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EP-4489199-B1 - BATTERY PACK

EP4489199B1EP 4489199 B1EP4489199 B1EP 4489199B1EP-4489199-B1

Inventors

  • HUR, NAM HOON
  • SHIN, JU HWAN
  • JEON, JONG PIL
  • KIM, MIN BUM
  • LEE, HYOUNG SUK

Dates

Publication Date
20260506
Application Date
20230927

Claims (12)

  1. A battery pack accommodating a battery module (M), comprising: a pack case (1000) including a module area (Am) where the battery module (M) is seated, wherein the pack case (1000) comprises: a base plate (100); a side wall (200) coupled along the perimeter of the base plate (100); and a support wall (300) coupled to an inner surface of the side wall (200), wherein the support wall (300) includes a coupling part (310) protruding in a ribbed shape on one side opposite the side wall (200), characterized in that the side wall (200) includes an insertion groove (200h1) recessed for insertion of the coupling part (310) of the support wall (300) on the inside, the support wall (300) is coupled to the side wall (200) by the coupling part (310) being inserted into the insertion groove (200h1), and the coupling part (310) and insertion groove (200h1) are fixed to each other by welding.
  2. The battery pack of claim 1, wherein the side wall (200) comprises: a front frame (210) including terminals for the battery pack; a rear frame (220) disposed opposite the front frame (210); and a pair of side frames (230) coupled to ends of the front frame (210) and rear frame (220), respectively, on each side of the base plate (100), wherein the support wall (300) is coupled to at least one of the front frame (210) and rear frame (220).
  3. The battery pack of claim 2, wherein the insertion groove (200h1) is formed extending along a longitudinal direction of the front frame (210) or rear frame (220), and the coupling part (310) of the support wall (300) coupled to the insertion groove (200h1) is formed extending along a longitudinal direction of the support wall (300) corresponding to the insertion groove (200h1).
  4. The battery pack of claim 2, wherein the battery module (M) includes a cell stack (L) having a plurality of cells (C) stacked thereon, and a pair of reinforcement plates (Pr) coupled to support both side surfaces located at outermost part in the cell stack (L), wherein the battery module (M) accommodated in the pack case (1000) to abut the front frame (210) or the rear frame (220) is fixed to the pack case (1000) by at least one of the reinforcement plates (Pr) coupled to the support wall (300).
  5. The battery pack of claim 4, wherein the battery module (M) is fixed to the pack case (1000) by bolts (Bt) passing through the coupled support wall (300) and reinforcement plate (Pr) and screwed to the base plate (100).
  6. The battery pack of claim 4, wherein the reinforcement plate (Pr) included in the battery module (M) includes a protrusion part (Pr1) at the upper part that protrudes to form a step along the height direction of the battery module (M), wherein the height of the support wall (300) is less than the lower end height of the protrusion part (Pr1) included in the reinforcement plate (Pr) coupled to the support wall (300).
  7. The battery pack of claim 4, wherein the reinforcement plate (Pr) included in the battery module (M) includes a protrusion part (Pr1) that protrudes to form a step along the height direction of the battery module, wherein the battery module (M) is coupled to the support wall (300) by being positioned so that the lower part of the protrusion part (Pr1) of the reinforcement plate (Pr) is on the upper end of the support wall (300).
  8. The battery pack of claim 1, wherein the insertion groove (200h1) includes an inwardly inclined surface at the upper part, the coupling part (310) of the support wall (300) fits into a space excluding the inclined surface of the insertion groove (200h1), and weld beads (Bw) produced by welding is filled between the coupling part (310) and the inclined surface.
  9. The battery pack of claim 1, wherein the height of the support wall (300) is less than the height of the side wall (200), and the coupling part (310) is formed at an upper corner part of the support wall (300).
  10. The battery pack of claim 1, wherein the side wall (200) includes an inwardly inclined surface at the lower corner part where it couples to the base plate (100), and an auxiliary groove (200h3) formed by the inclined surface, wherein the lower end of the support wall (300), the lower end of the side wall (200), and the base plate (100) are fixed to each other by welding in the auxiliary grooves (200h3).
  11. The battery pack of claim 10, wherein the auxiliary grooves (200h3) are filled with weld beads (Bw) produced by welding.
  12. The battery pack of claim 1, wherein the insertion groove (200h1) includes inwardly inclined surface at the upper and lower parts, respectively, the coupling part (310) of the support wall (300) fits into a region excluding the inclined surface of the insertion groove (200h1), and weld beads (Bw) produced by welding is filled between the coupling part (310) and the inclined surface.

