Pouch-shaped battery case for secondary batteries capable of discharging gas

Abstract

Disclosed herein is a pouch-shaped battery case, including an electrode assembly, an outer coating layer, a metal barrier layer, and an inner adhesive layer sequentially stacked with one another, a first adhesive layer interposed between the outer coating layer and the metal barrier layer, a second adhesive layer interposed between the metal barrier layer and the inner adhesive layer, an upper case and a lower case sealed to one another by thermal fusion at outer edges thereof, such that the electrode assembly is mounted between the upper case and the lower case, and a gas discharge member providing gas communication between an inside and an outside of the pouch-shaped battery case, the gas discharge member being disposed within a fused portion of the pouch-shaped battery case that is formed by the inner adhesive layer of the upper case and the lower case being thermally fused to one another.

Claims

1. A pouch-shaped battery case, comprising: an electrode assembly mounted within the pouch-shaped battery case; an outer coating layer, a metal barrier layer, and an inner adhesive layer sequentially stacked with one another; a first adhesive layer interposed between the outer coating layer and the metal barrier layer in order to increase a force of adhesion therebetween; a second adhesive layer interposed between the metal barrier layer and the inner adhesive layer in order to increase a force of adhesion therebetween; an upper case and a lower case sealed to one another by thermal fusion at outer edges thereof, such that the electrode assembly is mounted between the upper case and the lower case; and a gas discharge member providing gas communication between an inside and an outside of the pouch-shaped battery case, the gas discharge member being disposed within a fused portion of the pouch-shaped battery case that is formed as by the inner adhesive layer of the upper case and the lower case being thermally fused to one another.

2. The pouch-shaped battery case according to claim 1, wherein the gas discharge member is an elongated pipe-shaped member.

3. The pouch-shaped battery case according to claim 2, wherein the gas discharge member has open pores formed therein.

4. The pouch-shaped battery case according to claim 1, wherein the gas discharge member includes a gas adsorption material.

5. The pouch-shaped battery case according to claim 2, wherein a longitudinal direction of the gas discharge member coincides with an outward direction extending through the fused portion of the pouch-shaped battery case from the inside to the outside of the pouch-shaped battery case.

6. The pouch-shaped battery case according to claim 1, wherein the gas discharge member is located in a middle part, in a vertical direction, of the fused portion of the pouch-shaped battery case that is formed by the inner adhesive layer of the upper case and the inner adhesive layer of the lower case.

7. The pouch-shaped battery case according to claim 1, wherein the gas discharge member is configured to prevents foreign matter from being introduced into the pouch-shaped battery case during normal operation of the electrode assembly, and the gas discharge member is configured to discharges gas from the pouch-shaped battery case when an inner pressure within the pouch-shaped battery case reaches or exceeds a predetermined pressure.

8. The pouch-shaped battery case according to claim 1, wherein the gas discharge member comprises a plurality of individual gas discharge members disposed at predetermined intervals throughout an entirety of the fused portion of the pouch-shaped battery case.

9. The pouch-shaped battery case according to claim 2, wherein a thickness of the pipe-shaped gas discharge member is smaller than a thickness of the fused portion of the pouch-shaped battery case.

10. The pouch-shaped battery case according to claim 1, wherein the gas discharge member thermally fused within the fused portion of the pouch-shaped battery case.

11. A pouch-shaped battery cell comprising the pouch-shaped battery case according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a vertical sectional view showing a sealed portion of a pouch-shaped battery case according to an embodiment of the present invention, in which a gas discharge member is disposed.

(2) FIG. 2 is a vertical sectional view showing the state in which the sealed portion of the pouch-shaped battery case of FIG. 1 is thermally fused.

(3) FIG. 3 is a vertical sectional view showing a portion of the pouch-shaped battery case of FIG. 2.

(4) FIG. 4 is a plan view showing a pouch-shaped battery according to an embodiment of the present invention.

BEST MODE

(5) Now, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that the preferred embodiments of the present invention can be easily implemented by a person having ordinary skill in the art to which the present invention pertains. In describing the principle of operation of the preferred embodiments of the present invention in detail, however, a detailed description of known functions and configurations incorporated herein will be omitted when the same may obscure the subject matter of the present invention.

(6) Wherever possible, the same reference numbers will be used throughout the drawings to refer to parts that perform similar functions or operations. Meanwhile, in the case in which one part is ‘connected’ to another part in the following description of the present invention, not only may the one part be directly connected to the another part, but also, the one part may be indirectly connected to the another part via a further part. In addition, that a certain element is ‘included’ means that other elements are not excluded, but may be further included unless mentioned otherwise.

(7) Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

(8) FIG. 1 is a vertical sectional view showing a sealed portion of a pouch-shaped battery case according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view schematically showing the state in which the sealed portion of the pouch-shaped battery case of FIG. 1 is thermally fused.

