Patent Description:
Also, the present application claims priority to <CIT> in the Republic of Korea. Also, the present application claims priority to <CIT> in the Republic of Korea.

In the case of a battery module adopting an indirect water cooling method using a cooling water, the cooling performance is limited because the cooling water does not directly contact battery cells but indirectly contacts the battery cells through a module housing that accommodates the battery cells. In addition, since a cooling device such as a separate heatsink must be provided outside the module housing to form a channel for cooling, the overall volume of the battery module is inevitably increased, which causes a loss in terms of energy density.

In order to solve the problem of the indirect water cooling method, it is demanded to develop a battery module having a structure that allows a cooling liquid to flow directly into the module housing and realize rapid cooling through direct contact with the battery cells and electrical connection parts.

Meanwhile, in the case of a battery module having a direct cooling structure using such an cooling liquid, it is important to develop a channel structure for efficient cooling, but it is also very important to maintain airtightness so that the insulation cooling liquid does not leak out of the module housing and an end plate.

In particular, in the case of a battery module having a structure in which the pair of external terminals functioning as high-potential terminals of the battery module are exposed to the outside of the sealing plate and the end plate, for the electrical connection between an external terminal located outside the sealing plate and an internal terminal located inside the sealing plate, the sealing plate must have a structure that is partially perforated. Therefore, there is a risk that the insulation cooling liquid inside the module housing may leak through the perforated portion of the sealing plate, and it is demanded to develop a sealing structure that may effectively prevent such leakage in the perforated portion of the sealing plate.

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 in which an insulation cooling liquid is introduced into a module housing and comes into direct contact with battery cells and electric connection components to realize efficient cooling and also the cooling liquid introduced into the module housing may smoothly flows.

In addition, the present disclosure is also directed to providing a battery module having a structure in which a pair of external terminals functioning as high-potential terminals of the battery module are exposed to the outside of the sealing plate and the end plate, where it is possible to efficiently prevent the cooling liquid from leaking through a perforated portion of the sealing plate.

In one aspect of the present disclosure, there is provided a battery module, comprising: a sub module including a cell stack assembly having a plurality of battery cells and a channel spacer interposed between adjacent battery cells, a front bus bar frame assembly coupled to one longitudinal side of the cell stack assembly, and a rear bus bar frame assembly coupled to the other longitudinal side of the cell stack assembly; a module housing configured to accommodate the sub module; a front sealing plate configured to cover an opening at one longitudinal side of the module housing and having an inlet for introducing an insulation cooling liquid; and a rear sealing plate configured to cover an opening at the other longitudinal side of the module housing and having an outlet for discharging the insulation cooling liquid.

The channel spacer may have a cooling liquid channel through which an insulation cooling liquid supplied into the battery module from the outside flows.

The cooling liquid channel may be formed through the channel spacer and extend along a longitudinal direction of the channel spacer.

The insulation cooling liquid flowing through the channel spacer may be in indirect contact with a body of the battery cell.

The front bus bar frame assembly includes a bus bar frame; and a plurality of bus bars fixed on the bus bar frame and coupled to electrode leads of the battery cells.

The bus bar frame may have a cooling liquid hole.

The battery module further comprises a pair of terminal assemblies having an external terminal located at an outer side of the front sealing plate and a stud provided through the front sealing plate to electrically connect the external terminal and the battery cell.

The front bus bar frame assembly may further include a pair of internal terminals fixed on the bus bar frame and connected to electrode leads of a battery cell located at an outermost side among the battery cells provided in the cell stack assembly.

The stud may be fixed to the internal terminal.

The terminal assembly may further include a terminal spacer inserted into a terminal hole formed in the front sealing plate.

The stud may be provided through the terminal spacer.

The terminal assembly may further include a fastening nut fastened to the stud provided through the terminal spacer and the external terminal so that the external terminal is closely fixed to the terminal spacer.

The terminal assembly may further include a first O-ring configured to cover an outer circumferential surface of the terminal spacer and interposed between an inner surface of the front sealing plate and the internal terminal.

