Patent Description:
Due to their characteristics of being easily applicable to various products and electrical properties such as a high energy density, secondary batteries are not only commonly applied to portable devices, but universally applied to electric vehicles (EVs) or hybrid electric vehicle (HEVs) that are driven by an electrical driving source. Such secondary batteries are gaining attention for their primary advantage of remarkably reducing the use of fossil fuels and not generating by-products from the use of energy, making it a new eco-friendly and energy efficient source of energy.

The types of secondary batteries widely used at present include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries or the like. This unit secondary battery cell, i.e., a unit battery cell has an operating voltage of about <NUM>. 5V to <NUM>. Accordingly, when a higher output voltage is required, a plurality of battery cells may be connected in series to form a battery pack. Additionally, the battery pack may be fabricated by connecting the plurality of battery cells in parallel according to the charge/discharge capacity required for the battery pack. Accordingly, the number of battery cells included in the battery pack may be variously set depending on the required output voltage or charge/discharge capacity.

Meanwhile, when fabricating the battery pack by connecting the plurality of battery cells in series/in parallel, it is general to make a battery module including at least one battery cell, and then fabricate a battery pack or a battery rack using at least one battery module with an addition of any other component.

In general, the conventional battery pack includes a plurality of battery cells and a cell frame to accommodate the plurality of battery cells. In general, the conventional cell frame includes an assembly of a plurality of plates including a front plate, a rear plate, a side plate, a lower plate and an upper plate.

However, the conventional battery pack has increases in manufacturing cost and assembly process complexity due to the characteristics of the cell frame structure including the assembly of the plurality of plates, and thus has price competitiveness and fabrication efficiency disadvantages.

Moreover, due to the cell frame structure including the assembly of the plurality of plates, the conventional battery pack increases in its total size and thus has an energy density disadvantage. Relevant prior art is document <CIT>.

Accordingly, the present disclosure is directed to providing a battery pack with increased energy density and strength and a vehicle comprising the same.

Additionally, the present disclosure is further directed to providing a battery pack with improved price competitiveness and fabrication efficiency and a vehicle comprising the same.

To solve the above-described problem, the present disclosure provides a battery pack which is mounted in a vehicle, the battery pack including a plurality of battery cells; a base plate to support the plurality of battery cells; and a cross beam unit which is positioned over a predetermined length along a widthwise direction of the base plate, and interposed between the plurality of battery cells in a lengthwise direction of the base plate to attach and fix the facing battery cells in the lengthwise direction.

A positive and negative electrode structure for electrical connection of the plurality of battery cells may be provided on one surface of the plurality of battery cells, and the cross beam unit is attached to an opposite surface of the plurality of battery cells.

One surface of the plurality of battery cells may be spaced a predetermined distance apart from one surface of the facing battery cells in the lengthwise direction.

The cross beam unit may include a cooling water channel to cool the plurality of battery cells.

The battery pack may include a cover plate to cover an upper portion of the plurality of battery cells, wherein the cover plate is disposed opposite the base plate with the plurality of battery cells interposed between the base plate and the cover plate.

The cross beam unit may be positioned between the base plate and the cover plate, and placed in contact with each of the base plate and the cover plate.

The cross beam unit may include a plurality of beam members, and the plurality of beam members may be spaced a predetermined distance apart along the lengthwise direction of the base plate.

The plurality of beam members may include a beam body which has a cooling water channel inside, and is formed over a predetermined length along the widthwise direction of the base plate; a first flange which is provided at a lower end of the beam body and placed in contact with the base plate; and a second flange which is provided at an upper end of the beam body opposite the first flange and placed in contact with the cover plate.

The first flange and the second flange may have a larger thickness than the beam body in the lengthwise direction.

The first flange may cover at least part of an upper portion of the plurality of battery cells in the lengthwise direction, and the second flange may cover at least part of a lower portion of the plurality of battery cells in the lengthwise direction.

The plurality of battery cells may be directly attached to each of two surfaces of the beam body in the lengthwise direction.

The plurality of battery cells may be symmetrically arranged with the beam body interposed between the plurality of battery cells in the lengthwise direction.

Additionally, the present disclosure provides a vehicle including at least one battery pack according to the above-described embodiments.

According to the various embodiments as described above, it is possible to provide a battery pack with increased energy density and strength and a vehicle comprising the same.

Additionally, according to the various embodiments as described above, it is possible to provide a battery pack with improved price competitiveness and fabrication efficiency and a vehicle comprising the same.

The present disclosure will become apparent by describing a preferred embodiment of the present disclosure in detail with reference to the accompanying drawings. The embodiment described herein is provided by way of illustration to help an understanding of the present disclosure, and it should be understood that various modifications may be made to the present disclosure in any other embodiment than the embodiments described herein. Additionally, to help an understanding of the present disclosure, the accompanying drawings are not shown in true scale and may depict some exaggerated elements.

