US 11,811,019 B2
Lithium secondary battery
Young Hoon Do, Daejeon (KR); Yoon Ji Lee, Daejeon (KR); Yong Hyun Cho, Daejeon (KR); and In Haeng Cho, Daejeon (KR)
Assigned to SK ON CO., LTD., Seoul (KR)
Filed by SK INNOVATION CO., LTD., Seoul (KR)
Filed on Aug. 26, 2020, as Appl. No. 17/003,635.
Claims priority of application No. 10-2019-0105944 (KR), filed on Aug. 28, 2019.
Prior Publication US 2021/0066743 A1, Mar. 4, 2021
Int. Cl. H01M 10/0525 (2010.01); H01M 50/46 (2021.01); H01M 4/505 (2010.01); H01M 4/525 (2010.01); H01M 10/0567 (2010.01); H01M 10/0569 (2010.01); H01M 4/36 (2006.01); H01M 4/02 (2006.01)
CPC H01M 10/0525 (2013.01) [H01M 4/364 (2013.01); H01M 4/505 (2013.01); H01M 4/525 (2013.01); H01M 10/0567 (2013.01); H01M 10/0569 (2013.01); H01M 50/46 (2021.01); H01M 2004/027 (2013.01); H01M 2004/028 (2013.01); H01M 2300/0034 (2013.01); H01M 2300/0051 (2013.01)] 13 Claims
 
1. A lithium secondary battery comprising:
a positive electrode comprising a first lithium-metal oxide comprising secondary particles formed by aggregating primary particles having a particle diameter of less than 2 μm, and a second lithium-metal oxide comprising nickel and at least one or more metals selected from the group consisting of manganese and cobalt and comprising primary particles having a particle diameter of 2 μm or more;
a negative electrode;
a separator interposed between the positive electrode and the negative electrode; and
an electrolyte comprising a lithium salt, a nonaqueous organic solvent, and a compound containing at least one or more difluorophosphite groups,
wherein the compound containing at least one or more difluorophosphite groups is the following Chemical Formula 2 or Chemical Formula 3:

OG Complex Work Unit Chemistry
wherein
R is hydrogen, cyano, or H—(CH2CH2O)m—; and
n is an integer of 2 to 8 and m is an integer of 1 or 2,

OG Complex Work Unit Chemistry
wherein
p is an integer of 1 to 3.