Amorphous and partially amorphous nanoscale ion storage materials
View Patent ↗Amorphous or partially amorphous nanoscale ion storage materials are provided. For example, lithium transition metal phosphate storage compounds are nanoscale and amorphous or partially amorphous in an as-prepared state, or become amorphous or partially amorphous upon electrochemical intercalation or de-intercalation by lithium. These nanoscale ion storage materials are useful for producing devices such as high energy and high power storage batteries.
1. A compound having the formula Li a C b M c N d X e O f , wherein M is one or more first-row transition metals; N is an element from Groups IIA, IIIA, IVA, VA, VIA, IIB, IIIB or VIIB of the periodic table; X is one or more of P, Si, Ge, As, S; 0≦a≦1; 0.001≦b≦0.10; 0.8≦c≦1.2; 0≦d≦0.10; 0.9≦e≦2.2; and 3.6≦f≦8.8.
2. The compound of claim 1 , wherein M includes at least one first row transition metal selected from the group consisting of Ti, V, Cr, Mn, Fe, Co and Ni.
3. The compound of claim 1 , wherein M is Fe.
4. The compound of claim 1 , wherein M includes Mn and Fe.
5. The compound of claim 1 , wherein N is Nb and 0<d≦0.10.
6. The compound of claim 1 , wherein X is P.
7. The compound of claim 1 , wherein the compound contains lithium at a concentration of at least about 5% by mole relative to the transition metal concentration.
8. The compound of claim 1 , wherein the compound contains lithium at a concentration of at least about 10% by mole relative to the transition metal concentration.
9. The compound of claim 1 , wherein the compound contains lithium at a concentration of no more than about 95% by mole relative to the transition metal concentration.
10. The compound of claim 1 , wherein the compound contains lithium at a concentration of no more than about 85% by mole relative to the transition metal concentration.
11. A material comprising the compound of claim 1 , wherein the material is at least partially amorphous.
12. A material comprising the compound of claim 1 , wherein the material has a specific surface area of at least about 10 m 2 /g.
13. A material comprising the compound f claim 1 , wherein the material has a specific surface area of at least about 25 m 2 /g.
14. A material comprising the compound of claim 1 , wherein the material has a specific surface area of at least about 50 m 2 /g.
15. A material comprising the compound of claim 1 , wherein the material has a primary particle size with an average smallest cross-sectional dimension of about 200 nm or less.
16. A material comprising the compound of claim 1 , wherein the material has a primary particle size with an average smallest cross-sectional dimension of about 100 nm or less.
17. A cathode comprising the compound of claim 1 .
18. An electrochemical cell comprising the cathode of claim 17 .