# US 12,119,476 B2 · Secondary battery electrode including mixture layer of double layer structure containing active materials of different particle diameters, and method for manufacturing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,476 B2 - Document ID: US12119476B2 - Status: Granted - Kind: B2 - Application number: 17/278,233 - Filed: 2020-07-29 - Published: 2022-09-29 - Granted: 2024-10-15 - Earliest claimed: 2019-11-14 - Assignees: LG Energy Solution, Ltd. - Applicants: LG Chem, Ltd. - Inventors: Dae Jin Lee; Dong Hwi Kim; Jin Tae Hwang; Hyeong Il Kim; Seul Ki Chae; Wang Mo Jung; Dong Hun Lee - Web page: https://patentgrep.com/patent/US12119476B2 ## CPC - H01M 4/0404: {by coating on electrode collectors} - H01M 4/0435: {Rolling or calendering} - H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - H01M 4/1391: of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy - H01M 4/623: {fluorinated polymers} - H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)} - H01M 4/664: {Ceramic materials} - H01M 4/667: {in the form of layers, e.g. coatings} - H01M 10/052: Li-accumulators - H01M 2004/028: {Positive electrodes} - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The present invention relates to an electrode of a double-layer structure including a different type of particulate active material having a different average particle diameter, and a secondary battery including the same, and according to the present invention, the mechanical strength and stability of the electrode increases, and the secondary battery to which they are applied exhibits excellent discharge capacity. ## Claims ### Claim 1 An electrode for a secondary battery, comprising: a current collector layer; a lower mixture layer disposed on one or both surfaces of the current collector layer and including a first active material; and an upper mixture layer disposed on a surface of the lower mixture layer which is opposite to a surface of the lower mixture layer that comes in contact with the current collector layer, and including a second active material, wherein the second active material includes particles having diameters within a first particle diameter range and particles having diameters within a third particle diameter range, wherein the first active material includes particles having diameters within a second particle diameter range and particles having diameters within the third particle diameter range, wherein following conditions 1 and 2 are satisfied: D1>D2>D3 [Condition 1] D1−D3≥5 (μm) [Condition 2] wherein in the conditions 1 and 2, D1 is an average particle diameter of the particles having diameters within the first particle diameter range, D2 is an average particle diameter of the particles having diameters within the second particle diameter range, and D3 is an average particle diameter of the particles having diameters within the third particle diameter range, and wherein in the upper mixture layer, a content ratio of the particles having diameters within the first particle diameter range to the particles having diameters within the third particle diameter range is in a range of 6:4 to 9:1 by weight, and a concentration of the particles having diameters within the first particle diameter range is higher in the upper mixture layer than in the lower mixture layer. ### Claim 2 (depends on 1) The electrode of claim 1, wherein the average particle diameter of the particles having diameters within the first particle diameter range is in a range of 14 to 20 μm, wherein the average particle diameter of the particles having diameters within the second particle diameter range is in a range of 10 to 13 μm, and wherein the average particle diameter of the active material particles having diameters within the third particle diameter range is in a range of 3 to 9 μm. ### Claim 3 (depends on 1) The electrode of claim 1, wherein in the lower mixture layer, a content ratio of the particles having diameters within the second particle size range to the particles having diameters within the third particle size range is in a range of 6:4 to 9:1 by weight. ### Claim 4 (depends on 1) The electrode of claim 1, further comprising: a buffer layer interposed between the current collector layer and the lower mixture layer, wherein the buffer layer contains a niobium-containing oxide. ### Claim 5 (depends on 4) The electrode of claim 4, wherein the niobium-containing oxide contained in the buffer layer includes at least one of Li3NbO4, LiNbO, or Nb2O5. ### Claim 6 (depends on 4) The electrode of claim 4, wherein an average thickness of the buffer layer is in a range of 1 to 10 μm. ### Claim 7 (depends on 1) The electrode of claim 1, wherein the current collector layer comprises a metal foil having an average thickness of 10 to 20 μm. ### Claim 8 (depends on 1) The electrode of claim 1, wherein the electrode is for a lithium secondary battery. ### Claim 9 A method of manufacturing an electrode for a secondary battery, comprising: forming a lower mixture layer on one or both sides of a current collector layer, and including active material containing particles having diameters