Active electrode material
The invention relates to active electrode materials and to methods for the manufacture of active electrode materials. Such materials are of interest as active electrode materials in lithium-ion or sodium-ion batteries. The invention provides an active electrode material expressed by the general formula M1 a M2 2-a M3 b Nb 34-b O 87-c-d Q d .
1. An active electrode material comprising a mixed niobium oxide, wherein the mixed niobium oxide has the composition M1 a Zn 2-a M3 b Nb 34-b O 87-c , wherein:
M1 is selected from Mg, Zr, V, Cr, Mo, W, Fe, Cu, Al, Ge, P, and mixtures thereof;
M3 is selected from Ti, Zr, V, Cr, Mo, W, Fe, Cu, Zn, Al, P, and mixtures thereof;
0<a<1.0; 0<b≤3.4; −0.5≤c≤4.35.
2. The active electrode material of claim 1 , wherein
0<a≤0.6.
3. The active electrode material of claim 1 , wherein
0<b≤1.5.
4. The active electrode material of claim 1 , wherein c≠0.
5. The active electrode material of claim 1 , wherein
0≤c≤4.35.
6. The active electrode material of claim 1 , wherein M1 has an equal or higher valency than 2+.
7. The active electrode material of claim 1 , wherein M3 has a lower valency than 5+.
8. The active electrode material of claim 1 , wherein M3 does not comprise Zn and/or Cu.
9. The active electrode material of claim 1 , wherein:
M1 is selected from Cr, Al, Ge, and mixtures thereof;
M3 is selected from Ti, Zr, Fe, and mixtures thereof
0 <a <1.0;
0 <b ≤1.5;
−0.5 ≤c≤ 4.35.
10. The active electrode material of claim 1 , wherein:
M1 is Cr;
M3 is selected from Ti, Zr, and mixtures thereof;
0.01< a< 1.0;
0.01< b< 1.0;
−0.5≤ c≤ 2.
11. The active electrode material of claim 1 , wherein the mixed niobium oxide is oxygen deficient.
12. The active electrode material of claim 1 , wherein the mixed niobium oxide is coated with carbon.
13. The active electrode material of claim 1 , wherein the mixed niobium oxide is in particulate form and has a D 50 particle diameter in the range of 0.1-100 μm.
14. The active electrode material of claim 1 , wherein the mixed niobium oxide has a BET surface area in the range of 0.1-100 m 2 /g.
15. The active electrode material of claim 1 , wherein the mixed niobium oxide further comprises Li and/or Na intercalated within a crystal structure of the mixed niobium oxide.
16. The active electrode material of claim 1 , wherein the crystal structure of the mixed niobium oxide as determined by X-ray diffraction corresponds to the crystal structure of Zn 2 Nb 34 O 87 .
17. The active electrode material of claim 1 comprising the mixed niobium oxide and at least one other component selected from a binder, a solvent, a conductive additive, a different active electrode material, and mixtures thereof.
18. An electrode comprising the active electrode material of claim 1 in electrical contact with a current collector.
19. A lithium-ion battery or a sodium-ion battery comprising an anode, a cathode, and an electrolyte disposed between the anode and the cathode, wherein the anode comprises the active electrode material of claim 1 .
20. A method of making the mixed niobium oxide of claim 1 , the method comprising steps of:
providing one or more precursor materials;
mixing said precursor materials to form a precursor material mixture; and
heat treating the precursor material mixture in a temperature range from 400° C.-1350° C., thereby providing the mixed niobium oxide.