EP-4742432-A1 - BATTERY MODULE

Abstract

The present invention relates to a battery module, and more particularly, to a battery module in which components inside the battery module is prevented from corroding by an electrolyte leaking when the electrolyte leaks from a secondary battery inside the battery module, and short circuit is prevented from occurring inside the battery module, thereby ultimately improving safety of the entire module. A battery module according to the present invention includes a cell assembly provided with a plurality of secondary batteries, each of which is provided with a plurality of electrode leads, and which are arranged to be stacked in at least one direction, and a busbar assembly provided with a plurality of busbars, which is configured to electrically connect the plurality secondary batteries to each other and in which at least one through-hole is defined so that the electrode leads are inserted, and a busbar frame configured so that the plurality of busbars are mounted, wherein each of the busbars has an immersion area that is an area immersed in an electrolyte when the electrolyte leaks from the secondary batteries, wherein the immersion area is treated to prevent corrosion.

Inventors

• SEON, SANG OK
• SHIN, JAE WOOK
• KIM, JEE WON
• LEE, YONG SEON

Assignees

• LG Energy Solution, Ltd.

Dates

Publication Date

20260513

Application Date

20240814

Claims (17)

1. A battery module comprising: a cell assembly provided with a plurality of secondary batteries, each of which is provided with a plurality of electrode leads, and which are arranged to be stacked in at least one direction; and a busbar assembly provided with a plurality of busbars, which is configured to electrically connect the plurality secondary batteries to each other and in which at least one through-hole is defined so that the electrode leads are inserted, and a busbar frame configured so that the plurality of busbars are mounted, wherein each of the busbars has an immersion area that is an area immersed in an electrolyte when the electrolyte leaks from the secondary batteries, wherein the immersion area is treated to prevent corrosion.
2. The battery module of claim 1, wherein the busbar is coated with an insulating material on the immersion area.
3. The battery module of claim 2, wherein the insulating material comprises epoxy.
4. The battery module of claim 2, wherein the insulating material is coated at a thickness of 200 um to 300 um.
5. The battery module of claim 2, wherein the insulating material is coated in at least one manner of dipping, air spray, and electrostatic coating methods.
6. The battery module of claim 1, wherein, in the busbar, the immersion area is removed.
7. The battery module of claim 6, wherein the through-hole has an opened lower side.
8. The battery module of claim 6, wherein the busbar has a closed-loop shape.
9. The battery module of claim 1, wherein the immersion area of the busbar is folded to a residual area disposed above the immersion area.
10. The battery module of claim 9, wherein the immersion area and the residual area are connected to each other in the form of hinge coupling.
11. The battery module of claim 10, wherein the immersion area comprises: an immersion area body; and a hinge protrusion protruding from an end of the immersion area body facing the residual area, and the residual area comprises: a residual area body; and a hinge recess recessed from an end of the residual area body facing the immersion area.
12. The battery module of claim 11, wherein the hinge protrusion comprises: a first protrusion protruding in a direction from an end of the immersion area body to the residual area body; and a second protrusion protruding from a side surface of the first protrusion, and the hinge recess has an area corresponding to that of the hinge protrusion so that the first protrusion and the second protrusion are inserted.
13. The battery module of claim 12, wherein the immersion area is folded by rotating around a virtual axis extending the second protrusion.
14. The battery module of claim 9 or 10, wherein the immersion area comprises: an immersion area body; and a coupling protrusion protruding from an outer surface of the immersion area body, which faces the residual area, and the residual area comprises: a residual area body; and a coupling recess provided in a recessed shape in an outer surface of the residual area body, which is recessed from an outer surface facing the immersion area, wherein the coupling protrusion is inserted into the coupling recess so that the immersion area is coupled to the residual area.
15. The battery module of claim 14, wherein the coupling protrusion comprises: a pillar portion protruding from the outer surface of the immersion area body; and a hook portion protruding from a sides surface of the pillar portion, wherein the coupling recess comprises a catch portion configured to allow the hook portion to be caught in the state in which the coupling protrusion is inserted.
16. The battery module of claim 9 or 10, wherein the residual area comprises: a residual area body; and a coupling protrusion protruding from an outer surface of the residual area body, which faces the immersion area, and the immersion area comprises: an immersion area body; and a coupling recess provided in a recessed shape in an outer surface of the immersion area body, which is recessed from an outer surface facing the residual area, wherein the coupling protrusion is inserted into the coupling recess so that the immersion area is coupled to the residual area.
17. The battery module of claim 16, wherein the coupling protrusion comprises: a pillar portion protruding from the outer surface of the residual area body; and a hook portion protruding from a sides surface of the pillar portion, wherein the coupling recess comprises a catch portion configured to allow the hook portion to be caught in the state in which the coupling protrusion is inserted.

