Carbon aerogel-based cathodes for lithium-air batteries
Nanoporous carbon-based scaffolds or structures, and specifically carbon aerogels and their manufacture and use thereof. Embodiments include a cathode material within a lithium-air battery, where the cathode is formed of a binder-free, monolithic, polyimide-derived carbon aerogel. The carbon aerogel includes pores that improve the oxygen transport properties of electrolyte solution and improve the formation of lithium peroxide along the surface and/or within the pores of the carbon aerogel. The cathode and underlying carbon aerogel provide optimal properties for use within the lithium-air battery.
1. A nanoporous carbon cathode comprising:
a carbonized aerogel material having:
a pore structure comprising a fibrillar morphology with a substantially uniform pore size distribution, where pores accommodate formation of lithium peroxide particles;
a Young's modulus of at least about 0.2 GPa; and
a density between about 0.10 g/cc and about 1.5 g/cc.
2. The nanoporous carbon cathode of claim 1 , wherein the carbonized nanoporous carbon material has an electrical conductivity of at least about 1 S/cm.
3. The nanoporous carbon cathode of claim 1 , wherein the carbonized nanoporous carbon material comprises a polyimide-derived carbon aerogel.
4. The nanoporous carbon cathode of claim 3 , wherein the polyimide-derived carbon aerogel is in a monolith form.
5. The nanoporous carbon cathode of claim 4 , wherein the carbon aerogel is substantially or completely binder-free.
6. The nanoporous carbon cathode of claim 4 , wherein the carbon aerogel has a thickness between about 10 μm and about 1000 μm.
7. The nanoporous carbon cathode of claim 1 , wherein the pore structure is characterized by pores surrounding the lithium peroxide particles.
8. The nanoporous carbon cathode of claim 7 , wherein the pores form interconnected structures around the lithium peroxide particles, characterized by a plurality of connection points between the lithium peroxide particles and pore walls of each pore in which the lithium peroxide particles are surrounded.
9. The nanoporous carbon cathode of claim 1 , wherein the nanoporous carbon cathode accommodates about 5%-90% of the lithium peroxide particles by weight of the carbonized nanoporous carbon material.
10. The nanoporous carbon cathode of claim 1 , wherein the carbonized nanoporous carbon material has a pore volume of at least 0.3 cc/g.
11. The nanoporous carbon cathode of claim 1 , wherein the carbonized nanoporous carbon material has a porosity between about 10% and about 90%.
12. The nanoporous carbon cathode of claim 1 , wherein the carbonized nanoporous carbon material has a capacity of at least about 800 mAh/g.
13. The nanoporous carbon cathode of claim 1 , wherein the pore structure comprises a full width at half max of about 50 nm or less.
14. The nanoporous carbon cathode of claim 1 , wherein the pore structure comprises a pore size at max peak from distribution of about 100 nm or less.
15. The nanoporous carbon cathode of claim 1 , wherein the fibrillar morphology comprises a plurality of struts, wherein the struts further comprise carbonized material and wherein at least some of the struts have an average strut width of about 2-10 nm.
16. An electrochemical cell comprising the carbonized nanoporous carbon cathode of claim 1 .
17. A lithium-air/oxygen or zinc-air/oxygen battery, comprising the electrochemical cell of claim 16 .