Cathode material for manufacturing a rechargeable battery
A cathode material has one of olivine and NASICON structures and includes micrometer-sized secondary particles having a particle size ranging from 1 to 50 μm. Each of the micrometer-sized secondary particles is composed of crystalline nanometer-sized primary particles of a metal compound having a particle size ranging from 10 to 500 nm.
1. A cathode material having a structure selected from the group consisting of olivine and NASICON structures, comprising micrometer-sized secondary particles having a particle size ranging from 1 to 50 μm, each of said micrometer-sized secondary particles being composed of crystalline nanometer-sized primary particles of a metal compound having a particle size ranging from 10 to 500 nm.
2. The cathode material of claim 1 , wherein each of said micrometer-sized secondary particles is formed by sintering of contacted portions of surfaces of adjacent ones of said crystalline nanometer-sized primary particles.
3. The cathode material of claim 2 , further comprising a carbonaceous component.
4. The cathode material of claim 2 , further comprising carbon particles adhered to the surfaces of said crystalline nanometer-sized primary particles of each of said micrometer-sized secondary particles.
5. The cathode material of claim 1 , wherein said metal compound has a formula of A 3x M 2y (PO 4 ) 3 , in which A represents a first metal element selected from the group consisting of Groups IA, IIA and IIIA; M represents a second metal element selected from the group consisting of Groups IIA and IIIA, and transition elements; and 0<x≦1.2, 0<y≦1.6.
6. The cathode material of claim 5 , wherein the first metal element is selected from the group consisting of Li, Na, K, Be, Mg, B, and Al, and the second metal element is selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Be, Mg, Ca, Sr, B, Al, Ge, Sn and Ga.
7. The cathode material of claim 1 , wherein said cathode material has a BET specific surface area ranging from 5 to 100 m 2 /g.
8. A cathode for a rechargeable battery, comprising an electrode plate and a coating of a cathode material coated on said electrode plate, wherein said cathode material comprises micrometer-sized secondary particles having a particle size ranging from 1 to 50 μm, each of said micrometer-sized secondary particles being composed of crystalline nanometer-sized primary particles of a metal compound having a particle size ranging from 10 to 500 nm.
9. The cathode of claim 8 , wherein each of said micrometer-sized secondary particles is formed by sintering of contacted portions of surfaces of adjacent ones of said crystalline nanometer-sized primary particles of said metal compound.
10. The cathode of claim 9 , wherein said cathode material further comprises a carbonaceous component.
11. The cathode of claim 9 , wherein said cathode material further comprises carbon particles adhered to the surfaces of said crystalline nanometer-sized primary particles of each of said micrometer-sized secondary particles.
12. The cathode of claim 8 , wherein the metal compound has a formula of A 3x M 2y (PO 4 ) 3 , in which A represents a first metal element selected from the group consisting of Groups IA, IIA and IIIA; M represents a second metal element selected from the group consisting of Groups IA and IIIA, and transition elements; and 0<x≦1.2, 0<y≦1.6.
13. The cathode of claim 12 , wherein the first metal element is selected from the group consisting of Li, Na, K, Be, Mg, B, and Al, and the second metal element is selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Be, Mg, Ca, Sr, B, Al, Ge, Sn and Ga.
14. The cathode of claim 8 , wherein said cathode material has a BET specific surface area ranging from 5 to 100 m 2 /g.
15. The cathode of claim 8 , wherein said cathode material further comprises an aqueous binder.
16. The cathode of claim 15 , wherein said aqueous binder is styrene-butadiene rubber (SBR).
17. The cathode of claim 8 , wherein said cathode material further includes a thickener.
18. The cathode of claim 17 , wherein said thickener is carboxymethyl cellulose (CMC).
19. The cathode of claim 8 , wherein said cathode material further comprises a non-aqueous binder.
20. The cathode of claim 19 , wherein said non-aqueous binder is polyvinylidene fluoride (PVDF).