KR-20260063370-A - Battery pack and vehicle comprising the same

KR20260063370AKR 20260063370 AKR20260063370 AKR 20260063370AKR-20260063370-A

Abstract

The present invention provides a battery pack capable of preventing tap disconnection problems caused by swelling of battery cells and an automobile including the same, comprising a cell assembly including a plurality of battery cells arranged in at least one row and a busbar assembly electrically connected to the cell assembly, wherein the busbar assembly comprises a busbar frame having a predetermined length along the arrangement direction of the plurality of battery cells and at least one busbar mounted on the busbar frame so as to be movable in the longitudinal direction of each busbar frame, connected to the electrode leads of the plurality of battery cells.

Inventors

문지선

Assignees

주식회사 엘지에너지솔루션

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (18)

A cell assembly comprising a plurality of battery cells arranged in at least one row; and It includes a busbar assembly electrically connected to the cell assembly above, and The above busbar assembly is, A busbar frame having a predetermined length along the arrangement direction of the plurality of battery cells; and A battery pack characterized by including at least one busbar mounted on a busbar frame, which is connected to the electrode leads of the plurality of battery cells and is movable independently in the longitudinal direction of each busbar frame.
In Article 1, The above busbar frame is, It is composed of a pair of guide frames arranged in parallel to each other at a predetermined distance, and A battery pack characterized in that at least one busbar is configured to slide along the longitudinal direction of the busbar frame between the pair of guide frames.
In Article 1, The above electrode lead is, A battery pack having a width smaller than the width of the busbar and welded to the busbar so as not to contact the busbar frame.
In Article 1, A battery pack characterized in that the length of the electrode lead positioned at the outermost among a plurality of electrode leads connected together to the busbar is longer than the length of the electrode lead positioned between them.
In Article 1, The above electrode lead is, It is bent at least once, and A battery pack characterized in that at least some of the plurality of electrode leads connected together to the busbar have a bending portion of the electrode lead partially straightened by the movement of the busbar due to swelling of the battery cell.
In Article 5, The bending portion of the electrode lead above is, A battery pack characterized by being located in the space between the cell case of the battery cell and the busbar.
In Article 5, A battery pack characterized in that a plurality of electrode leads connected together to the busbar are bent toward the center of the plurality of electrode leads.
In Article 1, The above busbar is, Multiple units are provided and spaced apart from each other by a predetermined distance along the length direction of the busbar frame, The above busbar assembly is, A battery pack characterized by including at least one section configured to be spaced apart from each busbar between mutually adjacent busbars.
In Article 8, The above busbar frame is, A first end portion and a second end portion provided at both ends in the longitudinal direction of the above-mentioned busbar frame; and It includes a groove portion that is recessed to a predetermined depth from one side of the busbar frame along the longitudinal direction of the busbar frame and extends from the first end portion to the second end portion. In the above compartment, A battery pack characterized by having a connecting portion that is inserted into the groove portion so as to be slidable along the longitudinal direction of the busbar frame.
In Article 8, In the above busbar frame, At least one fixed part having a through hole of a predetermined size is formed, and The above section is, A battery pack characterized by being fixed to the busbar frame through the above-mentioned fixing part.
In Article 8, In the above busbar frame, At least one recess is formed by being recessed to a predetermined depth from one side of the busbar frame, and The above section is, A battery pack characterized by being configured to be inserted into the above-mentioned recess and fixed in position.
In Article 1, The above busbar frame is, A first end portion and a second end portion provided at both ends in the longitudinal direction of the above-mentioned busbar frame; and It includes a groove portion that is recessed to a predetermined depth from one side of the busbar frame along the longitudinal direction of the busbar frame and extends from the first end portion to the second end portion. In the above busbar, A battery pack characterized by having a connecting portion that is inserted into the groove portion so as to be slidable along the longitudinal direction of the busbar frame.
In Article 12, The above busbar assembly is, A battery pack characterized in that at least one of the connecting portion of the busbar and the groove portion of the busbar frame is formed as a curved surface.
In Article 12, The above busbar assembly is, A battery pack characterized by including a finishing portion configured to make surface contact with at least one of the first end portion and the second end portion.
In Article 14, The above finishing part is, At least one protrusion protruding from one surface of the above-mentioned finishing portion; and It includes an elastic member connected to the end of the above-mentioned protrusion and composed of an elastic member having a cross-sectional area larger than the cross-sectional area of the above-mentioned protrusion, The above protrusion and the above elastic part are, A battery pack characterized by being fitted into an insert formed in either of the first end portion and the second end portion.
In Article 5, The above busbar is, A concave shape is formed in at least a portion of the side portion of the busbar that is not connected to the busbar frame and is arranged along the longitudinal direction of the busbar frame. The above electrode lead is, A battery pack characterized by being bent along the above-mentioned concave shape.
In Article 1, The above cell assembly is, A battery pack characterized by including at least one buffer portion provided between the plurality of battery cells.
A vehicle equipped with at least one battery pack according to any one of claims 1 to 17.

