Graphene-containing electrodes
A battery includes a first electrode including a plurality of particles containing lithium, a layer of carbon at least partially coating a surface of each particle, and electrochemically exfoliated graphene at least partially coating one or more of the plurality of particles. The battery includes a second electrode and an electrolyte. At least a portion of the first electrode and at least a portion of the second electrode contact the electrolyte.
1. A battery, comprising:
a first electrode comprising:
a plurality of particles containing lithium;
a layer of carbon at least partially coating a surface of each of at least some of the particles; and
electrochemically exfoliated graphene at least partially coating one or more of the plurality of particles, in which the electrochemically exfoliated graphene is produced using an electrochemical exfoliation process that includes:
immersing, in a solution containing an electrolyte, a portion of a third electrode and a portion of a fourth electrode, the immersed portion of the third electrode including a carbon material,
causing an electric potential to exist between the third and fourth electrodes, the third electrode having a higher electric potential than the fourth electrode, and
recovering, from the solution, graphene sheets exfoliated from the carbon material of the third electrode;
a second electrode; and
an electrolyte, wherein at least a portion of the first electrode and at least a portion of the second electrode contact the electrolyte.
2. The battery of claim 1 , wherein the first electrode is a cathode.
3. The battery of claim 1 , wherein the first electrode is an anode.
4. The battery of claim 1 , wherein the particles include at least one of lithium iron phosphate, lithium iron oxide, lithium iron phosphorous oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium cobalt manganese nickel, or lithium cobalt manganese nickel oxide.
5. The battery of claim 1 , wherein the electrochemically exfoliated graphene includes a plurality of flakes of electrochemically exfoliated graphene disposed on the carbon.
6. The battery of claim 1 , wherein the electrochemically exfoliated graphene forms about 0.001 wt % to about 5 wt % of the electrode.
7. The battery of claim 1 in which the first electrode comprises at least one of a transition metal dichalcogenide, triazine, or thiophene.
8. The battery of claim 7 in which the first electrode comprises at least one of MoS x , MoSe 2 , WS 2 , or WSe 2 .
9. The battery of claim 8 in which the first electrode comprises MoS 2 .
10. The battery of claim 1 , wherein the layer of carbon includes a layer of amorphous carbon.
11. The battery of claim 1 , wherein a specific capacity of the electrode material is at least about 180 mAh/g.
12. The battery of claim 11 , wherein the specific capacity of the electrode material is about 210 mAh/g.
13. The battery of claim 1 , wherein the electrochemically exfoliated graphene includes less than about 20 wt % oxygen.
14. The battery of claim 1 , wherein a permeability of the electrochemically exfoliated graphene is less than about 90% and a sheet resistance is less than about 10 kΩ/sq.
15. The battery of claim 1 , comprising an additive material including at least one of a conductive additive material, a bonding agent, a carbon material, or a solvent.
16. The battery of claim 15 , wherein the additive material includes at least one of graphite, soft carbon, hard carbon, carbon nanotubes, or carbon fibers.
17. The battery of claim 1 , comprising at least one of sulfur, silicon, tin, ceramic materials, or lithium sulfide.
18. The battery of claim 1 in which the electrochemical exfoliation process comprises:
immersing, in a solution containing an electrolyte, a portion of a third electrode and a portion of a fourth electrode, the immersed portion of the third electrode including a first carbon material and the immersed portion of the fourth electrode including a second carbon material or a metal;
causing a potential to exist between the third and fourth electrodes; and
recovering, from the solution, graphene sheets exfoliated from the carbon material(s).
19. A method of fabricating a battery, the method comprising:
producing electrochemically exfoliated graphene using an electrochemical exfoliation process that includes:
immersing, in a solution containing an electrolyte, a portion of a third electrode and a portion of a fourth electrode, the immersed portion of the third electrode including a carbon material,
causing an electric potential to exist between the third and fourth electrodes, the third electrode having a higher electric potential than the fourth electrode, and
recovering, from the solution, graphene sheets exfoliated from the carbon material of the third electrode;
providing a first electrode, including
providing a plurality of particles containing lithium and having a layer of carbon coating at least a portion of a surface of each of at least some of the particles, and
disposing the electrochemically exfoliated graphene among the plurality of particles, wherein the electrochemically exfoliated graphene at least partially coats one or more of the plurality of particles;
providing a second electrode; and
providing an electrolyte, wherein at least a portion of the first electrode and at least a portion of the second electrode contact the electrolyte.
20. The method of claim 19 in which providing the first electrode comprises providing a cathode.
21. The method of claim 19 in which providing the first electrode comprises providing an anode.
22. The method of claim 19 in which providing the plurality of particles comprises providing at least one of lithium iron phosphate, lithium iron oxide, lithium iron phosphorous oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium cobalt manganese nickel, or lithium cobalt manganese nickel oxide.
23. The method of claim 19 in which disposing the electrochemically exfoliated graphene comprises disposing a plurality of flakes of electrochemically exfoliated graphene on the carbon.
24. The method of claim 19 in which the electrochemically exfoliated graphene forms about 0.001 wt % to about 5 wt % of the first electrode.
25. The method of claim 19 in which providing the first electrode comprises providing a first electrode that comprises an additive material including at least one of a conductive additive material, a bonding agent, a carbon material, or a solvent.
26. The method of claim 19 in which providing the first electrode comprises providing a first electrode that includes at least one of sulfur, silicon, tin, ceramic materials, or lithium sulfide.
27. The method of claim 19 in which producing the electrochemically exfoliated graphene comprises producing electrochemically exfoliated graphene that includes less than about 20 wt % oxygen.
28. The method of claim 19 in which producing the electrochemically exfoliated graphene comprises producing electrochemically exfoliated graphene having a permeability less than about 90% and a sheet resistance less than about 10 kΩ/sq.