Search

KR-20260066255-A - A SLURRY COMPOSITION FOR AN ANODE-FREE PROTECTIVE LAYER FOR AN ALL-SOLID-STATE BATTERY, AN ANODE CURRENT COLLECTOR COMPRISING THE SAME, AND AN ALL-SOLID-STATE SECONDARY BATTERY

KR20260066255AKR 20260066255 AKR20260066255 AKR 20260066255AKR-20260066255-A

Abstract

The present specification discloses a non-cathode protective layer slurry composition for an all-solid-state battery comprising a lithium-affinity element, an amorphous carbon material, a binder, and an additive, wherein the additive is a nitrile rubber (NBR)-based additive and the additive improves the dispersibility of the lithium-affinity element.

Inventors

  • 김가연
  • 성상훈
  • 손정우
  • 이제권

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260512
Application Date
20241104

Claims (13)

  1. It includes a lithium-affinity element, an amorphous carbon material, a binder, and an additive, The above additive is a nitrile rubber (NBR)-based additive, and The above additive improves the dispersibility of the lithium affinity element, a non-cathode protective layer slurry composition for an all-solid-state battery.
  2. In paragraph 1, The above nitrile rubber-based additive is a non-cathode protective layer slurry composition for an all-solid-state battery comprising hydrogenated nitrile rubber (H-NBR).
  3. In paragraph 2, The above hydrogenated nitrile rubber is a non-cathode protective layer slurry composition for an all-solid-state battery having one or more characteristics of an acrylonitrile (ACN) content of 20 to 30% and a residual double bond amount (RDB) of 1% or less.
  4. In paragraph 1, A non-cathode protective layer slurry composition for an all-solid-state battery, wherein the lithium affinity element comprises one or more particles selected from the group consisting of silver (Ag), gold, platinum, palladium, silicon, aluminum, bismuth, tin, indium, and zinc.
  5. In paragraph 1, A non-cathode protective layer slurry composition for an all-solid-state battery, wherein the above-mentioned amorphous carbon material comprises one or more selected from the group consisting of carbon black, graphene, acetylene black, furnace black, and Ketjen black.
  6. In paragraph 1, A non-anode protective layer slurry composition for an all-solid-state battery, wherein the binder comprises one or more selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, and fluororubber.
  7. In paragraph 1, A non-anode protective layer slurry composition for an all-solid-state battery, wherein the above additive is included in an amount of 0.1 to 7.0 weight% based on the total weight of the slurry.
  8. In paragraph 1, A non-cathode protective layer slurry composition for an all-solid-state battery, wherein the lithium affinity element is silver nanoparticles, the amorphous carbon material is carbon black, and the binder is polyvinylidene fluoride (PVDF).
  9. In paragraph 1, The above-described non-cathode protective layer slurry composition is a non-cathode protective layer slurry composition for an all-solid-state battery having a viscosity range of 10,000 cP or less at a shear rate of 2.51/s.
  10. Metal current collector; and A negative electrode current collector comprising: a negative electrode protective layer formed from a negative electrode protective layer slurry composition for an all-solid-state battery according to any one of claims 1 to 9, and disposed on the metal current collector substrate.
  11. In Paragraph 10, The above-mentioned non-cathode protective layer is a cathode current collector having a thickness of 1 to 50 μm.
  12. The negative current collector of Clause 10; An anode facing the above-mentioned cathode current collector; and It includes a solid electrolyte layer interposed between the above-mentioned negative current collector and the above-mentioned positive electrode; The above-described non-cathode protective layer faces the above-described solid electrolyte layer, an all-solid-state secondary battery.
  13. In Paragraph 12, The above-described all-solid-state secondary battery further comprises a lithium metal layer formed between the metal current collector and the coating layer, and A solid-state secondary battery in which the lithium metal layer is formed by the movement of lithium ions from the positive electrode by the charging of the negative electrode battery.

