Lithium Ion Secondary Battery

Patent metadata

Field	Value
Publication number	US-2025219250-A1
Application number	US-202318850138-A
Country	US
Kind code	A1
Filing date	Oct 31, 2023
Priority date	Nov 18, 2022
Publication date	Jul 3, 2025
Grant date	—

Abstract

A lithium ion secondary battery includes a negative electrode portion, a porous layer formed on at least one surface of the negative electrode portion, and a positive electrode portion. The porous layer includes a polymer binder and inorganic fine particles dispersed on the polymer binder. The positive electrode portion is bonded onto the porous layer through an adhesive portion arranged continuously or discontinuously. The adhesive portion includes an ionic conductive polymer, and a ratio of an area occupied by the adhesive portion ranges from 0.02% to 50% based on an area of one surface of the positive electrode portion. A lithium ion secondary battery including an electrode assembly which has excellent adhesion durability without impairing ionic conductivity between electrodes is also provided.

First claim

1 . A lithium ion secondary battery comprising:
a negative electrode portion; a porous layer formed on at least one surface of the negative electrode portion, wherein the porous layer includes a polymer binder and inorganic fine particles dispersed on the polymer binder; and a positive electrode portion bonded onto the porous layer through an adhesive portion arranged continuously or discontinuously, wherein the adhesive portion includes an ionic conductive polymer, and wherein a ratio of an area occupied by the adhesive portion ranges from 0.02% to 50% based on an area of one surface of the positive electrode portion.

2 . The lithium ion secondary battery of claim 1 , wherein the ionic conductive polymer is one or more compounds selected from the group consisting of cyanoethylated polyvinyl alcohol, cyanoethyl cellulose, polyacrylonitrile, polyvinylpyrrolidone, polyethylene oxide, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polymethyl methacrylate, polyacrylonitrile-styrene copolymer, polyvinyl chloride, polyvinyl acetate, polyethylene vinyl acetate copolymer, cyanoethyl pullulan, cyanoethyl sucrose, pullulan, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyethylene glycol, polyethylene glycol dimethyl ether, and carboxymethyl cellulose.

3 . The lithium ion secondary battery of claim 1 , wherein the adhesive portion further includes a lithium salt.

4 . The lithium ion secondary battery of claim 1 , wherein the adhesive portion is arranged continuously or discontinuously along an edge of the positive electrode portion.

5 . The lithium ion secondary battery of claim 1 , wherein the adhesive portion has a width ranging from 50 μm to 700 μm along an edge of the positive electrode portion.

6 . The lithium ion secondary battery of claim 1 , wherein the adhesive portion is arranged discontinuously at regular intervals or discontinuously at irregular intervals along an edge of the positive electrode portion.

7 . The lithium ion secondary battery of claim 1 , wherein the adhesive portion includes an adhesive portion pattern including two or more adhesive portion units.

8 . The lithium ion secondary battery of claim 7 , wherein each of the two or more adhesive portion units independently has one or more transversal cross-sectional shapes selected from the group consisting of a circle, an ellipse, a sector, a polygon, and a concave polygon.

9 . The lithium ion secondary battery of claim 7 , wherein the adhesive portion pattern is a pattern in which a center part of each adhesive portion unit is arranged at equal intervals.

10 . The lithium ion secondary battery of claim 7 , wherein a transversal cross-section of each adhesive portion unit has a major axis diameter ranging from 200 nm to 5000 μm.

11 . The lithium ion secondary battery of claim 1 , wherein:
the negative electrode portion includes a negative electrode active material layer formed on at least one surface of a negative electrode current collector, and the porous layer is formed on the negative electrode active material layer.

12 . The lithium ion secondary battery of claim 1 , wherein:
the positive electrode portion includes a positive electrode active material layer formed on at least one surface of a positive electrode current collector, and the porous layer and the positive electrode active material layer are bonded through the adhesive portion pattern.

13 . The lithium ion secondary battery of claim 1 , wherein the polymer binder is one or more selected from the group consisting of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polyvinylidene fluoride-chlorotrifluoroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, ethylene vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethylated polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxymethylcellulose, acrylonitrile-styrene-butadiene copolymer, ethylene-propylene-diene terpolymer, sulfonated ethylene-propylene-diene terpolymer, styrene butadiene rubber, fluororubber, and polyimide.

14 . The lithium ion secondary battery of claim 1 , wherein the inorganic fine particles are one or more selected from the group consisting of SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , boehmite(AlO(OH)), Al(OH) 3 , TiO 2 , SiC, BaTiO 3 , Pb(Zr,Ti)O 3 , Pb 1-x La x Zr 1-y Ti y O 3 , Pb(Mg 1/3 Nb 2/3 )O 3 —PbTiO 3 , HfO 2 , Li 3 PO 4 , Li x Ti y (PO 4 ) 3 (0<x<2, 0<y<3), Li x Al y Ti z (PO 4 ) 3 (0<x<2, 0<y<1, 0<z<3), (LiAlTiP) x O y (0<x<4, 0<y<13), Li x La y TiO 3 (0<x<2, 0<y<3), Li x Ge y P z S w (0<x<4, 0<y<1, 0<z<1, 0<w<5), Li x N y (0<x<4, 0<y<2), Li x Si y S z (0<x<3, 0<y<2, 0<z<4), and Li x P y S z (0<x<3, 0<y<3, 0<z<7).

15 . The lithium ion secondary battery of claim 1 , wherein the inorganic fine particles have a particle size ranging from 0.001 μm to 10 μm.

16 . The lithium ion secondary battery of claim 1 , wherein the porous layer includes 10 to 99% by weight of the inorganic fine particles and 1 to 90% by weight of the polymer binder.

17 . The lithium ion secondary battery of claim 1 , comprising:
an electrode assembly including the negative electrode portion, the porous layer and the positive electrode portion; an electrolyte; and a battery case configured to seal and store the electrode assembly and the electrolyte.

Assignees

• Lg Chemical Ltd

Inventors

• Park Sangmin
• Kim Soyoung
• Kim Hyunsuk
• Jin Sun Mi
• Lee Su Hee
• Lee Junghyun
• Sim Hyeyeong

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0585 Primary

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title