KR-20260062891-A - POSITIVE ELECTRODE ACTIVE MATERIAL FOR ALL-SOLID-STATE BATTERY, POSITIVE ELECTRODE AND ALL-SOLID-STATE BATTERY COMPRISING SAME

Abstract

The present invention relates to a positive electrode active material for an all-solid-state battery, a positive electrode for an all-solid-state battery including the same, and an all-solid-state battery. More specifically, due to a coating layer comprising an oxide sulfide-based solid electrolyte formed on the positive electrode active material, side reactions between the positive electrode active material and solid electrolyte particles within the positive electrode are prevented, thereby enabling an effect of improving the output characteristics and lifespan characteristics of the all-solid-state battery.

Inventors

• 강소라
• 심성근

Assignees

• 주식회사 엘지에너지솔루션

Dates

Publication Date

20260507

Application Date

20251029

Priority Date

20241029

Claims (13)

1. A positive electrode active material for an all-solid-state battery comprising a core particle; and a coating layer located on the surface of the core particle, A positive electrode active material for an all-solid-state battery, wherein the above coating layer comprises an oxysulfide-based solid electrolyte.
2. In paragraph 1, The above oxosulfide-based solid electrolyte is a positive electrode active material for an all-solid-state battery, comprising oxygen (O) and sulfur (S) in a weight ratio of 0.02:1 to 0.1:1.
3. In paragraph 1, A positive electrode active material for an all-solid-state battery, wherein the above oxysulfide-based solid electrolyte is represented by the following chemical formula 1: <Chemical Formula 1> Li (7-x) PS (6-xy) O y Ha x In the above chemical formula 1, Ha is Cl, Br, or I, 0 < x < 1.6, and 0.1 < y < 1.
4. In paragraph 1, The above oxalide-based solid electrolyte is a positive electrode active material for an all-solid-state battery having an azirodite-type crystal structure.
5. In paragraph 1, A positive electrode active material for an all-solid-state battery, wherein the above oxosulfide-based solid electrolyte is included in an amount of 0.1% to 2% by weight based on the total weight of the positive electrode active material.
6. In paragraph 1, A positive electrode active material for an all-solid-state battery, wherein the coating layer further comprises a lithium metal oxide.
7. In paragraph 6, A positive electrode active material for an all-solid-state battery, wherein the coating layer comprises a first coating layer comprising a lithium metal oxide and a second coating layer comprising an oxalate-sulfide-based solid electrolyte.
8. In paragraph 1, The above-mentioned core particle is a multi-particle form formed by the aggregation of multiple single particles of the positive active material, a positive active material for an all-solid-state battery.
9. In paragraph 8, A positive electrode active material for an all-solid-state battery, wherein the above plurality of single particles are aggregated with orientation.
10. In paragraph 8, A positive electrode active material for an all-solid-state battery, wherein the aspect ratio of the above single particles is 0.05:1 to 0.5:1.
11. In paragraph 1, A positive electrode active material for an all-solid-state battery, wherein the particle size (D50) of the positive electrode active material is 3.3 μm to 6.3 μm.
12. A positive electrode for an all-solid-state battery comprising a positive electrode active material, a solid electrolyte particle, a binder, and a conductive material according to any one of claims 1 to 11.
13. All-solid-state battery comprising the positive electrode of Clause 12.

Description

Positive ELECTRODE ACTIVE MATERIAL FOR ALL-SOLID-STATE BATTERY, POSITIVE ELECTRODE AND ALL-SOLID-STATE BATTERY COMPRISING SAME The present invention relates to a positive electrode active material for an all-solid-state battery, a positive electrode for an all-solid-state battery including the same, and an all-solid-state battery. Various batteries capable of overcoming the current limitations of lithium-ion batteries are being researched in terms of capacity, safety, output, scaling up, and miniaturization. Continuous research is being conducted in academia and industry on representative technologies, such as metal-air batteries, which have a much larger theoretical capacity compared to lithium-ion batteries; all-solid-state batteries, which pose no risk of explosion in terms of safety; supercapacitors in terms of output; NaS batteries or RFBs (redox flow batteries) in terms of scale; and thin-film batteries in terms of miniaturization. All-solid-state batteries refer to batteries in which the liquid electrolyte used in conventional lithium-ion batteries is replaced with a solid electrolyte. Since they do not use flammable solvents within the battery, there is absolutely no ignition or explosion caused by decomposition reactions of conventional electrolytes, thereby significantly improving safety. Furthermore, among all-solid-state batteries, technological development is continuing for sulfide-based all-solid-state batteries, which possess high ionic conductivity of the solid electrolyte and can theoretically achieve a high energy density of over 900 Wh/L. In this context, a sulfide-based all-solid-state battery refers to an all-solid-state battery containing a sulfide-based solid electrolyte. In all-solid-state battery systems, lithium ion conduction does not occur due to the liquid electrolyte contained in conventional lithium-ion batteries (LIBs). Therefore, when manufacturing a cathode for a sulfide-based all-solid-state battery, small-diameter sulfide-based solid electrolyte particles must be added to the cathode to increase the contact interface between the cathode active material and the sulfide-based solid electrolyte particles, thereby increasing the ionic conductivity of lithium ions. However, a chemical reaction occurs at the interface between the positive active material and the sulfide-based solid electrolyte particles merely through physical contact due to their level difference. A resistive material may be formed by this chemical reaction. Due to this resistive material, the initial capacity and long-life characteristics of the all-solid-state battery may be degraded during operation. In addition, during charging and discharging, an electrochemical reaction occurs at the interface between the positive electrode active material and the sulfide-based solid electrolyte particles, which can not only consume active lithium but also increase resistance. Therefore, there is a need for the development of technology that can improve the output and lifespan characteristics of all-solid-state batteries by preventing side reactions at the interface between the positive electrode active material and sulfide-based solid electrolyte particles. FIG. 1 is a schematic diagram of a positive electrode active material for an all-solid-state battery according to one embodiment of the present invention. Hereinafter, the present invention will be described in more detail to aid in understanding the invention. Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. As used in this specification, the term “anode active material” refers to an active material that generates electrical energy at the anode and serves to provide lithium ions to the cathode during charging. In other words, while the “anode active material” generally refers to a commonly used anode active material, in this specification, the anode active material has a structure comprising a core particle and a coating layer formed on the surface of the core particle; therefore, the active material contained within the core particle is referred to as an anode active material to distinguish it from the anode active material. Cathode active material for all-solid-state batteries The present invention relates to a positive electrode active material for an all-solid-state battery. A positive electrode active material for an all-solid-state battery according to the present invention comprises a core particle; and a coating layer located on the surface of the core particle, wherein the coating layer comprises an oxysulfide-based solid electrolyte. In one embodiment, the core particle may include a positively active material. In one embodiment, a coating lay