# US 2023/0057582 A1 · Three-dimensional batteries using constraint adhesive > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0057582 A1 - Document ID: US20230057582A1 - Status: Published application - Kind: A1 - Application number: 17/974,923 - Filed: 2022-10-27 - Published: 2023-02-23 - Earliest claimed: 2021-03-31 - Assignees: Enovix Operations Inc. - Applicants: Enovix Operations Inc. - Inventors: Robert Keith ROSEN; Bruno A. VALDES; Murali RAMASUBRAMANIAN; Robert S. BUSACCA - Web page: https://patentgrep.com/patent/US20230057582A1 ## CPC - H01M 10/0585: of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators - H01M 50/209: adapted for prismatic or rectangular cells (H01M50/216 takes precedence) - H01M 4/0485: {Casting} - H01M 10/0413: {Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes} - H01M 10/0468: {Compression means for stacks of electrodes and separators} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 50/403: Manufacturing processes of separators, membranes or diaphragms - H01M 50/46: Separators, membranes or diaphragms characterised by their combination with electrodes - H01M 50/474: characterised by their position inside the cells - H01M 50/505: comprising a single busbar - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - 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 - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract An electrode assembly for a secondary battery and method are provided. The electrode assembly comprises a population of unit cells and a constraint system. The electrode assembly comprises a population of electrode structures, a population of counter-electrode structures, and an electrically insulating separator material. The constraint system comprises (i) first and second primary growth constraints separated in the longitudinal direction, (ii) first and second connecting members separated in the vertical direction that connect the first and second primary growth constraints and a subset of the members of the electrode or counter-electrode population. The first and second connecting members are adhered to the subset by an electrically-insulating, thermoplastic, hot-melt adhesive having (i) a melting temperature in the range of 75° C. to 130° C., and (ii) a melt index value as measured according to ASTM D1238 in a range of at least 20 to no more than 350. ## Claims ### Claim 1 An electrode assembly for a secondary battery comprising a population of unit cells, a constraint system, and an adhesive, wherein the electrode assembly has mutually perpendicular longitudinal, transverse, and vertical axes, a first longitudinal end surface and a second longitudinal end surface separated from each other in the longitudinal direction, and a lateral surface surrounding an electrode assembly longitudinal axis AEA and connecting the first and second longitudinal end surfaces, the lateral surface having opposing first and second regions on opposite sides of the longitudinal axis and separated in a first direction that is orthogonal to the longitudinal axis, the electrode assembly having a maximum width WEA measured in the longitudinal direction, a maximum length LEA bounded by the lateral surface and measured in the transverse direction, and a maximum height HEA bounded by the lateral surface and measured in the vertical direction, the electrode assembly further comprises a population of electrode structures, a population of counter-electrode structures, and an electrically insulating separator material electrically separating members of the electrode and counter-electrode populations, the members of the electrode and counter-electrode structure populations having opposing upper and lower end surfaces separated in the vertical direction, and wherein each member of the unit cell population comprises an electrode structure, a counter-electrode structure, and an electrically insulating separator between the electrode and counter-electrode structures, the constraint system comprises (i) first and second primary growth constraints separated in the longitudinal direction, (ii) first and second connecting members separated in the vertical direction that connect the first and second primary growth constraints, and a subset of the members of the electrode or counter-electrode population wherein the first and second connecting members have opposing upper and lower inner surfaces to which the upper and lower end surfaces of the subset are adhered, respectively, by an electrically-insulating, thermoplastic, hot-melt adhesive having (i) a melting temperature in the range of 75° C. to 130° C., and (ii) a melt index value as measured according to ASTM D1238 in a range of at least 20 to no more than 350. ### Claim 2 (depends on 1) A secondary battery comprising the electrode assembly of claim 1. ### Claim 3 (depends on 1) The electrode assembly according to claim 1, wherein the melting temperature of the hot-melt adhesive is in the range of 77° C. to 100° C. ### Claim 4 (depends on 1) The electrode assembly according to claim 1, wherein the melt index value as measured according to ASTM D1238 is in a range of at least 70 to no more than 350. ### Claim 5 (depends on 1) The electrode assembly of claim 1, wherein the members of the population of electrode structures comprise electrode current collectors having opposing upper and lower end surfaces in the vertical direction, and members of the population of counter-electrode structures comprise counter-electrode current collectors having opposing upper and lower end surfaces in the vertical direction, and wherein the first and second connecting members are adhered to vertical end surfaces of the electrode or counter-electrode current collectors of the subset of members of the electrode or counter-electrode population. ### Claim 6 (depends on 1) The electrode assembly of claim 1, wherein the hot-melt adhesive comprises a material selected from EAA (ethylene-co-acrylic acid), EMAA (ethylene-co-methacrylic acid), functionalized polyethylenes and polypropylenes, and combinations thereof. ### Claim 7 (depends on 1) The electrode assembly of claim 1, wherein the hot-melt adhesive comprises a mixture of EAA and EMAA copolymers. ### Claim 8 (depends on 1) The electrode assembly of claim 1, wherein the hot-melt adhesive does not significantly react or lose adhesion at temperatures at or above about 80° C. ### Claim 9 (depends on 1) The electrode assembly of claim 1, wherein the hot-melt adhesive does not significantly lose adhesion over 1000 consecutive cycles of the secondary battery. ### Claim 10 (depends on 1) The electrode assembly of claim 1, wherein the hot-melt adhesive has a film shape with a thickness in the range of about 10 to about 100 micrometers and a predetermined pattern geometry. ### Claim 11 (depends on 1) The electrode assembly of claim 1, wherein