US 12,148,875 B2
Lithium secondary battery
Eunkyung Park, Daejeon (KR); Minchul Jang, Daejeon (KR); Suk Il Youn, Daejeon (KR); Byoungkuk Son, Daejeon (KR); Changhun Park, Daejeon (KR); Doyeon Kim, Daejeon (KR); Bora Jung, Daejeon (KR); and Yeilin Ham, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 17/040,500
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Oct. 31, 2019, PCT No. PCT/KR2019/014570
§ 371(c)(1), (2) Date Sep. 22, 2020,
PCT Pub. No. WO2020/091448, PCT Pub. Date May 7, 2020.
Claims priority of application No. 10-2018-0131581 (KR), filed on Oct. 31, 2018; and application No. 10-2019-0137128 (KR), filed on Oct. 31, 2019.
Prior Publication US 2021/0028484 A1, Jan. 28, 2021
Int. Cl. H01M 10/052 (2010.01); C01G 51/00 (2006.01); C01G 53/00 (2006.01); H01M 4/04 (2006.01); H01M 4/131 (2010.01); H01M 4/136 (2010.01); H01M 4/1395 (2010.01); H01M 4/38 (2006.01); H01M 4/505 (2010.01); H01M 4/525 (2010.01); H01M 10/0565 (2010.01); H01M 10/0566 (2010.01)
CPC H01M 10/052 (2013.01) [C01G 51/42 (2013.01); C01G 53/42 (2013.01); H01M 4/0445 (2013.01); H01M 4/131 (2013.01); H01M 4/136 (2013.01); H01M 4/1395 (2013.01); H01M 4/382 (2013.01); H01M 4/505 (2013.01); H01M 4/525 (2013.01); H01M 10/0565 (2013.01); H01M 10/0566 (2013.01); H01M 2300/0094 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A lithium secondary battery comprising:
a positive electrode;
a negative electrode comprising a negative electrode current collector;
an electrolyte disposed between the positive electrode and the negative electrode; and
a lithium metal layer on the negative electrode current collector in the negative electrode,
wherein the electrolyte comprises a first electrolyte layer and a second electrolyte layer disposed on the first electrolyte layer,
wherein the first electrolyte layer faces the negative electrode, and the second electrolyte layer faces the positive electrode;
wherein the first electrolyte layer has higher ion conductivity than the second electrolyte layer, and a difference in the ion conductivity between the first electrolyte layer and the second electrolyte layer is from 2 times to 104 times;
wherein the first electrolyte layer comprises LiFSI, and the second electrolyte layer comprises poly(ethylene glycol) methyl ether acrylate (PEGMEA), poly(ethylene glycol) diacrylate (PEGDA), succinonitrile (SN), and LiTFSI;
wherein the lithium metal layer is formed by migration of lithium ions from the positive electrode after charging, and
wherein the positive electrode comprises a lithium metal compound represented by any one of the following Chemical Formula 3 to 8, or mixtures thereof:
LiM3eMn1-eO2  [Chemical Formula 3]
in Chemical Formula 3, 0≤e<0.5, and M3 is an element of one or more types selected from the group consisting of Cr, Al, Ni, Mn and Co,
Li2M4O2  [Chemical Formula 4]
in Chemical Formula 4, M4 is Cu,
Li3+fNb1-gM5gS4-h  [Chemical Formula 5]
in Chemical Formula 5, −0.1≤f≤1, 0≤g≤0.5, −0.1≤h≤0.5, and M5 is an element of one or more types selected from the group consisting of Mn, Fe, Co, Cu, Zn, Mg and Cd,
LiM6iMn1-iO2  [Chemical Formula 6]
in Chemical Formula 6, i is 0.05≤i<0.5, and M6 is an element of one or more types selected from the group consisting of Cr, Al, Ni, Mn and Co,
LiM72jMn2-2jO4  [Chemical Formula 7]
in Chemical Formula 7, j is 0.05≤j<0.5, and M7 is an element of one or more types selected from the group consisting of Cr, Al, Ni, Mn and Co, and
Lik-M8m-Nn  [Chemical Formula 8]
in Chemical Formula 8, M8 represents an alkaline-earth metal, k/(k+m+n) is from 0.10 to 0.40, m/(k+m+n) is from 0.20 to 0.50, and n/(k+m+n) is from 0.20 to 0.50).