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KR-102962293-B1 - Binder composition for electrode production, and electrode for secondary battery comprising the same

KR102962293B1KR 102962293 B1KR102962293 B1KR 102962293B1KR-102962293-B1

Abstract

The present invention relates to a binder composition for manufacturing electrodes, an electrode slurry composition comprising the same, an electrode for a secondary battery comprising the same, and a secondary battery comprising the same. The binder composition for manufacturing electrodes according to the present invention is manufactured using a composite binder comprising a hydrophilic binder containing a hydrophobic binder and a non-fluorine compound that is easy to dispose of without adverse environmental effects, thereby enabling an environmentally friendly process. Furthermore, the electrode slurry composition comprising the binder composition induces the formation of a bonding network between carbon materials as the carbon materials included therein are evenly dispersed and coated within the composition, resulting in excellent bonding strength between carbon materials. Consequently, it exhibits superior electrical conductivity compared to conventional secondary battery electrodes, and as a result, the secondary battery manufactured thereby has low battery resistance, thus enabling excellent lifespan. Additionally, since the electrode slurry composition can improve the bonding strength with the electrode layer while inducing the formation of a bonding network between the carbon materials included therein, the electrode for a secondary battery manufactured thereby does not hinder the diffusion of the electrolyte contained in the battery and has low interfacial resistance. Superior interfacial stability and mechanical stability compared to conventional electrodes can be achieved, and consequently, secondary batteries manufactured therefrom can achieve excellent lifespan due to stable discharge capacity.

Inventors

  • 심진용
  • 정호영

Assignees

  • 현대자동차주식회사
  • 기아 주식회사
  • 전남대학교산학협력단

Dates

Publication Date
20260507
Application Date
20200720

Claims (16)

  1. Binder composition; and Includes carbon material, The above binder composition is a composite binder comprising a hydrophobic binder and a hydrophilic binder; and It includes a solvent, An electrode slurry composition in which the content of the above composite binder is 10 to 20 weight percent based on 100 weight percent of the electrode slurry composition.
  2. In paragraph 1, 0.01 to 50 wt% of the above hydrophobic binder; 0.01 to 50 wt% of the above hydrophilic binder; and Electrode slurry composition containing a residual amount of solvent.
  3. In paragraph 1, The above-mentioned hydrophobic binder comprises one or more selected from the group consisting of aliphatic polymers and aromatic polymers, forming an electrode slurry composition.
  4. In paragraph 1, The above-mentioned hydrophilic binder comprises one or more selected from the group consisting of natural cellulose, polyacrylate resins, polysaccharides, and proteins, forming an electrode slurry composition.
  5. In paragraph 1, The above solvent is an electrode slurry composition comprising one or more selected from the group consisting of distilled water, ethanol, isopropanol, and methanol.
  6. delete
  7. In paragraph 1, 10 to 95 weight% of the above binder composition; and An electrode slurry composition comprising 5 to 90 weight percent of the above carbon material.
  8. delete
  9. In paragraph 1, An electrode slurry composition having a specific surface area of 1 to 5000 m² /g of the carbon material.
  10. In paragraph 1, An electrode slurry composition having a particle diameter of 0.01 to 50 μm of the carbon material.
  11. First electrode layer; and A second electrode layer located on the first electrode layer and comprising the electrode slurry composition of claim 1; An electrode for a secondary battery comprising
  12. In Paragraph 11, The first electrode layer comprises one or more materials selected from the group consisting of lead (Pb) and gold (Au), for use as an electrode for a secondary battery.
  13. In Paragraph 11, An electrode for a secondary battery having a second electrode layer thickness of 1 to 100 μm.
  14. In Paragraph 11, An electrode for a secondary battery having a specific surface area of the second electrode layer of 10 to 2000 m² /g.
  15. A secondary battery comprising the electrode for a secondary battery of claim 11 as a negative electrode.
  16. In paragraph 15, A lead-acid battery, or an ultra-rechargeable battery.

