JP-7855801-B2 - Busbar assembly and battery pack containing it

JP7855801B2JP 7855801 B2JP7855801 B2JP 7855801B2JP-7855801-B2

Inventors

ユン，ソンウ

Assignees

エルジーエナジーソリューションリミテッド

Dates

Publication Date: 20260508
Application Date: 20250210
Priority Date: 20240216

Claims (15)

A busbar comprising a main body and end portions located at both ends of the main body ; A first insulating portion surrounding the outer surface of the main body of the busbar; and Including the second insulating part, The second insulating portion includes a pair of cap portions that surround the upper and side surfaces of each of the two ends of the busbar , and a connecting portion located between the pair of cap portions and integrated with the pair of cap portions. The connecting portion extends along the length of the busbar and is located on the outer surface of the main body of the busbar, forming a busbar assembly.
The busbar assembly according to claim 1, further comprising a cover portion that surrounds the outer surface of the first insulating portion, with the connecting portion positioned on the outer surface of the main body portion of the busbar.
The busbar assembly according to claim 2, wherein the cover portion is made of glass fiber material.
The first insulating portion has a recessed portion formed on its outer surface toward the main body of the busbar, The busbar assembly according to claim 1, wherein the connecting portion is inserted into the recessed portion.
The busbar assembly according to claim 4, wherein the recessed portion is formed to a thickness smaller than the thickness of the first insulating portion.
The busbar assembly according to claim 1, wherein the connecting portion is inserted inside the first insulating portion.
The busbar assembly according to claim 6, wherein the connecting portion is separated from the main body portion of the busbar.
The busbar assembly according to claim 1, wherein the width of the connecting portion is smaller than the width of the first insulating portion.
The connecting portion further includes a first reinforcing portion and a second reinforcing portion which are integrated with the connecting portion and made of the same material. The first reinforcing portion is formed at a position where one of the pair of cap portions and the connecting portion are in contact with each other. The busbar assembly according to claim 1, wherein the second reinforcing portion is formed at a position where one of the pair of cap portions and the connecting portion are in contact with each other.
The busbar assembly according to claim 9, wherein the first reinforcing portion and the second reinforcing portion have a greater width than the connecting portion, or a greater thickness than the connecting portion, or both a greater width and a greater thickness than the connecting portion.
The connecting portion further includes at least one third reinforcing portion which is integrated with the connecting portion and made of the same material, The busbar assembly according to claim 1, wherein the at least one third reinforcing portion is formed between the two ends of the connecting portion.
The busbar assembly according to claim 11, wherein the third reinforcing portion has a greater width than the connecting portion, or a greater thickness than the connecting portion, or both a greater width and a greater thickness than the connecting portion.
The first insulating part is made of fire-resistant silicone, fire-resistant plastic, or a material which is a mixture of fire-resistant silicone and fire-resistant plastic. The busbar assembly according to claim 1, wherein each of the second insulating parts is made of fire-resistant silicone material.
A battery pack comprising at least one busbar assembly according to any one of claims 1 to 13, Includes a pack frame that houses multiple battery modules, The busbar assembly electrically connects adjacent pairs of battery modules among the plurality of battery modules, A battery pack in which both ends of the busbar are electrically connected to the pair of adjacent battery modules, respectively.
The battery pack according to claim 14, further comprising fixing portions that penetrate both ends of the busbar and fix both ends of the busbar to the adjacent pair of battery modules, respectively.

Description

[Cross-reference of related applications] This application claims priority based on Korean Patent Application No. 10-2024-0022667, filed on 16 February 2024, and all content disclosed in the said Korean Patent Application is incorporated herein by reference. This invention relates to a busbar assembly and a battery pack including the same, and more specifically, to a busbar assembly and a battery pack including the same that can prevent electrical short circuits and heat propagation between the busbar and surrounding metal structures in high-temperature environments caused by the generation of internal flames. Rechargeable batteries, with their high applicability across product lines and superior electrical properties such as high energy density, are universally applied not only to portable devices but also to electric vehicles, hybrid vehicles, and power storage devices powered by electrical sources. Such rechargeable batteries are attracting attention not only for their primary advantage of dramatically reducing fossil fuel use, but also as a new energy source for improving environmental friendliness and energy efficiency, as they produce no by-products from energy use. Currently, commercially available rechargeable batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention due to their advantages over nickel-based batteries, such as virtually no memory effect, flexible charging and discharging, extremely low self-discharge rate, and high energy density. Generally, lithium-ion secondary batteries can be classified into cylindrical or prismatic secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in an aluminum laminate sheet pouch, depending on the shape of the outer casing. Recently, the need for high-capacity secondary battery structures has increased, particularly in relation to the use of secondary batteries as energy storage sources. This has led to a growing demand for medium- and large-sized modular battery packs, which consist of multiple battery modules connected in series or parallel. Such battery modules improve capacity and output by connecting numerous battery cells in series or parallel, forming a battery cell stack. Furthermore, multiple battery modules can be assembled with various control and protection systems, such as a Battery Management System (BMS) and cooling systems, to form a battery pack. In particular, multiple battery modules are installed inside the battery pack, and adjacent battery modules may be electrically connected via busbars. In this case, the outer surface of the busbars is protected by heat-insulating and insulating materials, thereby preventing electrical short circuits caused by electrical contact with other metal structures (components). However, when abnormal conditions such as overcurrent, overheating, or thermal runaway occur inside the battery pack, a high-temperature environment exceeding 1000 degrees Celsius is created. This causes the heat-insulating and insulating materials formed on the outer surface of the busbars to disappear, resulting in the outer surface of the busbars being exposed to the outside. Thus, when the outer surface of the busbar is exposed to the outside, there is a high possibility of an electrical short circuit occurring due to contact between the exposed busbar's outer surface and other metal structures (components) inside the battery pack 1000. This short circuit can then form an electrically closed circuit inside the battery pack, accelerating phenomena such as thermal runaway. This highlights the need to develop a busbar assembly and a battery pack containing it that can effectively prevent the outer surface of the busbar from being directly exposed to a high-temperature environment even when a high-temperature environment is formed inside the battery pack, thereby preventing the aforementioned electrical short-circuit phenomenon and the resulting heat propagation or thermal runaway between adjacent battery modules. Figure 1 shows one side of a busbar assembly according to one embodiment of the present invention.Figure 2 shows one side of the busbar assembly from Figure 1 with the cover removed.Figure 3 shows one side of the busbar assembly in the state after removing the second insulating section from the busbar assembly in Figure 2.Figure 4 shows a cross-section obtained by cutting along the a-a' axis in Figure 1.Figure 5 shows a cross-section obtained by cutting along the b-b' axis in Figure 1.Figure 6 shows a busbar assembly according to another embodiment of the present invention, specifically a view of the busbar assembly with the cover removed.Figure 7 shows one side of the busbar assembly after the second insulating section has been removed from the busbar assembly shown in Figure 6.Figure 8 shows a c