JP-2026514323-A - Battery module and battery pack containing it

JP2026514323AJP 2026514323 AJP2026514323 AJP 2026514323AJP-2026514323-A

Abstract

The battery module according to the present invention includes a laminate consisting of stacked battery cells, a module case having gas vent holes in the bottom plate and housing the cell laminate, and a venting guide member including a main body portion having the property of warping in shape due to heat and a needle portion connected to the main body portion, wherein the venting guide member may be positioned on the bottom plate such that when the main body portion rises above a predetermined temperature, the main body portion warps, causing the needle portion to contact the battery cells. [Selection Diagram] Figure 10

Inventors

パク，ジョンフン

Assignees

エルジーエナジーソリューションリミテッド

Dates

Publication Date: 20260511
Application Date: 20250204
Priority Date: 20240229

Claims (14)

A cell stack consisting of stacked battery cells, A module case for housing the cell stack, with a gas vent hole in the bottom plate, A venting guide member comprising a main body having the property of warping in shape due to heat, and a needle portion connected to the main body, The venting guide member is positioned on the bottom plate such that when the main body rises above a predetermined temperature, the main body bends, causing the needle portion to contact the battery cell, in a battery module.
The battery module according to claim 1, characterized in that the main body portion includes a first metal portion and a second metal portion stacked vertically, each made of dissimilar metals with different coefficients of thermal expansion.
The second metal portion has a higher coefficient of thermal expansion than the first metal portion. The battery module according to claim 2, characterized in that the venting guide member is positioned on the bottom plate of the module case such that the second metal portion faces the bottom plate of the module case.
The main body is, The battery module according to claim 1, characterized in that it includes a needle insertion hole into which the needle portion is inserted, and an elastic member disposed in the needle insertion hole and coupled with the needle portion.
The battery module according to claim 4, characterized in that the bottom plate of the module case includes a needle blocking portion configured to compress the elastic member and block the front of the needle portion so that the needle portion inserted into the needle insertion hole does not protrude.
The main body portion includes a rotating shaft portion formed to protrude from the side, The battery module according to claim 1, characterized in that the bottom plate of the module case is provided with a shaft mounting portion that engages with the rotating shaft portion.
The bottom plate of the module case includes a groove that is recessed to correspond to the main body, The battery module according to claim 1, characterized in that the venting guide member is inserted into the groove.
The battery module according to claim 1, characterized in that the needle portions are multiple, and the spacing between the needle portions corresponds to the thickness of the battery cell.
The aforementioned module case is An upper plate covering the upper part of the cell stack, A lower plate that covers the lower part of the cell stack and forms the bottom plate, A pair of side plates that cover both sides of the cell stack, The battery module according to claim 1, characterized by comprising a pair of end covers that cover the front and rear of the cell stack, respectively.
The aforementioned battery cell is a pouch-type battery cell, The gas vent holes are provided at predetermined intervals along the width direction of the lower plate, The battery module according to claim 9, characterized in that the gas vent holes are provided at positions corresponding to the cell terraces formed by heat welding of the pouch sheet in the pouch-type battery cell, above and below.
The battery module according to claim 10, characterized in that the venting guide members are arranged alternately with the gas vent holes along the width direction of the lower plate on the lower plate.
A busbar electrically connected to electrode leads provided in the aforementioned battery cell, The present invention further includes a busbar frame that supports the busbar, has lead slots through which the electrode leads pass, and is attached to the front or rear of the cell stack, The battery module according to claim 1, wherein the busbars include a first busbar and a second busbar arranged to overlap the electrode leads, and the electrode leads are crimped and fixed between the first busbar and the second busbar.
The aforementioned battery cells are pouch-type battery cells, each with its wide surface raised and stacked in one direction. The cell stack includes a plurality of barrier plates that are sandwiched between the battery cells at predetermined intervals along one direction to restrict the movement of heat or gas between the battery cells. The battery module according to claim 12, characterized in that each of the plurality of barrier plates is joined to the busbar frame at its end so that the battery cells and gas vent holes are divided into a predetermined number of units.
A battery pack comprising the battery module described in any one of claims 1 to 13.

Description

This invention relates to a battery module and a battery pack including the same, and more particularly to a battery module and a battery pack including the same with improved safety against thermal events. This application claims priority under Korean Patent Application No. 10-2024-0029489, filed on February 29, 2024, and all information disclosed in the specification and drawings of said application is incorporated herein by reference. As technological development and demand for various mobile devices, electric vehicles, and energy storage systems (ESS) increase, interest in and demand for rechargeable batteries as an energy source are rapidly growing. While nickel-cadmium or nickel-metal hydride batteries were traditionally commonly used as rechargeable batteries, this year, lithium-ion batteries are gaining popularity due to their minimal memory effect, flexible charging and discharging, extremely low self-discharge rate, and high energy density compared to nickel-based batteries. Such lithium-ion secondary batteries primarily use lithium-based oxides and carbon materials as the positive electrode active material and negative electrode active material, respectively. A lithium-ion secondary battery comprises an electrode assembly in which a positive electrode plate and a negative electrode plate, each coated with the respective positive and negative electrode active materials, are arranged with a separator in between; and an outer casing, i.e., a battery case, that seals and houses the electrode assembly along with the electrolyte. Lithium-ion batteries are generally classified into two types based on the shape of their casing: can-type batteries, where the electrode assembly is housed in a metal can, and pouch-type batteries, where the electrode assembly is housed in an aluminum laminate sheet pouch. Lithium-ion batteries commonly used today have an operating voltage of approximately 2.5V to 4.5V per unit. Therefore, in electric vehicles and power storage devices requiring high capacity and output, multiple lithium-ion batteries are connected in series and/or parallel to form battery modules or battery packs, which are used as the energy source. In particular, to meet the output and capacity requirements of electric vehicles, battery modules and battery packs contain a large number of lithium-ion batteries. On the other hand, such battery modules or battery packs may experience a thermal event, such as a gas or flame, which causes heat to accumulate internally and rapidly propagate between battery cells (thermal runaway). As a result, the battery cells could explode in a chain reaction, posing a serious risk to the user's life and property. Therefore, when a thermal event occurs, it is necessary to actively dissipate the heat and pressure from inside the battery module to minimize damage before the heat and pressure inside the battery module rapidly increase, causing a chain reaction of battery cell explosions or the battery module to collapse. This is a schematic perspective view of a battery module according to one embodiment of the present invention. Figure 1 is an exploded perspective view of the battery module. Figure 2 is a perspective view of the cell stack. This figure shows the lower plate of the module case in Figure 2. This figure shows a venting guide member according to one embodiment of the present invention, with a main body portion and a needle portion partially inserted into the main body portion. This figure shows a venting guide member according to one embodiment of the present invention, comprising a main body and a needle portion protruding from the main body. This is a schematic cross-sectional view of the venting guide member along line A-A' in Figure 6. This is a magnified view of a portion of the lower plate according to one embodiment of the present invention. This figure shows the venting guide member attached to the lower plate of Figure 8. This figure shows the state of the venting guide member before operation according to one embodiment of the present invention. This figure shows the operating state of a venting guide member according to one embodiment of the present invention. This figure illustrates an example of assembling a cell stack and a busbar frame according to one embodiment of the present invention. Figure 12 shows a busbar frame in which the frame cover and the crimped busbar are connected. This is a schematic cross-sectional view of an interconnected cell stack and busbar frame according to one embodiment of the present invention. This diagram schematically shows an automobile including a battery pack according to one embodiment of the present invention. The following describes preferred embodiments of the present invention in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and the claims should not be interpreted in their ordinary or dictionary sense, but rather in accordance with the principle that th