Cation-disordered rocksalt lithium metal oxides and oxyfluorides and methods of making same
A disordered rocksalt lithium metal oxide and oxyfluoride as in manganese-vanadium oxides and oxyfluorides well suited for use in high capacity lithium-ion battery electrodes such as those found in lithium-ion rechargeable batteries. A lithium metal oxide or oxyfluoride example is one having a general formula: Li x M′ a M″ b O 2-y F y , with the lithium metal oxide or oxyfluoride having a cation-disordered rocksalt structure of one of (a) or (b), with (a) 1.09≤x≤1.35, 0.1≤a≤0.7, 0.1≤b≤0.7, and 0≤y≤0.7; M′ is a low valent transition metal and M″ is a high-valent transition metal; and (b) 1.1≤x≤1.33, 0.1≤a≤0.41, 0.39≤b≤0.67, and 0≤y≤0.3; M′ is Mn; and M″ is V or Mo. The oxides or oxyfluorides balance accessible Li capacity and transition metal capacity. An immediate application example is for high energy density Li-cathode battery materials, where the cathode energy is a key limiting factor to overall performance. The second structure (b) is optimized for maximal accessible Li capacity.
1. A lithium metal oxyfluoride having a general formula: Li x M′ a M″ b O 2-y F y , said lithium metal oxyfluoride having a cation-disordered rocksalt structure of one of (a) or (b), wherein
(a) 1.09≤x≤1.35, 0.1≤a≤0.7, 0.1≤b≤0.7, and 0<y≤0.7; M′ is a low-valent transition metal and M″ is a high-valent transition metal; and
(b) 1.1≤x≤1.33, 0.1≤a≤0.41, 0.39≤b≤0.67, and 0<y≤0.3; M′ is Mn; and M″ is V or Mo.
2. The lithium metal oxyfluoride of claim 1 , wherein the rocksalt structure is (a) and M′ is selected from the group consisting of Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ , and combinations thereof.
3. The lithium metal oxyfluoride of claim 2 , wherein M′ is Mn 2+ .
4. The lithium metal oxyfluoride of claim 1 , wherein the rocksalt structure is (a) and M″ is selected from the group consisting of V 3+ , V 4+ , Mo 4+ , Mo 5+ , and combinations thereof.
5. The lithium metal oxyfluoride of claim 4 , wherein M″ is V 4+ or Mo 5+ .
6. The lithium metal oxyfluoride of claim 4 having a formula: Li x M′ a V b O 2-y F y , wherein 1.09≤x≤1.35, 0.1≤a≤0.7, 0.1≤b≤0.7, and 0<y≤0.7.
7. The lithium metal oxyfluoride of claim 1 , wherein the rocksalt structure is (a) and 1.1≤x≤1.2, 0.25≤a≤0.4, 0.4≤b≤0.6, and 0<y≤0.3.
8. The lithium metal oxyfluoride of claim 1 , having a cation-disordered rocksalt structure characterized by a crystallographic space group Fm- 3 m.
9. The lithium metal oxyfluoride of claim 1 , having a discharge capacity of about 250 mAh/g to about 400 mAh/g.
10. The lithium metal oxyfluoride of claim 1 , having an energy density of about 700 Wh/kg to about 900 Wh/kg.
11. A positive electrode material, comprising:
a lithium metal oxyfluoride of claim 1 .
12. A lithium-ion battery, comprising:
a negative electrode material;
an electrolyte; and
the positive electrode material of claim 11 .
13. A portable electronic device, an automobile, or an energy storage system, comprising:
the lithium-ion battery of claim 12 .
14. A lithium metal oxyfluoride having a general formula: Li x M′ a M″ b O 2-y F y , said lithium metal oxyfluoride having a cation-disordered rocksalt structure, wherein 1.1≤x≤1.33, 0.1≤a≤0.41, 0.39≤b≤0.67, and 0<y≤0.3; M′ is Mn; and M″ is V or Mo.
15. The lithium metal oxyfluoride of claim 14 is Li 1.23 Mn 0.255 V 0.515 O 1.8 F 0.2 (LR-LMVF20).
16. The lithium metal oxyfluoride of claim 14 , wherein M′ is Mn 2+ .
17. The lithium metal oxyfluoride of claim 14 , wherein M″ is selected from the group consisting of V 3+ , V 4+ , Mo 4+ , Mo 5+ .
18. The lithium metal oxyfluoride of claim 17 , wherein M″ is V 4+ or Mo 5+ .
19. The lithium metal oxyfluoride of claim 14 , wherein M″ is V.
20. The lithium metal oxyfluoride of claim 14 , wherein 1.1≤x≤1.2, 0.25≤a≤0.4, 0.4≤b≤0.6, and 0<y≤0.3.
21. The lithium metal oxyfluoride of claim 14 , having a cation-disordered rocksalt structure characterized by a crystallographic space group Fm- 3 m.
22. The lithium metal oxyfluoride of claim 14 , having a discharge capacity of about 250 mAh/g to about 400 mAh/g.
23. The lithium metal oxyfluoride of claim 14 , having an energy density of about 700 Wh/kg to about 900 Wh/kg.
24. A positive electrode material, comprising:
a lithium metal oxyfluoride of claim 14 .
25. A lithium-ion battery, comprising:
a negative electrode material;
an electrolyte; and
the positive electrode material of claim 24 .
26. A portable electronic device, an automobile, or an energy storage system, comprising:
the lithium-ion battery of claim 25 .