Method of coating substrate for lithium secondary battery with inorganic particles and lithium secondary battery comprising substrate coated by the method

Patent metadata

Field	Value
Publication number	US-10069132-B2
Application number	US-201414299124-A
Country	US
Kind code	B2
Filing date	Jun 9, 2014
Priority date	Mar 5, 2012
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

The present invention provides a method of coating a substrate for a lithium secondary battery with inorganic particles, comprising charging the inorganic particles to form charged inorganic particles; transferring the charged inorganic particles on the substrate for a lithium secondary battery to form a coating layer; and fixing the coating layer with heat and pressure. Such a coating method according to one embodiment of the present invention uses electrostatic force without the addition of a solvent, and therefore, non use of a solvent can result in cost-reducing effects since there is no burden on the handling and storing of the solvent, and since a drying procedure after slurry coating is not needed, it allows for the preparation of a lithium secondary battery in a highly effective and rapid manner.

First claim

What is claimed is:

1. A method of coating a substrate for a lithium secondary battery with inorganic particles, comprising:
modifying the surface of the inorganic particles by using only a surface-modifier selected from the group consisting of a substituted or unsubstituted saline-based compound, a substituted or unsubstituted siloxane-based compound, a substituted or unsubstituted silazane-based compound, a substituted or unsubstituted silanol-based compound, and a mixture thereof;
charging the inorganic particles having the surface-modifying layer formed on the surface thereof to form charged inorganic particles;
transferring the charged inorganic particles on the substrate for the lithium secondary battery to form a coating layer; and
fixing the coating layer with heat and pressure
wherein the charging of the inorganic particles to form charged inorganic particles actuates the inorganic particles so that the inorganic particles can be instantly or continuously adhered to the substrate without the use of a solvent.

2. The method of coating the substrate for the lithium secondary battery according to claim 1 , wherein the silane-based compound is a compound having a structure of Si(OR 1 ) 4-n R 2 n wherein R 1 and R 2 are each independently a substituent selected from hydrogen, alkyl, vinyl, amine and aryl, and n is an integer of 4 or less;
the siloxane-based compound is a compound having a structure of R 1 R 2 SiO wherein R 1 and R 2 are each independently a substituent selected from hydrogen, alkyl, vinyl, amine and aryl;
the silazane-based compound is a compound having a structure of Si 2 NR 1 R 2 R 3 R 4 R 5 R 6 R 7 wherein R 1 to R 7 are each independently a substituent selected from hydrogen, alkyl, vinyl, amine and aryl;
the silanol-based compound is a compound having a structure of SiOHR 1 R 2 R 3 wherein R 1 to R 3 are each independently a substituent selected from hydrogen, alkyl, vinyl, amine and aryl.

3. The method of coating the substrate for the lithium secondary battery according to claim 1 , wherein the surface-modifier is any one selected from the group consisting of dimethyl dimethoxy silane, dimethyl diethoxy silane, methyl trimethoxy silane, vinyl trimethoxy silane, phenyl trimethoxy silane, tetraethoxy silane, dimethyl dichloro silane, 3-aminopropyl triethoxy silane, polydimethylsiloxane, polydiethylsiloxane, octamethyl cyclotetrasiloxane, hexamethyldisilazane, hexamethylcyclotrisilazane, heptamethyldisilazane, trimethylsilanol, triethylsilanol, triphenylsilanol, t-butyl dimethyl silanol, and a mixture thereof.

4. The method of coating the substrate for the lithium secondary battery according to claim 1 , wherein the inorganic particles are metallic lithium, a carbon material, a metal compound or a mixture thereof, and the substrate for a lithium secondary battery is a current collector for an anode.

5. The method of coating the substrate for the lithium secondary battery according to claim 4 , wherein the metal compound is a compound containing at least one selected from the group consisting of Si, Ge, Sn, Pb, P, Sb, Bi, Al, Ga, In, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ag, Mg, Sr and Ba, and a mixture thereof.

6. The method of coating the substrate for the lithium secondary battery according to claim 1 , wherein the inorganic particles are a lithium-containing oxide, and the substrate for a lithium secondary battery is a current collector for a cathode.

7. The method of coating the substrate for the lithium secondary battery according to claim 6 , wherein the lithium-containing oxide is a lithium-containing transition metal oxide.