<FIG> is a diagram illustrating a battery pack according to an embodiment of the present disclosure, <FIG> is an exploded perspective view of the battery pack of <FIG>, <FIG> is a diagram illustrating a beam member of a cross beam unit of the battery pack of <FIG>, <FIG> is a cross-sectional view of the beam member of <FIG>, <FIG> is a diagram illustrating a battery cell fixed to the beam member of <FIG>, and <FIG> is a cross-sectional view of the battery pack of <FIG>.

Referring to <FIG>, the battery pack <NUM> is mounted in a vehicle, and may include a battery cell <NUM>, a base plate <NUM> and a cross beam unit <NUM>.

Additionally, the battery pack <NUM> may further include a cover plate <NUM>.

Hereinafter, the battery pack <NUM> will be described in more detail.

At least one battery cell <NUM> may be provided. Hereinafter, in this embodiment, a description is made based on a plurality of battery cells <NUM>.

The plurality of battery cells <NUM> may include secondary batteries, for example, pouch type secondary batteries, prismatic secondary batteries or cylindrical secondary batteries. Hereinafter, in this embodiment, a description is made based on cylindrical secondary batteries as the plurality of battery cells <NUM>.

An electrical connection structure having a positive and negative electrode structure for electrical connection of the plurality of battery cells <NUM> may be formed on one surface of the plurality of battery cells <NUM>.

One surface of the plurality of battery cells <NUM> may be spaced a predetermined distance apart from one surface of the facing battery cells <NUM> for the connection to a busbar plate for electrical connection of the positive and negative electrode structure in the lengthwise direction of the base plate <NUM> as described below.

The positive and negative electrode structure may not be formed on the opposite surface of the plurality of battery cells <NUM>. The opposite surface of the plurality of battery cells <NUM> may be attached to the cross beam unit <NUM> as described below.

The base plate <NUM> is used to support the plurality of battery cells <NUM>, and may have an appropriate shape and size for seating the plurality of battery cells <NUM>.

The base plate <NUM> may be mounted in the vehicle. The lengthwise direction of the base plate <NUM> may be parallel to the lengthwise direction of the vehicle, and the widthwise direction of the base plate <NUM> may be the widthwise direction of left and right sides of the vehicle.

The cross beam unit <NUM> may be positioned over a predetermined length along the widthwise direction of the base plate <NUM>, and may be interposed between the plurality of battery cells <NUM> in the lengthwise direction of the base plate <NUM> to attach and fix the facing battery cells <NUM> in the lengthwise direction. The cross beam unit <NUM> may include a cooling water channel <NUM> inside.

The cross beam unit <NUM> may be made of a metal having a predetermined strength to ensure strength. In this embodiment, the attachment of the cross beam unit <NUM> and the plurality of battery cells <NUM> is performed on the opposite surface of the plurality of battery cells <NUM> in which the electrode of the battery cells <NUM> is not formed, thereby preventing an electrical short caused by the attachment.

The cross beam unit <NUM> may be positioned between the base plate <NUM> and the cover plate <NUM> as described below, and may be placed in contact with each of the base plate <NUM> and the cover plate <NUM> as described below.

The cross beam unit <NUM> may enhance the strength of the battery pack <NUM>, and prevent the transfer of impacts to the plurality of battery cells <NUM> or absorb the impacts when external impacts occur in the widthwise direction of the base plate <NUM>, i.e., in the widthwise direction of the battery pack <NUM>.

To this end, the cross beam unit <NUM> may extended out from the plurality of battery cells <NUM> in the widthwise direction of the base plate <NUM>.

Accordingly, when external impacts occur in the widthwise direction, the cross beam unit <NUM> may be subjected to the external impacts earlier than the plurality of battery cells <NUM> and mitigate or absorb the impacts, thereby minimizing the transfer of the impacts to the plurality of battery cells <NUM>.

For example, when external impacts occur at one side of the widthwise direction, the cross beam unit <NUM> may be subjected to the external impacts earlier than the plurality of battery cells <NUM> and transfer the impacts to the opposite side of the widthwise direction, thereby effectively preventing the transfer of the impacts to the plurality of battery cells <NUM>.

Hereinafter, the cross beam unit <NUM> according to this embodiment will be described in more detail.

The cross beam unit <NUM> may include a plurality of beam members <NUM>.

The plurality of beam members <NUM> may be spaced a predetermined distance apart along the lengthwise direction of the base plate <NUM>. The plurality of beam members <NUM> may be extended from the plurality of battery cells <NUM> in the widthwise direction of the base plate <NUM>.