Description

[Technical Field] The present invention relates to a battery pack. More specifically, the present invention relates to a battery pack that accommodates a battery module with a reinforcement plate on both sides supporting each side, wherein the battery pack of the present invention is characterized by improved space efficiency by creating a separate weld bead space generated during welding to fix the battery module. This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0124949, filed on September 30, 2022. [Background Art] Types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. These unit secondary battery cells, i.e., unit battery cells, have an operating voltage of approximately 2.5 to 4.2 V. Therefore, if a higher output voltage is required, a plurality of battery cells may be connected in series to form a battery pack. Also, depending on the charge and discharge capacity required for the battery pack, a plurality of battery cells may be connected in parallel to form a battery pack. Thus, the number of battery cells included in the battery pack may be varied depending on the required output voltage or charge/discharge capacity. For example, when configuring a battery pack by connecting a plurality of battery cells in series/parallel, a battery module consisting of a plurality of battery cells is first configured. Typically, a battery module includes a plurality of battery cells, and depending on the need, the battery module may be protected by a module frame enclosing the cells, or by a reinforcement plate or the like supporting both sides. FIG. 1 illustrates one type of battery module 10 supported on both sides by a reinforcement plate 30. According to FIG. 1, the battery module 10 includes a cell stack 20 in which a plurality of cells is unidirectionally stacked, and end plates 40 are coupled to the front and rear of the cell stack 20 respectively. There is also a reinforcement plate 30 coupled to both sides to protect the cell stack 20. At this time, the reinforcement plate 30 may form a step along the up and down directions to facilitate coupling with neighboring battery modules 10. FIG. 2 illustrates a pack case 50 of a battery pack in which the battery module 10 shown in FIG. 1 may be accommodated, and FIG. 3 illustrates the battery module 10 of FIG. 1 accommodated in the pack case 50 of FIG. 2. Referring to FIG. 2, the pack case 50 includes a base plate 60 supporting a lower part of the battery module 10 and side walls 70 coupled along a perimeter of the base plate 60. A portion of the side wall 70 may be provided with a support wall 90 against which the reinforcement plate 30 of the battery module 10 may be seated or coupled. It also includes a main separation wall 80 that runs across its center and is coupled to the base plate 60. The battery module 10 may be seated on and be accommodated in the space compartmentalized by the side walls 70 and main separation wall 80, as shown in FIG. 3. FIG. 4(a) is a cross-sectional view of the support wall 90 and side walls 70 in the pack case 50 of FIG. 2, and FIG. 4(b) illustrates a state in which the reinforcement plate 30 and support wall 90 are coupled by seating the battery module 10 of FIG. 4(a). The support wall 90 has a height corresponding to the height of the stepped part of the battery module 10 so as to be coupled to the reinforcement plate 30 of the battery module 10 in which a step is formed. The support wall 90 is coupled by welding so as to be fixed to the inner side wall 70 of the pack case 50, wherein the support wall 90 includes a joint part 100 projecting forwardly from the top to provide a welding site. The welding may proceed on the joint part 100 as shown, and the welding may produce a weld bead Bw across the upper part of the joint part 100 and the side walls 70. The support wall 90 is coupled to the side walls 70 by welding, as shown in FIG. 4, and the battery module 10 is seated to the base plate 60 by positioning so that a portion of the reinforcement plate 30 is coupled the support wall 90 fixed to the side walls 70, as shown in FIG. 4. However, conventional battery packs have the disadvantage of not being able to utilize the space occupied by the joint part 100 for welding the support wall 90 to the side wall 70 as described above. Example of the background art can be found in US 2020/066686 A1. [Disclosure] [Technical Problem] Accordingly, the present invention is directed to solving the above problems, and aims to provide a battery pack with improved internal space utilization. Other objects and advantages of the present invention will be understood from the following description, and will become apparent from the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by the means and combina