Patent Description:
Batteries are generally mounted within vehicles to store electrical energy and a battery module outputs a predetermined voltage by connecting a plurality of battery cells, each of which outputs a unit voltage. A plurality of the battery modules are connected to output a desired voltage. Battery modules of the related art include cartridges for fixing battery cells. In other words, battery modules of the related art have a structure with cartridges between stacked battery cells. Additionally, the battery modules of the related art further include cooling fins disposed between battery cells in surface contact with the battery cells. The ends of the cooling fins indirectly discharge heat from the battery cells by coming into contact with a cooling block.

As described above, since battery modules of the related art use cartridges, the size of the structure of stacked battery cells is increased. In particular, the module size is further increased by the cooling fins. Battery modules of the related art also use an indirect cooling method that discharges heat from battery cells using heat transfer through cooling fins disposed between the battery cells and thus, cooling efficiency is reduced.

The description provided above as a related art of the present disclosure is merely for helping understanding the background of the present disclosure and should not be construed as being included in the related art known by those skilled in the art.

<CIT> discloses a battery module, comprising: a module frame having a top and sides that extend down from the top, a cell-stacking structure disposed between the sides of the module frame and including a plurality of stacked battery cells, and a bottom disposed under the cell-stacking structure, the stacking structure further including intermediate cells disposed between a predetermined number of the battery cells.

<CIT> discloses a battery pack configured to have a structure in which two or more battery modules are mounted in a space defined between a pack case and a base plate, wherein cooling members are mounted at interfaces between the unit cells.

<CIT> discloses a battery module having a cell assembly.

The present disclosure provides a battery module that allows for simplifying and downsizing of a structure by reducing the number of parts and can achieve high energy density by securing an excellent heat dissipation ability.

In accordance with the present invention, a battery module includes: a module frame having a top and sides that extend down from the top; a cell-stacking structure disposed between the both sides of the module frame and including a plurality of stacked battery cells; a bottom plate disposed under the cell-stacking structure and bonded to lower ends of the sides of the module frame; and a cooling water block attached to the bottom of the bottom plate to supply cooling water to the bottom of the bottom plate. The cell-stacking structure further includes surface pressure pads disposed between some of the battery cells (e.g., a predetermined number of the battery cells) to be compressed in the stacking direction of the battery cells. The battery cells each may have electrode cell taps on both ends and may be stacked with the cell taps facing a front portion and a rear portion of the module frame.

In an exemplary embodiment of the present disclosure, the battery cells may be stacked in surface contact with one another from a first side to a second side of the module frame.

An exemplary embodiment of the present disclosure may further include a heat transfer substance disposed between the cell-stacking structure and the bottom plate. The heat transfer substance may be a gap filler of which thermal conductivity is increased by pressure and the bottom plate may be bonded to lower ends of the sides of the module frame while being pressed toward the cell-stacking structure. The bottom plate may be bonded to lower ends of the sides of the module frame with the sides of the module frame pressed toward the cell-stacking structure.

A front cover and a rear cover made of an electrical insulating material may be respectively coupled to the front portion and the rear portion of the module frame. In particular, the front cover and the rear cover each may have separation walls that extend between pairs of bonded cell taps on surfaces facing the cell taps.

According to the battery module, since a module frame has a structure with a top and sides that extend from both ends of the top and battery cells are stacked with sides facing one another, specific cartridges for stacking the battery cell may be omitted and thus, the module may be downsized. Further, since the bottom of the module frame is open, it may be possible to more easily apply a heat transfer substance to the bottom of the cell-stacking structure after disposing the cell-stacking structure having the stacked battery cells between both sides of the module frame. According to the battery module, since a bottom plate may be bonded to the module frame while being pressed toward the cell-stacking structure after the heat transfer substance is applied, when a heat transfer substance of which thermal conductivity is increased as pressure is increased is used, a heat transfer effect may be considerably improved.

As described above, according to the battery module, cooling performance may be improved by reducing the size and the heat transfer ability of the battery module may be improved. Therefore, high energy density of the battery module may be achieved. Further, according to the battery module, by bonding the bottom plate to the module frame while pressing both sides of the module frame toward the cell-stacking structure after disposing the cell-stacking structure between both sides of the module frame, the battery module may be manufactured with a predetermined level of surface pressure between the battery cells and thus, the initial performance of the battery module may be improved.