The stud may be press-fitted through the internal terminal.

The terminal assembly may further include a second O-ring located around the stud and interposed between the internal terminal and the bus bar frame.

Meanwhile, a battery pack and a vehicle according to an embodiment of the present disclosure comprises the battery module according to an embodiment of the present disclosure as described above.

According to the present disclosure, the insulation cooling liquid may be introduced into the battery module to directly contact the battery cells and electrical connection parts, and the cooling liquid introduced into the battery module may flow smoothly, thereby enabling efficient and rapid cooling.

In addition, according to the present disclosure, it is possible to effectively prevent the insulation cooling liquid flowing inside the module housing for cooling the battery module from leaking. According to the present disclosure, in particular, in the battery module having a structure in which a pair of external terminals functioning as high-potential terminals of the battery module are exposed to the outside of the sealing plate and the end plate, it is possible to effectively prevent the insulation cooling liquid from leaking at the perforated portion of the sealing plate.

Referring to <FIG> and <FIG>, a battery module according to an embodiment of the present disclosure includes a sub module <NUM>, a module housing <NUM>, a front sealing plate <NUM> and a rear sealing plate <NUM>. The battery module may further include a front end plate <NUM> and/or a rear end plate <NUM> and/or a pair of terminal assemblies <NUM> in addition to the above components.

Referring to <FIG>, the sub module <NUM> includes a cell stack assembly <NUM>. The sub module <NUM> may further include a front bus bar frame assembly 120A and a rear bus bar frame assembly 120B coupled to the cell stack assembly <NUM>, in addition to the cell stack assembly <NUM>.

The cell stack assembly <NUM> includes a plurality of battery cells <NUM> and at least one channel spacer <NUM> interposed between adjacent battery cells <NUM>. The cell stack assembly <NUM> may further include at least one buffer pad <NUM> interposed between adjacent battery cells <NUM>. The battery cells <NUM>, the channel spacer <NUM> and the buffer pad <NUM> are stacked in a vertical standing form on the ground (a surface parallel to the X-Y plane) to form a single cell stack assembly <NUM>.

As the battery cell <NUM>, a pouch-type battery cell having a pair of electrode leads 111a drawn out in opposite directions along a longitudinal direction of the battery cell <NUM>(a direction parallel to the X-axis) may be used.

The channel spacer <NUM> includes at least one cooling liquid channel 112a through which an insulation cooling liquid supplied into the battery module from the outside may flow. The cooling liquid channel 112a is formed through the channel spacer <NUM> and extends along a longitudinal direction of the channel spacer <NUM> (a direction parallel to the X-axis). If a plurality of cooling liquid channels 112a are provided, the plurality of cooling liquid channels 112a are disposed to be spaced apart from each other in a height direction of the channel spacer <NUM> (a direction parallel to the Z-axis). In the present disclosure, the insulation cooling liquid used for cooling is a cooling liquid with improved insulation, and, for example, an insulation oil may be used.

The channel spacer <NUM> may be interposed between adjacent battery cells <NUM>, respectively. In this case, each battery cell <NUM> is configured such that both one surface and the other surface thereof are in contact with the channel spacer <NUM>, so the battery cell <NUM> has an advantage in that the cooling effect is maximized and the flow of the insulation cooling liquid introduced into the battery module becomes smoother.

Meanwhile, unlike this, the number of the channel spacers <NUM> may also be applied only by approximately <NUM>/<NUM> of the number of the battery cells <NUM>. Specifically, the plurality of channel spacers <NUM> may also be arranged such that a pair of battery cells <NUM> contacting each other is positioned between a pair of adjacent channel spacers <NUM>. In this case, all the battery cells <NUM> are configured such that only one side thereof is in contact with the channel spacer <NUM>. If the plurality of channel spacers <NUM> are arranged in this way, both the cooling efficiency of the battery cell <NUM> and the energy density may be improved. The cooling liquid channel 112a has a hole shape formed therethrough along the longitudinal direction of the channel spacer <NUM> (a direction parallel to the X-axis). Therefore, the insulation cooling liquid flowing through the channel spacer <NUM> does not directly contact a body of the battery cell <NUM>, but indirectly contacts the body of the battery cell <NUM> through the channel spacer <NUM>. The cooling liquid channel 112a may be provided in plural. In this case, the cooling liquid channels 112a may be formed to be spaced apart from each other along a height direction of the channel spacer <NUM> (a direction parallel to the Z-axis).

