EP-4738541-A1 - BATTERY MODULE, BATTERY PACK AND VEHICLE INCLUDING SAME

Abstract

The present disclosure relates to a battery module including: a cell stack including a plurality of battery cells; a module case configured to accommodate the cell stack; and a thermally conductive layer provided between the module case and the cell stack and configured so that bonding strength varies from the outside to the inside.

Inventors

• KIM, JEE-WON
• SHIN, JAE-WOOK

Assignees

• LG Energy Solution, Ltd.

Dates

Publication Date

20260506

Application Date

20241113

Claims (14)

1. A battery module comprising: a cell stack comprising a plurality of battery cells; a module case configured to accommodate the cell stack; and a thermally conductive layer provided between the module case and the cell stack and configured so that bonding strength varies from an outside to an inside.
2. The battery module according to claim 1, wherein the thermally conductive layer is configured so that the bonding strength is reduced from the outside to the inside.
3. The battery module according to claim 1, wherein the thermally conductive layer comprises a first thermally conductive layer configured to be in contact with the module case, and a second thermally conductive layer provided further inward than the first thermally conductive layer so as to be in contact with the cell stack.
4. The battery module according to claim 3, wherein the first thermally conductive layer and the second thermally conductive layer are configured to be different in bonding strength.
5. The battery module according to claim 3, wherein a bonding strength of the second thermally conductive layer is configured to be lower than a bonding strength of the first thermally conductive layer.
6. The battery module according to claim 3, wherein the second thermally conductive layer is formed of a material having a lower degree of hardening than the first thermally conductive layer.
7. The battery module according to claim 3, wherein the second thermally conductive layer is formed of a material comprising silicon.
8. The battery module according to claim 3, wherein the second thermally conductive layer is configured to surround ends of the battery cells.
9. The battery module according to claim 8, wherein the second thermally conductive layer is configured to be inserted between the plurality of battery cells when swelling of the battery cell occurs.
10. The battery module according to claim 8, wherein the first thermally conductive layer is configured to be in contact with the ends of the battery cells.
11. The battery module according to claim 8, wherein the first thermally conductive layer is configured to surround the ends of the battery cell.
12. The battery module according to claim 3, wherein the thermally conductive layer is configured to include a portion in which a thickness of the second thermally conductive layer varies as it gets closer to an outermost portion in a stacking direction of the battery cells.
13. A battery pack comprising a battery module according to any one of claims 1 to 12.
14. A vehicle comprising a battery module according to any one of claims 1 to 12.

Description

TECHNICAL FIELD The present disclosure relates to a battery module, and a battery pack and a vehicle including the same. This application is based on and claims priority from Korean Patent Application No. 10-2023-0162568, filed on November 21, 2023, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. BACKGROUND ART Secondary batteries, which are easy to apply depending on the product group and have electrical features such as high energy density and the like, are generally used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) that are driven by an electrical drive source, as well as in portable devices. These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency because of the primary advantage of dramatically reducing the use of fossil fuels and another advantage of not generating by-products resulting from energy use. Secondary batteries currently widely used include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and the like. When a higher output voltage is required, a battery module or battery pack may be configured by connecting a plurality of battery cells in series. In addition, a battery module or battery pack may be configured by connecting multiple battery cells in parallel to increase the charge/discharge capacity. When configuring a battery pack by connecting multiple battery cells in series/parallel, it is common to preferentially configure a battery module including one or more battery cells and then add other components using at least one battery module to configure a battery pack or battery rack. Alternatively, recently, a battery pack has been manufactured in a cell-to-pack type in which multiple battery cells are directly stored in a pack housing or the like, instead of modularizing the same. Meanwhile, in a conventional battery module, a thermally conductive adhesive may be applied to one side of a cell stack, which are obtained by stacking these battery cells, to cool the battery cells. The conventional battery module may have various problems caused by swelling of the battery cells during the charge/discharge cycle. For example, when swelling occurs in the battery cells, all the battery cells of the cell stack move to the outermost part, whereas one side of the cell stack that is in direct contact with the thermally conductive adhesive is fixed by the thermally conductive adhesive cured. As a result, a problem may occur in which a part of the cell case with relatively low elongation is damaged. Alternatively, when swelling occurs in the battery cells, the thermally conductive adhesive cured may be damaged as the cell stack moves, causing partial or entire structural collapse of the cell stack or battery device. In addition, during this process, the battery cell may be separated from the thermally conductive adhesive, thereby degrading the heat dissipation performance of the battery cell. DISCLOSURE Technical Problem The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module with an improved structure capable of securing stability even when swelling occurs, and a battery pack and a vehicle including the same. However, the technical problems that the present disclosure seeks to solve are not limited to the above-mentioned problems, and other problems not mentioned above will be clearly understood by those skilled in the art from the description of the invention described below. Technical Solution In one aspect of the present disclosure, there is provided a battery module including: a cell stack including a plurality of battery cells; a module case configured to accommodate the cell stack; and a thermally conductive layer provided between the module case and the cell stack and configured so that bonding strength varies from an outside to an inside. The thermally conductive layer may be configured so that the bonding strength is reduced from the outside to the inside. The thermally conductive layer may include a first thermally conductive layer configured to be in contact with the module case, and a second thermally conductive layer provided further inward than the first thermally conductive layer so as to be in contact with the cell stack. The first thermally conductive layer and the second thermally conductive layer may be configured to be different in bonding strength. The bonding strength of the second thermally conductive layer may be configured to be lower than the bonding strength of the first thermally conductive layer. The second thermally conductive layer may be formed of a material having a lower degree of hardening than the first thermally conductive layer. The second thermally conductive layer may be formed of a material including silicon. The second therma