Patent ID: 7255957

Claim:
A non-aqueous electrolyte cell comprising: an exterior material having an inner surface; a cathode including a cathode current collector, a cathode active material, and an exposed portion, wherein said cathode active material is deposited on said cathode current collector except at said exposed portion, and wherein said cathode active material is a compound of an olivinic crystal structure having the formula Li x Fe 1-y M y PO 4 , wherein 0.05≦x≦1.2 and 0≦y≦0.8, wherein M is at least one element selected from the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B and Nb, said compound being used alone or in combination with other materials; an anode including an anode current collector, an anode active material, and an exposed portion, wherein said anode active material is deposited on said anode current collector except at said exposed portion; a separator for separating said cathode and said anode from each other; and a non-aqueous electrolyte solution; wherein said cathode, said separator, and said anode are layered and spirally-wound together to form a generally spirally-shaped cell device; wherein the exposed portion comprises (i) a portion of cathode and anode current collector leads protruding from the spirally-wound portion and (ii) a non-protruding radially outermost spirally-wound portion of said cathode facing said inner surface of said exterior material, wherein the exposed portion does not contribute to cell reaction; wherein said cell device is encapsulated within said exterior material except for said protruding collector leads; wherein the carbon material of said LiFePO 4 carbon composite material has a strength to area ratio of a diffraction line appearing at wave numbers 1570 to 1590 cm −1 (G peak) to a diffraction line appearing at wave numbers 1340 to 1360 cm −1 (D peak) of the Raman spectrum in Raman spectrometry, or A(D/G), equal to 0.3 or higher; and wherein the carbon content per unit volume in said LiFePO 4 is not less than 3 wt %.