The channel spacer <NUM> is configured such that both surfaces thereof are entirely in contact with the body of the battery cell <NUM>. Therefore, when the battery cell <NUM> swells, a uniform pressure may be applied to the body of the battery cell <NUM> as a whole, and accordingly, a phenomenon that the pressure is applied intensively to only a partial region of the battery cell <NUM> does not occur, thereby preventing the battery cell <NUM> from being damaged.

The channel spacer <NUM> may be made of, for example, a metal material with excellent thermal conductivity, such as aluminum. In this case, although the battery module of the present disclosure has a structure in which the insulation cooling liquid and the body of the battery cell <NUM> do not directly contact, the cooling efficiency for the body of the battery cell <NUM> is practically not inferior, compared to the case where the insulation cooling liquid directly contacts the body of the battery cell <NUM>. That is, the channel spacer <NUM> of the present disclosure has both a function as a buffer member for stably buffering the battery cell <NUM> without damage when the battery cell <NUM> swells, and a function as a cooling member for realizing efficient cooling.

The insulation cooling liquid is introduced into the battery module through an inlet P1 to cool the electrode lead 111a and a bus bar <NUM> provided at one side of the battery cell <NUM> in a longitudinal direction (a direction parallel to the X-axis), and then cools the body of battery cell <NUM> while passing through the channel spacer <NUM>. In addition, after cooling the body of the battery cell <NUM>, the insulation cooling liquid cools the electrode lead 111a and a bus bar <NUM> provided at the other longitudinal side of the battery cell <NUM> while being discharged to the outside of the battery module through an outlet P2. In addition, if the front bus bar frame assembly 120A of the present disclosure includes an internal terminal <NUM>, explained later, the insulation cooling liquid may also contact the internal terminal <NUM> to quickly cool the internal terminal <NUM>. Through this process, the insulation cooling liquid may effectively cool the sub module <NUM> inside the module housing <NUM> as a whole. In the battery cell <NUM>, the place where heat is most intensively generated is the electrode lead 111a. Since the battery module of the present disclosure allows the electrode lead 111a to be efficiently cooled, it is possible to improve the cooling efficiency of the overall battery module. In addition, a lot of heat may also be generated from the bus bar <NUM> and the internal terminal <NUM>, where currents generated from the plurality of battery cells <NUM> are collected, and the battery module of the present disclosure may allow these electrically connected components to be efficiently cooled, thereby providing excellent cooling efficiency.

The buffer pad <NUM> may be interposed between adjacent battery cells <NUM> to absorb volume expansion caused by swelling of the battery cells <NUM>.

The front bus bar frame assembly 120A and the rear bus bar frame assembly 120B are respectively coupled to one side and the other side of the cell stack assembly <NUM> in the longitudinal direction (a direction parallel to the X-axis) to electrically connect the plurality of battery cells <NUM>. According to an embodiment, the front bus bar frame assembly 120A may have an internal terminal <NUM>, and the rear bus bar frame assembly 120B has substantially the same structure as the front bus bar frame assembly 120A, except that it does not include the internal terminal <NUM>. Accordingly, the specific structure of the rear bus bar frame assembly 120B will not be described in detail, and the specific structure of the front bus bar frame assembly 120A will be intensively described.

Referring to <FIG>, the front bus bar frame assembly 120A includes a bus bar frame <NUM> and a plurality of bus bars <NUM>. In addition, the front bus bar frame assembly 120A may further include a pair of internal terminals <NUM>. The bus bar frame <NUM> covers one side of the cell stack assembly <NUM> in the longitudinal direction (a direction parallel to the X-axis).