within a second particle diameter range and particles having diameters within a third particle diameter range; forming an upper mixture layer on the lower mixture layer, and including active material containing particles having diameter within a first particle diameter range and particles having diameter within the third particle diameter range; and rolling the electrode on which the lower and upper mixture layers are applied, wherein following conditions 1 and 2 are satisfied: D1>D2>D3 [Condition 1] D1−D3≥5 (μm) [Condition 2] wherein in the conditions 1 and 2, D1 is an average particle diameter of the particles having diameters within the first particle diameter range, D2 is an average particle diameter of the particles having diameters within the second particle diameter range, and D3 is an average particle diameter of the particles having diameters within the third particle diameter range, wherein in the upper mixture layer, a content ratio of the particles having diameters within the first particle diameter range to the particles having diameters within the third particle diameter range is in a range of 6:4 to 9:1 by weight, and a concentration of the particles having diameters within the first particle diameter range is higher in the upper mixture layer than in the lower mixture layer. ### Claim 10 (depends on 9) The method of claim 9, wherein a porosity of the first and second mixture layers after the rolling is in a range of 20 to 30% (v/v). ### Claim 11 (depends on 9) The method of claim 9, wherein a thickness ratio of the lower mixture layer to the upper mixture layer is in a range of 1:9 to 4:6. ### Claim 12 (depends on 9) The method of claim 9, wherein the current collector layer comprises a metal foil having an average thickness of 10 to 20 μm. ### Claim 13 (depends on 9) The method of claim 9, further comprising: forming a buffer layer containing an oxide containing niobium on the current collector before the lower mixture layer is formed. ### Claim 14 (depends on 1) The electrode of claim 1, wherein in the upper mixture layer, the content ratio of the particles having diameters within the first particle diameter range to the particles having diameters within the third particle diameter range is in a range of 7:3 to 8:2 by weight. ### Claim 15 (depends on 1) The electrode of claim 1, wherein in the lower mixture layer, a content ratio of the particles having diameters within the second particle size range to the particles having diameters within the third particle size range is in a range of 7:3 to 8:2 by weight. ### Claim 16 (depends on 9) The method of claim 9, wherein in the upper mixture layer, the content ratio of the particles having diameters within the first particle diameter range to the particles having diameters within the third particle diameter range is in a range of 7:3 to 8:2 by weight. ### Claim 17 (depends on 9) The method of claim 9, wherein in the lower mixture layer, a content ratio of the particles having diameters within the second particle size range to the particles having diameters within the third particle size range is in a range of 6:4 to 9:1 by weight. ### Claim 18 (depends on 9) The method of claim 9, wherein in the lower mixture layer, a content ratio of the particles having diameters within the second particle size range to the particles having diameters within the third particle size range is in a range of 7:3 to 8:2 by weight. ### Claim 19 An electrode for a secondary battery, comprising: a current collector layer; a lower mixture layer disposed on one or both surfaces of the current collector layer and including a first active material; and an upper mixture layer disposed on a surface of the lower mixture layer which is opposite to a surface of the lower mixture layer that comes in contact with the current collector layer, and including a second active material; and a buffer layer interposed between the current collector layer and the lower mixture layer, wherein the buffer layer contains a niobium-containing oxide, wherein the second active material includes particles having diameters within a first particle diameter range and particles having diameters within a third particle diameter range, wherein the first active material includes particles having diameters within a second particle diameter range and particles having diameters within the third particle diameter range, wherein following conditions 1 and 2 are satisfied: D1>D2>D3 [Condition 1] D1−D3≥5 (μm) [Condition 2] wherein in the conditions 1 and 2, D1 is an average particle diameter of the particles having diameters within the first particle diameter range, D2 is an average particle diameter of the particles having diameters within the second particle diameter range, and D3 is an average particle diameter of the active material particles having diameters within the third particle diameter range, and wherein in the upper mixture layer, a content ratio of the particles having diameters within the first particle diameter range to the particles having diameters within the third particle diameter range is in a range of 6:4 to 9:1 by weight.