Mixed phase lithium metal oxide compositions with desirable battery performance
View Patent ↗Mixed phase complex lithium metal oxides are described with an overall stoichiometry represented by a formula Li 1+a Ni b Co c Mn d O x , −0.05≦a≦0.14, 0.1≦b≦0.25, 0≦c≦0.2, 0.45≦d≦0.8, a+b+c+d=1 and (1+a)/(b+c+d)≦1.325. The compositions are generally very high in manganese content. The compositions can have x-ray diffractograms and differential capacity profiles suggesting the presence of a layered (Li 2 MnO 3 )—layered (LiMetalO 2 )—spinel crystal structure. The compositions can exhibit surprisingly low first cycle irreversible capacity losses while maintaining high specific discharge capacities, even at high discharge rates. Stabilizing coatings have been found to further significantly improve performance.
1. A composition having a formula Li 1+a Ni b Co c Mn d M e O x , with −0.05≦a≦0.14, 0.1≦b≦0.25, 0≦c≦0.2, 0.45≦d≦0.8, 0≦e≦0.02, a+b+c+d+e=1, (1+a)/(b+c+d+e)≦1.34 and M is a metal element different from Li, Ni, Co and Mn, wherein the composition exhibits a first cycle irreversible capacity loss in a lithium battery of no more than about 10% of the first charge specific capacity when discharged at C/20 from 4.6V to 2V.
2. The composition of claim 1 wherein (1+a)/(b+c+d)≦1.3.
3. The composition of claim 1 wherein 0.025≦a≦0.13.
4. The composition of claim 1 wherein 0.05≦a≦0.125.
5. The composition of claim 4 wherein e=0 and 0.125≦b≦0.20, 0.075≦c≦0.175, 0.5≦d≦0.65.
6. The composition of claim 1 wherein the composition exhibits a 50th cycle specific discharge capacity of at least 150 mAh/g at a discharge rate of 2 C when discharged from 4.6V to 2V.
7. The composition of claim 1 wherein the composition exhibits an X-ray diffractogram with an R-value ([I (006) +I (102) ]/I (101) ])≧0.285 and a 5th cycle discharge specific capacity of at least about 225 mAh/g when discharged at a rate of C/3 from 4.6V to 2V.
8. The composition of claim 1 wherein the composition exhibits a 5th cycle discharge specific capacity of at least about 225 mAh/g when discharged at a rate of C/3 from 4.6V to 2V.
9. The composition of claim 1 wherein 0≦e≦0.02 and M is Mg, Sr, Ba, Cd, Zn, Al, Ga, B, Zr, Ti, Ca, Ce, Y, Nb, Cr, Fe, V, or combinations thereof.
10. The composition if claim 1 further comprising a stabilizing coating.
11. The composition of claim 10 wherein the stabilizing coating comprises a metal halide.
12. The composition of claim 10 wherein the stabilizing coating comprises a metal oxide.
13. The composition of claim 10 wherein the composition exhibits a first cycle irreversible capacity loss in a lithium battery of no more than about 8% of the first charge specific capacity when discharged at C/20 from 4.6V to 2V.
14. The composition of claim 10 wherein the composition exhibits a specific discharge capacity of at least about 190 mAh/g at a discharge rate of 2 C when discharged from 4.6V to 2V.
15. A battery comprising a cathode comprising the composition of claim 1 , an anode comprising a lithium alloying/intercalation composition, a separator between the anode and cathode and an electrolyte comprising an organic solvent and lithium ions.
16. A composition having a formula Li 1+a Ni b Co c Mn d M e O x , −0.05≦a≦0.14, 0.1≦b≦0.25, 0≦c≦0.2, 0.45≦d≦0.8, 0≦e≦0.02, a+b+c+d+e=1, (1+a)/(b+c+d+e)≦1.325 and M is a metal element different from Li, Ni, Co, and Mn, wherein the composition exhibits an X-ray diffractogram indicating the presence of a spinel phase and a 5th cycle discharge specific capacity of at least about 225 mAh/g when discharged at a rate of C/3 from 4.6V to 2V.
17. The composition of claim 16 wherein (1+a)/(b+c+d)≦1.3.
18. The composition of claim 16 wherein 0.05≦a≦0.125, 0.125≦b≦0.20, 0.075≦c≦0.175, 0.5≦d≦0.65.
19. The composition of claim 16 wherein the composition exhibits a 5th cycle discharge specific capacity of at least about 235 mAh/g when discharged from 4.6V to 2V at a rate of C/3.
20. The composition of claim 16 further comprising a stabilizing coating.
21. The composition of claim 16 wherein the composition exhibits a 50th cycle specific discharge capacity of at least about 150 mAh/g at a discharge rate of 2 C when discharged from 4.6V to 2V.
22. The composition of claim 16 wherein the composition exhibits a 50th cycle specific discharge capacity of at least about 160 mAh/g at a discharge rate of 2 C when discharged from 4.6V to 2V.
23. The composition of claim 16 wherein the composition exhibits an X-ray diffractogram with an R-value ([I (006) +I (102) ]/I (101) ])≧0.285.
24. The composition of claim 16 having a 5th cycle discharge specific capacity of at least about 225 mAh/g when discharged from 4.6V to 2V.