Alkali metal titanates, and electrodes and batteries based on the same
View Patent ↗Disclosed is a lithium titanate material, which may include an additive, and its use as an electrode in a battery. Specifically disclosed is a lithium titanate based material, with primary particle size larger than 100 nm, having very good high rate charge and discharge capabilities when incorporated into a lithium battery.
1. A lithium titanate material comprised of aggregates and agglomeration of particles, said particles having an average size of more than 100 nm and a surface area of no more than 20 m 2 /g as measured by the BET method, said material including a zirconium additive.
2. The material of claim 1 , wherein said particles have an average size of more than 150 nm.
3. The material of claim 1 , wherein said particles have an average size in the range of 150-500 nm.
4. The material of claim 1 , wherein the surface area of said material, as measured by the BET method, is less than 15 m 2 /g.
5. The material of claim 1 , wherein the surface area of said material, as measured by the BET method, is in the range of 3-7 m 2 /g.
6. The material of claim 1 , wherein said particles have a crystallite size, as measured by XRD, is more than 100 nm.
7. The material of claim 1 , wherein said particles have a crystallite size, as measured by XRD, is in the range of 150-250 nm.
8. The material of claim 1 , wherein said material has a pore size distribution such that it includes a first distribution of pore sizes in the range of 0.1-1 micron, and a second distribution of pore sizes in the range of 1-100 microns.
9. The material of claim 8 , wherein the volume of the pores in said first distribution is greater than the volume of the pores in said second distribution.
10. The material of claim 8 , wherein the first distribution of pore sizes are in the range of 0.2-0.6 micron.
11. The material of claim 8 , wherein the second distribution of pore sizes are in the range of 5-50 microns.
12. The material of claim 1 , wherein the inclusion of said zirconium additive results in one or more of following: reducing the particle size of said material, reducing the crystallite size of said material, increasing the surface area of said material, producing more separated particles of said material, producing more faceted particles of said material, and improving the rate capability of said material.
13. The material of claim 1 , wherein said zirconium additive comprises 0.01-20 weight percent of said material.
14. The material of claim 1 , wherein said zirconium additive comprises 0.1-5 weight percent of said material.
15. An electrode which includes the material of claim 1 .
16. The electrode of claim 15 , wherein the porosity of said electrode prior to calendering is in the range of 10-50%, as measured by SEM image analysis.
17. The electrode of claim 15 , wherein the porosity of said electrode prior to calendering is greater than 20%, as measured by SEM image analysis.
18. A battery which includes the electrode of claim 15 .