US 12,341,183 B2
Method of preparing cathode active material, cathode for lithium secondary battery and lithium secondary battery
Sang Han Lee, Daejeon (KR); Jung Hwan Kim, Daejeon (KR); Jong Hyuk Lee, Daejeon (KR); In Haeng Cho, Daejeon (KR); and Dong Wook Ha, Daejeon (KR)
Assigned to SK ON CO., LTD., Seoul (KR)
Filed by SK ON CO., LTD., Seoul (KR)
Filed on Aug. 1, 2023, as Appl. No. 18/362,966.
Claims priority of application No. 10-2022-0097383 (KR), filed on Aug. 4, 2022.
Prior Publication US 2024/0047646 A1, Feb. 8, 2024
Int. Cl. H01M 4/131 (2010.01); H01M 4/525 (2010.01); H01M 4/62 (2006.01); H01M 10/0525 (2010.01); C01G 53/50 (2025.01); H01M 4/02 (2006.01)
CPC H01M 4/131 (2013.01) [H01M 4/525 (2013.01); H01M 4/62 (2013.01); H01M 10/0525 (2013.01); C01G 53/50 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A cathode for a lithium secondary battery, comprising:
a cathode current collector; and
a cathode active material layer on the cathode current collector, the cathode active material layer comprising a plurality of lithium-metal oxide particles that have a shape of a single particle,
wherein each of the plurality of lithium-metal oxide particles has a chemical structure represented by Chemical Formula I
LixNi1-yMyO2+z  [Chemical Formula 1]
where 0.9≤x≤1.2, 0≤y≤0.7, and −0.1≤z≤0.1, M may include at least one element selected from the group consisting of Na, Mg, Ca, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Fe, Cu, Ag, Zn, B, Al, Ga, C, Si, Sn and Zr,
wherein an activation energy (Ea) of the cathode in Equation 1 is in a range from 50 kJ/mol to 80 KJ/mol:
R′=R0 exp(−Ea/RT)  [Equation 1]
wherein, in Equation 1, R is a gas constant, T is an absolute temperature, R′ represents a sum of all charge transfer resistances (Rct) from an analysis by an electrochemical impedance spectroscopy using a half-cell that includes the cathode and a lithium counter electrode as a Randles circuit, and R0 is a constant representing a resistance having no temperature dependence among the charge transfer resistances,
wherein a cation mixing ratio of the plurality of lithium-metal oxide particles is 1% to 4%, and
wherein the lithium-metal oxide particles include a lithium-metal oxide particle having poly-crystalline structure in a crystallographic aspect.