8. The method of coating the substrate for the lithium secondary battery according to claim 7 , wherein the lithium-containing transition metal oxide is selected from the group consisting of Li x CoO 2 (0.5<x<1.3), Li x NiO 2 (0.5<x<1.3), Li x MnO 2 (0.5<x<1.3), Li x Mn 2 O 4 (0.5<x<1.3), Li x (Ni a Co b Mn c )O 2 (0.5<x<1.3, 0<a<1, 0<b<1, 0<c<1, a+b+c=1), Li x Ni 1-y Co y O 2 (0.5<x<1.3, 0<y<1), Li x Co 1-y Mn y O 2 (0.5<x<1.3, 0≤y<1), Li x Ni 1-y Mn y O 2 (0.5<x<1.3, O≤y<1), Li x (Ni a Co b Mn c )O 4 (0.5<x<1.3, 0<a<2, 0<b<2, 0<c<2, a+b+c=2), Li x Mn 2-z Ni z O 4 (0.5<x<1.3, 0<z<2), Li x Mn 2-z Co z O 4 (0.5<x<1.3, 0<z<2), Li x CoPO 4 (0.5<x<1.3), Li x FePO 4 (0.5<x<1.3) and a mixture thereof.

9. The method of coating the substrate for the lithium secondary battery according to claim 1 , wherein the inorganic particles are any one selected from the group consisting of SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , SiO 2 , Y 2 O 3 , Al 2 O 3 , AlOOH, Al(OH) 3 , TiO 2 , SiC, BaTiO 3 , Pb(Zr x , Ti 1-x )O 3 (PZT, 0<x<1), Pb 1-x La x Zr 1-y Ti y O 3 (PLZT, 0<x<1, and 0<y<1), (1−x)Pb(Mg 1/3 Nb 2/3 )O 3 -xPbTiO 3 (PMN-PT, 0<x<1), HfO 2 , and a mixture thereof, and the substrate for a lithium secondary battery is a porous substrate.

10. The method of coating the substrate for the lithium secondary battery according to claim 9 , wherein the porous substrate is a polyolefin-based porous substrate, or a non-woven fabric made of any one selected from the group consisting of polyethylene terephthalates, polybutylene terephthalates, polyesters, polyacetals, polyamides, polycarbonates, polyimides, polyether ether ketones, polyether sulfones, polyphenylene oxides, polyphenylene sulfides, polyethylene naphthalenes and a mixture thereof.

11. The method of coating the substrate for the lithium secondary battery according to claim 1 , wherein the inorganic particles have an average diameter of 0.001 to 100 μm.

12. The method of coating the substrate for the lithium secondary battery according to claim 1 , wherein the coating layer has a thickness of 1 to 250 μm.

13. A method of coating a substrate for a lithium secondary battery with inorganic particles, comprising:
modifying the surface of inorganic particles by using only a surface-modifier selected from the group consisting of a substituted or unsubstituted silane-based compound, a substituted or unsubstituted siloxane-based compound, a substituted or unsubstituted silazane-based compound, a substituted or unsubstituted silanol-based compound, and a mixture thereof;
mixing inorganic particles having the surface-modifying layer formed on the surface thereof and a polymer binder to obtain a mixture;
charging the mixture to form a charged mixture;
transferring the charged inorganic particles on the substrate for a lithium secondary battery to form a coating layer; and
fixing the coating layer with heat and pressure
wherein the charging of the mixture to form a charged mixture actuates the inorganic particles so that the inorganic particles can be instantly or continuously adhered to the substrate without the use of a solvent.

14. The method of coating the substrate for the lithium secondary battery according to claim 13 , wherein the polymer binder is any one selected from the group consisting of polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride-co-trichloro ethylene, polymethyl methacrylate, polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinylalcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, and a mixture thereof.

15. A method of coating a substrate for a lithium secondary battery with inorganic particles, comprising:
modifying th

Assignees

• Lg Chemical Ltd

Inventors

• Lee Joo-Sung
• Kim Jong-Hun
• Ha Jeong-Min
• Ryu Bo-Kyung
• Kim Jin-Woo

Classifications

• H01M4/139 Primary

  Processes of manufacture · CPC title

• H01M4/0414

  by screen printing · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title