US 11,742,549 B2
Separator including coating layer of lithium-containing composite, lithium secondary battery including the same, and method for manufacturing the secondary battery
Oh-Byong Chae, Daejeon (KR); Sang-Wook Woo, Daejeon (KR); and Je-Young Kim, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 16/641,750
Filed by LG CHEM, LTD., Seoul (KR)
PCT Filed Mar. 20, 2019, PCT No. PCT/KR2019/003270
§ 371(c)(1), (2) Date Feb. 25, 2020,
PCT Pub. No. WO2019/182364, PCT Pub. Date Sep. 26, 2019.
Claims priority of application No. 10-2018-0032220 (KR), filed on Mar. 20, 2018.
Prior Publication US 2020/0266413 A1, Aug. 20, 2020
Int. Cl. H01M 50/46 (2021.01); H01M 4/1391 (2010.01); H01M 4/1393 (2010.01); H01M 4/1395 (2010.01); H01M 4/36 (2006.01); H01M 4/525 (2010.01); H01M 4/62 (2006.01); H01M 10/0525 (2010.01); H01M 10/0569 (2010.01); H01M 50/449 (2021.01); H01M 50/403 (2021.01); H01M 4/02 (2006.01)
CPC H01M 50/46 (2021.01) [H01M 4/1391 (2013.01); H01M 4/1393 (2013.01); H01M 4/1395 (2013.01); H01M 4/366 (2013.01); H01M 4/525 (2013.01); H01M 4/621 (2013.01); H01M 10/0525 (2013.01); H01M 10/0569 (2013.01); H01M 50/403 (2021.01); H01M 50/449 (2021.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01); H01M 2004/028 (2013.01)] 15 Claims
 
1. A separator comprising:
a porous polymer substrate having a plurality of pores; and
a coating layer formed on at least one surface of the porous polymer substrate,
wherein the coating layer comprises a plurality of lithium-containing composite particles and a binder positioned on a whole or a part of a surface of the lithium-containing composite particles to connect and fix the lithium-containing composite particles with each other,
wherein the lithium-containing composite particles consist of a lithiated compound and a passivation film formed on a surface of the lithiated compound, and the passivation film comprises a solid electrolyte interface (SEI),
wherein the SEI film comprises one or more selected from the group consisting of LiF, LiOH, and Li2CO3,
wherein the lithiated compound comprises lithium silicide (LixSi, 0<x<4.4), and one or more selected from the group consisting of LixSn (0<x<4.4), LixGe (0<x<4.4), LixAl (0<x<3), LixSb (0<x<3), LixZn (0<x<1), Co—Li2O, Ni—Li2O, Fe—Li2O, LixC (0<x<0.17), Li4+xTi5O12 (0<x<3), LixMoO2 (0<x<4), LixTiO2 (0<x<3), LixV2O5 (0<x<5).
 
8. A method for manufacturing a lithium secondary battery, comprising the steps of:
(S1) adding a mixture of a lithium-intercalatable material and lithium metal particles to an electrolyte, and agitating the mixture at room temperature and washing the mixture to obtain lithium-containing composite particles comprising lithium ions intercalated into the lithium-intercalatable material and a passivation film on a surface of the lithium-containing composite particles;
(S2) dispersing the lithium-containing composite particles in a solvent with a binder to obtain a slurry, and coating the slurry onto at least one surface of a porous polymer substrate having a plurality of pores, followed by drying, to obtain a separator having a coating layer comprising the lithium-containing composite particles; and
(S3) interposing the separator between a positive electrode and a negative electrode wherein the coating layer of lithium-containing composite particles is present at least on a surface of the porous polymer substrate that faces the negative electrode,
wherein the passivation film comprises a solid electrolyte interface (SEI) film formed by a reaction of lithium ions with the electrolyte.