Non-aqueous electrolyte cell and solid electrolyte cell

Abstract

A non-aqueous electrolyte cell is provided having improved cell characteristics and which maintains a cell shape encapsulated in a laminate film even when overdischarged to a cell voltage of 0 V. The cell includes an anode, an electrolyte, and a cathode containing a compound having the formula Li x Fe 1-y M y PO 4 , wherein 0.05≦x≦1.2 and 0≦y≦0.8, and 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. Exposed portions of an anode current collector and a cathode current collector prevent internal shorting of the cell.

What is claimed is: 
     
       1. 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 carbon composite material comprising (a) 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 and (b) a carbon material, said compound carbon composite material 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  Li x Fe 1-y M y PO 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  Li x Fe 1-y M y PO 4  carbon composite material is not less than 3 wt %. 
 
     
     
       2. The non-aqueous electrolyte cell according to  claim 1  wherein said anode active material is capable of doping and undoping lithium. 
     
     
       3. The non-aqueous electrolyte cell according to  claim 1  wherein said cathode active material is a LiFePO 4  carbon composite material comprising said compound and a carbon material. 
     
     
       4. The non-aqueous electrolyte cell according to claim  3  1 wherein the powder density of said LiFePO 4  Li x Fe 1-y M y PO 4  carbon composite material not less than 2.2 g/cm 3 . 
     
     
       5. The non-aqueous electrolyte cell according to claim  3  1 wherein the Bullnauer Emmet Teller specific surface area of said LiFePO 4  Li x Fe 1-y M y PO 4  carbon composite material is not less than 10.3 m 2 /g. 
     
     
       6. The non-aqueous electrolyte cell according to claim  3  1 wherein the first-order particle size of said LiFePO 4  Li x Fe 1-y M y PO 4  carbon composite material is not larger than 3.1 μm. 
     
     
       7. A solid electrolyte cell comprising:
 a laminate film 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 carbon composite material comprising (a) 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, and 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, and (b) a carbon material, said compound carbon composite material 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; and 
 a solid electrolyte; 
 wherein said cathode and said anode are layered and coiled together to form a 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 by said laminate film except for said protruding collector leads; 
 wherein the carbon material of said LiFePO 4  Li x Fe 1-y M y PO 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, A(D/G), equal to 0.3 or higher; and 
 wherein the carbon content per unit volume in said LiFePO 4  Li x Fe 1-y M y PO 4  carbon composite material is not less than 3 wt %. 
 
     
     
       8. The solid electrolyte cell according to  claim 7  wherein a separator is provided between said cathode and said anode. 
     
     
       9. The solid electrolyte cell according to  claim 7  wherein said anode active material is capable of doping and undoping lithium. 
     
     
       10. The solid electrolyte cell according to  claim 7  wherein said cathode active material is a LiFePO 4  carbon composite material comprising said compound and a carbon material. 
     
     
       11. The solid electrolyte cell according to claim  10  7 wherein the powder density of said LiFePO 4  Li x Fe 1-y M y PO 4  carbon composite material is not less than 2.2 g/cm 3 . 
     
     
       12. The solid electrolyte cell according to claim  10  7 wherein the Bullnauer Emmet Teller specific surface area of said LiFePO 4  Li x Fe 1-y M y PO 4  carbon composite material is not less than 10.3 m 2 /g. 
     
     
       13. The solid electrolyte cell according to claim  10  7 wherein the first-order particle size of said LiFePO 4  Li x Fe 1-y M y PO 4  carbon composite material is not larger than 3.1 μm. 
     
     
       14. The non-aqueous electrolyte cell according to  claim 7  wherein the exposed portion further comprises non-protruding self-facing portions of a radially innermost spirally-wound portion of said anode. 
     
     
       15. The non-aqueous electrolyte cell according to  claim 1  wherein the exposed portion further comprises non-protruding self-facing portions of a radially innermost spirally-wound portion of said anode. 
     
     
       16. 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 carbon composite material comprising (a) 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, and (b) a carbon material said compound carbon composite material 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; and (iii) a non-protruding self-facing portion of a radially innermost spirally-wound portion of said anode; 
 wherein the exposed portion does not contribute to cell reaction; 
 wherein said cell device is substantially encapsulated within said exterior material except for said protruding collector leads; 
 wherein the carbon material of said LiFePO 4  Li x Fe 1-y M y PO 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  Li x Fe 1-y M y PO 4 , is not less than 3 wt %. 
 
     
     
       17. A solid electrolyte cell comprising:
 a laminate film 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 carbon composite material comprising (a) 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, and 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, and (b) a carbon material, said compound carbon composite material 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; and 
 a solid electrolyte; 
 wherein said cathode and said anode are layered and coiled together to form a 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; and (iii) a non-protruding self-facing portion of a radially innermost spirally-wound portion of said anode; 
 wherein the exposed portion does not contribute to cell reaction; 
 wherein said cell device is substantially encapsulated by said laminate film except for said protruding collector leads; 
 wherein the carbon material of said LiFePO 4  Li x Fe 1-y M y PO 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, A(D/G), equal to 0.3 or higher; and 
 wherein the carbon content per unit volume in said LiFePO 4  Li x Fe 1-y M y PO 4 , carbon composite material is not less than 3 wt %.