Each of the plurality of beam members <NUM> may include a beam body <NUM>, a first flange <NUM> and a second flange <NUM>.

The beam body <NUM> may have the cooling water channel <NUM> inside, and may be formed over a predetermined length along the widthwise direction of the base plate <NUM>. When external impacts occur, the beam body <NUM> may be subjected to the external impacts and mitigate and absorb the impacts earlier than the plurality of battery cells <NUM>.

The plurality of battery cells <NUM> may be attached to each of two surfaces along the lengthwise direction of the beam body <NUM>. Accordingly, the plurality of battery cells <NUM> may be symmetrically arranged with the beam body <NUM> interposed between them in the lengthwise direction.

For example, the plurality of battery cells <NUM> may be directly attached to each of the two surfaces of the beam body <NUM> in the lengthwise direction. Specifically, the opposite surface of the plurality of battery cells <NUM> may be directly attached to each of the two surfaces of the beam body <NUM> in the lengthwise direction.

The attachment of the plurality of battery cells <NUM> may be performed with an adhesive or a double-sided tape. The present disclosure is not limited thereto, and the beam body <NUM> may have, on the two surfaces, a groove of a predetermined shape, through which the opposite surface of the plurality of battery cells <NUM> is inserted. Additionally, an attachment guide member may be provided between the beam body <NUM> and the opposite surface of the plurality of battery cells <NUM> to guide the attachment between them. The attachment guide member may be attached to each of the two surfaces of the beam body <NUM> after the insertion of the opposite surface of the plurality of battery cells <NUM>.

Meanwhile, a heat transfer material having an adhesive substance may be provided between the plurality of battery cells <NUM> and the beam body <NUM> to increase the cooling performance of the plurality of battery cells <NUM>.

The cooling water channel <NUM> is used to cool the plurality of battery cells <NUM>, and cooling water for cooling the plurality of battery cells <NUM> may flow in the cooling water channel <NUM>.

The first flange <NUM> is used to enhance the strength of the beam body <NUM>, and may be provided at the lower end of the beam body <NUM>. The first flange <NUM> may be placed in contact with the base plate <NUM>.

The first flange <NUM> may have a larger thickness than the beam body <NUM> in the lengthwise direction. The first flange <NUM> may cover at least part of the upper portion of the plurality of battery cells <NUM> in the lengthwise direction.

Accordingly, the first flange <NUM> may effectively guide the more stable fixing and support of the plurality of battery cells <NUM> to the beam body <NUM>.

The second flange <NUM> is used to enhance the strength of the beam body <NUM>, and may be provided at the upper end of the beam body <NUM> opposite the first flange <NUM> and placed in contact with the cover plate <NUM> as described below.

The second flange <NUM> may have a larger thickness than the beam body <NUM> in the lengthwise direction. The second flange <NUM> may cover at least part of the lower portion of the plurality of battery cells <NUM> in the lengthwise direction.

Accordingly, the second flange <NUM> may effectively guide the more stable fixing and support of the plurality of battery cells <NUM> to the beam body <NUM>.

The cover plate <NUM> may cover the plurality of battery cells <NUM> from above, and may be disposed opposite the base plate <NUM> with the plurality of battery cells <NUM> interposed between the cover plate <NUM> and the base plate <NUM>.

As described above, the battery pack <NUM> according to this embodiment may enhance the strength of the battery pack <NUM> and fix the plurality of battery cells <NUM> more stably without the conventional cell frame structure including a plurality of plate members through the cross beam unit <NUM>.

Accordingly, the battery pack <NUM> according to this embodiment may omit the conventional cell frame structure, thereby reducing the total size of the battery pack <NUM> and increasing the energy density of the battery pack <NUM>.

Additionally, since the conventional cell frame structure including a plurality of plate members is omitted, the battery pack <NUM> according to this embodiment may reduce the fabrication cost of the battery pack <NUM> and significantly increase the assembly process rate.

Accordingly, the battery pack <NUM> according to this embodiment may increase the cost competitiveness in the manufacture of the battery pack <NUM>, and significantly increase the assembly process efficiency in the fabrication process.

Furthermore, as the battery pack <NUM> according to this embodiment includes the cooling water channel <NUM> for the flow of the cooling water in the cross beam unit <NUM>, it is possible to effectively cool the plurality of battery cells <NUM> without any additional structure such as a heat sink.

Accordingly, the battery pack <NUM> according to this embodiment may also omit the stack structure of the conventional structure such as a heat sink, thereby reducing the total size of the battery pack <NUM> and significantly increasing the energy density of the battery pack <NUM>.

