CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of and priority to Korean Patent Application No. 10-2018-0119749, filed on Oct. 8, 2018 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. This application incorporates, in their entirety, by reference U.S. application Ser. Nos. 16/596,503, 16/595,906, and 16/595,900, filed on even date herewith.

BACKGROUND

1. Field

Aspects of one or more embodiments of the present disclosure relate to a battery pack.

2. Description of the Related Art

In general, secondary batteries are designed to be rechargeable unlike primary batteries, which are not designed to be recharged. Secondary batteries are used as energy sources for devices, such as mobile devices, electric vehicles, hybrid electric vehicles, electric bicycles, and uninterruptible power supplies. Single-cell secondary batteries or multi-cell secondary batteries (e.g., secondary battery packs) in which a plurality of battery cells are electrically connected to each other are used according to the type of external device to be powered by the secondary batteries.

Small mobile devices, such as cellular phones, may be operated by using single-cell secondary batteries (e.g., may be operated for a predetermined time by using single-cell secondary batteries). However, multi-cell secondary batteries (e.g., secondary battery packs) having high-output, high-capacity features may be suitable for devices having long operating times and requiring high power, such as electric vehicles or hybrid electric vehicles, which consume relatively large amounts of power. The output voltage or current of a battery pack may be increased by adjusting the number of batteries (e.g., the number of battery cells) included in the battery pack.

SUMMARY

One or more embodiments of the present disclosure include a battery pack having an accommodation space through which a cooling fluid flows and makes direct contact with battery cells to provide improved heat dissipation.

One or more embodiments of the present disclosure include a battery pack having a relatively simple inlet/outlet connection structure that improves the cooling performance of the cooling fluid.

Additional aspects of the present disclosure will be set forth, in part, in the description which follows and, in part, will be apparent from the description or may be learned by practice of the presented embodiments.

According to one or more embodiments, a battery pack includes: a plurality of battery cells; a case providing an accommodation space for accommodating the battery cells and a cooling fluid for cooling the battery cells; and a barrier wall extending across the accommodation space and dividing the accommodation space into an upstream area in communication with an inlet for the cooling fluid and a downstream area in communication with an outlet for the cooling fluid. The barrier wall provides a communication area where the upstream area and the downstream area communicate with each other. The inlet and the outlet are at a portion of the case corresponding to a first end of the barrier wall in an extension direction of the barrier wall, and the communication area is at a second end of the barrier wall in the extension direction of the barrier wall.

The communication area may be configured to reverse a direction of an upstream flow of the cooling fluid from the inlet at the first end of the barrier wall to a downstream flow toward the outlet at the first end of the barrier wall.

Both the inlet and the outlet for the cooling fluid may be provided in a first short-side portion of the case.

A second short-side portion of the case opposite the first short-side portion may not include an inlet or an outlet for the cooling fluid.

The communication area may include an opening in the second end of the barrier wall.

The barrier wall may have a step difference between a first height at the first end of the barrier wall and a second height at the second end of the barrier wall, and the communication area may be formed by the step difference between the first height and the second height.

A first section of the barrier wall having the second height may be at a middle position of a second section of the barrier wall having the first height such that an upper step difference and a lower step difference are formed between the first and second sections of the barrier wall.

The communication area may include: a first communication area formed by the upper step difference; and a second communication area formed by the lower step difference.

The battery cells may be arranged in a plurality of rows extending in the extension direction of the barrier wall, and the barrier wall may extend along a gap between a first row and a second row to divide the rows of the battery cells into two groups.

The first and second rows may be adjacent to each other such that the battery cells of the first row are at least partially between the battery cells of the second row, and the barrier wall may have a zigzag shape along the gap between the first and second rows.

The case may include a first cover, a middle case, and a second cover. The first and second covers may face each other with the middle case therebetween, and the first and second covers may be coupled to the middle case.

The barrier wall and the middle case may be integrally formed by injection molding.

The middle case and the first and second covers may be formed separately from each other, and the case and the first and second covers may seal the accommodation space.

The case may include: a first laser weld zone along a boundary between the middle case and the first cover; and a second laser weld zone along a boundary between the middle case and the second cover.

The middle case and the first and second covers may include an engineering plastic material for injection molding and laser welding.

The first and second covers may include guide ribs protruding from the first and second covers and extending around first and second end portions of the battery cells.

The guide ribs may have a ring shape and may surround peripheries of the first and second end portions of the battery cells.

The guide ribs may be arranged in rows such that the guide ribs of one row are between the guide ribs of an adjacent row. The guide ribs may be spaced apart from each other by gap portions, and the guide ribs may face each other with the gap portions therebetween.

Each of the gap portions may be in a space between four adjacent guide ribs.

Peripheries of each of the gap portions may be surrounded by the guide ribs.

The barrier wall may include first and second coupling portions arranged from the first end to the second end of the barrier wall in the extension direction of the barrier wall. Each of the first and second coupling portions may protrude toward respective ones of the gap portions of the first and second covers, and the first and second coupling portions may be respectively fitted into the gap portion of the first and second covers and are welded thereto.

The barrier wall and the middle case may be integrally formed by injection molding, and the first and second coupling portions may protrude from the barrier wall toward the first and second covers.