the first or second connecting members comprise apertures formed through a vertical thickness of the respective members, and wherein the first or second connecting members comprise bonding regions of the inner surfaces that are adjacent the apertures, where the hot melt adhesive is provided for adhering to the subset of the members of the electrode or counter-electrode population. ### Claim 12 (depends on 11) The electrode assembly of claim 11, wherein both first and second connecting members comprise apertures through the vertical thicknesses thereof. ### Claim 13 (depends on 11) The electrode assembly according to claim 11, wherein the apertures comprise a plurality of slots extending in the longitudinal direction, and wherein the bonding regions to adhere to the subset are located on inner surface regions in between the slots of the first or second connecting members. ### Claim 14 (depends on 1) The electrode assembly of claim 1, where the surface area of the first and second longitudinal end surfaces is less than 33% of the surface area of the electrode assembly. ### Claim 15 (depends on 1) The electrode assembly of claim 1, wherein a length LE of each member of the electrode structure population and a length LCE of each member of the counter-electrode structure population are measured in the transverse direction of their central longitudinal axis AE and ACE, a width WE of each member of the electrode structure population and a width WCE of each member of the counter-electrode structure population are measured in the longitudinal direction, and a height HE of each member the electrode structure population and a height HCE of each member of the counter-electrode structure population is measured in the vertical direction that is perpendicular to the central longitudinal axis AE or ACE of each such member and to the longitudinal direction, the ratio of LE to each of WE and HE of each member of the electrode structure population being at least 5:1, respectively, the ratio of HE to WE for each member of the electrode structure population being between 0.4:1 and 1000:1, and the ratio of LCE to each of WCE and HCE of each member of the counter-electrode structure population being at least 5:1, respectively, the ratio of HCE to WCE for each member of the counter-electrode structure population being between 0.4:1 and 1000:1. ### Claim 16 (depends on 1) The electrode assembly of claim 1, wherein the ratio of each of LEA and WEA, to HEA, is at least 2:1. ### Claim 17 (depends on 1) The electrode assembly of claim 1, wherein a projection of members of the electrode structure population and the counter electrode structure populations onto the first longitudinal surface circumscribes a first projected area and a projection of the members of the electrode structure population and the counter electrode structure population onto the second longitudinal surface circumscribes a second projected area, and wherein the first and second primary growth constraints comprises first and second compression members that overlie the first and second projected areas. ### Claim 18 (depends on 1) The electrode assembly of claim 1, wherein the first and second primary growth constraints maintain a pressure on the electrode assembly in the longitudinal direction that exceeds the pressure maintained on the electrode assembly in the each of the two directions that are mutually perpendicular and perpendicular to the longitudinal direction, exceeds the pressure maintained on the electrode assembly in the each of the two directions that are mutually perpendicular and perpendicular to the longitudinal direction. ### Claim 19 (depends on 1) The electrode assembly of claim 1, wherein the first and second primary growth constraints maintain a pressure on the electrode assembly in the longitudinal direction that exceeds the pressure maintained on the electrode assembly in the each of the two directions that are mutually perpendicular and perpendicular to the longitudinal direction by a factor of at least 3, at least 4, or at least 5. ### Claim 20 (depends on 1) The electrode assembly of claim 1, wherein the primary growth constraint system restrains growth of the electrode assembly in the longitudinal direction such that any increase in the Feret diameter of the electrode assembly in the longitudinal direction over 20 consecutive cycles is less than 20%. ### Claim 21 (depends on 1) The electrode assembly of claim 1, wherein the primary growth constraint system restrains growth of the electrode assembly in the longitudinal direction such that any increase in the Feret diameter of the electrode assembly in the longitudinal direction over 10 consecutive cycles is less than 10% ### Claim 22 (depends on 1) The electrode assembly of claim 1, wherein the primary growth constraint system restrains growth of the electrode assembly in the longitudinal direction such that any increase in the Feret diameter of the electrode assembly in the longitudinal direction over 5 consecutive cycles is less than 10%. ### Claim 23 (depends on 1) The electrode assembly of claim 1, wherein the primary growth constraint system restrains growth of the electrode assembly in the longitudinal direction such that any increase in the Feret diameter of the electrode assembly in the longitudinal direction is less than 1% per cycle. ### Claim 24 (depends on 1) The electrode assembly of claim 1, wherein the first and second connecting member comprise a secondary growth constraint system that restrains growth of the electrode assembly in the vertical direction, such that any increase in the Feret diameter of the electrode assembly in the vertical direction over 20 consecutive cycles is less than 20% ### Claim 25 (depends on 1) The electrode assembly of claim 1, wherein the first and second connecting member comprise a secondary growth constraint system that restrains growth of the electrode assembly in the vertical direction, such that any increase in the Feret diameter of the electrode assembly in the vertical direction over 10 consecutive cycles is less than 10% ### Claim 26 (depends on 1) The electrode assembly of claim 1, wherein the first and second connecting member comprise a secondary growth constraint system that restrains growth of the electrode assembly in the vertical direction, such that any increase in the Feret diameter of the electrode assembly in the vertical direction over 5 consecutive cycles is less than 10%. ### Claim 27 (depends on 1) The electrode assembly of claim 1, wherein the first and second connecting member comprise a secondary growth constraint system that restrains growth of the electrode assembly in the vertical direction, such that any increase in the Feret diameter of the electrode assembly in the vertical direction is less than 1% per cycle. ### Claim at position 28 -30. (canceled)