Conductivity control in electrochemical cells
Electrochemical cells having desirable electronic and ionic conductivities, and associated systems and methods, are generally described.
1. An energy storage device, comprising:
a first electrode comprising a first electrode active material and a total pore volume;
an electrolyte; and
a second electrode comprising a second electrode active material, wherein:
the energy storage device is configured such that the first and second electrode active materials undergo a reaction to generate electricity, the reaction forming a volume of solid reaction product during operation of the energy storage device, and
the total pore volume of the first electrode is between about 100% and about 300% of the volume of the solid reaction product formed when the reaction used to generate the electricity has proceeded to substantial completion.
2. The energy storage device of claim 1 , wherein:
the first electrode has a first electrode electronic conductivity;
the electrolyte has an ionic conductivity; and
the first electrode electronic conductivity is less than or equal to about 50% of the ionic conductivity of the electrolyte.
3. The energy storage device of claim 2 , wherein the second electrode has a second electrode electronic conductivity, and the second electrode electronic conductivity is less than or equal to about 50% of the ionic conductivity of the electrolyte.
4. The energy storage device of claim 3 , wherein the second electrode electronic conductivity is from about 1% to about 50% of the ionic conductivity of the electrolyte.
5. The energy storage device of claim 1 , wherein the first electrode is a cathode, and the second electrode is an anode.
6. The energy storage device of claim 5 , wherein the first electrode active material comprises sulfur.
7. The energy storage device of claim 6 , wherein the device is capable of utilizing at least about 90% of the total sulfur in the energy storage device through at least 100 charge and discharge cycles subsequent to a first charge and discharge cycle, wherein 100% utilization corresponds to 1675 mAh per gram of total sulfur in the energy storage device.
8. The energy storage device of claim 6 , wherein the sulfur comprises elemental sulfur.
9. The energy storage device of claim 5 , wherein the second electrode active material comprises lithium.
10. The energy storage device of claim 9 , wherein the lithium comprises lithium metal.
11. The energy storage device of claim 1 , wherein the first electrode is an anode, and the second electrode is a cathode.
12. The energy storage device of claim 1 , wherein the first electrode has an electrode electronic conductivity that is less than or equal to about 700 mS/cm.
13. The energy storage device of claim 1 , wherein the first electrode comprises a porous support structure comprising a plurality of pores, and the first electrode active material is at least partially disposed within the pores of the porous support structure.
14. The energy storage device of claim 13 , wherein each pore of the plurality of pores has a pore volume, and the plurality of pores has a total pore volume defined by the sum of each of the individual pore volumes, and at least about 50% of the total pore volume is occupied by pores having cross-sectional diameters of between about 0.1 microns and about 10 microns.
15. The energy storage device of claim 13 , wherein at least a portion of the porous support structure is made of at least one of carbon, a metal carbide, a metal nitride, silicon, and a polymer.
16. The energy storage device of claim 1 , wherein the energy storage device is a zinc-air electrochemical cell.
17. The energy storage device of claim 1 , wherein the energy storage device is an aluminum-air electrochemical cell.
18. The energy storage device of claim 1 , wherein the energy storage device is a lithium-air electrochemical cell.
19. The energy storage device of claim 1 , wherein the energy storage device is a lithium-sulfur dioxide electrochemical cell.
20. The energy storage device of claim 1 , wherein the energy storage device is a lithium-thionyl chloride electrochemical cell.
21. The energy storage device of claim 1 , wherein the energy storage device is a lithium-sulfuryl chloride electrochemical cell.