Jelly-roll type electrode assembly pattern-coated with active material and secondary battery including the same

1. A jelly-roll electrode assembly pattern-coated with active materials, manufactured by winding and compressing a separator and an anode and a cathode arranged on both sides of the separator,

wherein the anode comprises an anode flat coated portion coated with an anode active material and an anode curved uncoated portion not coated with the anode active material, which are alternately formed,

wherein the cathode comprises a cathode flat coated portion coated with a cathode active material and a cathode curved uncoated portion not coated with the cathode active material, which are alternately formed,

wherein the anode flat coated portion is coated with the anode active material on both sides of the anode, which are outside and inside of the anode,

wherein the cathode flat coated portion is coated with the cathode active material on both sides of the cathode, which are outside and inside of the cathode,

wherein the anode flat coated portion formed outside of the anode has a width smaller than that of the anode flat coated portion formed inside of the anode in a location corresponding thereto, and

wherein the cathode flat coated portion formed outside of the cathode has a width smaller than that of the cathode flat coated portion formed inside of the cathode in a location corresponding thereto.

2. The jelly-roll electrode assembly of claim 1 , wherein the anode curved uncoated portion has widths increasing progressively from a first end to a last end of the anode in contact with a core for winding the electrode assembly.

3. The jelly-roll electrode assembly of claim 1 , wherein a first radius curvature of the anode curved uncoated portion is smaller than a first radius curvature of the cathode curved uncoated portion.

4. The jelly-roll electrode assembly of claim 3 , wherein a width of an inner side of the anode curved uncoated portion satisfies a following equation,

W ( I ) n anode ≦π{( Ts/ 2)+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (1)]

wherein W(I)n anode designates a width of an inner side of an nth anode curved uncoated portion, Ts designates a thickness of the separator, Ta designates a thickness of the anode, Tc designates a thickness of the cathode, and n is an integer.

5. The jelly-roll electrode assembly of claim 3 , wherein a width of an outer side of the anode curved uncoated portion satisfies a following equation,

W ( II ) n anode ≦π{( Ts/ 2+ Ta )+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (2)]

wherein W(II)n anode designates a width of an outer side of an nth anode curved uncoated portion, Ts designates a thickness of the separator, Ta designates a thickness of the anode, Tc designates a thickness of the cathode, and n is an integer.

6. The jelly-roll electrode assembly of claim 3 , wherein the cathode curved uncoated portion has widths increasing progressively from a first end to a last end of the cathode in contact with a core for winding the electrode assembly.

7. The jelly-roll electrode assembly of claim 3 , wherein a width of an inner side of the cathode curved uncoated portion satisfies a following equation,

W ( III ) n cathode ≦π{(3 Ts/ 2+ Ta )+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (3)]

wherein W(III)n cathode designates a width of an inner side of an nth cathode curved uncoated portion, Ts designates a thickness of the separator, Ta designates a thickness of the anode, Tc designates a thickness of the cathode, and n is an integer.

8. The jelly-roll electrode assembly of claim 3 , wherein a width of an outer side of the cathode curved uncoated portion satisfies a following equation,

W ( IV ) n cathode ≦π{(3 Ts/ 2+ Ta+Tc )+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (4)]

wherein W(IV)n cathode designates a width of an outer side of the nth cathode curved uncoated portion, Ts designates the thickness of the separator, Ta designates a thickness of the anode, Tc designates a thickness of the cathode, and n is an integer.

9. The jelly-roll electrode assembly of claim 1 , wherein a first radius curvature of the cathode curved uncoated portion is smaller than a first radius curvature of the anode curved uncoated portion.

10. The jelly-roll electrode assembly of claim 9 , wherein a width of an inner side of the cathode curved uncoated portion satisfies a following equation

W ( I ) n cathode ≦π{( Ts/ 2)+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (5)]

wherein W(I)n cathode designates a width of an inner side of an nth cathode curved uncoated portion, Ts designates a thickness of the separator, Ta designates a thickness of the cathode, Tc designates a thickness of the anode, and n is an integer.

11. The jelly-roll electrode assembly of claim 9 , wherein a width of an outer side of the cathode curved uncoated portion satisfies a following equation,

W ( II ) n cathode ≦π{( Ts/ 2+ Ta )+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (6)]

wherein W(II)n cathode designates a width of an outer side of the nth cathode curved uncoated portion, Ts designates the thickness of the separator, Ta designates a thickness of the cathode, Tc designates a thickness of the anode, and n is an integer.

12. The jelly-roll electrode assembly of claim 9 , wherein a width of an inner side of the anode curved uncoated portion satisfies a following equation,

W ( III ) n anode ≦π{(3 Ts/ 2+ Ta )+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (7)]

wherein W(III)n anode designates a width of an inner side of an nth anode curved uncoated portion, Ts designates a thickness of the separator, Ta designates a thickness of the cathode, Tc designates a thickness of the anode, and n is an integer.

13. The jelly-roll electrode assembly of claim 9 , wherein a width of an outer side of the anode curved uncoated portion satisfies a following equation,

W ( IV ) n anode ≦π{(3 Ts/ 2+ Ta+Tc )+( n− 1)( Ts+Ta/ 2+ Tc/ 2)}  [Equation (8)]

wherein W(IV)n anode designates a width of an outer side of the nth anode curved uncoated portion, Ts designates the thickness of the separator, Ta designates a thickness of the cathode, Tc designates a thickness of the anode, and n is an integer.

14. The jelly-roll electrode assembly of claim 1 , wherein the cathode active material is lithium iron phosphate having an olivine crystal structure having a composition satisfying a following formula,

Li 1+a Fe 1−x M x (PO 4−b )X b   Formula (1)

wherein M is at least one selected from the group consisting Al, Mg, Ni, Co, Mn, Ti, Ga, Cu, V, Nb, Zr, Ce, In, Zn, and Y, X is at least one selected from the group consisting of F, S, and N, and −0.5≦a≦+0.5, 0≦x≦0.5, 0≦b≦0.1.

15. The jelly-roll electrode assembly of claim 14 , wherein lithium iron phosphate is LiFePO 4 .

16. A secondary battery comprising the jelly-roll electrode assembly of claim 1 .

17. A medium-large sized battery module comprising a plurality of secondary batteries of claim 16 , which are electrically connected to one another.

18. The medium-large sized battery module of claim 17 , being used as a medium-large sized device power source of one or more of power tools, electric vehicles comprising electric vehicles (EVs), hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), electric trucks, electric commercial vehicles, and power storage systems.

19. A medium-large sized battery pack comprising a plurality of secondary batteries of claim 16 , which are electrically connected to one another.

20. The medium-large sized battery pack of claim 19 , being used as a medium-large sized device power source of one or more of power tools, electric vehicles comprising electric vehicles (EVs), hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), electric trucks, electric commercial vehicles, and power storage systems.