(9) Referring to FIGS. 1 and 2, a pouch-shaped battery case 100 includes an upper case 110 and a lower case 120. The upper case 110 and the lower case 120 are configured to have the same structure. Specifically, the upper case 110 is configured to have a structure in which an outer coating layer 101, a metal barrier layer 102, and an inner adhesive layer 103 are sequentially stacked from the outside in the inward direction, in which an adhesive layer 104 is interposed between the outer coating layer 101 and the metal barrier layer 102 in order to increase the force of adhesion therebetween, and in which an adhesive layer 104 is also interposed between the metal barrier layer 102 and the inner adhesive layer 103 in order to increase the force of adhesion therebetween.

(10) Between the inner adhesive layer 103 of the upper case 110 and an inner adhesive layer 123 of the lower case 120 is disposed an elongated pipe-shaped gas discharge member 130 so as to extend through the inside and the outside of the battery case.

(11) In the case in which heat and pressure are applied to the upper surface and the lower surface of the pouch-shaped battery case 100 in directions indicated by arrows, the inner adhesive layers of the upper case and the lower case are melted to form a single adhesive layer 113, as shown in FIG. 2. As a result, the outer surface of the gas discharge member 130 may be surrounded by the adhesive layer 113, whereby the gas discharge member 130 may be fixed. The diameter of the gas discharge member 130 may be 50% to 90% of the height of the adhesive layer 113. The gas discharge member 130 may be located in the middle of the adhesive layer 113 in the vertical direction.

(12) FIG. 3 is a vertical sectional view schematically showing a portion of the pouch-shaped battery case of FIG. 2.

(13) Referring to FIG. 3, an electrode assembly 240, configured to have a structure in which a separator is interposed between a positive electrode and a negative electrode, is mounted in a battery case including an upper case 210 and a lower case 220. The outer edges of the upper case 210 and the lower case 220 are sealed by thermal fusion.

(14) A gas discharge member 230 is disposed in a sealed portion formed as the result of an inner adhesive layer of the upper case 210 and an inner adhesive layer of the lower case 220 being melted. The inside and the outside of the battery case communicate with each other via the gas discharge member 230, whereby gas may be discharged from a battery through the gas discharge member 230.

(15) A single gas discharge member 230 is shown. Alternatively, a plurality of gas discharge members may be interposed between the inner adhesive layers of the upper and lower cases in the vertical direction.

(16) FIG. 4 is a plan view schematically showing a pouch-shaped battery according to an embodiment of the present invention.

(17) Referring to FIG. 4, a pouch-shaped battery 300 includes a battery case having formed therein a concave unit 307 for receiving an electrode assembly 310, to which a positive electrode tab 301 and a negative electrode tab 303, which protrude in different directions, are attached. A positive electrode lead 302 connected to the positive electrode tab 301 and a negative electrode lead 304 connected to the negative electrode tab 303 extend out of the battery case.

(18) Individual gas discharge members 330 are disposed in a left sealed portion 311, a right sealed portion 312, an upper sealed portion 313, and a lower sealed portion 314 of the battery case when viewed in a plan view. The individual gas discharge members 330 are disposed at equal intervals. Alternatively, the individual gas discharge members 330 are disposed at different intervals. As another alternative, the individual gas discharge members may be disposed in the middle of the battery case in the longitudinal direction at smaller intervals in consideration of the fact that the middle of the battery case in the longitudinal direction swells more than the remaining portions of the battery case.

(19) Of course, the individual gas discharge members may be disposed in only one of the sealed portions, or may be disposed in only two or three sealed portions selected from among the four seals portions.

(20) Those skilled in the art to which the present invention pertains will appreciate that various applications and modifications are possible based on the above description, without departing from the scope of the present invention.

INDUSTRIAL APPLICABILITY

(21) As is apparent from the above description, the pouch-shaped battery case according to the present invention includes an upper case and a lower case, the outer edges of which are sealed by thermal fusion in the state in which an electrode assembly is mounted therein, wherein a gas discharge member for allowing the inside and the outside of the battery case to communicate with each other is disposed in a sealed portion formed as the result of the upper case and the lower case being sealed, whereby it is possible to discharge gas from a battery through the gas discharge member.

(22) In addition, since the gas discharge member is located in the sealed portion of the battery case, the overall size and/or shape of a pouch-shaped battery are not changed, and since the gas discharge member can be disposed in the sealed portion of the battery case in the process of manufacturing the pouch-shaped battery, it is not necessary to perform an additional process of installing the gas discharge member.

(23) Furthermore, in the case in which the pressure in the pouch-shaped battery increases during the use of the pouch-shaped battery, gas is discharged from the pouch-shaped battery, and in the case in which the pressure in the pouch-shaped battery decreases during the use of the pouch-shaped battery, gas is prevented from being discharged from the pouch-shaped battery, which are performed repeatedly. Consequently, it is possible to continuously use the battery.