Pouch-type battery and method of assembling for the same

Abstract

A pouch, in which an electrode assembly of a battery is held, including a frame, including a groove into which the electrode assembly is inserted with a front of the electrode assembly temporarily exposed, upper and lower flanges bordering upper and lower ends of the groove, and extended parts on either side of the groove, front and upper sealing parts formed when the extended parts are folded over the front of the electrode assembly and the upper and lower flanges and sealed together and to the upper flange, respectively, the front and upper sealing parts defining a pocket in which an electrolyte solution is injected toward the electrode assembly, and a lower sealing part formed when the folded extended parts are sealed to the lower flange.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a perspective view of a conventional pouch-type lithium secondary battery illustrating a status in which a pouch is not sealed;

FIG. 2 is a perspective view of a conventional pouch-type lithium secondary battery illustrating a status in which edges of two sides of a bare cell opposed to each other from which the electrode taps are not drawn out, are folded;

FIG. 3 is an enlarged cross-sectional view of the conventional pouch-type lithium secondary battery taken along line A-A in FIG. 2

FIGS. 4 to 7 are state diagrams to illustrate an assembly of a pouch-type lithium secondary battery according to an embodiment of the present invention; and

FIGS. 8 and 9 illustrate another embodiment of the present invention.

Claims

1. A pouch-type battery, comprising: an electrode assembly, in which first and second electrodes, each comprising an electrode tap, and a separator interposed between the first and second electrodes are stacked and wound; anda pouch-type case including: a rear part having a side wall of a groove, in which the electrode assembly is disposed,a bottom surface of the groove, anda flange part extending from a first pair of opposite sides around the groove and a front part having two extended parts extending from a pair of second opposite sides around the groove, sides of the flange part being connected to the second pair of the sides to cover the electrode assembly disposed in the groove,wherein ends of the two extended parts overlap and are welded to form a front sealing part, andwherein the overlapped portion of the front sealing part over the flange part is at least partially welded to a corresponding portion of the flange part to form upper and lower sealing parts.

2. The pouch-type battery according to claim 1, wherein a predetermined tensile force is applied to the pouch-type case in a direction similar to that of a wrapping direction of the outer circumference of the electronic assembly.

3. The pouch-type battery according to claim 1, wherein the electrode taps are drawn out of the upper sealing part, and wherein the lower sealing part is bent toward the groove to contact the bottom surface of the pouch-type case.

4. The pouch-type battery according to claim 1, wherein the front sealing part is formed by welding the ends of the two extended parts to each other in a state in which the inner surfaces are opposed to each other.

5. The pouch-type battery according to claim 4, wherein the front sealing part is bent so as to contact the front part.

6. The pouch-type battery according to claim 1, wherein positions at which the electrode taps are drawn out are separated from each other in a longitudinal direction of the first pair of the sides, and wherein the front sealing part is formed between the positions at which the electrode taps are drawn out.

7. The pouch-type battery according to claim 6, wherein the electrode taps are substantially symmetric with respect to a center-line of the pouch, and wherein the front sealing part is disposed between the positions at which the electrode taps are drawn out.

8. The pouch-type battery according to claim 1, wherein a trace of an opening portion is formed in a lower side wall among the side walls forming the groove.

9. The pouch-type battery according to claim 1, wherein two side walls connected to the second pair of the sides among the four side walls forming the groove and portions at which the two side walls and the two extended parts are connected comprise curved surfaces.

10. The pouch-type battery according to claim 9, wherein the curved surfaces are similarly shaped as the corresponding outer circumferential surfaces of the electrode assembly.

11. A method of assembling a pouch-type battery, the method comprising: preparing a pouch exterior frame having a groove, two flange parts which are located around the groove and which are opposed to each other, and two extended parts which are opposed to each other;winding an electrode assembly, including two electrodes having electrode taps and a separator interposed between the two electrodes;disposing the electrode assembly in the groove with the electrode taps being drawn out of the pouch exterior frame through one of the flange parts;partially overlapping and welding two ends of the two extended parts with each other on the electrode assembly to form a front sealing part; andforming a seal between at least one of the flange parts and the overlapped portion of the two extended parts.

12. The method according to claim 11, the method further comprising: injecting an electrolyte solution into an opening portion of each of the flange parts and the overlapped portion of the two extended parts;forming a seal at the opening portions; andconnecting external electric terminals to the electrode taps to perform an initial charging.

13. The method according to claim 12, wherein the forming of the seal at the opening portions comprises: sealing an end, which is separated from the groove, of the lower flange part, from which the electrode taps are not drawn out;sealing an end portion, which is close to the groove, of the lower flange part to form a lower sealing part after the connecting of the external electric terminals to the electrode taps to perform the initial charging; andremoving a lower portion of the lower sealing part.

14. The method according to claim 13, wherein the preparing of the pouch exterior frame comprises forming a gas room in the lower flange part, and wherein the removing of the lower portion of the lower sealing part comprises removing a portion in which the gas room is formed.

15. The method according to claim 11, wherein the welding of the two extended parts comprises applying a tensile force to the two ends during the welding.

16. The method according to claim 11, further comprising bending the lower sealing part so as to contact the bottom surface of the pouch-type case, after the removing of the lower portion of the lower sealing part.

17. The method according to claim 11, wherein the forming of the front sealing part and the welding at least one of the flange part and the overlapped portion of the two extended parts are performed substantially simultaneously.

18. A pouch, in which an electrode assembly of a battery is held, comprising: a frame, including a groove into which the electrode assembly is inserted with a front of the electrode assembly temporarily exposed, upper and lower flanges bordering upper and lower ends of the groove, respectively, and extended parts on either side of the groove;front and upper seals formed when the extended parts are folded over the front of the electrode assembly and the upper and lower flanges and sealed to each other and to the upper flange, respectively, the front and upper seals defining a pocket to allow for an electrolyte solution to be injected toward the electrode assembly; anda lower seal formed when the folded extended parts are sealed to the lower flange.

19. The pouch according to claim 18, wherein electrode taps, which are coupled to the electrode assembly, are drawn out from the electrode assembly through the upper seal.

20. The pouch according to claim 19, wherein insulating tape is provided around the electrode taps.

21. The pouch according to claim 18, wherein the lower seal is folded toward a bottom exterior surface of the groove.

22. The pouch according to claim 18, wherein the front seal is folded toward one of the extended parts.

23. The pouch according to claim 18, wherein a shape of the groove is substantially similar to that of the electrode assembly.

24. A pouch, in which an electrode assembly of a battery is held, the electrode assembly having curved sides, the pouch comprising: a frame, including a groove into which the electrode assembly is inserted with a front of the electrode assembly temporarily exposed, upper and lower flanges bordering upper and lower ends of the groove, respectively, and extended parts on either side of the groove, the groove having curved sides which tightly fit around the curved sides of the electrode assembly;front and upper seals formed when the extended parts are folded over the front of the electrode assembly and the upper and lower flanges and sealed to each other and to the upper flange, respectively, the front and upper seals defining a pocket to allow for an electrolyte solution to be injected toward the electrode assembly; anda lower seal formed when the folded extended parts are sealed to the lower flange.