Description

A slurry composition for an anode-free protective layer for an all-solid-state battery, an anode current collector comprising the same, and an all-solid-state secondary battery. The present specification discloses a non-cathode protective layer slurry composition for an all-solid-state battery, a negative electrode current collector comprising the same, and an all-solid-state secondary battery. With the recent rapid proliferation of battery-powered electronic devices such as mobile phones, laptop computers, and electric vehicles, the demand for rechargeable batteries—which are small, lightweight, and relatively high-capacity—is increasing rapidly. In particular, lithium-ion batteries are gaining prominence as power sources for portable devices due to their lightweight nature and high energy density. Consequently, active research and development efforts are underway to improve the performance of lithium-ion batteries. Meanwhile, anodeless lithium-ion secondary batteries are known as all-solid-state lithium-ion secondary batteries that utilize a negative electrode active material layer comprising a metal and a carbon material that forms an alloy with lithium. Such anodeless lithium-ion secondary batteries are driven by a mechanism in which metallic lithium is deposited between the negative electrode active material layer and the current collector during charging, and the deposited metallic lithium ionizes and moves to the positive electrode during discharging. However, these conventional technologies have room for improvement due to problems such as metallic lithium precipitating between the negative electrode active material layer and the current collector during charging in the form of dendrites, and voids forming as metallic lithium dissolves during discharge. FIG. 1 shows a surface SEM image (200x magnification) of an electrode according to Example 1 of the present invention. FIG. 2 shows a surface SEM image (200x magnification) of an electrode according to Comparative Example 1 of the present invention. Figure 3 illustrates a comparison of viscosity measurement results for the non-cathode protective layer slurry compositions of Example 1 and Comparative Example 1. Figure 4 illustrates a comparison of the adhesion strength measurements for the electrodes of Example 1 and Comparative Example 1. Hereinafter, embodiments of the present invention are described in detail so that those skilled in the art can easily practice the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Example 1 A pre-dispersion solution was prepared by pre-dispersing a lithium-affinity element (silver nanoparticles) and a portion of the binder (PVDF) (90 mass% of the total binder content). Then, the pre-dispersion solution, amorphous carbon (carbon black), the remaining binder (10 mass% of the total binder content), an H-NBR-based additive (residual double bonding amount 1% or less, ACN content 20-30%), and a solvent (NMP) were added to a homo mixer (300 mL) and mixed at 3000 rpm for 90 minutes to prepare a non-cathode protective layer slurry composition. The prepared slurry was coated onto a SUS foil and dried to manufacture an electrode. Comparative Example 1 A non-cathode protective layer slurry and an electrode were prepared in the same manner as in Example 1, except that no additives were added and the binder content was adjusted to the same amount as the composition excluded. Experimental Example Electrode surface SEM The surfaces of the electrodes of Example 1 and Comparative Example 1 were measured using 200x magnification SEM images. As a result, as shown in Fig. 1, it was confirmed that Example 1 had good coating properties with improved physical properties of the non-cathode slurry, whereas Comparative Example 1 in Fig. 2 showed that cracks occurred on the electrode surface. Viscosity measurement For the slurries of Example 1 and Comparative Example 1, a rheometer (Anton Paar, MCR302) was used to measure the viscosity at a temperature of 23°C and a shear rate of 0.01 to 1000 1/s, and the results are shown in Table 1 and Figure 3. Adhesion strength measurement The electrodes of Example 1 and Comparative Example 1 were punched to a size of 20 mm × 150 mm and fixed to the center of a 25 mm × 75 mm slide glass using tape. Then, the 90° peel strength was measured while peeling off the current collector using a UTM, and the results are shown in Table 1 and Figure 4. viscosity (cP @ 2.5 1/s)Adhesion (gf/20 mm)Example 1457428.8Comparative Example 19400416.1 Generally, when the viscosity value at a shear rate of 2.5 1/s is 10,000 cP or less, the coating processability is excellent, and as the electrode adhesion strength increases, the electrode processability improves and the battery defect rate decreases. Referring to Table 1 and Figures 3-4, it can be confirmed that in the case of Example 1, the viscosity at a shear rate of 2.5 1/s decreased