Coated electroactive materials

1. A process comprising:

suspending an electroactive material in a solvent;

dissolving a carbon precursor in the solvent; and

depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material, wherein the carbon coating is present from about 0.001 wt % to about 55 wt % based on the weight of the electroactive material;

wherein:

the electroactive material is a positive electroactive material or a negative electrode material;

the positive electrode material is selected from the group consisting of a spinel, a olivine, LiFePO 4 , LiMnPO 4 , LiCoPO 4 , LiNiPO 4 , LiCoO 2 , LiNiO 2 , LiNi 1−x Co y Met z O 2 , LiMn 0.5 Ni 0.5 O 2 , LiMn 0.3 Co 0.3 Ni 0.3 O 2 , LiMn 2 O 4 , LiFeO 2 , LiMet 0.5 Mn 1.5 O 4 , Li 1+x′ Ni α Mn β Co γ Met′ δ O 2−z′ F z′ , A n′ B 2 (XO 4 ) 3 , vanadium oxide, and a mixture of any two or more thereof;

wherein:

Met is Al, Mg, Ti, B, Ga, Si, Mn, or Co;

Met′ is Mg, Zn, Al, Ga, B, Zr, or Ti;

A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu, or Zn;

B is Ti, V, Cr, Fe, or Zr;

X is P, S, Si, W, or Mo;

0≦x≦0.3; 0≦y≦0.5; 0≦z≦0.5; 0≦x′≦0.4; 0≦α≦1; 0≦β≦1; 0≦γ≦1; 0≦δ≦0.4; 0≦z′≦0.4; and 0≦n′≦3; and

the negative electroactive material is selected from the group consisting of Li 4 Ti 5 O 12 , TiO 2 , metal nitrides, metal phosphides, metal oxides, lithium metal oxides, and a mixture of any two or more thereof;

wherein the carbon precursor is selected from the group consisting of graphene, graphene oxide, carbon nano-tubes, derivatives thereof, and a combination of any two or more thereof.

2. The process of claim 1 , wherein the solvent is selected from the group consisting of an organic solvent and water.

3. The process of claim 1 , wherein the depositing comprises heating the dissolved carbon precursor, the solvent, and the electroactive material.

4. The process of claim 1 , wherein the graphene, graphene oxide, or carbon nano-tubes are functionalized with a moiety that is an amine, an isocyanate, a phosphonate, a sulfonate, a phosphine, a thiocyanates, or a mixture of any two or more thereof.

5. The process of claim 1 , wherein the graphene, graphene oxide, or carbon nano-tubes are functionalized by reaction with a compound selected from the group consisting of allylamine, phenylisocyanate, methylisocyanate, and p-phenyl-SO 3 H.

6. The process of claim 1 , wherein the graphene, graphene oxide, or carbon nano-tubes are oxygenated, hydrated, hydrogenated, halogenated, sulfonated, or a combination of any two or more thereof.

7. The process of claim 1 , wherein the carbon precursor is graphene oxide and the depositing comprises adding a reducing agent.

8. The process of claim 7 , wherein the reducing agent is hydrazine.

9. The process of claim 3 , wherein the heating is performed in an inert, reducing, or oxidizing atmosphere.

10. The process of claim 9 , wherein the heating is performed at a temperature in the range from about 250° C. to about 450° C.

11. A composition comprising a carbon-coated electroactive material prepared by the process of claim 1 .

12. An electrochemical device comprising the composition of claim 11 .

13. The electrochemical device of claim 12 that is a lithium secondary battery, a lithium primary battery, a capacitor, a lithium air battery, or a sodium sulfur battery.

14. The process of claim 1 , wherein the carbon-coating is present from about 0.01 wt % to about 55 wt %.

15. The process of claim 1 , wherein the carbon-coating is present from about 2 wt % to about 5 wt %.

16. A process comprising:

suspending an electroactive material in a solvent selected from the group consisting of an alcohol, ether, ester, ketone, aromatic, heterocyclic, or a mixture of any two or more thereof;

dissolving a carbon precursor in the solvent; and

depositing the carbon precursor on the electroactive material to form a carbon-coated electroactive material, wherein the carbon coating is present from about 0.001 wt % to about 55 wt % based on the weight of the electroactive material;

wherein:

the electroactive material is a positive electroactive material or a negative electroactive material;

the positive electroactive is selected from the group consisting of a spinel, a olivine, LiFePO 4 , LiMnPO 4 , LiCoPO 4 , LiNiPO 4 , LiCoO 2 , LiNiO 2 , LiNi 1−x Co y Met z O 2 , LiMn 0.5 Ni 0.5 O 2 , LiMn 0.3 Co 0.3 Ni 0.3 O 2 , LiMn 2 O 4 , LiFeO 2 , LiMet 0.5 Mn 1.5 O 4 , LiMet 0.5 Mn 1 O 4 , Li 1+x′ Ni α Mn β Co γ Met′ δ O 2−z F z′ , A n′ B 2 (XO 4 ) 3 , vanadium oxide, and a mixture of any two or more thereof;

wherein:

Met is Al, Mg, Ti, B, Ga, Si, Mn, or Co;

Met′ is Mg, Zn, Al, Ga, B, Zr, or Ti;

A is Li, Ag, Cu, Na, Mn, Fe, Co, Ni, Cu, or Zn;

B is Ti, V, Cr, Fe, or Zr;

X is P, S, Si, W, or Mo;

0≦x≦0.3; 0≦y≦0.5; 0≦z≦0.5; 0≦x′≦0.4; 0≦α≦1; 0≦β≦1; 0≦γ≦1; 0≦δ≦0.4; 0≦z′≦0.4; and 0≦n′≦3 and

the negative electroactive material is selected from the group consisting of amorphous carbon, Li 4 Ti 5 O 12 , TiO 2 , tin, tin alloys, silicon, silicon alloys, metal nitrides, metal phosphides, intermetallic compounds, metal oxide, lithium metal oxide, and a mixture of any two or more thereof.