JP-7856399-B2 - Method for manufacturing a positive electrode material and a positive electrode containing the positive electrode material manufactured thereby.

Inventors

• ユン、ヨンソプ
• ミン、ホンソク
• 土屋 元
• 佐々木 勇樹

Assignees

• 現代自動車株式会社
• 起亞株式会社

Dates

Publication Date

20260511

Application Date

20210928

Priority Date

20201005

Claims (14)

1. A step of preparing a coating solution by adding coating material raw materials containing lithium (Li) and niobium (Nb) to a solvent containing water ( H₂O ), mixing and dissolving them, The steps include: spraying the coating liquid onto the surface of lithium oxide particles to form a coating layer; The step includes heat-treating the coating layer, Further additives are added to the aforementioned solvent. The aforementioned auxiliary agent contains a surfactant, A method for producing a cathode material, characterized in that the surfactant comprises at least one of an anionic surfactant and a nonionic surfactant.
2. The method for producing a positive electrode material according to claim 1, wherein the auxiliary agent is contained in an amount of 0.001 to 0.30 parts by weight based on 100 parts by weight of the solvent.
3. The coating solution contains lithium at a concentration of 1 M to 10 M. A method for producing a cathode material according to claim 1, comprising niobium at a concentration of 1 M to 10 M.
4. The method for producing a positive electrode material according to claim 1, wherein the molar ratio of lithium and niobium contained in the coating liquid is Li/Nb = 0.9 to 1.2.
5. The steps for manufacturing the coating solution include an input step in which coating material raw materials are added to a solvent containing water, A dissolution step in which coating material raw materials are dissolved in the solvent, A method for producing a cathode material according to claim 1, comprising a neutralization step of adding a hydroxide to the solvent and causing a neutralization reaction.
6. In the input step, hydrogen peroxide ( H₂O₂ ) is added along with the coating material raw materials , creating a weakly acidic environment. In the dissolution step, ammonia ( NH3 ) is added to the solvent to create a strongly alkaline environment. The method for producing a cathode material according to claim 5, wherein the coating material raw material dissolves in the solvent in the strongly alkaline environment.
7. The coating material raw materials introduced change in solubility depending on the environment of the hydrogen ion concentration of the solvent. The method for producing a cathode material according to claim 5, wherein the hydrogen ion concentration of the solvent is adjusted using the hydrogen peroxide, ammonia, and hydroxide introduced.
8. The hydrogen ion concentration in the input step is pH 3 or less. The hydrogen ion concentration during the dissolution step is pH 3 to pH 12. The method for producing a cathode material according to claim 5, wherein the hydrogen ion concentration in the neutralization step is pH 6 to pH 8.
9. In the step of forming a coating layer, the coating liquid is sprayed onto the surface of lithium oxide particles by a spray coating method and adheres to them, as described in claim 1.
10. The method for manufacturing a cathode material according to claim 1, wherein the heat treatment step is performed at a temperature of 300°C to 450°C.
11. A step of preparing a positive electrode material by the manufacturing method described in claim 1, A method for manufacturing a positive electrode, comprising the steps of: manufacturing a positive electrode comprising the positive electrode material, lithium oxide-based particles having a coating layer formed on their surface, and at least one additive of a solid electrolyte, a conductive material, and a binder.
12. The method for manufacturing a positive electrode according to claim 11, wherein the thickness of the coating layer contained in the positive electrode material is 3 nm to 50 nm.
13. The method for manufacturing a positive electrode according to claim 11, wherein the positive electrode material comprises lithium and at least two elements: nickel (Ni), cobalt (Co), manganese (Mn), and aluminum (Al).
14. A step of preparing a positive electrode by the method of claim 11, A method for manufacturing an all-solid-state battery, comprising the steps of manufacturing an all-solid-state battery comprising a positive electrode, a negative electrode containing carbon, and a solid electrolyte interposed between the positive electrode and the negative electrode.

Description

This invention relates to a method for manufacturing a positive electrode material and a positive electrode containing the positive electrode material manufactured thereby. More specifically, this invention is characterized by providing a manufacturing method for producing a positive electrode for an all-solid-state battery that improves the efficiency of the process while improving the positive electrode performance, with the practical application of all-solid-state batteries in mind. The cathode material for all-solid-state batteries is used after undergoing a surface modification process in which a lithium ion conductor such as LiNbO3 or Li4Ti5O12 is uniformly coated to a thickness of several nanometers on the surface of Li( Ni /Co/Mn) O2 lithium oxide powder with a layered crystalline structure. In particular, the LiNbO3 surface coating layer is effective in significantly reducing the resistance of lithium ion movement through the "space charge layer mechanism," thereby improving battery capacity and output performance, and in suppressing chemical reactions between dissimilar materials between the oxide (cathode) and sulfide (electrolyte) within the cathode composite layer, thereby maintaining lifespan (K. Takada, "LiNbO3 - coated LiCoO2 as cathode material for all solid-state lithium secondary batteries"). However, current positive electrode surface coating technology has two main problems: the interfacial resistance between the positive electrode and electrolyte accounts for more than 70% of the total resistance component of the all-solid-state battery cell, and the current cost of "positive electrode surface coating" (coating raw material cost / coating process cost) is limited to 20-40% of the total price of all-solid-state batteries. This diagram briefly illustrates the process for manufacturing the cathode material of the present invention.This figure shows a flowchart relating to the method for manufacturing the cathode material of the present invention.This figure shows the surface of the cathode material manufactured in Example 1, observed by Auger electron spectroscopy (AES). The above-described objectives, other objectives, features, and advantages of the present invention will be readily apparent through the following preferred embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in multiple forms. Rather, the embodiments presented herein are provided to ensure that the disclosed content is thorough and complete, and that the idea of the present invention is fully conveyed to a person of the ordinary skill. In describing each drawing, similar reference numerals were used for similar components. In the attached drawings, the dimensions of the structures are enlarged for clarity of the invention. Terms such as "first," "second," etc., are used to describe various components, but the components should not be limited by such terms. These terms are used solely to distinguish one component from another. For example, without departing the scope of the invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “includes” or “having” are intended to specify the presence of features, figures, stages, actions, components, parts, or combinations thereof described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, actions, components, parts, or combinations thereof. Furthermore, when a layer, film, region, plate, or similar part is described as being “on top” of another part, this includes not only cases where it is “directly on top” of the other part, but also cases where there are other parts in between. Conversely, when a layer, film, region, plate, or similar part is described as being “below” another part, this includes not only cases where it is “directly below” the other part, but also cases where there are other parts in between. Unless otherwise explicitly stated, all numbers, values, and/or expressions used herein to describe the quantities of components, reaction conditions, polymer compositions, and formulations should be understood to be approximate, as such numbers are approximations that reflect the various uncertainties of measurement that arise in obtaining these values among inherently different numbers. Furthermore, where numerical ranges are disclosed herein, such ranges are continuous and, unless otherwise noted, include all values from the minimum to the maximum value within such range. Additionally, where such ranges refer to integers, unless otherwise noted, they include all integers from the minimum to the maximum value within such range. In this specification,