to 0.3% by mass both inclusive,
a breaking strength of the secondary particle is 40 MPa or more,
the secondary particle has an aspect ratio of from 0.6 to 1.0 both inclusive,
the secondary particles have an open pore volume ratio which is determined by a mercury intrusion method and which is 20% or less in a pore diameter range of from 0.1 μm to 0.5 μm both inclusive, and
the cathode active material for a lithium ion secondary battery has a moisture content of 250 ppm or less,
Li1+aNixCoyM11−x−y−zM2zO2+α  (1)
provided that (a) in the formula (1), M1 is Mn, (b) M2 is Ti, and (c) a, x, y, z, and α are numbers satisfying 0.02≤a≤0.2, 0.8≤x≤0.9, 0.03≤y≤0.15, 0≤z≤0.02, 0.05≤1−x−y−z≤0.1, and −0.2≤α≤0.2 respectively.