Patent Description:
In order to sufficiently secure the capacity of a secondary battery, the number of battery cells located in a battery module should increase, and as the number of battery cells increases, a volume increment due to swelling also increases. As the volume increment increases, a force applied to a side wall of a module housing due to the swelling also increases. In order for the module housing to withstand the force without being deformed, a thickness of a plate of the module housing should be increased.

In order to absorb expansion caused by the battery cell swelling without excessively increasing the thickness of the module housing, in the prior art, a swelling absorbing pad having a certain thickness may be applied between adjacent battery cells and/or to both outmost edge portions of a battery cell stack. However, when the swelling absorbing pad is applied, because there is no separate fixing structure for holding the swelling absorbing pad, a process of accommodating a stack including the absorbing pad and the battery cells in the module housing is not easy.

That is, in order to prevent the battery cells and the absorbing pad from moving in the module housing, the battery cells and the swelling absorbing pad should be stacked to have a thickness greater than a width of the module housing, and then both sides of the stack should be pressed so that the pressed stack is accommodated in the module housing.

However, when the number of battery cells increases in order to secure the capacity of the secondary battery, the thickness of the stack including the battery cells and the swelling absorbing pad may inevitably increase, and thus the process of accommodating the stack in the module housing may not be easy and the battery cells may be interfered with the module housing and may be damaged during the accommodating process.

Accordingly, there is a demand for the development of a battery module structure capable of effectively absorbing volume expansion due to swelling of a battery cell and facilitating a process of inserting a battery cell stack into a module housing.

An example of a secondary battery module and a wall of the secondary battery module is described in <CIT>. An example of a battery crush protection system is described in <CIT>. An example of a horizontal battery container is described in <CIT>.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module having a structure capable of effectively absorbing volume expansion due to swelling of a battery cell and facilitating a process of inserting a battery cell stack into a module housing.

Also, the present disclosure is directed to providing a battery module having a structure capable of easily handling the battery module in consideration of an increase in the weight of the battery module as the size and the number of battery cells applied to one battery module increases to secure capacity.

However, technical problems to be solved by the present disclosure are not limited to the above-described technical problems and one of ordinary skill in the art will understand other technical problems from the following description.

The present disclosure provides a battery module as defined by the independent claim <NUM>, a battery pack as defined by the claim <NUM>, and a vehicle as defined by the claim <NUM>. Preferred embodiments are defined in the appended dependent claims.

The battery module is defined according to claim <NUM>.

The plurality of insertion slits may be formed at positions corresponding to the pair of partition walls.

The pair of partition walls may be inserted into a pair of insertion slits that are spaced apart from each other.

The pair of connectors may be spaced apart from each other by a distance corresponding to a height of the module housing.

Each of the pair of partition walls may include at least one handling hole formed in a portion exposed to the outside of the module housing through the insertion slit.

Each of the pair of partition walls may have the length corresponding to an electrode assembly receiver of the battery cell.

Each of the module housing and the partition wall assembly may be formed of a metal material.

The module housing may include: a lower housing including a base plate and a pair of side plates; and an upper housing coupled from the top of the cell stack to the lower housing.

The base plate and the pair of side plates constituting the lower housing may be integrally formed with each other, and a welding portion may be formed between the upper housing and the lower housing.

The welding portion may be formed between an inner surface of the insertion slit and the partition wall.

There are also provided the battery pack (claim <NUM>) and the vehicle (claim <NUM>) including the battery module.

According to an aspect of the present disclosure, volume expansion due to swelling of a battery cell may be effectively absorbed, and a process of inserting a battery cell stack into a module housing may be facilitated.

Also, according to another aspect of the present disclosure, despite an increase in the weight of a battery module as the size and the number of battery cells applied to one battery module increases to secure capacity, the battery module may be easily handled.

The accompanying drawings illustrate a preferred embodiment of the present disclosure and together with the foregoing disclosure, serve to provide further understanding of the technical features of the present disclosure, and thus, the present disclosure is not construed as being limited to the drawings.

Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the present disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the scope of the present disclosure.

Referring to <FIG>, a battery module according to an embodiment of the present disclosure includes a cell stack <NUM>, a module housing <NUM>, and a partition wall assembly <NUM>.

Referring to <FIG> and <FIG>, the cell stack <NUM> includes a plurality of unit stacks <NUM>. The partition wall assembly <NUM> is located between adjacent unit stacks <NUM>. The unit stack <NUM> includes a plurality of battery cells <NUM> that are stacked to face each other.

For example, a pouch-type battery cell may be used as the battery cell <NUM>. In this case, the battery cell <NUM> includes an electrode assembly receiver 111a, a sealing portion 111b formed around the electrode assembly receiver 111a, and a pair of electrode leads 111c connected to an electrode assembly (not shown) and drawn out to the outside of a pouch case through the sealing portion 111b. The pair of electrode leads 111c may be drawn out in opposite directions. The pair of electrode leads 111c may be exposed through front and rear opening portions of the module housing <NUM>. The front and rear opening portions may be respectively formed on both sides in a longitudinal direction (direction parallel to an X-axis) of the module housing <NUM>.

