Lithium-based active materials and preparation thereof
View Patent ↗The invention provides novel lithium-mixed metal materials which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-mixed metal materials. Methods for making the novel lithium-mixed metal materials and methods for using such lithium-mixed metal materials in electrochemical cells are also provided. The lithium-mixed metal materials comprise lithium and at least one other metal besides lithium. Preferred materials are lithium-mixed metal phosphates which contain lithium and two other metals besides lithium.
1. A battery, comprising:
a first electrode comprising an active material represented by the nominal formula LiMI 1-y MII y PO 4 , wherein MI is V, MII is at least one element selected from the group consisting of elements from Groups 2, 12, and 14 of the Periodic Table, and 0<y<1;
a second electrode which is a counter-electrode to the first electrode; and
an electrolyte.
2. The battery of claim 1 , wherein MII is selected from the group consisting of Mg, Ca, Zn, Sr, Pb, Cd, Sn, Ba, Be, and mixtures thereof.
3. The battery of claim 1 , wherein MII is selected from the group consisting of Mg, Ca, Ba, Zn, and mixtures thereof.
4. The battery of claim 1 , wherein 0<y<0.5.
5. The battery of claim 4 , wherein 0<y≦0.2.
6. The battery of claim 5 , wherein 0<y≦0.1.
7. The battery of claim 1 , wherein the active material has an olivine structure.
8. The battery of claim 1 , wherein the active material is a single phase compound.
9. The battery of claim 1 , wherein y=0.2.
10. The battery of claim 1 , wherein y=0.1.
11. The battery of claim 1 , wherein the first electrode further comprises an electrically conductive diluent, and a binder.
12. The battery of claim 11 , wherein the electrically conductive diluent is carbon.
13. The battery of claim 12 , wherein the electrically conductive diluent is carbon black.
14. The battery of claim 11 , wherein the binder is a copolymer of polyvinylidene difluoride (PVdF) and hexafluoropropylene (HFP).
15. The battery of claim 1 , wherein the second electrode comprises an insertion active material.
16. The battery of claim 15 , wherein the insertion active material is selected from the group consisting of a metal oxide, metal chalcogenide, carbon, graphite, and mixtures thereof.
17. The battery of claim 15 , wherein the insertion active material is graphite.
18. The battery of claim 15 , wherein the first and second electrodes each further comprise an electrically conductive diluent, and a binder.
19. The battery of claim 18 , wherein the electrically conductive diluent is carbon.
20. The battery of claim 19 , wherein the electrically conductive diluent is carbon black.
21. The battery of claim 18 , wherein the binder is a copolymer of polyvinylidene difluoride (PVdF) and hexafluoropropylene (HFP).
22. The battery of claim 1 , wherein the electrolyte comprises a lithium salt and a solvent selected from the group consisting of dimethyl carbonate (DMC), diethylcarbonate (DEC), dipropylcarbonate (DPC), ethylmethylcarbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, lactones, esters, glymes, sulfoxides, sulfolanes, and mixtures thereof.
23. The battery of claim 22 , wherein the electrolyte comprises a solvent selected from the group consisting of EC/DMC, EC/DEC, EC/DPC and EC/EMC.
24. The battery of claim 22 , wherein the electrolyte comprises from 5% to 65% by weight lithium salt.
25. The battery of claim 24 , wherein the electrolyte comprises from 8% to 35% by weight lithium salt.