The bus bar frame <NUM> has a plurality of cooling liquid holes 121a. The cooling liquid hole 121a functions as a passage through which the insulation cooling liquid introduced into the module housing <NUM> through the inlet P1 provided at the front sealing plate <NUM> may flow into the cell stack assembly <NUM> through the bus bar frame <NUM>.

In consideration of this function, the cooling liquid hole 121a may be formed at a position corresponding to the channel spacer <NUM> provided at the cell stack assembly <NUM>. Also, the cooling liquid hole 121a may have a size corresponding to the channel spacer <NUM>.

The cooling liquid introduced into the cell stack assembly <NUM> through the cooling liquid hole 121a formed in the front bus bar frame assembly 120A moves toward the rear bus bar frame assembly 120B through the cooling liquid channel 112a formed at the channel spacer <NUM> along an arrow (see <FIG> and <FIG>). The insulation cooling liquid that has moved toward the rear bus bar frame assembly 120B flows into the rear sealing plate <NUM> through cooling liquid hole 121a formed in the rear bus bar frame assembly 120B, and is discharged to the outside of the battery module through the outlet P2 provided at the rear sealing plate <NUM>. In this process, the insulation cooling liquid comes into direct contact with electrical connection parts such as the electrode lead 111a of the battery cell <NUM> and comes into indirect contact with the body of the battery cell <NUM> to cool the inside of the battery module.

The bus bar <NUM> is fixed on the bus bar frame <NUM> and is coupled to the electrode lead 111a drawn out through a lead slit formed at the bus bar frame <NUM> to electrically connect the plurality of battery cells <NUM>.

The internal terminal <NUM> is fixed on the bus bar frame <NUM> and is coupled to the electrode lead 111a of a battery cell <NUM> located at an outermost side among the battery cells <NUM> provided in the cell stack assembly <NUM>. The internal terminal <NUM> functions as a high-potential terminal. The internal terminal <NUM> located at one side of the bus bar frame <NUM> in the longitudinal direction (a direction to parallel to the Y-axis) functions as a positive electrode high-potential terminal, and the internal terminal <NUM> located at the other longitudinal side of the bus bar frame <NUM> functions as a negative electrode high-potential terminal. The internal terminal <NUM> is electrically connected to an external terminal <NUM> (see <FIG> and <FIG>), explained later.

The insulation cooling liquid introduced into the battery module may fill the space between the front sealing plate <NUM> and the front bus bar frame assembly 120A, and may also fill the space between the rear sealing plate <NUM> and the rear bus bar frame assembly 120B. Accordingly, the insulation cooling liquid comes into contact with the electrode lead 111a, the bus bar <NUM> and the internal terminal <NUM>, which are components that may generate heat intensively, thereby cooling the battery module efficiently.

Meanwhile, referring to <FIG>, <FIG> and <FIG>, the bus bar frame <NUM> of the front bus bar frame assembly 120A and the bus bar frame <NUM> of the rear bus bar frame assembly 120B have a plurality of guide ribs 121b formed at the top and bottom thereof along the longitudinal direction of the bus bar frame <NUM> (a direction parallel to the Y-axis). The guide rib 121b has a shape extending toward the cell stack assembly <NUM>. The guide rib 121b is formed at a position corresponding to the channel spacer <NUM>.

Meanwhile, at both ends of the channel spacer <NUM> in the longitudinal direction (a direction parallel to the X-axis), fixing portions 112b having a shape corresponding to the guide ribs 121b and provided at positions corresponding to the guide ribs 121b are formed. Movement of the channel spacer <NUM> in a vertical direction (a direction parallel to the Z-axis) and a longitudinal direction (a direction parallel to the X-axis) is restricted by the guide ribs 121b and the fixing portions 112b. Accordingly, when the front bus bar frame assembly 120A and the rear bus bar frame assembly 120B are coupled to the cell stack assembly <NUM>, the coupling position may be guided, thereby increasing the convenience of assembly.

Referring to <FIG>, the module housing <NUM> accommodates the sub module <NUM> including the cell stack assembly <NUM>, the front bus bar frame assembly 120A and the rear bus bar frame assembly 120B. The module housing <NUM> is configured such that one side and the other side thereof in the longitudinal direction (a direction parallel to the X-axis) are opened.

