US 11,990,616 B2
Positive electrode active material for lithium secondary battery and lithium secondary battery including the same
Moon Ho Choi, Cheongju-si (KR); Gyeong Jae Heo, Cheongju-si (KR); Hyun Jong Yu, Cheongju-si (KR); Jung bae Park, Cheongju-si (KR); and Eun byeol Hyeong, Cheongju-si (KR)
Assigned to ECOPRO BM CO., LTD., Cheongju-si (KR)
Filed by ECOPRO BM CO., LTD., Cheongju-si (KR)
Filed on Sep. 6, 2019, as Appl. No. 16/563,359.
Claims priority of application No. 10-2018-0108210 (KR), filed on Sep. 11, 2018; and application No. 10-2018-0123130 (KR), filed on Oct. 16, 2018.
Prior Publication US 2020/0083531 A1, Mar. 12, 2020
Int. Cl. H01M 4/525 (2010.01); H01M 4/36 (2006.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/525 (2013.01) [H01M 4/366 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A positive electrode active material for a lithium secondary battery, comprising:
a plurality of secondary particles including a primary particle, which is a lithium-based composite oxide, having a single-crystal structure,
wherein the positive electrode active material is an assembly of first secondary particles, which have a first grain boundary density of 0.5 or less and second secondary particles, which have a second grain boundary density of more than 0.5 and equal to or less than 2.0,
wherein the proportion of the first secondary particles among the plurality of secondary particles constituting the positive electrode active material is 30% or more,
Grain boundary density=(the number of boundaries between primary particles in secondary particle/the number of primary particles constituting secondary particle).