| abstract |
A compound comprising a composition A x (M′ 1-a M″ a ) y (XD 4 ) z , A x (M′ 1-a M″ a ) y (DXD 4 ) z , or A x (M′ 1-a M″ a ) y (X 2 D 7 ) z , and have values such that x, plus y(1-a) times a formal valence or valences of M′, plus ya times a formal valence or valence of M″, is equal to z times a formal valence of the XD 4 , X 2 D 7 , or DXD 4 group; or a compound comprising a composition (A 1-a M″ a ) x M′ y (XD 4 ) z , (A 1-a M″ a ) x M′ y (DXD 4 ) z (A 1-a M″ a ) x M′ y (X 2 D 7 ) z and have values such that (1-a) x plus the quantity ax times the formal valence or valences of M″ plus y times the formal valence or valences of M′ is equal to z times the formal valence of the XD 4 , X 2 D 7 or DXD 4 group. In the compound, A is at least one of an alkali metal and hydrogen, M′ is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, molybdenum, and tungsten, M″ any of a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D is at least one of oxygen, nitrogen, carbon, or a halogen, 0.0001<a≦0.1, and x, y, and z are greater than zero. The compound can have a conductivity at 27° C. of at least about 10 −8 S/cm. The compound can be a doped lithium phosphate that can intercalate lithium or hydrogen. The compound can be used in an electrochemical device including electrodes and storage batteries and can have a gravimetric capacity of at least about 80 mAh/g while being charged/discharged at greater than about C rate of the compound. |