US 12,155,063 B2
Lithium-sulfur secondary battery
Minsu Kim, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 17/601,103
Filed by LG ENERGY SOLUTION, LTD., Seoul (KR)
PCT Filed Jul. 2, 2020, PCT No. PCT/KR2020/008650
§ 371(c)(1), (2) Date Oct. 4, 2021,
PCT Pub. No. WO2021/010625, PCT Pub. Date Jan. 21, 2021.
Claims priority of application No. 10-2019-0086693 (KR), filed on Jul. 18, 2019; and application No. 10-2020-0080073 (KR), filed on Jun. 30, 2020.
Prior Publication US 2022/0173382 A1, Jun. 2, 2022
Int. Cl. H01M 4/00 (2006.01); H01M 4/36 (2006.01); H01M 4/38 (2006.01); H01M 4/587 (2010.01); H01M 4/62 (2006.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01); H01M 4/58 (2010.01)
CPC H01M 4/364 (2013.01) [H01M 4/362 (2013.01); H01M 4/38 (2013.01); H01M 4/587 (2013.01); H01M 4/625 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01); H01M 4/5815 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A lithium-sulfur secondary battery comprising:
a positive electrode;
a negative electrode;
a separator; and
an electrolyte liquid,
wherein the positive electrode comprises a sulfur-carbon composite including a catalytic site-introduced porous carbon material; and
the positive electrode has an SC factor value represented by the following Mathematical Formula 1 of 0.45 or greater:

OG Complex Work Unit Math
in Mathematical Formula 1,
P is porosity (%) of a positive electrode active material layer in the positive electrode;
L is a mass of sulfur per unit area (mg/cm2) of the positive electrode active material layer in the positive electrode; and
α is 10,
wherein the SC factor defines the relationship between α, P, and L,
wherein the electrolyte liquid comprises a solvent and a lithium salt; and
the solvent comprises a first solvent having a DV2 factor value represented by the following Mathematical Formula 2 of 1.75 or less and a second solvent that is a fluorinated ether-based solvent:

OG Complex Work Unit Math
in Mathematical Formula 2,
DV is a dipole moment per unit volume (D·mol/L); μis viscosity of the solvent (cP, 25° C.); and γ is 100,
wherein the DV2 factor defines the relationship between μ, γ, and DV; and
wherein the first solvent is present in the solvent in an amount of 1% by weight to 50% by weight based on a total weight of the solvent,
wherein the catalytic site comprises at least one selected from the group consisting of iron phthalocyanine, nickel phthalocyanine, manganese phthalocyanine, copper phthalocyanine, cobalt phthalocyanine, and zinc phthalocyanine.