Description

TECHNICAL FIELD CROSS-REFERENCE TO RELATED APPLICATION The present application claims the benefit of the priority of Korean Patent Application No. 10-2023-0107254, filed on August 16, 2023, which is hereby incorporated by reference in its entirety. TECHNICAL FIELD The present invention relates to a battery module, and more particularly, to a battery module in which components inside the battery module is prevented from corroding by an electrolyte leaking when the electrolyte leaks from a secondary battery inside the battery module, and short circuit is prevented from occurring inside the battery module, thereby ultimately improving safety of the entire module. BACKGROUND ART In recent years, the price of energy sources increases due to the depletion of fossil fuels, the interest in environmental pollution is amplified, and the demand for eco-friendly alternative energy sources is becoming an indispensable factor for future life. Accordingly, studies on various power generation technologies such as solar power, wind power, and tidal power are continuing, and power storage devices such as batteries for more efficiently using the generated electrical energy are also of great interest. Furthermore, as technology development and demand for electronic mobile devices and electric vehicles using batteries increase, the demands for batteries as energy sources are rapidly increasing. Thus, many studies on batteries which are capable of meeting various demands have been conducted. Particularly, in terms of materials, there is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries that have advantages such as high energy density, a discharge voltage, and output stability. Secondary batteries may be classified into cylindrical and prismatic batteries, in which an electrode assembly is built in a cylindrical or prismatic metal can, and pouch-type batteries, in which an electrode assembly is built in a pouch-type case made of an aluminum laminate sheet, depending on the shapes of the battery cases. However, an operating voltage of a unit cell, i.e., a unit battery cell is about 2.5 V to about 4.2 V. Thus, when a higher output voltage is required, the secondary battery module is manufactured by connecting a plurality of individual battery cells, and the plurality of battery modules are assembled to constitute a battery pack. FIG. 1 is a perspective view of a battery module according to the related art. FIG. 2 is a cross-sectional view taken along line A-A' of FIG. 1. FIG. 3 is a cross-sectional view taken along the line B-B' of FIG. 1. Referring to FIGS. 1 to 3, in a battery module 1 constituted by pouch-type secondary batteries 11, a cell assembly 10, in which a plurality of cells manufactured as the pouch-type secondary batteries 11 are stacked in a predetermined number, is mounted inside a module case having a rectangular shape. The module case 50 may include a top plate 51 covering an upper portion of the cell assembly 10, a side plate 52 covering a side surface of the cell assembly 10, and an endplate 53 coupled to the top plate 51 and the side plate 52 in a front and rear direction of the module case 50. A busbar assembly 30 may be disposed between the endplate 53 and the cell assembly 10. The busbar assembly 30 includes a busbar 31 and a busbar frame 32. The busbar 31 may have a shape in which a through-hole 31-1 is defined in a center of the rectangular plate configuration. The secondary battery 11 may be provided with an electrode lead 12 electrically connected to an internal electrode assembly to protrude, and the electrode lead 12 may be disposed on the busbar 31 to pass through the through-hole 31-1 and then be coupled to the busbar 31. In the battery module 1, the secondary batteries may be electrically connected to each other in parallel and/or series. For this, one end of the electrode lead 12 may be fixed in contact with the busbar through welding to electrically connect the secondary batteries 11 to each other. In addition, the busbar frame 32 may be a frame configuration capable of mounting the busbar 31. In order to apply a plurality of busbars 31, the busbar frame 32 made of an insulating material and capable of mounting the plurality of busbars 31 may be provided. An electrolyte is injected into the secondary batteries 11 constituting the cell assembly 10. When using the battery module 1, the electrolyte may leak out of the secondary batteries 11. This may be called electrolyte leakage. If the electrolyte leaks, the electrolyte may be stagnated at a lower side of the module case 50. In addition, as an amount of electrolyte gradually increases, a level of the electrolyte may ascend toward an upper side of the module case 50. Referring to FIGS. 2 and 3, the level of the leaking electrolyte is indicated by a dotted line E. The level of the electrolyte at the time of initial leakage is close to a bottom surface of the module case 50, but as the amount