ANODE SLURRY FOR SECONDARY BATTERY FOR IMPROVING DISPERSIBILITY AND REDUCING RESISTANCE, AND ANODE COMPRISING SAME

• US 20180358622A1
• Filed: 10/19/2016
• Published: 12/13/2018
• Est. Priority Date: 11/11/2015
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: YOO, Jung Woo, CHO, Hyung Suk, RHO, Ye Cheol, WOO, Kyung Hwa, JEONG, Kwang Ho, KIM, Je Young
• Granted Patent: US 10,644,316 B2
• Time in Patent Office: Days
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/1393 of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

The present invention provides an anode slurry for a secondary battery and an anode comprising the same, in which the dispersibility of an anode active material is improved by increasing the adsorption amount of CMC with respect to the anode active material by adjusting the degree of substitution or physical properties such as molecular weight, and a CMC blend amount is reduced so as to increase the slurry solid content and reduce the resistance of a battery.

Claims

1. An anode slurry for a secondary battery comprising an anode active material and a thickening agent,

wherein the anode active material has a tap density of 1.0 g/cc or less and a slurry solid content of 48% by weight or more based on the total weight of the slurry.

2. The anode slurry of claim 1, wherein the thickening agent comprises one or more selected from the group consisting of carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxypropyl cellulose (HPC), methyl hydroxypropyl cellulose (MHPC), ethyl hydroxyethyl cellulose (EHEC), methyl ethyl hydroxyethyl cellulose (MEHEC), and cellulose gum.

3. The anode slurry of claim 1, wherein the thickening agent is CMC.

4. The anode slurry of claim 3, wherein the CMC has an adsorption amount of 0.8 to 0.9% by weight with respect to the anode active material.

5. The anode slurry of claim 3, wherein the CMC has a degree of substitution of 0.7 to 1.3.

6. The anode slurry of claim 3, wherein the CMC has a degree of substitution of 0.7 to 0.9.

7. The anode slurry of claim 3, wherein the CMC has a weight average molecular weight of 700,000 to 4,200,000.

8. The anode slurry of claim 3, wherein the CMC has a weight average molecular weight of 700,000 to 3,500,000.

9. The anode slurry of claim 3, wherein the CMC comprises low molecular weight CMC having a weight average molecular weight of 1,000,000 or less and high molecular weight CMC having a weight average molecular weight of 2,000,000 or more, and

the low molecular weight CMC and the high molecular weight CMC are blended in a weight ratio of 1:

3 to 3;

1.

10. The anode slurry of claim 3, wherein the CMC is present at a content of 1% by weight, based on the total weight of the anode slurry.

11. The anode slurry of claim 10, wherein a slurry precipitation rate of the anode slurry for a secondary battery is less than or equal to 7%.

12. An anode for a secondary battery comprising the anode slurry for a secondary battery defined in claim 1.

13. A lithium secondary battery comprising a cathode, an anode, an electrolyte, and a separator,

wherein the anode comprises the anode slurry for a secondary battery defined in claim 12.

14-16. -16. (canceled)