Layered-spinel electrodes for lithium batteries
An electrode for a lithium-ion cell comprising a ‘layered-spinel’ composite oxide material is disclosed. The ‘layered-spinel’ can be a material of formula xLiMO 2 .(1−x)Li y M′ z O 4 , wherein 0<x<1; LiMO 2 is a lithium metal oxide having a layered structure in which M comprises one or more transition metals and optionally lithium, and has a combined average oxidation state of +3; and Li y M′ z O 4 is a lithium metal oxide having a spinel structure, 1≤y≤1.33, 1.66≤z≤2, and M′ comprises one or more transition metals, and has a combined average metal oxidation state in the range of about +3.5 to about +4.
1. An electrode for a lithium-ion cell comprising metal oxide particles, wherein the metal oxide particles consist essentially of a structurally integrated ‘layered-spinel’ composite oxide structure of formula xLiMO 2 .(1−x)Li y M′ z O 4 , wherein 0<x<1; LiMO 2 is a lithium metal oxide having a layered structure in which M comprises one or more transition metal elements, and has a combined average metal oxidation state of about +3 in an initial discharged state thereof; and Li y M′ z O 4 is a lithium metal oxide having a spinel structure, 1≤y≤1.33, 1.66≤z≤2, and M′ comprises one or more transition metal elements, and has a combined average metal oxidation state in the range of about +3.5 to about +4 in an initial discharged state thereof; and wherein the integrated ‘layered-spinel’ composite oxide structure is formed by heating a precursor composition in air at a temperature in the range of about 600 to about 850° C., wherein the precursor composition comprises either (a) LiMO 2 mixed with a targeted stoichiometric amount of Li and M′ nitrates, or (b) a mixture of Li, M, and M′ hydroxides, carbonates, and/or oxalates in a targeted stoichiometric ratio of Li, M and M′.
2. The electrode of claim 1 , wherein M and M′ comprise one or more first row transition metal elements.
3. The electrode of claim 1 , wherein the transition metal elements comprise one or more of Mn, Ni and Co.
4. The electrode of claim 1 , wherein one or more of M and M′ further comprises Ti.
5. The electrode of claim 1 , wherein one or more of M and M′ further comprises Al.
6. The electrode of claim 1 , wherein the metal oxide having a layered structure comprises a material of formula Li[Li 0.33 Mn 0.67 ]O 2 .
7. The electrode of claim 1 , wherein the metal oxide having a layered structure comprises a material of formula Li[Li 0.33 Ti 0.67 ]O 2 .
8. The electrode of claim 1 , wherein the metal oxide having a layered structure comprises a LiCoO 2 material.
9. The electrode of claim 1 , wherein the metal oxide having a layered structure comprises a LiNi 0.80 Co 0.15 Al 0.05 O 2 material.
10. The electrode of claim 1 , wherein the metal oxide having a layered structure comprises a LiNi 1-a-b Mn a Co b O 2 , material, wherein 0≤a≤1; 0≤b<1.
11. The electrode of claim 1 , wherein the metal oxide having a spinel structure comprises a material of formula Li 1+w M′ 2-w O 4 (0≤w≤0.33).
12. The electrode of claim 11 , wherein the metal oxide having a spinel structure comprises a material of formula Li 1+w Mn 2-w O 4 .
13. The electrode of claim 11 , wherein the metal oxide having a spinel structure comprises a material of formula Li 1+w Ti 2-w O 4 .
14. The electrode of claim 1 , wherein the metal oxide having a spinel structure comprises a material of formula Li 1-t M′ 2 O 4 , wherein 0≤t≤1.
