Conductive lithium storage electrode

1. A composition comprising a compound selected from the group consisting of (Li 1−a M″ a ) x M′(PO 4 ) and (Li b−a M″ a ) x M′(PO 4 ), wherein M′ is a first-row transition metal, M″ is one or more dopants selected from a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, 0.0001<a≦0.1, a≦b≦1, and x is greater than zero, wherein

(i) the composition has a specific surface area of at least 15 m 2 /g;

(ii) the composition crystallizes in an ordered or partially disordered structure of the olivine Li x M(PO 4 ) structure type; and

(iii) M″ is an ion selected to be supervalent to the lowest valence state of M′ in the compound; and

additionally having a molar concentration of the metals (M′+M″) relative to the concentration of P that exceeds the ideal stoichiometric ratio of 1:1 in the olivine structure type compound by at least 0.0001.

2. A composition comprising a compound Li x (M′ 1−a M″ a )PO 4 , wherein M′ is a first-row transition metal, M″ is one or more dopants selected from a Group IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIIB, VB, and VIB metal, 0.0001<a≦0.1, and x is greater than zero, wherein

(i) the composition has a specific surface area of at least 15 m 2 /g;

(ii) the composition crystallizes in an ordered or partially disordered structure of the olivine Li x M(PO 4 ) structure type; and

(iii) M″ is an ion selected to be supervalent to the lowest valence state of M′ in the compound.

3. The composition of claim 1 , wherein the molar concentration of the metals (M′+M″) relative to the concentration of P exceeds the ideal stoichiometric ratio of 1:1 in of the olivine structure type compound by at least 0.01.

4. The composition of claim 1 , wherein the molar concentration of the metals (M′+M″) relative to the concentration of P exceeds the ideal stoichiometric ratio of 1:1 in of the olivine structure type compound by at least 0.002.

5. The composition of claim 1 , wherein the molar concentration of the metals (M′+M″) relative to the concentration of P that exceeds the ideal stoichiometric ratio of 1:1 in of the olivine structure type compound by an amount in the range of 0.001 to 0.04.

6. The composition of claim 1 or 2 , wherein M′ is a first row transition metals selected from the group consisting of iron, vanadium, chromium, manganese, cobalt and nickel and the mixture thereof.

7. The composition of claim 6 , wherein M′ is Fe 2+ .

8. The composition of claim 7 , wherein M′ further comprises an additional first-row transition metal.

9. The composition of claim 1 , wherein M″ is any of one or more dopants selected from aluminum, titanium, zirconium, niobium, tantalum, tungsten, or magnesium or combinations thereof.

10. The composition of claim 2 , wherein M″ is any of one or more dopants selected from aluminum, titanium, zirconium, niobium, tantalum, tungsten, and combinations thereof.

11. The composition of claims 1 or 2 , wherein the compound, upon delithiation, undergoes phase-separation into a substantially lithiated compound and a substantially delithiated compound, each of which has an electronic conductivity of at least 10 −6 S/cm.

12. The composition of claims 1 or 2 , wherein the composition contains in crystalline solid solution, amongst the metals M′ and M″, simultaneously the metal ions Fe 2+ and Fe 3+ , Mn 2+ and Mn 3+ , Co 2+ and Co 3+ , Ni 2+ and Ni 3+ , V 2+ and V 3+ , or Cr 2+ and Cr 3+ , with the ion of lesser concentration being at least 10 parts per million of the sum of the two ion concentrations.

13. The composition of claims 1 or 2 , wherein the M″ includes a metal with ionic radius less than the average ionic radius of the M′ ions.

14. The composition of claims 1 or 2 , wherein vacancy defects are present on a lattice site.

15. The composition of claims 1 or 2 , wherein lithium is substituted onto a M2 site of a crystal of the composition at a concentration of at least 10 18 per cubic centimeter, or x and a are selected such that lithium can substitute into an M2 site of a crystal of the composition as an acceptor defect.

16. The composition of claims 1 or 2 , wherein the composition compound is Li x vac y (M 1 −a M″ a )PO 4 , Li x−ay M″ a vac y M′PO 4 , Li x (M′ 1−a−y M″ a vac y )PO 4 or Li x−a M″ a M′ 1−y vac y PO 4 , wherein vac represents a vacancy in a structure of the compound.

17. The composition of claim 16 , wherein M′ is Fe.

18. The composition of claims 1 or 2 , wherein M″ has a concentration of at least 0.01 atom % relative to the concentration of M′.

19. The composition of claims 1 or 2 , wherein M″ has a concentration of at least 0.02 mole % relative to the concentration of M′.

20. The composition of claims 1 or 2 , wherein M″ has a concentration of at least 0.05 mole % relative to the concentration of M′.

21. The composition of claims 1 or 2 , wherein M″ has a concentration of at least 0.1 mole % relative to the concentration of M′.

