Electrodes including an embedded compressible or shape changing component
One exemplary embodiment includes an electrode including an embedded compressible or shape changing component.
1. A product comprising:
a first electrode comprising an embedded compressible shape changing component constructed and arranged to reduce in size or change shape to accommodate insertion of lithium into the electrode thereby reducing electrode expansion, wherein the component comprises electrically conductive microballoons.
2. A product as set forth in claim 1 wherein the first electrode further comprises an active material into which and from which lithium ions can migrate.
3. A product as set forth in claim 2 wherein the active material comprises silicon.
4. A product as set forth in claim 2 wherein the active material comprises carbon.
5. A product as set forth in claim 2 wherein the active material comprises at least one of cobalt dioxide, nickel-cobalt-manganese, nickel-cobalt-aluminum, magnesium oxide spinel, iron phosphate, manganese phosphate intermetallics of active and inactive components or fluorides.
6. A product as set forth in claim 1 wherein the electrically conductive microballoons comprise an electrically conductive polymer.
7. A product as set forth in claim 1 wherein the electrically conductive microballoons comprise a polymer and electrically conductive particles dispersed throughout the polymer.
8. A product as set forth in claim 1 wherein the electrically conductive microballoons comprise a polymeric shell and a layer of electrically conductive material over the shell.
9. A product as set forth in claim 8 wherein the electrically conductive layer comprises at least one of graphite, nickel silicon, gold, aluminum, silver, copper, platinum, palladium or ruthenium.
10. A product as set forth in claim 1 wherein the microballoons include a gas trapped therein.
11. A product as set forth in claim 2 wherein microballoons have a first shape when substantially no lithium ions are in the electrode, and wherein the microballoons have a sufficient flexibility so that upon migration of lithium ions into the electrode, the microballoons are compressed to a second shape, and upon migration of lithium ions out of the electrode, the microballoons have a sufficient resilience to return to the first shape or substantial the first shape.
12. A product as set forth in claim 2 further comprising a second electrode.
13. A product as set forth in claim 12 further comprising a porous separator positioned between the first electrode and the second electrode, the porous separator being constructed and arranged to allow lithium ions to travel therethrough and to prevent an electrical connection being made between the first electrode and the second electrode.
14. A product as set forth in claim 13 further comprising an electrolyte to facilitate movement of lithium ions from the first electrode through the porous separator to the second electrode, and from the second electrode through the porous separator to the first electrode.
15. A product as set forth in claim 1 wherein the microballoons comprise a polymeric shell and a catalyst over the shell.
16. A product as set forth in claim 15 wherein the catalyst comprises at least one of platinum, palladium, or ruthenium.
17. A product as set forth in claim 15 further comprising second electrode comprising a catalyst and a proton exchange membrane interposed between the first electrode and the second electrode.
18. A product as set forth in claim 1 further comprising a second electrode, and a proton exchange membrane interposed between the first electrode and the second electrode.
19. A product comprising:
a first electrode comprising an active material comprising at least one of carbon or silicon, and electrically conductive microballoons;
a second electrode, comprising an active material comprising at least one of cobalt dioxide, nickel-cobalt-manganese, nickel-cobalt-aluminum, manganese oxide spinel, iron phosphate, manganese phosphate intermetallics of active and inactive components or metal fluorides, and electrically conductive microballoons;
an insulative porous separator interposed between the first electrode and the second electrode being constructed and arranged to allow passage of lithium ions therethrough;
an electrolyte to facilitate the movement of lithium ions from the first electrode to the second electrode and from the second electrode back to the first electrode;
wherein the electrically conductive microballoons of each of the first electrode and second electrode having a first shape in the electrode when no lithium ions are present in the electrode, and having sufficient flexibility to be compressed upon migration of lithium ions into the electrode, and having sufficient resiliency to return to the first shape upon migration of lithium ions out of the electrode.