Positive electrode slurry composition for lithium secondary battery, positive electrode comprising the same, and lithium secondary battery

Abstract

The present invention relates to a positive electrode slurry composition for a lithium secondary battery, and a positive electrode and a lithium secondary battery comprising the same, more specifically, when a method of manufacturing a positive electrode for a lithium secondary battery including a slurry coating process is used, by using a positive electrode slurry composition having thixotropy which can ensure flowability sufficient to flexibly respond to a change in slurry coating rate, the processability when manufacturing a positive electrode for a lithium secondary battery can be improved.

Claims

1. A positive electrode slurry composition for lithium secondary batteries, said positive electrode slurry composition comprising a positive electrode active material, a conductive material, a binder, a thickener, additives, and a solvent. in, The thickener comprises lithium-ionized carboxymethyl cellulose, and The additive contains carbodiimide compounds. The thixotropic index of the positive electrode slurry composition is 0.1 to 0.

4. Based on the total weight of the solids in the cathode slurry composition, the content of the additive is from 0.01% to 5% by weight. The content of the thickener is from 0.5% to 5% by weight, based on the total weight of the solids in the cathode slurry composition.

2. The positive electrode slurry composition for lithium secondary batteries according to claim 1, wherein, The carbodiimide compounds include at least one selected from the following: 1-ethyl-3-[3-(dimethylamino)propyl]-carbodiimide hydrochloride, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, N,N'-diisopropylcarbodiimide, and N,N'-di-tert-butylcarbodiimide.

3. The positive electrode slurry composition for lithium secondary batteries according to claim 1, wherein, The solvent includes at least one selected from organic solvents and aqueous solvents. The organic solvent comprises at least one selected from the following: N-methyl-2-pyrrolidone, methoxypropyl acetate, butyl acetate, glycolic acid, butyl ester, ethylene glycol butyl ether, methylalkyl polysiloxane, alkylbenzene, propylene glycol, ethylene glycol monophenyl ether, polyacrylate, diisobutyl ketone, organically modified polysiloxane, butanol, isobutanol, modified polyacrylate, and modified polyurethane. The aqueous solvent includes water.

4. The positive electrode slurry composition for lithium secondary batteries according to claim 1, wherein, The solvent includes at least one selected from organic solvents and aqueous solvents, wherein the organic solvent includes at least one selected from xylene, aralkyl-modified methylalkyl polysiloxane, polyether-modified dimethyl polysiloxane copolymer, and... The aqueous solvent includes water.

5. The positive electrode slurry composition for lithium secondary batteries according to claim 1, wherein, The solvent includes at least one selected from organic solvents and aqueous solvents, wherein the organic solvent includes a polysiloxane-modified polymer, and The aqueous solvent includes water.

6. The positive electrode slurry composition for lithium secondary batteries according to claim 1, wherein, The positive electrode active material includes at least one selected from the following: elemental sulfur S8; Li2S n Where n≥1, n is an integer; organic sulfur compounds; and carbon-sulfur polymers (C2S) x ) n , where 2.5≤x≤50, n≥2, and x and n are integers.

7. A positive electrode for a lithium secondary battery, the positive electrode comprising: Positive current collector; and A layer of positive electrode active material is formed on one surface of the positive electrode current collector. in, The positive electrode active material layer is formed from the positive electrode slurry composition according to claim 1.

8. A method for manufacturing a positive electrode for a lithium secondary battery, the method comprising the following steps: (S1) Coating the positive electrode slurry composition of claim 1 onto one surface of the positive electrode current collector; (S2) Dry the coating formed in step (S1); and (S3) Roll the coating to form a positive electrode active material layer.

9. The method for manufacturing a positive electrode for a lithium secondary battery according to claim 8, wherein, The coating method is selected from at least one of the following: bar coating, roller-to-roll coating, spin coating, nozzle printing, inkjet printing, slot coating, and dip coating.

10. A lithium secondary battery, the lithium secondary battery comprising: The positive electrode as described in claim 7, negative electrode, Diaphragm, and Electrolyte.

11. The lithium secondary battery according to claim 10, wherein, The lithium secondary battery is a lithium-sulfur secondary battery.

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