Three-dimensional batteries using constraint adhesive

Patent metadata

Field	Value
Publication number	US-12087913-B2
Application number	US-202217974923-A
Country	US
Kind code	B2
Filing date	Oct 27, 2022
Priority date	Mar 31, 2021
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

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.

First claim

What is claimed is:

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 a longitudinal direction, and a lateral surface surrounding an electrode assembly longitudinal axis A EA 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 W EA measured in the longitudinal direction, a maximum length L EA bounded by the lateral surface and measured in a transverse direction, and a maximum height H EA bounded by the lateral surface and measured in a 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, wherein:
the adhesive comprises a plurality of strips;
a first strip of the plurality of strips partially covers the upper inner surface of the first connecting member;
a second strip of the plurality of strips partially covers the lower inner surface of the second connecting member; and
the adhesive has (i) a melting temperature in a 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.

2. A secondary battery comprising the electrode assembly of claim 1 .

3. The electrode assembly according to claim 1 , wherein the melting temperature of the hot-melt adhesive is in a range of 77° C. to 100° C.

4. 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.

5. 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.

6. 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.

7. The electrode assembly of claim 1 , wherein the hot-melt adhesive comprises a mixture of EAA and EMAA copolymers.

8. The electrode assembly of claim 1 , wherein the hot-melt adhesive has a film shape with a thickness in a range of about 10 to about 100 micrometers and a predetermined pattern geometry.

9. 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 upper and lower 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.

10. The electrode assembly of claim 9 , wherein both first and second connecting members comprise apertures through the vertical thicknesses thereof.

11. The electrode assembly according to claim 9 , 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.

12. The electrode assembly of claim 1 , where a surface area of the first and second longitudinal end surfaces is less than 33% of the surface area of the electrode assembly.

13. The electrode assembly of claim 1 , wherein a length LE of each member of the electrode structure population and a length L CE of each member of the counter-electrode structure population are measured in the transverse direction of their central longitudinal axis A E and A CE , a width W E of each member of the electrode structure population and a width W CE of each member of the counter-electrode structure population are measured in the longitudinal direction, and a height H E of each member the electrode structure population and a height H CE of each member of the counter-electrode structure population is measured in the vertical direction that is perpendicular to the central longitudinal axis A E or A CE of each such member and to the longitudinal direction, a ratio of L E to each of W E and H E of each member of the electrode structure population being at least 5:1, respectively, a ratio of H E to W E for each member of the electrode structure population being between 0.4:1 and 1000:1, and a ratio of L CE to each of W CE and H CE of each member of the counter-electrode structure population being at least 5:1, respectively, a ratio of H CE to W CE for each member of the counter-electrode structure population being between 0.4:1 and 1000:1.

14. The electrode assembly of claim 1 , wherein a ratio of each of L EA and W EA to H EA is at least 2:1.

15. 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.

16. 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 a 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 a

Assignees

• Enovix Corp

Inventors

• Rosen Robert Keith
• Valdes Bruno A
• Ramasubramanian Murali
• Busacca Robert S

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/0485

  Casting · CPC title

• H01M50/46

  Separators, membranes or diaphragms characterised by their combination with electrodes · CPC title

• H01M50/403

  Manufacturing processes of separators, membranes or diaphragms · CPC title

• H01M50/474

  characterised by their position inside the cells · CPC title