Longitudinal constraints for energy storage devices
A energy storage device for cycling between a charged state and a discharged state, the energy storage device including an enclosure, an electrode assembly and a non-aqueous liquid electrolyte within the enclosure, and a constraint that maintains a pressure on the electrode assembly as the energy storage device is cycled between the charged and the discharged states.
1. A structure for use in an energy storage device, the structure comprising an electrode assembly and a constraint that maintains a pressure on the electrode assembly as the energy storage device is cycled between charged and discharged states,
the electrode assembly comprising a population of electrode structures, a population of counter-electrode structures and an electrically insulating separator material between members of the electrode and counter-electrode populations, wherein
the electrode assembly has opposing first and second longitudinal end surfaces separated along a longitudinal axis, and a lateral surface surrounding the longitudinal axis and connecting the first and second longitudinal end surfaces, the surface area of the first and second longitudinal end surfaces being less than 33% of the surface area of the electrode assembly,
members of the electrode population and members of the counter-electrode population are arranged in an alternating sequence in a stacking direction that parallels the longitudinal axis within the electrode assembly, and wherein each member of the electrode population has a bottom, a top, a length L E , a width W E , a height H E , and a central longitudinal axis A E extending from the bottom to the top of each such member and in a direction that is generally transverse to the stacking direction, the length L E of each member of the electrode population being measured in the direction of its central longitudinal axis A E , the width W E of each member of the electrode population being measured in the stacking direction, and the height H E of each member of the electrode population being measured in a direction that is perpendicular to the central longitudinal axis A E of each such member and to the stacking direction, the ratio of L E to each of W E and H E of each member of the electrode population being at least 5:1, respectively, the ratio of H E to W E for each member of the electrode population being between 0.4:1 and 1000:1, respectively, and
the constraint comprises first and second compression members that overlie first and second projected areas, respectively, wherein the first and second projected areas overlie the first and second longitudinal end surfaces, and at least one compression member that is internal to the longitudinal end surfaces, the compression members being connected by at least one tension member that overlies the lateral surface of the electrode assembly and pulls the first and second compression members toward each other.
2. The structure of claim 1 wherein the surface area of the first and second longitudinal end surfaces is less than 25% of the surface area of the electrode assembly.
3. The structure of claim 1 wherein the surface area of the first and second longitudinal end surfaces is less than 15% of the surface area of the electrode assembly.
4. The structure of claim 1 wherein each of the first and second longitudinal end surfaces are under a compressive load of at least 689 kPa (100 psi).
5. The structure of claim 1 wherein each of the first and second longitudinal end surfaces are under a compressive load of at least 3447 kPa (500 psi).
6. The structure of claim 1 wherein each of the first and second longitudinal end surfaces are under a compressive load of at least 5516 kPa (800 psi).
7. The structure of claim 1 , wherein the electrode assembly comprises at least 10 electrode structures and at least 10 counter-electrode structures.
8. The structure of claim 1 , wherein the electrode assembly comprises at least 50 electrode structures and at least 50 counter-electrode structures.
9. The structure of claim 1 , wherein the electrode assembly comprises at least 100 electrode structures and at least 100 counter-electrode structures.
10. The structure of claim 1 wherein the constraint comprises a material having an ultimate tensile strength of >68.948 MPa (at least 10,000 psi).
11. The structure of claim 1 wherein the constraint comprises metal, metal alloy, ceramic, glass, plastic, or a combination thereof, and/or wherein the constraint comprises carbon fibers at >50% packing density.
12. The structure of claim 1 wherein the constraint comprises a sheet of material having a thickness in the range of about 10 to about 100 micrometers.
13. The structure of claim 1 wherein the first and second compression members exert a pressure on the first and second longitudinal end surfaces that exceeds the pressure maintained on the electrode assembly in each of two directions that are mutually perpendicular and perpendicular to the stacking direction by factor of at least 2.
14. The structure of claim 1 wherein the first and second compression members exert a pressure on the first and second longitudinal end surfaces that exceeds the pressure maintained on the electrode assembly in each of two directions that are mutually perpendicular and perpendicular to the stacking direction by factor of at least 3.
15. The structure of claim 1 wherein the first and second compression members exert a pressure on the first and second longitudinal end surfaces that exceeds the pressure maintained on the electrode assembly in each of two directions that are mutually perpendicular and perpendicular to the stacking direction by factor of at least 4.
16. The structure of claim 1 , wherein the electrode structures comprise an anodically active electroactive material and the counter-electrode structures comprise a cathodically active electroactive material.
17. The structure of claim 1 , wherein the constraint and enclosure have a combined volume that is less than 60% of the volume enclosed by the battery enclosure.
18. The structure of claim 1 , wherein the constraint and enclosure have a combined volume that is less than 45% of the volume enclosed by the battery enclosure.
19. The structure of claim 1 , wherein the constraint and enclosure have a combined volume that is less than 30% of the volume enclosed by the battery enclosure.
20. The structure of claim 1 wherein the at least one compression member that is internal to the longitudinal end surfaces comprises at least a portion of an electrode structure or a counter-electrode structure.
21. The structure of claim 1 wherein the at least one compression member that is internal to the longitudinal end surfaces comprises at least a portion of a counter-electrode active material, an electrode current collector, a counter-electrode current collector, an electrode backbone, or a counter-electrode backbone.
22. A secondary battery comprising the structure of claim 1 , a battery enclosure, and a non-aqueous liquid electrolyte within the battery enclosure.