The plurality of battery cells <NUM> are erected and stacked facing each other on a bottom surface (surface parallel to an X-Y plane) of the module housing <NUM>, to form the unit stack <NUM>. Although only three unit stacks <NUM> each including the plurality of battery cells <NUM> are illustrated in the present disclosure, this is merely an example and the number of unit stacks <NUM> may be two, or four or more.

Referring to <FIG> and <FIG>, the module housing <NUM> accommodates the cell stack <NUM> therein, and includes a plurality of insertion slits S formed in a top surface and a bottom surface of the module housing <NUM>. The module housing <NUM> may have open front and rear surfaces (surfaces parallel to a Y-Z plane). The module housing <NUM> may be formed of a metal material in consideration of rapid heat dissipation and rigidity.

The module housing <NUM> includes a lower housing <NUM> and an upper housing <NUM>. The lower housing <NUM> includes a base plate <NUM> supporting the cell stack <NUM>, and a pair of side plates <NUM> extending upward from both end portions in a width direction (direction parallel to a Y-axis) of the base plate <NUM>. The base plate <NUM> and the side plates <NUM> may be integrally formed with each other.

The base plate <NUM> includes a plurality of insertion slits S longitudinally extending in a longitudinal direction (direction parallel to the X-axis) of the base plate <NUM>. The number of the insertion slits S corresponds to the number of partition walls <NUM> (see <FIG> and <FIG>) constituting the partition wall assembly <NUM> described below. The insertion slit S formed in the base plate <NUM> provides a space into which a lower end of the partition wall assembly <NUM> may be inserted and fixed. The side plates <NUM> face outermost battery cells <NUM> of the cell stack <NUM>. When the partition wall assembly <NUM> is inserted and fixed through the insertion slit S formed in the base plate <NUM>, a space into which each unit stack <NUM> may be inserted is formed between the side plate <NUM> and the partition wall assembly <NUM> and between a pair of adjacent partition wall assemblies <NUM>.

The upper housing <NUM> is coupled to the lower housing <NUM> from the top of the cell stack <NUM> in a state where the cell stack <NUM> is seated on the lower housing <NUM>. Both end portions in a width direction (direction parallel to the Y-axis) of the upper housing <NUM> are respectively coupled to the pair of side plates <NUM>. For convenience of a process and prevention of damage to the cell stack <NUM>, it is preferable that a process of coupling the upper housing <NUM> to the lower housing <NUM> is performed after a plurality of unit stacks 110A, 110B, 110C are respectively seated in a plurality of spaces formed by coupling between the lower housing <NUM> and the partition wall assembly <NUM>.

A welding portion is formed between the partition wall assembly <NUM> and an inner surface of the insertion slit S. That is, the partition wall assembly <NUM> and the lower housing <NUM> are coupled to each other by using welding. A welding portion may also be formed between the lower housing <NUM> and the upper housing <NUM>. That is, the lower housing <NUM> and the upper housing <NUM> may be coupled to each other by using welding. However, a coupling method between the lower housing <NUM> and the upper housing <NUM> is not limited thereto, and the lower housing <NUM> and the upper housing <NUM> may be coupled to each other by using a method such as bolting instead of welding.

The upper housing <NUM> includes a plurality of insertion slits S respectively formed at positions facing the insertion slits S formed in the lower housing <NUM>. Accordingly, when the upper housing <NUM> is coupled to the lower housing <NUM>, an upper end of the partition wall assembly <NUM> already fixed to the lower housing <NUM> is exposed beyond the top of the module housing <NUM> through the insertion slit S formed in the upper housing <NUM>. To increase a fastening force between the module housing <NUM> and the partition wall assembly <NUM>, a welding portion may be formed between the partition wall assembly <NUM> and an inner surface of the insertion slit S formed in the upper housing <NUM>. That is, the inner surface of the insertion slit S formed in the upper housing <NUM> and the partition wall assembly <NUM> may be coupled to each other by using welding.

Referring to <FIG>, the partition wall assembly <NUM> includes a pair of partition walls <NUM> and a pair of connectors <NUM> for connecting the pair of partition walls <NUM>. The partition wall assembly <NUM> may be formed of a metal material, like the module housing <NUM>.

The pair of partition walls <NUM> are spaced apart from each other to face each other. The pair of partition walls <NUM> are each in close contact with the electrode assembly receiver 111a, and are elastically deformed so that central portions thereof are closer to each other by pressure applied due to swelling of the battery cell <NUM> (see <FIG>). That is, the partition wall assembly <NUM> functions to absorb the swelling of the battery cell <NUM>. The partition wall <NUM> has a length and a width corresponding to the insertion slit S, and an upper end and a lower end of the partition wall <NUM> pass through the insertion slits S to be exposed to the outside of the module housing <NUM>.

