Active electrode material
The present invention provides a phosphorus niobium oxide active electrode material with the composition M1aPx-aM2bNb9-bO25-c-dQd, wherein: M1 is selected from Na, K, Mg, Ca, Sr, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, Si, Ge, Sn, Bi, Sb, and mixtures thereof; M2 is selected from Na, K, Mg, Ca, Sr, Y, Ti, Zr, Hf, V, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, Si, Ge, Sn, Bi, P, Sb, and mixtures thereof; Q is selected from F, Cl, Br, I, N, S, Se, and mixtures thereof; 0≤a≤0.5; 0≤b'2; −0.5≤c≤1.25; 0≤d≤5; 1≤x≤2; one or more of a, b, c, and d does not equal 0; with the proviso that if M1 consists of Nb and if M2 consists of P then c is >0. Such materials are of interest as active electrode materials in lithium-ion or sodium-ion batteries.
1. An electrode comprising a phosphorus niobium oxide active electrode material in electrical contact with a current collector, wherein the active electrode material has the composition
M1 a P x-a M2 b Nb 9-b O 25-c-d Q d , wherein:
M1 is selected from Na, K, Mg, Ca, Sr, Y, Ti, Zr, Hf, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, Si, Ge, Sn, Bi, Sb, and mixtures thereof;
M2 is selected from Na, K, Mg, Ca, Sr, Y, Ti, Zr, Hf, V, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, Si, Ge, Sn, Bi, P, Sb, and mixtures thereof;
Q is selected from F, Cl, Br, I, N, S, Se, and mixtures thereof;
0≤a≤0.5; 0≤b≤2; −0.5≤c≤1.25; 0≤d≤5; 1≤x≤2; and
one or more of a, b, c, and d does not equal 0;
with the proviso that if M1 consists of Nb and if M2 consists of P then c is >0.
2. The electrode of claim 1 , wherein
(i) a>0; and/or
(ii) 0≤a≤0.3.
3. The electrode of claim 1 , wherein
(i) b>0; and/or
(ii) 0≤b≤1.5.
4. The electrode of claim 1 , wherein
(i) c ≠0; or
(ii) 0≤c≤1.25.
5. The electrode of claim 1 , wherein
(i) d>0; and/or
(ii) 0≤d≤2.5.
6. The electrode of claim 1 , wherein 1≤x≤1.25.
7. The electrode of claim 1 , wherein at least one of a and b is >0.
8. The electrode of claim 1 , wherein M1 is selected from Ti, Zr, Hf, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, Si, Ge, Sn, Bi, Sb, and mixtures thereof.
9. The electrode of claim 1 , wherein M2 is selected from Ti, Zr, Hf, V, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, Si, Ge, Sn, Bi, P, Sb, and mixtures thereof.
10. The electrode of claim 1 , wherein M1 does not comprise Nb and wherein M2 does not comprise P.
11. The electrode of claim 1 , wherein Q is selected from F, Cl, N, S, and mixtures thereof.
12. The electrode according to claim 1 , wherein the active electrode material is oxygen deficient.
13. The electrode according to claim 1 , wherein the active electrode material is coated with carbon.
14. The electrode according to claim 13 , wherein the carbon coating comprises polyaromatic sp 2 carbon.
15. The electrode according to claim 1 , wherein the active electrode material is in particulate form, wherein the active electrode material has a D 50 particle diameter in the range of 0.1-100 μm.
16. The electrode according to claim 1 , wherein the active electrode material has a BET surface area in the range of 0.1-100 m 2 /g.
17. The electrode according to claim 1 , wherein the active electrode material further comprises Li and/or Na.
18. The electrode according to claim 1 , wherein the crystal structure of the active electrode material as determined by X-ray diffraction corresponds to the crystal structure of one or more of PNb 9 O 25 , and P 2.5 Nb 18 O 50 .
19. An electrochemical device comprising an anode, a cathode, and an electrolyte disposed between the anode and the cathode, wherein the anode comprises an active electrode material as defined in claim 1 ;
wherein the electrochemical device is a lithium-ion battery or a sodium-ion battery.
20. The electrode according to claim 14 , wherein the carbon coating is derived from pitch carbons.