Description

Battery pack and vehicle comprising the same The present invention relates to a battery pack and an automobile including the same, and more specifically, to a battery pack capable of preventing tap disconnection due to swelling of a battery cell and an automobile including the same. Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product groups, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, not only for the primary advantage of drastically reducing the use of fossil fuels but also because they generate no by-products from energy use. Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge/discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Accordingly, the number of battery cells included in the battery pack can be varied depending on the required output voltage or charge/discharge capacity. Meanwhile, techniques such as increasing the number and size of electrode tabs and leads have been applied to adapt to high-capacity environments for secondary batteries. However, simply increasing the number and/or size of electrode tabs and leads alone makes it difficult to guarantee a stable and reliable connection between them. Furthermore, as the number and/or size of electrode tabs and leads increase, particularly in pouch-type secondary batteries, there is a problem where electrode tabs may break due to load during the electrode tab and lead welding process. Here, the electrode assembly consists of alternating positive and negative electrode plates. The positive and negative electrode plates are separated by a separator. Electrode tabs are connected to these plates according to their respective polarities. Leads are welded to the stack of electrode tabs where they are assembled. Conventionally, the starting position of the electrode tab stacking section is located very close to the electrode assembly, and the welding position of the electrode tab and the lead is also located very close to the electrode assembly. Consequently, the part of the electrode tab protruding from the electrode assembly is inclined at a steep angle and pulled taut, making it highly vulnerable to stress. When a load is applied to that part during welding, a problem arises where a wire breaks. Furthermore, in this structure, as the overall width of the cell assembly increases due to swelling of the battery cells during use, significant tension is placed on the welded lead portion. As a result, the electrode tab portion, which is inclined at a steep angle and pulled taut, may break. Therefore, it is necessary to develop a battery pack with a structure that prevents the electrode tab from becoming disconnected even if swelling occurs due to battery use. FIG. 1 is a schematic plan view of a battery pack according to one embodiment of the present invention. Figure 2 is a drawing for explaining the movement of a busbar of a busbar assembly of a battery pack according to Figure 1. FIG. 3 is a schematic cross-sectional view of a battery pack cut along the AA' line of FIG. 1. FIG. 4 is a schematic cross-sectional view of a battery pack cut along the BB' line of FIG. 1. FIG. 5 is a diagram illustrating the swollen state of multiple battery cells of a battery pack according to FIG. 4. FIG. 6 is an exploded perspective view schematically showing a busbar assembly of a battery pack according to FIG. 1. Figure 7 is a drawing for explaining the assembly structure of a busbar assembly according to Figure 6. FIG. 8 is a schematic cross-sectional view of a busbar assembly cut along the CC' line of FIG. 7. FIG. 9 is an exploded perspective view schematically showing another embodiment of the busbar assembly according to FIG. 7. FIG. 10 is a drawing for explaining the assembly structure of a busbar assembly according to FIG. 9. FIG. 11 is a schematic cross-sectional view of a busbar assembly cut along the EE' line of FIG. 10. FIG. 12 is a schematic cross-sectional view of a busbar assembly cut along the line DD' of FIG. 7. FIG. 13 is a schematic cross-sectional view showing another embodiment of the busbar assembly according to FIG. 12. FIG. 14 is a drawing for explaining the assembly structure of the finishing portion of the busbar assembly according to FIG. 6. FIG. 15 is a cross-sectional vi