The partition wall <NUM> has a length corresponding to the electrode assembly receiver 111a of the outermost battery cell <NUM> of the unit stack <NUM>. This is to enable the partition wall assembly <NUM> to effectively function as a cooling fin and function as an absorbing member for absorbing swelling, and to prevent a short-circuit by securing a certain distance or more between the electrode lead 111c and the partition wall assembly <NUM>.

One of the pair of connectors <NUM> is formed at a position downwardly spaced apart by a certain distance from the upper end of the partition wall <NUM>. The remaining one of the pair of connectors <NUM> is formed at a position upwardly spaced apart by a certain distance from the lower end of the partition wall <NUM>. The connector <NUM> may function as a stopper for preventing the partition wall assembly <NUM> from being separated upward or downward from the module housing <NUM> through the insertion slit S. That is, the connector <NUM> is located inside the module housing <NUM>. The pair of connectors <NUM> are spaced apart from each other by a distance corresponding to a height of the module housing <NUM>, that is, a distance between the base plate <NUM> and the upper housing <NUM>.

As described above, because the battery module according to an embodiment of the present disclosure includes the partition wall assembly <NUM> in the module housing <NUM>, swelling of the battery cell <NUM> of the cell stack <NUM> may be absorbed.

Also, according to a battery module structure according to an embodiment of the present disclosure, the unit stacks 110A, 110B, 110C may be individually seated in a plurality of spaces formed when the partition wall assembly <NUM> is fixedly installed on the lower housing <NUM>, and then the upper housing <NUM> may be fastened. Accordingly, when the number of the battery cells <NUM> constituting the cell stack <NUM> is very large, a process of seating the cell stack <NUM> may be easily performed, and thus damage to the cell stack <NUM> in a manufacturing process of the battery module may be prevented.

A battery module according to another embodiment of the present disclosure will now be described with reference to <FIG> and <FIG>. When compared to the battery module according to an embodiment of the present disclosure described above, the battery module according to another embodiment of the present disclosure has a difference in a structure of a partition wall assembly <NUM>, but the remaining elements are substantially the same. Accordingly, in describing the battery module according to another embodiment of the present disclosure, the same description as that made in the above embodiment will be omitted and the following will focus on a difference.

The partition wall assembly <NUM> includes at least one handling hole 310a formed in a portion exposed to the outside of the module housing <NUM> through the insertion slit S formed in a top surface of the module housing <NUM>, that is, in the upper housing <NUM>. The handling hole 310a may be formed in each of the pair of partition walls <NUM> constituting the partition wall assembly <NUM>, or may be formed in only one of the pair of partition walls <NUM>. The handling hole 310a may help an operator to easily handle the battery module.

To secure sufficient capacity, when the size and the number of the battery cells <NUM> constituting the battery module increase, the weight of the battery module inevitably increases. Accordingly, in order for the operator to easily handle the battery module, a gripping means formed on an outer surface of the battery module is required. The battery module according to another embodiment of the present disclosure may fulfill the requirement by providing the handling hole 310a formed by using the partition wall assembly <NUM> exposed to the outside of the module housing <NUM>.

Claim 1:
A battery module comprising:
a cell stack (<NUM>) comprising a plurality of unit stacks (<NUM>) each comprising a plurality of battery cells (<NUM>);
a module housing (<NUM>) accommodating the cell stack (<NUM>) therein and comprising a plurality of insertion slits (S) respectively formed in a top surface and a bottom surface; and
at least one partition wall assembly (<NUM>) located parallel to each of the plurality of battery cells (<NUM>), and located between adjacent unit stacks (<NUM>) and deformed due to volume expansion due to swelling of the plurality battery cells (<NUM>) to absorb the swelling, wherein the at least one partition wall assembly (<NUM>) comprises:
a pair of partition walls (<NUM>) spaced apart from each other to face each other; and
a pair of connectors (<NUM>) respectively formed at a position downwardly spaced apart by a certain distance from upper ends of the pair of partition walls (<NUM>) and at a position upwardly spaced apart by a certain distance from lower ends of the pair of partition walls (<NUM>), and configured to connect the pair of partition walls (<NUM>);
wherein the upper ends and the lower ends of the pair of partition walls (<NUM>) are configured to be inserted and fixed through the plurality of insertion slits (S), such that the upper and lower ends of the pair of partition walls (<NUM>) are configured to pass through the plurality of insertion slits (S) to be exposed to the outside of the module housing (<NUM>);
wherein each of the pair of partition walls (<NUM>) has a length and a width corresponding to the respective insertion slit (S), and wherein the number of insertion slits (S) corresponds to the number of the partition walls (<NUM>).