22. The composition of claims 1 or 2 , wherein the compound has a specific surface area of at least 20 m 2 /g.

23. The composition of claims 1 or 2 , wherein the compound has a specific surface area of at least 30 m 2 /g.

24. The composition of claims 1 or 2 , wherein the compound has a specific surface area of at least 40 m 2 /g.

25. The composition of claims 1 or 2 , wherein the compound has a specific surface area of at least 50 m 2 /g.

26. The composition of claims 1 or 2 , wherein the conductivity is at least 10 −7 S/cm.

27. The composition of claims 1 or 2 , wherein the conductivity is at least 10 −6 S/cm.

28. The composition of claims 1 or 2 , wherein the conductivity is at least 10 −5 S/cm.

29. The composition of claims 1 or 2 , wherein the conductivity is at least 10 −4 S/cm.

30. The composition of claims 1 or 2 , wherein the conductivity is at least 10 −3 S/cm.

31. The composition of claims 1 or 2 , wherein the conductivity is at least 10 −2 S/cm.

32. An electrode comprising the composition of claims 1 or 2 as a storage material.

33. The electrode of claim 32 , having a material energy density that while:

charging or discharging at a rate ≧30 mA per g of storage compound, is greater than 350 Wh/kg, or

charging or discharging at a rate ≧150 mA per g of storage compound, is greater than 280 Wh/kg, or

charging or discharging at a rate ≧300 mA per g of storage compound, is greater than 270 Wh/kg, or

charging or discharging at a rate ≧750 mA per g of storage compound, is greater than 250 Wh/kg, or

charging or discharging at a rate ≧1.5 A per g of storage compound, is greater than 180 Wh/kg, or

charging or discharging at a rate ≧3 A per g of storage compound, is greater than 40 Wh/kg, or

charging or discharging at a rate ≧4.5 A per g of storage compound, is greater than 10 Wh/kg.

34. The electrode of claim 32 , having a material energy density that while:

charging or discharging at a rate ≧30 mA per g of storage compound, is greater than 420 Wh/kg, or

charging or discharging at a rate ≧150 mA per g of storage compound, is greater than 400 Wh/kg, or

charging or discharging at a rate ≧300 mA per g of storage compound, is greater than 370 Wh/kg, or

charging or discharging at a rate ≧750 mA per g of storage compound, is greater than 350 Wh/kg, or

charging or discharging at a rate ≧1.5 A per g of storage compound, is greater than 270 Wh/kg, or

charging or discharging at a rate ≧3 A per g of storage compound, is greater than 150 Wh/kg, or

charging or discharging at a rate ≧4.5 A per g of storage compound, is greater than 80 Wh/kg, or

charging or discharging at a rate ≧6 A per g of storage compound, is greater than 35 Wh/kg, or

charging or discharging at a rate ≧7.5 A per g of storage compound, is greater than 50 Wh/kg, or

charging or discharging at a rate ≧15 A per g of storage compound, is greater than 10 Wh/kg.

35. The electrode of claim 32 , having a material energy density that while:

charging or discharging at a rate ≧30 mA per g of storage compound, is greater than 475 Wh/kg, or

charging or discharging at a rate ≧150 mA per g of storage compound, is greater than 450 Wh/kg, or

charging or discharging at a rate ≧300 mA per g of storage compound, is greater than 430 Wh/kg, or

charging or discharging at a rate ≧750 mA per g of storage compound, is greater than 390 Wh/kg, or

charging or discharging at a rate ≧1.5 A per g of storage compound, is greater than 350 Wh/kg, or

charging or discharging at a rate ≧3 A per g of storage compound, is greater than 300 Wh/kg, or

charging or discharging at a rate ≧4.5 A per g of storage compound, is greater than 250 Wh/kg, or

charging or discharging at a rate ≧7.5 A per g of storage compound, is greater than 150 Wh/kg, or

charging or discharging at a rate ≧11 A per g of storage compound, is greater than 50 Wh/kg, or

charging or discharging at a rate ≧15 A per g of storage compound, is greater than 30 Wh/kg.

36. The electrode of claim 32 , wherein the electrode is a sheet or mesh of electronically conductive material coated with a loading of 4 mg to 20 mg of said storage compound per square centimeter of projected area of the sheet or mesh.

37. The electrode of claim 32 , wherein said electrode is a sheet or mesh of electronically conductive material coated with said storage material and has a total thickness of 20 micrometers to 200 micrometers.

38. The electrode of claim 32 , wherein M′ includes Fe 2+ .

39. The electrode of claim 32 wherein M′ further comprises an additional first-row transition metal.

40. A battery cell comprising:

a positive electrode;

a negative electrode; and

a separator positioned between the positive electrode and the negative electrode, wherein at least one of the positive electrode or negative electrode comprises the composition of claims 1 or 2 .

41. The battery cell of claim 40 , wherein the cell is incorporated into disposable battery or a rechargeable battery.