The effects of the present disclosure are not limited to the effects described above and other effects may be clearly understood by those skilled in the art from the following description.

The above and other aspects, features and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:.

It is understood that the term "vehicle" or "vehicular" or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.

A battery module according to various exemplary embodiments of the present disclosure is described hereafter in detail with reference to the accompanying drawings.

<FIG> is a perspective view of a battery module according to an exemplary embodiment of the present disclosure, <FIG> is a detailed view of the battery module according to an exemplary embodiment of the present disclosure shown in <FIG>, and <FIG> is a cross-sectional view of the battery module of <FIG> according to an exemplary embodiment of the present disclosure taken along line A-A'.

Referring to <FIG>, a battery module according to an exemplary embodiment of the present disclosure may include: a module frame <NUM> having a top <NUM> and sides <NUM> and <NUM> that extend down from the top <NUM>; a cell-stacking structure <NUM> disposed between both sides <NUM> and <NUM> of the module frame <NUM> and including a plurality of stacked battery cells <NUM>; and a bottom plate <NUM> disposed under the cell-stacking structure <NUM> and bonded to the lower ends of the sides <NUM> and <NUM>.

The module frame <NUM> functions as a case that covers and encloses the top and two sides of the battery module and may include the top <NUM> (e.g., a top surface) and the sides <NUM> and <NUM> (e.g., a first side surface and a second side surface) that extend down from the top. In other words, the module frame <NUM> may have a rectangular parallelepiped shape with the front, rear, and bottom removed. The top <NUM> and the sides <NUM> and <NUM> of the module frame <NUM> may be formed integrally by extruding a metallic material such as aluminum. The cell-stacking structure <NUM> in which a plurality of battery cells <NUM> is stacked in parallel in surface contact with one another may be disposed between both sides <NUM> and <NUM> of the module frame <NUM>.

The cell-stacking structure <NUM> may be formed by stacking a plurality of cells <NUM> having a pouch shape in surface contact with one another. The battery cells <NUM> may each have a cell tap <NUM> that functions as an electrode thereof. Additionally, the battery cells <NUM> may be stacked in the cell-stacking structure <NUM> from a first side <NUM> to a second side <NUM> of the module frame <NUM>, and the cell taps <NUM> of the battery cells <NUM> may be arranged to face the front portion and the rear portion of the module frame <NUM> (e.g., protrude toward <NUM> and <NUM>). The cell-stacking structure <NUM> may include a surface pressure pad <NUM> capable of being compressed in the stacking direction between the stacked cells <NUM>. The surface pressure pad <NUM> may attenuate and generate uniform the surface pressure acting between the stacked battery cells <NUM>.

In an exemplary embodiment of the present disclosure, the cell-stacking structure <NUM> may omit specific cartridges and the outermost cells <NUM> of the cell-stacking structure <NUM> may be in contact with the sides <NUM> and <NUM> of the module frame <NUM>. In other words, in an exemplary embodiment of the present disclosure, the module frame <NUM> functions as a case of the battery module <NUM> and functions as a frame inside which the cell-stacking structure <NUM> is installed. Accordingly, specific cartridges may be omitted from the structure when stacking battery cell and thus, a battery module may be downsized.

Further, the bottom plate <NUM> may be disposed under the cell-stacking structure <NUM> after the cell-stacking structure <NUM> is disposed between the sides <NUM> and <NUM> of the module frame <NUM>, and may be bonded to the sides <NUM> and <NUM> of the module frame <NUM> by welding or other bonding methods. In particular, the bottom plate <NUM> may be brought in contact with the cell-stacking structure <NUM> through a heat transfer substance <NUM>. The heat transfer substance <NUM> may be provided to enable heat generated from the cell-stacking structure <NUM> including the battery cells <NUM> to transfer to the bottom plate <NUM>.

The heat transfer substance <NUM> may be a gap filler having excellent thermal conductivity. When the heat transfer substance <NUM> is liquid, it may be applied to the bottom of the cell-stacking structure <NUM> disposed between the sides <NUM> and <NUM> of the module frame <NUM> during the process of manufacturing the battery module. According to an exemplary embodiment of the present disclosure, since the bottom of the module frame <NUM> is open, the heat transfer substance <NUM> may be applied more easily. If necessary, the heat transfer substance <NUM> may be applied to the entire bottom, exposed through the open bottom, of the cell-stacking structure <NUM> or may be applied in various patterns such as a zigzag shape.

In particular, in an exemplary embodiment of the present disclosure, when a gap filler of which the thermal conductivity is increased, as pressure is increased, is used as the heat transfer substance <NUM>, the ability to transmit heat generated from the cell-stacking structure <NUM> to the bottom plate <NUM> may be improved by welding the bottom plate <NUM> to the lower ends of the sides <NUM> and <NUM> of the module frame <NUM> while pressing the bottom plate <NUM> toward the cell-stacking structure <NUM>.

The bottom plate <NUM> may be bonded to the lower ends of the sides <NUM> and <NUM> of the module frame <NUM> by welding or other bonding methods with the sides <NUM> and <NUM> of the module frame <NUM> pressed toward the cell-stacking structure <NUM>. The performance of a battery module may be improved when a predetermined level of uniform surface pressure is maintained between battery cells stacked in the battery module. In addition, the lower ends of the sides <NUM> and <NUM> of the module frame <NUM> may be freely moved in some extent and thus, sufficient surface pressure may be applied between the battery cells <NUM> in the cell-stacking structure <NUM> by attaching the bottom plate <NUM> to the module frame <NUM> using welding or other bonding methods while pressing the sides <NUM> and <NUM> of the module frame <NUM> toward the cell-stacking structure, whereby it may be possible to improve the performance of the battery module.

The battery module <NUM> according to an exemplary embodiment of the present disclosure may further include a cooling water block <NUM> attached to the bottom of the bottom plate <NUM>. In particular, a cooling water pattern through which cooling water flows may be engraved (e.g., a groove passage may be formed) on the cooling water block <NUM> when seen from the bottom plate <NUM> and edges of the cooling block <NUM> may be bonded to the bottom of the bottom plate <NUM> and thus, cooling water flowing through the cooling water pattern may come in direct contact with the bottom plate <NUM>. According to this structure, the heat generated from the cell-stacking structure <NUM> including the battery cells <NUM> may transfer to the cooling water flowing on the cooling water block <NUM> through the heat transfer substance <NUM> and the bottom plate <NUM>.

As described above, the battery module <NUM> according to an exemplary embodiment of the present disclosure has a shortened heat transfer path through which the heat transfers to the cooling water through the bottom plate <NUM> and the heat transfer substance <NUM> being in direct contact with the battery cells <NUM> that generates the heat, thus improving cooling performance. Additionally, by reducing the size and improving the cooling performance of the battery module <NUM>, the battery module <NUM> may output greater or equal level of energy with a relatively small size in comparison to battery modules of the related art and thus, energy density may be improved.

The battery module <NUM> according to an exemplary embodiment of the present disclosure may further include a front cover <NUM> and a rear cover <NUM> that are coupled to the front portion and the rear portion of the module frame <NUM>. The inner sides of the front cover <NUM> and the rear cover <NUM> face the cell taps <NUM> on the battery cells <NUM> of the cell-stacking structure <NUM>. In an exemplary embodiment of the present disclosure, the front cover <NUM> and the rear cover <NUM> may be made of an insulating material. The insulating material thus provides an overall insulating effect to the structure.

<FIG> is a cross-sectional view of the battery module of <FIG> according to an exemplary embodiment of the present disclosure taken along line B-B'. Referring to <FIG>, the cell taps <NUM> included in the battery cells <NUM> may be bonded to one another to form electrical connection with the cell taps <NUM> of adj acent battery cells <NUM>. In general, cell taps may be bonded such that battery cells included in battery modules are connected in series, and thus, a pair of cell taps bonded to each other may be insulated from another adjacent pair of cell taps.

Claim 1:
A battery module, comprising:
a module frame (<NUM>) having a top (<NUM>) and sides (<NUM>, <NUM>) that extend down from the top (<NUM>);
a cell-stacking structure (<NUM>) disposed between the sides (<NUM>, <NUM>) of the module frame (<NUM>) and including a plurality of stacked battery cells (<NUM>) and surface pressure pads (<NUM>) disposed between a predetermined number of the battery cells (<NUM>) to be compressed in the stacking direction of the battery cells (<NUM>);
a bottom plate (<NUM>) disposed under the cell-stacking structure (<NUM>) and bonded to lower ends of the sides (<NUM>, <NUM>) of the module frame (<NUM>); and
a cooling water block (<NUM>) attached to the bottom of the bottom plate (<NUM>) to supply cooling water to the bottom of the bottom plate (<NUM>).