<FIG> is a diagram illustrating a battery pack according to another embodiment of the present disclosure.

The battery pack <NUM> according to this embodiment is similar to the battery pack <NUM> of the previous embodiment, and an overlapping description of the elements that are substantially identical or similar to the previous embodiment is omitted, and the following description will be made based on difference(s) between this embodiment and the previous embodiment.

Referring to <FIG>, the battery pack <NUM> may include the plurality of battery cells <NUM>, the base plate <NUM>, the cross beam unit <NUM>, the cover plate <NUM> and a cell support guider <NUM>.

The plurality of battery cells <NUM>, the base plate <NUM>, the cross beam unit <NUM> and the cover plate <NUM> are substantially identical or similar to the previous embodiment, and an overlapping description is omitted.

The cell support guider <NUM> may support the upper and lower portions of the plurality of battery cells <NUM> between the base plate <NUM> and the cover plate <NUM>.

The cell support guider <NUM> may have a support space having a corrugated shape corresponding to the stack shape of the battery cells <NUM> to support the upper and lower portions of the plurality of battery cells <NUM> more stably.

Accordingly, in this embodiment, the plurality of battery cells <NUM> may be fixed and supported between the base plate <NUM> and the cover plate <NUM> more firmly through the cell support guider <NUM>.

Furthermore, the cell support guider <NUM> may include a heat transfer material to increase the cooling performance of the plurality of battery cells <NUM>. Accordingly, in this embodiment, it is possible to further improve the cooling performance of the battery pack <NUM>. The heat transfer material may include, for example, a thermal grease, an elastomer pad, a graphite pad and a thermal silicone pad.

<FIG> is a diagram illustrating a vehicle according to an embodiment of the present disclosure.

Referring to <FIG>, the battery pack <NUM>,<NUM> may be provided in the vehicle <NUM> as a fuel source of the vehicle. The battery pack <NUM>,<NUM> may be provided in the vehicle <NUM>, for example, an electric vehicle, a hybrid electric vehicle and any other application using the battery pack <NUM>,<NUM> as a fuel source.

The battery pack <NUM>,<NUM> of this embodiment may be mounted in the vehicle <NUM> in a modularized form. For example, a plurality of battery packs <NUM>,<NUM> may be provided to meet the required capacity and may be mounted in the vehicle <NUM> such that they are electrically connected to each other in the vehicle <NUM>.

In this embodiment, as the battery pack <NUM>,<NUM> includes the cross beam unit <NUM>, it is possible to omit a structure such as a cross beam that has been separately provided in the vehicle through the mounted battery pack <NUM>,<NUM>.

Accordingly, the vehicle <NUM> according to this embodiment may have a more space for mounting the battery pack <NUM>,<NUM> in the vehicle <NUM>, thereby increasing the energy density of the battery pack <NUM>,<NUM> mounted in the vehicle <NUM>.

Furthermore, as the vehicle <NUM> according to this embodiment includes the cooling water channel <NUM> in the cross beam unit <NUM> of the battery pack <NUM>,<NUM>, it is possible to simplify the structure of the cooling unit such as a heat sink for cooling the battery pack <NUM>,<NUM>, and additionally have a space in which the battery pack <NUM>,<NUM> is mounted in the vehicle <NUM>, thereby significantly increasing the energy density of the battery pack <NUM>,<NUM> mounted in the vehicle <NUM>.

Additionally, in addition to the vehicle <NUM>, the battery pack <NUM>,<NUM> may be provided in any other device, apparatus and equipment using secondary batteries, for example, an energy storage system.

According to the various embodiments as described above, it is possible to provide the battery pack <NUM>,<NUM> with increased energy density and strength and the vehicle <NUM> comprising the same.

Additionally, according to the various embodiments as described above, it is possible to provide the battery pack <NUM>,<NUM> with improved cost competitiveness and fabrication efficiency and the vehicle <NUM> comprising the same.

Claim 1:
A battery pack (<NUM>) which is mounted in a vehicle, the battery pack (<NUM>) comprising:
a plurality of battery cells (<NUM>);
a base plate (<NUM>) to support the plurality of battery cells (<NUM>); and
a cross beam unit (<NUM>) which is positioned over a predetermined length along a widthwise direction of the base plate (<NUM>), and interposed between the plurality of battery cells (<NUM>) in a lengthwise direction of the base plate (<NUM>) to attach and fix the facing battery cells (<NUM>) in the lengthwise direction,
characterized in that
a positive and negative electrode structure for electrical connection of the plurality of battery cells (<NUM>) is provided on one surface of the plurality of battery cells (<NUM>),
wherein the cross beam unit (<NUM>) is attached to an opposite surface of the plurality of battery cells (<NUM>).