Electrode for secondary battery, preparation thereof, and secondary battery and cable-type secondary battery comprising the same

Patent metadata

Field	Value
Publication number	US-9065143-B2
Application number	US-201414477317-A
Country	US
Kind code	B2
Filing date	Sep 4, 2014
Priority date	May 7, 2013
Publication date	Jun 23, 2015
Grant date	Jun 23, 2015

Abstract

A sheet-form electrode for a secondary battery, includes a current collector; an electrode active material layer formed on one surface of the current collector; a conductive layer formed on the electrode active material layer and including a conductive material and a binder; and a first porous supporting layer formed on the conductive layer. The sheet-form electrode for a secondary battery has supporting layers on at least one surfaces thereof to exhibit surprisingly improved flexibility and prevent the release of the electrode active material layer from a current collector even if intense external forces are applied to the electrode, thereby preventing the decrease of battery capacity and improving the cycle life characteristic of the battery.

First claim

What is claimed is:

1. A cable-type secondary battery, comprising:
an inner electrode;
a separation layer surrounding an outer surface of the inner electrode to prevent a short circuit between electrodes; and
an outer electrode helically wound to surround an outer surface of the separation layer,
wherein at least one of the inner electrode and the outer electrode is formed from a sheet-form electrode for a secondary battery, comprising a current collector, an electrode active material layer formed on one surface of the current collector, a conductive layer formed on the electrode active material layer and comprising a conductive material and a binder, and a first porous supporting layer formed on the conductive layer.

2. The cable-type secondary battery according to claim 1 , wherein the outer electrode is in the form of a uniaxially extended strip.

3. The cable-type secondary battery according to claim 1 , wherein the outer electrode is helically wound so that it does not overlapped itself.

4. The cable-type secondary battery according to claim 3 , wherein the outer electrode is helically wound so that each pass of its helical winding is separated by a space.

5. The cable-type secondary battery according to claim 1 , wherein the outer electrode is helically wound so that is overlaps itself.

6. The cable-type secondary battery according to claim 5 , wherein the outer electrode is helically wound so that a width of its overlapped part is less than or equal to 90% of a width of the outer electrode.

7. The cable-type secondary battery according to claim 1 , wherein the inner electrode is a hollow structure whose central part is empty.

8. The cable-type secondary battery according to claim 7 , wherein one or more electrodes according to claim 1 are helically wound as the inner electrode.

9. The cable-type secondary battery according to claim 7 , wherein the inner electrode is provided with a core of inner current collector, a core for supplying lithium ions, which comprises an electrolyte, or a filling core therein.

10. The cable-type secondary battery according to claim 9 , wherein the core of inner current collector is made of carbon nanotube, stainless steel, aluminum, nickel, titanium, sintered carbon, or copper; stainless steel treated with carbon, nickel, titanium or silver on a surface thereof; an aluminum-cadmium alloy; a non-conductive polymer treated with a conductive material on a surface thereof; or a conductive polymer.

11. The cable-type secondary battery according to claim 9 , wherein the core for supplying lithium ions comprises a gel polymer electrolyte and a support.

12. The cable-type secondary battery according to claim 9 , wherein the core for supplying lithium ions comprises a liquid electrolyte and a porous carrier.

13. The cable-type secondary battery according to claim 9 , wherein the electrolyte is selected from a non-aqueous electrolyte solution using ethylene carbonate (EC), propylene carbonate (PC), butylenes carbonate (BC), vinylene carbonate (VC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl formate (MF), γ-butyrolactone (γ-BL), sulfolane, methyl acetate (MA) or methyl propionate (MP); a gel polymer electrolyte using PEO, PVdF, PVdF-HFP, PMMA, PAN, or PVAc; and a solid electrolyte using PEO, polypropylene oxide (PPO), polyether imine (PEI), polyethylene sulphide (PES), or polyvinyl acetate (PVAc).

14. The cable-type secondary battery according to claim 9 , wherein the electrolyte further comprises a lithium salt.

15. The cable-type secondary battery according to claim 14 , wherein the lithium salt is selected from LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, lithium chloroborate, lower aliphatic lithium carbonate, lithium tetraphenylborate, and a mixture thereof.

16. The cable-type secondary battery according to claim 9 , the filling core is made of polymer resins, rubber and inorganics in the form of a wire, a fiber, a powder, a mesh or a foam.

17. The cable-type secondary battery according to claim 1 , wherein the inner electrode is an anode or a cathode, and the outer electrode is a cathode or an anode corresponding to the inner electrode.

18. The cable-type secondary battery according to claim 1 , wherein the separation layer is an electrolyte layer or a separator.

19. The cable-type secondary battery according to claim 18 , wherein the electrolyte layer comprises an electrolyte selected from a gel polymer electrolyte using PEO, PVdF, PMMA, PVdF-HFP, PAN, or PVAc; and a solid electrolyte using PEO, polypropylene oxide (PPO), polyether imine (PEI), polyethylene sulphide (PES), or polyvinyl acetate (PVAc).

20. The cable-type secondary battery according to claim 18 , wherein the electrolyte layer further comprises a lithium salt.

21. The cable-type secondary battery according to claim 20 , wherein the lithium salt is selected from the group consisting of LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, lithium chloroborate, lower aliphatic lithium carbonate, lithium tetraphenylborate, and a mixture thereof.

22. The cable-type secondary battery according to claim 18 , wherein the separator is a porous polymer substrate made of a polyolefin-based polymer selected from the group consisting of ethylene homopolymers, propylene homopolymers, ethylene-butene copolymers, ethylene-hexene copolymers, and ethylene-methacrylate copolymers; a porous polymer substrate made of a polymer selected from the group consisting of polyesters, polyacetals, polyamides, polycarbonates, polyimides, polyether ether ketones, polyether sulfones, polyphenylene oxides, polyphenylene sulfides and polyethylene naphthalates; a porous substrate made of a mixture of inorganic particles and a binder polymer; or a separator having a porous coating layer formed on at least one surface of the porous polymer substrate and comprising inorganic particles and a binder polymer.

23. The cable-type secondary battery according to claim 22 , wherein the porous polymer substrate is a porous polymer film substrate or a porous non-woven fabric substrate.

24. The cable-type secondary battery according to claim 1 , which further comprises a protection coating surrounding an outer surface of the outer electrode.

25. The cable-type secondary battery according to claim 24 , wherein the protection coating is made of a polymer resin.

26. The cable-type secondary battery according to claim 25 , wherein the polymer resin comprises any one selected from the group consisting of PET, PVC, HDPE, an epoxy resin and a mixture thereof.

27. The cable-type secondary battery according to claim 25 , wherein the protection coating further comprises a moisture-blocking layer.

28. The cable-type secondary battery according to claim 27 , wherein the moisture-blocking layer is made of aluminum or a liquid-crystalline polymer.

29. A cable-type secondary battery, comprising:
a core for supplying lithium ions, which comprises an electrolyte;
an inner electrode surrounding an outer surface of the core for supplying lithium ions and comprising a current collector and an electrode active material layer;
a separation lay

Assignees

• Lg Chemical Ltd

Inventors

• Kwon Yo-Han
• Jung Hye-Ran
• Kim Eun-Kyung
• Kim Je-Young
• Kim Hyo-Mi

Classifications

• H01M10/0568

  characterised by the solutes · CPC title

• H01M10/0431

  Cells with wound or folded electrodes (H01M10/045 takes precedence) · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M4/139

  Processes of manufacture · CPC title

• H01M2004/027

  Negative electrodes · CPC title