Coating of electrode materials for energy storage devices
Cathode materials, batteries, and methods of forming one or more electrodes for batteries are disclosed. A coated cathode material includes a lithium battery cathode material, a first sub-nanoscale lithium metal oxide coating on the lithium transition metal oxide and a sub-nanoscale metal oxide coating on top of the first sub-nanoscale lithium metal oxide coating. The first sub-nanoscale lithium metal oxide and the sub-nanoscale metal oxide coating are each less than 1 nm thick.
1. A coated cathode material comprising:
a lithium battery cathode material comprising a lithium transition metal oxide;
a first sub-nanoscale lithium metal oxide coating on the lithium battery cathode material; and
a second sub-nanoscale metal oxide coating disposed on the first sub-nanoscale lithium metal oxide coating; wherein the first sub-nanoscale lithium metal oxide and the second sub-nanoscale metal oxide coating are each less than 1 nm thick.
2. The coated cathode material of claim 1 , wherein the lithium battery cathode material comprises:
Li 1+a Ni x Co y Mn z Al 1-x-y-z O 2 , wherein 0.0<=a<=1.0, 0.5<=x<=1.0, 0.0<=y<=0.1, 0.0<=z<=0.1, and further wherein the lithium transition metal oxide material has less than 0.05 mol of impurities and other elements and less than 5 percent by weight of residual lithium compounds on the surface; and
one or more of single crystalline primary particles and-secondary particles.
3. The coated cathode material of claim 1 ,
wherein the lithium battery cathode material comprises:
LiFe x Mn 1-x PO 4 , wherein 0.0<=x<=1.0, and further wherein the lithium transition metal oxide material has less than 0.05 mol of impurities and other elements;
and one or more of a single crystalline primary particles and secondary particles.
4. The coated cathode material of claim 1 , wherein:
the lithium battery cathode material further comprises a carbon coating by one or more carbonaceous materials, and wherein the carbonaceous materials include one or more of amorphous carbon, conductive carbon, conductive graphite, hard carbon, soft carbon, carbon nanotubes, and graphene.
5. The coated cathode material of claim 1 , wherein:
the lithium battery cathode material further comprises a conductive polymer coating.
6. The coated cathode material of claim 5 , wherein the conductive polymer coating is disposed on the battery cathode material by one or more of solution mixing, vacuum filtration, cross-linking, and vacuum drying.
7. The coated cathode material of claim 5 , wherein the conductive polymer and additive comprises:
one or more of polypyrrole, polyaniline, and poly (3,4-ethylenedioxythiophene) polymer, carbon nanotubes, graphene, conductive carbon, Cu, Ag, Au, Pt, and Os.
8. The coated cathode material of claim 5 , wherein the conductive polymer coating is applied, at least in part, by:
dissolving a surfactant into a solvent by stirring for 10 min to 1 hours, dependent on the solubility at a temperature between 10° C. and 50° C.;
mixing the conductive polymer and additive into a solution for 1 to 24 hours at a temperature between 50° C. and 120° C.;
drying in a vacuum at a temperature between 80° C. and 200° C. for 6 to 24 hours; and
collecting the coated powder by using filtration.
9. The coated cathode material of claim 8 , wherein the surfactant comprises one or more of sodium dodecyl sulfonate, benalkonium chloride, cocamidopropyl betain, polyvinylpyrrolidone, polyurethane, polystyrene, polyvinylidene fluoride, cetyl alcohol, polytetrafluoroethylene, ethyl cellulose, nitrocellulose, and carboxymethyl cellulose.
10. The coated cathode material of claim 8 , wherein the solvent comprises one or more of N-methyl-2-pyrrolidinone, ethanol, isopropyl alcohol, acetone, dimethyl carbonate, diethyl carbonate, and ethyl-methyl carbonate.
11. The coated cathode material of claim 1 , wherein the first sub-nanoscale metal oxide coating comprises one or more metals selected from the group consisting of: Al, Ti, Co, Ni, Cu, Si, Ge, Se, Zr, Nb, W, Sn, Ga, Li, Mg, Sr, Ba, Fe, Hf, Ru, Ta, V, and Y.
12. The coated cathode material of claim 1 , wherein the first sub-nanoscale lithium metal oxide coating forms Li-metal-oxide coatings without adding additional Li source during the coating process and wherein the first sub-nanoscale lithium metal oxide coating comprises one or more metals selected from the group consisting of: Al, Ti, Co, Ni, Cu, Si, Ge, Se, Zr, Nb, W, Sn, Ga, Li, Mg, Sr, Ba, Fe, Hf, Ru, Ta, V, and Y.