Cathode material for lithium batteries
A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.
1. An electrochemical device comprising a positive electrode of lithium molybdenum composite transition metal oxide, a negative electrode and a non-aqueous electrolyte wherein the positive electrode has a composition selected from the group consisting of Li 1+x Ni α′ Co β′ Mn γ′ Mo δ ′M k O 2-z X z , wherein M is selected from the group of Mg, Zn, Al, Ga, B, Zr, Si, Ti, Nb, or W and wherein X includes at least one of F, S, Cl, I; x ranges from about 0 to 0.33; α′, β′, and γ′ independently range from about 0 to 1; δ′ ranges from about 0 to 0.2, κ ranges from 0.01 to 0.15, and z ranges from about 0 to 0.3.
2. The electrochemical device of claim 1 wherein the positive electrode and the negative electrode are separated by a porous separator.
3. The electrochemical device of claim 1 comprising a positive active material with nano-sized plurality of particles with less than about 50 microns in average diameter.
4. The electrochemical device of claim 2 further including a positive active material with tap density in excess of 2.2 g/ml.
5. The electrochemical device of claim 1 , wherein the non-aqueous electrolyte comprises an alkali metal salt and a polar aprotic solvent.
6. The electrochemical device of claim 5 wherein the alkali metal salt is a lithium salt.
7. The electrochemical device of claim 6 wherein the lithium salt is selected from the group consisting of Li[(C 2 C 4 ) 2 B], Li(C 2 C 4 )BF 2 , Li[PF 2 (C 2 C 4 ) 2 ], LiClO 4 , LiBF 4 , LiAsF 6 , LiPF 6 , LiCF 3 SO 3 , Li(CF 3 SO 2 ) 2 N, Li(CF 3 SO 2 ) 3 C, LiN(SO 2 C 2 F 5 ) 2 , lithium alkyl fluorophosphates, and mixtures thereof.
8. The electrochemical device of claim 1 , wherein the polar aprotic solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dimethyl ether, gamma-butyrolactone, and mixtures of any two or more thereof.
9. The electrochemical device of claim 1 wherein the positive electrode has a composition selected from the group consisting of Li 1+x Ni α′ Co β′ Mn γ′ Mo δ ′ M k O 4-z X z , wherein M is selected from the group of Mg, Zn, Al, Ga, B, Zr, Si, Ti, Nb, or W and wherein X includes at least one of F, S, Cl, I; x ranges from about 0 to 0.33; α′, β′, and γ′ independently range from about 0 to 2; 6′ ranges from about 0 to 0.2, κ ranges from about 0.01 to 0.15, and z ranges from about 0 to 0.3.
10. The electrochemical device as defined in claim 1 wherein the positive electrode comprises secondary particles of a spherical morphology.
11. The electrochemical device as defined in claim 1 wherein the positive electrode comprises a plurality of layers.
12. The electrochemical device as defined in claim 9 wherein the positive electrode comprises a plurality of layers.
13. The electrochemical device as defined in claim 1 wherein the molybdenum is less than about 15 wt % of the positive electrode.
14. The electrochemical device as defined in claim 9 wherein the molybdenum is less than about 15 wt % of the positive electrode.
15. The electrochemical device as defined in claim 1 wherein the molybdenum comprises a phase related from the group of MoO 3 , MoCl 3 and MoO 2 and mixtures thereof.
16. The electrochemical device as defined in claim 9 wherein the molybdenum comprises a phase related from the group of MoO 3 , MoCl 3 and MoO 2 and mixtures thereof.
17. The electrochemical device as defined in claim 1 wherein the positive electrode comprises nano-size plurality of particles having a diameter between about 1-50 microns.