15. The electrode of claim 1 , wherein the ‘layered-spinel’ composite oxide is a material selected from the group consisting of:
0.95LiCoO 2 .0.05LiMn 2 O 4 ;
0.95LiCoO 2 .0.05Li 1.1 Mn 1.9 O 4 ;
0.95LiCoO 2 .0.05Li 1.33 Mn 1.67 O 4 ;
0.95LiCoO 2 .0.05Li 1.33 Ti 1.67 O 4 ;
0.95LiNi 0.80 CO 0.15 Al 0.05 O 2 .0.05LiMn 2 O 4 ;
0.95LiNi 0.80 Co 0.15 Al 0.05 O 2 .0.05Li 1.1 Mn 1.9 O 4 ;
0.95LiNi 0.80 Co 0.15 Al 0.05 O 2 .0.05Li 1.33 Mn 1.67 O 4 ;
0.90LiNi 0.80 Co 0.15 Al 0.05 O 2 .0.10Li 1.33 Ti 1.67 O 4 ;
0.90LiNi 0.80 Co 0.15 Al 0.05 O 2 .0.10Li 2 [CO 2 ]O 4 ;
0.95LiNi 0.33 Mn 0.33 Co 0.33 O 2 .0.05LiMn 2 O 4 ;
0.95LiNi 0.33 Mn 0.33 Co 0.33 O 2 .0.05Li 1.1 Mn 19 O 4 ;
0.95LiNi 0.33 Mn 0.33 Co 0.33 O 2 .0.05Li 1.33 Mn 1.67 O 4 ;
0.90LiNi 0.33 Mn 0.33 Co 0.33 O 2 .0.10Li 1.33 Ti 1.67 O 4 ; and
0.95LiNi 0.50 Mn 0.30 Co 0.20 O 2 .0.05Li 1.1 Mn 1.9 O 4 .
16. The electrode of claim 1 , wherein the composite oxide includes one or more localized configurations or regions comprising (a) disordered layered-, spinel-, lithiated-spinel-, and/or rocksalt structures, (b) partially disordered layered-, spinel-, lithiated-spinel-, and/or rocksalt structures, (c) crystallographic cationic defects, (d) crystallographic anionic defects, and/or (e) cation distributions that are intermediate between layered, spinel, lithiated-spinel and/or rocksalt cation distributions.
17. The electrode of claim 1 , wherein M and M′ of the composite oxide together comprise a combination of Co, Mn and Ni, in which the cobalt content of the combination is higher than the combined manganese and nickel content thereof.
18. The electrode of claim 1 , wherein M and M′ of the composite oxide together comprise a combination of Co, Mn and Ni, in which the nickel content of the combination is higher than the combined manganese and the cobalt content thereof.
19. The electrode of claim 1 , wherein M and M′ of the composite oxide together comprise a combination of Co, Mn and Ni, in which the combined content of cobalt and nickel in the composite oxide is higher than the manganese content thereof.
20. An electrochemical cell comprising an anode, a cathode comprising the electrode of claim 1 , and a lithium-containing electrolyte contacting the anode and the cathode.
21. The electrochemical cell of claim 20 , wherein the cathode further comprises carbon particles and a binder.
22. The electrochemical cell of claim 21 , wherein the binder comprises polyvinylidene difluoride (PVDF).
23. The electrochemical cell of claim 20 , wherein the electrolyte comprises a solution of LiPF 6 in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC).
24. A battery comprising a plurality of electrically connected electrochemical cells of claim 20 , arranged in series, parallel, or both.
25. An electrode for a lithium-ion cell comprising metal oxide particles, wherein the metal oxide particles consist essentially of a structurally integrated ‘layered-spinel’ composite oxide structure of formula xLiMO 2 .(1−x)Li y M′ z O 4 , wherein 0.90≤x≤0.95; LiMO 2 is a lithium metal oxide having a layered structure in which M comprises one or more transition metal elements, and has a combined average metal oxidation state of about +3 in an initial discharged state thereof; and Li y M′ z O 4 is a lithium metal oxide having a spinel structure, 1≤y≤1.33, 1.66≤z≤2, and M′ comprises one or more transition metal elements, and has a combined average metal oxidation state in the range of about +3.5 to about +4 in an initial discharged state thereof; and wherein the integrated ‘layered-spinel’ composite oxide structure is formed by heating a precursor composition in air at a temperature in the range of about 600 to about 850° C., wherein the precursor composition comprises either (a) LiMO 2 mixed with a targeted stoichiometric amount of Li and M′ nitrates, or (b) a mixture of Li, M, and M′ hydroxides, carbonates, and/or oxalates in a targeted stoichiometric ratio of Li, M and M′.