Battery case having gas adsorption layer

Abstract

Disclosed herein is a battery case configured to receive an electrode assembly and an electrolytic solution therein, the electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, the battery case including a layer structure and a gas adsorption layer formed on the inner surface of the layer structure, the gas adsorption layer including a gas adsorption material layer configured to adsorb a reaction gas that may be generated within the battery case during abnormal functioning of the electrode assembly, and a blocking layer formed on an exposed surface of the gas adsorption material layer, the blocking layer configured to prevent the gas adsorption material layer from being exposed to an ambient gas during assembly of the battery case.

Claims

1. A battery case configured to receive an electrode assembly and an electrolytic solution therein, the electrode assembly comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, the battery case comprising: a layer structure; and a gas adsorption layer formed on an inner surface of the layer structure, the gas adsorption layer comprising: a gas adsorption material layer configured to adsorb a reaction gas that may be generated within the battery case during abnormal functioning of the electrode assembly; and a blocking layer formed on an exposed surface of the gas adsorption material layer, the blocking layer configured to prevent the gas adsorption material layer from being exposed to an ambient gas during assembly of the battery case, the blocking layer being a film having a structure that does not transmit air to the gas adsorption material layer, the blocking layer covering all of the gas adsorption material layer during assembly of the battery case, wherein the blocking layer is configured to be dissolved by the electrolytic solution after assembly of the battery case, such that the gas adsorption material layer is exposed to the electrolytic solution, wherein the blocking layer consists of a polymer film selected from among polyamide, polyvinyl alcohol, polycarbonate and polyethylene vinyl acetate.

2. The battery case according to claim 1, wherein, after assembly of the battery case, the electrolytic solution contacts the gas adsorption layer.

3. The battery case according to claim 1, wherein the gas adsorption material layer comprises at least one gas adsorption material selected from a group consisting of organic compounds or metals.

4. The battery case according to claim 1, wherein the layer structure comprises an outer coating layer and a metal layer disposed adjacent to the outer coating layer, the battery case further comprising an inner resin layer disposed adjacent to the metal layer, the layer structure and the inner resin layer together forming a laminate pouch.

5. The battery case according to claim 4, wherein the inner resin layer has the gas adsorption material contained therein.

6. A battery cell comprising a battery case according to claim 1.

7. The battery case according to claim 1, wherein the layer structure comprises a can-shaped metal.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a vertical sectional view showing a pouch-shaped battery case according to an embodiment of the present invention.

(2) FIG. 2 is a vertical sectional view showing a pouch-shaped battery case according to another embodiment of the present invention.

(3) FIG. 3 is a vertical sectional view showing a can-shaped battery case according to an embodiment of the present invention.

(4) FIG. 4 is a partial vertical sectional view showing a pouch-shaped secondary battery configured to have a structure in which an electrode assembly is received in the battery case of FIG. 1 together with an electrolytic solution.

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 pouch-shaped battery case 100 according to an embodiment of the present invention.

(9) The pouch-shaped battery case 100 of FIG. 1 is configured to have a structure in which a gas adsorption layer 120 is attached to an inner surface of a laminate sheet 110, which includes an outer coating layer 111, a metal layer 112, and an inner resin layer 113, which are sequentially stacked from the outside.

(10) The gas adsorption layer 120 includes a gas adsorption material layer 121 for adsorbing gas generated in a battery and a blocking layer 122 formed on the outer surface of the gas adsorption material layer 121 for preventing the gas adsorption material layer 121 from being exposed to the outside.

(11) FIG. 2 is a vertical sectional view showing a pouch-shaped battery case 200 according to another embodiment of the present invention.

(12) Referring to FIG. 2, the pouch-shaped battery case 200 is configured to have a structure in which a blocking layer 222 is attached to an inner surface of a laminate sheet 210, which includes an outer coating layer 211, a metal layer 212, and an inner resin layer 213, which are sequentially stacked from the outside.

(13) The pouch-shaped battery case 200 does not include a separate gas adsorption material layer. Instead, a gas adsorption material 223 is included in the inner resin layer 213.

(14) FIG. 3 is a vertical sectional view showing a can-shaped battery case 300 according to an embodiment of the present invention.

(15) Referring to FIG. 3, a gas adsorption layer 320, which includes a gas adsorption material layer 321 and a blocking layer 322, is formed in the can-shaped battery case 300.

(16) Referring to FIGS. 1 and 4, particularly FIG. 4 is a partial vertical sectional view showing a pouch-shaped secondary battery configured to have a structure in which an electrode assembly 140 is received in the pouch-shaped battery case 100 together with an electrolytic solution 130.

(17) The electrode assembly 140 is placed in the pouch-shaped battery case 100, the electrolytic solution 130 is injected into the pouch-shaped battery case 100, and a final sealing process is performed. As a result, the blocking layer is dissolved or dispersed by the electrolytic solution 130, whereby the gas adsorption material layer 121 is exposed to the inner surface of the pouch-shaped battery case 100.

(18) The gas adsorption material layer 121 exposed to the inner surface of the pouch-shaped battery case adsorbs gas generated in the battery. Although only the gas adsorption layer 120 is shown in FIG. 4, the gas adsorption material layer 121 is dissolved or dispersed by the electrolytic solution.

(19) In the above structure, gas that is inevitably generated when the battery is usually used, as well as gas that is generated when the battery is abnormally used, directly reacts with a gas adsorption material constituting the gas adsorption material layer, whereby the gases are more rapidly removed. As a result, a swelling phenomenon is reduced. Consequently, it is possible to maximally preventing the battery from exploding or catching fire, whereby it is possible to improve the safety of the battery. In particular, the pouch-shaped secondary battery according to the present invention is characterized in that the pouch-shaped secondary battery is configured to have a structure that is capable of preventing non-ideal adsorption of gas that may occur when the battery is assembled and that is capable of allowing the adsorption of gas only when the battery is actually used, which has not yet been disclosed or suggested in the conventional art. Consequently, the present invention provides strong effects through the very simple structure described above.

(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.

DESCRIPTION OF REFERENCE NUMERALS

(21) 100, 200: Pouch-shaped battery cases

(22) 300: Can-shaped battery case

(23) 110, 210: Laminate sheets

(24) 111, 211: Outer coating layers

(25) 112, 212: Metal layers

(26) 113, 213: Inner resin layers

(27) 120, 320: Gas adsorption layers

(28) 121, 321: Gas adsorption material layers

(29) 122, 222, 322: Blocking layers

(30) 223: Gas adsorption material

(31) 130: Electrolytic solution

(32) 140: Electrode assembly

INDUSTRIAL APPLICABILITY

(33) As is apparent from the above description, a battery case according to the present invention is configured to have a structure in which a blocking layer is formed on the outer surface of a gas adsorption material layer. As a result, gas in the air is not adsorbed when a battery is assembled. After the battery is finally sealed, the blocking layer is dissolved by an electrolytic solution, whereby only the gas that is generated in the battery is effectively adsorbed. Consequently, it is possible to prevent the thickness or the inner pressure of the battery from being increased due to the gas generated in the battery, whereby it is possible to greatly improve the safety of the battery.

(34) In addition, the size of a useless space in the battery is reduced, whereby it is possible to improve the energy density of the battery.

(35) In addition, the electrolytic solution that is consumed when the battery is charged and discharged is replenished, since the blocking layer may be made of a solid-type or gel-type electrolyte, whereby it is possible to increase the lifespan of the battery.