Description

Binder composition for electrode production, and electrode for secondary battery comprising the same The present invention relates to a binder composition for manufacturing an electrode, an electrode slurry composition containing the same, an electrode for a secondary battery containing the same, and a secondary battery containing the same. Rechargeable batteries used in automobiles either utilize lead-acid batteries or combine lead-acid batteries with ultracapacitors (supercapacitors) connected in parallel or series with other electronic devices. Generally, ultracapacitors absorb peak power and regenerative braking, which require high output, thereby preventing sulfation of the lead-acid battery's negative electrode and improving its lifespan. However, while this system satisfies the requirements of hybrid vehicles in terms of price and performance, it has the disadvantage of being bulky. Meanwhile, in the transitional phase of the hybrid vehicle market prior to the commercialization of lithium batteries or fuel cells, nickel-hydrogen batteries currently account for the majority of the market. Nickel-hydrogen batteries not only fully satisfy the requirements of hybrid vehicles in terms of energy and power density but also offer excellent lifespan performance. However, they have the disadvantage of being very expensive. To compensate for this, "ultra batteries" are being developed to deliver performance highly suitable for hybrid vehicles by combining inexpensive lead-acid batteries, which have high energy density, with ultracapacitors, which have high power density. An ultra battery refers to a battery for hybrid vehicles made by combining lead-acid batteries, which are used in conventional internal combustion engines, with ultracapacitors. However, due to issues with interface stability and resistance between the ultracapacitor and the lead cathode, the electrical conductivity and mechanical stability of the electrode were deteriorating. FIG. 1a is a graph showing N2 adsorption-desorption according to the composite binder content of the second electrode layer in the electrode for a secondary battery of Examples 1 and 2 and Comparative Examples 1 and 2, according to one embodiment of the present invention. FIG. 1b is a graph showing the BET (Brunauer Emmett Teller) according to the composite binder content of the second electrode layer in the electrode for a secondary battery of Examples 1 and 2 and Comparative Examples 1 and 2, according to one embodiment of the present invention. FIG. 1c is a graph showing the total pore volume according to the composite binder content of the second electrode layer in the electrode for a secondary battery of Examples 1 and 2 and Comparative Examples 1 and 2, according to one embodiment of the present invention. FIG. 2 is an SEM image of the composite binder content of the second electrode layer in the electrode for a secondary battery according to Example 1 and Example 2 and Comparative Example 1 and Comparative Example 2, according to one embodiment of the present invention. Figure 3 is a graph showing the results of a comparative analysis of PEIS (Potentiostatic electrochemical impedance spectroscopy) according to the composite binder content of the second electrode layer in the secondary battery of Examples 3 and 4 and Comparative Examples 3 and 4, in accordance with one embodiment of the present invention. FIGS. 4a to 4f are graphs showing the results of cyclic voltammetry (CV) analysis according to the composite binder content and scanning speed (Fig. 4a: 10 mV/s, Fig. 4b: 20 mV/s, Fig. 4c: 40 mV/s, Fig. 4d: 60 mV/s, Fig. 4e: 80 mV/s, Fig. 4f: 100 mV/s) of the second electrode layer in the secondary battery of Example 3 and Example 4 and Comparative Example 3 and Comparative Example 4, according to one embodiment of the present invention. FIG. 5 is a graph showing the capacitance values according to the composite binder content of the second electrode layer in the secondary battery of Examples 3 and 4 and Comparative Examples 3 and 4, according to one embodiment of the present invention. FIGS. 6a to 6f are discharge graphs according to the composite binder content and C-rate of the second electrode layer in the secondary battery of Example 3 and Example 4 and Comparative Example 3 and Comparative Example 4, according to one embodiment of the present invention (Fig. 6a: 0.1C, Fig. 6b: 0.2C, Fig. 6c: 0.5C, Fig. 6d: 1C, Fig. 6e: 2C, Fig. 6f: 5C). FIG. 7 is a graph showing the discharge capacity according to the composite binder content of the second electrode layer in the secondary battery of Examples 3 and 4 and Comparative Examples 3 and 4, according to one embodiment of the present invention. The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein