Battery module

A battery module includes a case with at least one face which is opened, a plurality of partition walls fixedly installed at predetermined intervals in the case, and a plurality of unit batteries which are separated from each other with the partition walls therebetween to be inserted into the case. The battery module may include a battery fixing structure which is installed between the case and the unit batteries to fix the unit batteries so as to prevent positional movement of the unit batteries in the case. The battery fixing structure may be a concavo-convex engaging structure including fixing projections and projection receiving portions.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application Nos. 10-2004-0086602 and 10-2004-0086603, both filed with the Korean Intellectual Property Office on Oct. 28, 2004, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a battery module, and more particularly, to a battery module capable of holding partition walls at fixed installation positions and enhancing an engaging force of the unit batteries within a case.

2. Related Art

Generally, secondary batteries are rechargeable and can be repeatedly used. In particular, secondary batteries including only one battery cell are mainly used for various small portable electronic apparatuses, such as cellular phones, laptop computers, cameras, and camcorders. High-capacity secondary batteries (hereinafter referred to as a ‘battery module’) are formed by connecting a plurality of battery cells (hereinafter referred to as ‘unit batteries’), and are mainly used as power sources for driving motors, such as, for example, motors for hybrid electric vehicles (HEVs), electrical vehicles (EVs), and the like.

Each of the unit batteries constituting the battery module includes: an electrode assembly having a positive plate, a negative plate, and a separator serving as an insulator interposed therebetween, a case having a space for accommodating the electrode assembly, a cap assembly combined with the case to tightly close the case, and positive and negative terminals protruding from the cap assembly and electrically connected to the positive plate and the negative plate, respectively.

Further, when the respective unit batteries are generally prismatic batteries, a positive terminal and a negative terminal of one unit battery protruding upward from the cap assembly are arranged so as to alternate with a positive terminal and a negative terminal of another unit battery adjacent to the one unit battery, and a conductor is connected between the threaded positive and negative terminals to be fixed thereto with nuts, thereby forming a battery module.

Since the battery module is constructed by connecting several or tens of unit batteries to each other, the battery module has a problem in that its overall volume is increased because the typical battery module needs a cooling structure, a safety means, a system circuit, etc., which are adapted to be easily capable of radiating heat generated in each unit battery.

In order to solve the problem, a method of reducing the size of the battery module by reducing the interval between the unit batteries is used, but this causes another problem in that it is difficult to radiate the heat generated in the unit batteries.

Thus, a structure capable of easily radiating the heat generated in respective unit batteries as well as being capable of minimizing the volume of a battery module at the time of designing the battery module is needed. If the heat generated in the respective unit batteries cannot be efficiently radiated, this will increase the temperature which will result in malfunction of apparatuses to which the battery module is applied.

Particularly, it is of primary importance to radiate heat in high-output and high-capacity battery modules for HEVs, EVs, and the like. If the size of the battery modules is increased, there is a problem in that not only the weight of the battery modules increases but also the design of the apparatuses (particularly, vehicles) equipped with the battery modules becomes complex.

Therefore, the development of battery modules capable of improving heat radiation characteristics while minimizing their size in battery modules required to have high output and high capacity becomes significant in modern battery practice.

Also, in a conventional battery module, spaces are provided between respective unit batteries for circulation of cooling air. Partition walls are installed for preventing structural deformation of the unit batteries. End plates are installed at opposite ends of the battery module. The unit batteries and the partition walls are supported by fixing the end plates using elongated restraint rods.

However, such a conventional battery module has problems in that, when an external force is applied, nonuniform deformation may occur in the battery module, which may lower reliability of the battery module, making it difficult to hold installation positions of the partition walls (interval between the partition walls) constant, and to prevent positional movement of the unit batteries.

SUMMARY OF THE INVENTION

The present invention provides a battery module capable of keeping installation positions of partition walls constant and capable of inducing uniform deformation of the partition walls and a case, by securely fixing the partition walls within the case or by forming the partition walls integrally with the case.

The present invention also provides a battery module capable of preventing the positional movement of the battery units by forming a battery fixing structure to improve the engaging force between the case and the unit batteries or between the case and the partition walls.

A battery module according to one aspect of the present invention includes a case with at least one face which is opened, a plurality of partition walls fixedly installed at predetermined intervals in the case, and a plurality of unit batteries which are separated from each other with the partition walls therebetween to be inserted into the case.

The case has a pair of supporting plates located so as to face to each other at opposite sides of the case, and which are arranged parallel to the partition walls, and a pair of side plates which are connected with the supporting plates at their opposite ends to integrally fix opposite edges of each of the partition walls and which are arranged perpendicular to the partition walls.

The partition walls may be integrally formed with the side plates of the case. Further, the interval between the adjacent partition walls is set to be equal to the thickness of each of the unit batteries.

The battery module may further include a fixing portion formed so as to protrude from one edge of each of the supporting plates of the case, and a fixing rod installed so as to connect the fixing portions of both of the supporting plates to each other to support them.

The battery module may further includes partition wall fixing grooves formed at predetermined intervals on the inner surfaces of the side plates of the case such that the partition walls are inserted thereinto.

In this case, the thickness of the partition walls may be set to be smaller than the external width of each of the partition wall fixing grooves. Also, the battery module may further include battery fixing grooves formed at predetermined intervals on the inner surfaces of the side plates of the case such that the unit batteries are inserted thereinto.

A plurality of projections may be formed on the partition walls so as to maintain predetermined gaps between the unit batteries.

The battery module according to another aspect of the present invention includes a battery fixing structure which is installed between the case and the unit batteries to fix the unit batteries so as to prevent the positional movement of the unit batteries from the case. The battery fixing structure may be a concavo-convex engaging structure including fixing projections and projection receiving portions.

The battery fixing structure may have fixing projections formed so as to protrude from the side faces of the unit batteries which face the case and cutouts formed at positions of the side plates of the case corresponding to the fixing projections.

Further, the battery fixing structure may have fixing projections formed so as to protrude from the side faces of the unit batteries which face the case and fixing grooves formed at positions of the side plates of the case corresponding to the fixing projections such that the fixing projections are inserted thereinto.

Moreover, the battery fixing structure may have fixing grooves formed on the side faces of the unit batteries which face the case and fixing projections protrudingly formed at positions of the side plates of the case corresponding to the fixing grooves.

The battery fixing structure may be formed between the side faces of the unit batteries which face the partition walls and the partition walls.

All the above battery modules may be used for driving a motor.

According to the battery module of the present invention as described above, since the battery module is formed and assembled with the partition walls and the case securely fixed, installation positions and alignment of the partition walls can be kept constant, thereby improving the assembling quality of the unit batteries.

Also, since the partition walls are connected to each other by the side plates of the case to form a single structure, if an external force is applied, uniform deformation is induced as a whole, so that safety can be improved and irregular changes in characteristics can be prevented.

In addition, since the projections can be formed on the partition walls or the gaps can be formed between the partition walls and the unit batteries, the heat generated in the unit batteries can be efficiently radiated, and the reliability of the batteries can be improved.

According to the battery module of the present invention, since the fixing projections are inserted into cutout portions or fixing grooves and are fixed thereto when the unit batteries are assembled into the case, the positional movement of the unit batteries can be effectively prevented, and it is also possible to prevent occurrence of problems that an operator may be injured or the unit batteries may be damaged when the unit batteries are dropped.

In addition, since the assembling work is finished simply by inserting the unit batteries into spaces between the case and the partition walls, the work time can be shortened and the productivity can be greatly improved.

DETAILED DESCRIPTION

Referring now toFIGS. 1 and 2, the battery module according to the present embodiment includes a box-shaped case10, at least one face of which is opened, a plurality of partition walls16which are integrally formed at regular intervals within the case10, and a plurality of unit batteries20separated from each other with the partition walls16therebetween to be inserted into the case10.

As the plurality of partition walls16are installed at regular intervals within the case10as described above, spaces11are formed between the partition walls16so that the unit batteries20are inserted thereinto.

The case10has a pair of supporting plates12formed so as to face to each other at both sides of the case, and a pair of side plates14which are connected with the supporting plates12at their both ends to integrally fix both edges of each of the partition walls16. The supporting plates12of the case10are installed parallel to the partition walls16, and the side plates14are installed perpendicular to the partition walls16.

The interval between the adjacent partition walls16can be set to be equal to the thickness of each of the unit batteries20.

The remaining one face (a bottom face, not shown) of the case10can be closed to prevent the positional movement of the unit batteries20inserted into the spaces11between the partition walls16.

FIG. 3is a perspective view showing a battery module according to a second embodiment of the present invention. Fixing portions13are formed so as to protrude from one (upper) edge of each of the supporting plates22of the case10, and fixing rods30with associated coupling nuts at each end are installed so as to connect the fixing portions13of both the supporting plates22to each other to support them. One fixing portion13may be formed at the center of each of the supporting plates, and two or more fixing portions may be formed with a predetermined distance therebetween.

As described above, when the fixing portions13are formed and the fixing rods30are installed, the supporting strength for supporting the unit batteries20can be greatly enhanced, and any deformation when an external force is applied can be minimized. Also, the fixing rods30may be used as handgrips when the battery module is carried and moved.

Although the above embodiment has been described having a configuration in which the fixing portions13and the fixing rods30are installed only on the top side, the present invention is not limited thereto. For example, it is possible to adopt a configuration in which the unit batteries20are supported by forming the case10with its bottom face removed, and installing the fixing portions13and the fixing rods30on the bottom side as well.

Since the same battery installation configuration as the first embodiment can also be embodied in the above-described second embodiment, its detailed description will be omitted.

FIG. 4is an exploded perspective view showing a battery module according to a third embodiment of the present invention. Partition wall fixing grooves19for allowing the insertable partition walls16′ to be inserted thereinto are formed at regular intervals on the inner surfaces of the side plates14of the case10of the battery module according to the present embodiment. These partition wall fixing grooves19may be formed by fixedly installing U-shaped guide rails18in the side plates14of the case10.

By inserting the insertable partition walls16′ into the partition wall fixing grooves19formed by the guide rails18, the partition walls16′ can be securely fixed within the case10.

Alternatively, the guide rails18may be formed as separate members and then attached onto the surfaces of the side plates14of the case10, or may be formed so as to protrude integrally from the side plates14of the case10.

In the above configuration, the thickness of opposite ends of each of the partition walls16′ to be inserted into the partition wall fixing grooves19of the guide rails18is set such that the ends are securely fitted into the fixing grooves19, thereby preventing the partition walls16′ from being detached from the fixing grooves19.

In an exemplary embodiment both the ends of the partition walls16′ and the partition wall fixing grooves19may be formed in complementary dove-tail shapes. Also, both the ends of the partition walls16′ and the partition wall fixing grooves19may be formed in a round shape such as a semicircular shape or a circular-arc shape.

When the thickness of the partition walls16′ is set to be smaller than the external width of the guide rails18, gaps may be defined between the partition walls16′ and the unit cells20by the thickness of the guide rails18forming the partition wall fixing grooves19to allow heat radiation therethrough.

Since the same battery installation configuration as the first and second embodiments can also be embodied in the above-described third embodiment, its detailed description will also be omitted.

FIG. 5is a perspective view showing another exemplary embodiment of partition walls applied to the embodiments of the present invention. For the first to third embodiments, a plurality of projections27may be formed on the partition walls26so as to maintain predetermined gaps between the unit batteries20.

The projections27may be formed as a separate member and then attached on the partition wall26, or may be formed integrally on the partition walls26. The projections27may be formed integrally on the partition walls26by embossing, drawing or the like. Also, the projections27may be formed only on one side of each of the partition walls26or may be formed on both sides thereof.

When the projections27are formed on the partition walls27, heat radiation can be effectively performed due to the existence of the gaps between the partition walls26and the unit batteries20, as well as improving the strength of the partition walls26.

FIG. 6is an exploded perspective view showing a battery module according to a fourth embodiment of the present invention. In the battery module according to the present embodiment, battery fixing grooves29for allowing the unit batteries20to be inserted thereinto are formed at regular intervals on the inner surfaces of the side plates14. These battery fixing grooves29may be formed by fixedly installing with U-shaped guide rails28in the side plates14of the case10.

Alternatively, the guide rails28may be formed as separate members and then attached on the inner surfaces of the side plates14of the case10, or may be formed so as to protrude integrally from the side plates14of the case10.

By forming the guide rails28as described above and inserting the partition walls16into partition wall fixing grooves19′ formed between adjacent guide rails28, the partition walls16can be securely fixed within the case10.

In an exemplary embodiment the width of the partition wall fixing grooves19′ (the spacing between adjacent guide rails28) is set to a dimension equal to the thickness of the partition walls16. Also, the width of the partition wall fixing grooves19′ is set such that the partition walls16are securely fitted into the grooves, thereby preventing the partition walls16from being deviated from the grooves.

Also, the width of the battery fixing grooves29is set such that the unit batteries20are securely fitted into the battery fixing grooves29, thereby preventing positional movement of the unit batteries20.

As described above, when the unit batteries20are inserted into the battery fixing grooves29and the partition walls16are inserted into the partition wall fixing grooves19′ between the guide rails28, gaps may be defined between the partition walls16and the unit cells20by the thickness of the guide rails28to allow heat radiation therethrough.

Since the same battery installation configuration as the first and second embodiments can also be embodied in the above-described fourth embodiment, its detailed description will be omitted.

FIG. 7is an exploded perspective view showing a battery module according to a fifth embodiment of the present invention, andFIG. 8is a perspective view showing a state in which unit batteries are inserted into a case of the battery module according to the fifth embodiment of the present invention. The battery module according to the present embodiment includes a box-shaped case40, at least one face of which is opened, a plurality of partition walls46fixedly installed at regular intervals within the case40, and a plurality of unit batteries50which are separated from each other with the partition walls46therebetween, and a battery fixing structure which is installed between the case40and the unit batteries50to fix the unit batteries50so as to prevent positional movement of the unit batteries from the case40. This battery fixing structure may be a concavo-convex engaging structure including fixing projections and projection receiving portions.

As the plurality of partition walls46are located (or installed) at regular intervals within the case40, spaces41are formed between the partition walls46for allowing the unit batteries50to be inserted thereinto.

The case40is composed of a pair of supporting plates42located at opposite ends in the direction in which the partition walls46are arranged, and a pair of side plates44which join the supporting plates42to each other on their opposite sides to integrally fix opposite edges of each of the partition walls46. The supporting plates42of the case40are installed parallel to the partition walls46, and the side plates44are installed perpendicular to the partition walls46.

It is noted from the above that the interval between the partition walls46can be set to be equal to the thickness of each of the unit batteries50.

In order to effectively radiate the heat generated in the unit batteries50, the projections as shown inFIG. 5may be formed on the partition walls46so that a predetermined gap can be maintained from the unit batteries50.

The remaining one face (bottom face, not shown) of the case40can be closed to prevent positional movement of the unit batteries50inserted into the spaces41between the partition walls46.

FIG. 9is an enlarged sectional view showing a battery fixing structure of a battery module according to a fifth embodiment of the present invention.

As shown inFIGS. 7 and 9, the battery fixing structure has fixing projections52formed so as to protrude from the side faces of the unit batteries50which face the case40and, in particular, cutouts62formed at positions of the side plates44of the case40corresponding to the fixing projections52. Cutouts62may be formed by cutting the case in the shape of the letter “H”.

In an exemplary embodiment at least front faces of the fixing projections52in their insertion direction may be formed having inclined surfaces so that the fixing projections can be easily inserted. Accordingly, the fixing projections52may have trapezoidal side faces, or otherwise may have side faces in various shapes, such as a rectangular shape, a triangular shape, a semicircular shape, and a semispherical shape.

In an exemplary embodiment the side plates44of the case40on which the cutouts62are formed are made of a material having a predetermined elastic force to hold a fastening force (supporting force) to the fixing projections52.

The procedure of assembling the battery module when the battery fixing structure is formed as inFIGS. 7 to 9will now be described.

First, when the unit batteries50are inserted into the spaces41formed between the partition walls46of the case40, the fixing projections52reach the cutouts62. Then, cutout pieces63are pushed outwardly while the cutouts62are spread by the protruding fixing projections52. Then, the fixing projections52are located at the centers of the cutouts62. At this time, the cutout pieces63are maintained in close contact with the fixing projections52due to a predetermined elastic force to prevent the positional movement of the unit batteries50.

FIG. 10is an enlarged sectional view showing a battery fixing structure of a battery module according to a sixth embodiment of the present invention. In the battery fixing structure according to the present embodiment, fixing projections52are formed so as to protrude from the side faces of the unit batteries50which face the case40, and fixing grooves64are formed at positions of the side plates54of the case40corresponding to the fixing projections52for allowing the fixing projections52to be inserted thereinto.

By forming the battery fixing structure as described above, the positional movement of the unit batteries50can be prevented since the fixing projections52are inserted into the fixing grooves64.

FIG. 11is an enlarged sectional view showing a battery fixing structure of a battery module according to a seventh embodiment of the present invention. In the battery fixing structure according to the present invention, fixing grooves53are formed on the side faces of the unit batteries51which face the case40, and fixing projections65are formed at positions of the side plates55of the case40corresponding to the fixing grooves53.

Although the above embodiments have been described with respect to the configuration in which the battery fixing structure is installed between the unit batteries and the side plates of the case, the present invention is not limited thereto. For example, the battery fixing structure may be installed between the unit batteries and the partition walls, such embodiments are shown inFIGS. 12 and 13.

FIG. 12is an exploded perspective view showing a battery module according to an eighth embodiment of the present invention, andFIG. 13is a sectional view of the battery module ofFIG. 12in an assembled configuration. The battery fixing structure according to the present invention includes fixing projections57formed so as to protrude from the side faces of the unit batteries50′ on the side of the partition walls46′, and fixing grooves67formed at positions of the partition walls46′ corresponding to the fixing projections57for allowing the fixing projections57to be inserted therethrough.

In an alternative embodiment, fixing grooves may be formed on the side faces of the unit batteries which face the partition walls and fixing projections may be formed at positions of the partition walls corresponding to the fixing grooves.

In still another embodiment, the battery fixing structure may be installed not only between the unit batteries and the partition walls but also between the unit batteries and the side plates. As such, fastening of the unit batteries within the case can be even more reliably ensured.

FIG. 14is a perspective view showing a battery module according to a ninth embodiment of the present invention. In the battery module according to the present embodiment, expanding upon the embodiments shown inFIGS. 7-9, fixing portions73are formed so as to protrude from one (upper) edge of each of the supporting plates72of the case40, and fixing rods75with coupling nuts are installed so as to connect the fixing portions73of both of the supporting plates72to each other to support them.

One fixing portion73may be formed at the center of each of the supporting plates, and two or more fixing portions may be formed with a predetermined distance therebetween.

When the fixing portions73are formed and the fixing rods75are installed, the supporting strength for supporting the unit batteries50can be greatly improved, and any deformation which may be caused when an external force is applied can be minimized. Also, the fixing rods75may be used as handgrips when the battery module is carried and moved.

Although the present embodiment has been described for a configuration in which the fixing portions73and the fixing rods75are installed only on the top side, the present invention is not limited thereto. For example, it is possible to adopt a configuration in which the unit batteries50are supported by forming the case40with its bottom face removed, and providing the fixing portions73and the fixing rods75on the bottom side as well.

Since the same battery installation configuration as the fifth to eighth embodiments can also be embodied in the above-described ninth embodiment, its detailed description will be omitted.

FIG. 15is a perspective view showing a battery module according to a tenth embodiment of the present invention. Two rows of battery fixing structures are formed in the battery module according to the present embodiment.

Specifically, two rows, i.e., upper and lower rows of fixing projections52are formed so as to protrude from the side faces of the unit batteries50″ which face the case40and two rows76,78of cutouts62and cutout pieces63are formed at positions of the side plates74of the case40corresponding to the fixing projections52and formed by cutting the case substantially in the shape of the letter “H”.

Also, three more rows of the fixing projections52and the cutouts62may be formed.

Since the same battery installation configuration as the sixth to ninth embodiments can also be embodied in the above-described tenth embodiment, its detailed description will be omitted.

The battery modules according to the embodiments of the present invention configured as described above can be used as power sources for driving motors in motor-operated apparatuses, such as HEVs, EVs, cordless cleaners, electric-powered bicycles, and electric-powered scooters, and in various applications which require high output and high capacity.

FIG. 16is a block diagram showing an example in which the battery module70is used for a driving motor80.

Although the battery modules according to exemplary embodiments of the present invention have been shown and described, it should be appreciated by those skilled in the art that changes may be made to the disclosed embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.