Referring to <FIG>, <FIG>, <FIG> and <FIG>, the front sealing plate <NUM> covers the opening formed at one side of the module housing <NUM> in the longitudinal direction (a direction parallel to the X-axis). The front sealing plate <NUM> has an inlet P1 for introducing the insulation cooling liquid. In order to prevent the cooling liquid from leaking, an insulation sealing member G may be interposed between an edge surface of the front sealing plate <NUM> and an inner surface of the module housing <NUM> (see <FIG> ). The sealing member G may be, for example, a gasket.

The front sealing plate <NUM> has a pair of terminal holes 300a through which parts for electrical connection between the internal terminal <NUM> provided at the front bus bar frame assembly 120A and the external terminal <NUM>, explained later, may pass. The terminal hole 300a is formed at a position corresponding to the internal terminal <NUM>.

Referring to <FIG>, the rear sealing plate <NUM> covers the opening at the other side of the module housing <NUM> in the longitudinal direction (a direction parallel to the X-axis), and has an outlet P2 for discharging the insulation cooling liquid. Similar to the front sealing plate <NUM>, a sealing member G may be interposed between the edge surface of the reat sealing plate <NUM> and the inner surface of the module housing <NUM> to prevent the insulation cooling liquid from leaking. The sealing member G may be, for example, a gasket.

The front sealing plate <NUM> and the rear sealing plate <NUM> may be made of an insulating resin for electrical insulation.

Referring to <FIG> and <FIG>, the terminal assembly <NUM> includes an external terminal <NUM> positioned at an outer side of the front sealing plate <NUM> and a stud <NUM> for electrically connecting the external terminal <NUM> and the battery cell <NUM>. The stud <NUM> is fixed to the internal terminal <NUM>. The stud <NUM> may be fixed to the internal terminal <NUM> by being press-fitted through the internal terminal <NUM>. The stud <NUM> fixed to the internal terminal <NUM> is drawn out through the terminal hole 300a formed in the front sealing plate <NUM> and coupled to the external terminal <NUM>.

The terminal assembly <NUM> may further include a ring-shaped terminal spacer <NUM> inserted into the terminal hole 300a formed in the front sealing plate <NUM>. The terminal spacer <NUM> may be made of a metal material. If the terminal spacer <NUM> is provided, stud <NUM> passes through the terminal spacer <NUM>.

The terminal assembly <NUM> may further include a fastening nut <NUM> for fastening the external terminal <NUM> to the stud <NUM>. The fastening nut <NUM> is fastened to the stud <NUM> passing through the terminal spacer <NUM> and the fastening portion <NUM> of the external terminal <NUM> so that the fastening portion <NUM> of the external terminal <NUM> is closely fixed to the terminal spacer <NUM>. Accordingly, the internal terminal <NUM> and the external terminal <NUM> are electrically connected to each other through the terminal spacer <NUM>.

The terminal assembly <NUM> may further include a first O-ring <NUM> that covers an outer circumferential surface of the terminal spacer <NUM> and is interposed between the inner surface of the front sealing plate <NUM> and the internal terminal <NUM>. Referring to <FIG>, the first O-ring <NUM> prevents the insulation cooling liquid introduced into the space between the front sealing plate <NUM> and the bus bar frame <NUM> from leaking to the outside of the front sealing plate <NUM> through the space between the inner surface of the terminal hole 300a and the terminal spacer <NUM>.

In addition, the terminal assembly <NUM> may be further include a second O-ring <NUM> that is located around the stud <NUM> press-fitted into the internal terminal <NUM> and exposed to the space between the internal terminal <NUM> and the bus bar frame <NUM> and is interposed between the internal terminal <NUM> and the bus bar frame <NUM>. The second O-ring <NUM> prevents the insulation cooling liquid introduced into the space between the front sealing plate <NUM> and the bus bar frame <NUM> from leaking to the outside of the front sealing plate <NUM> through the space between the internal terminal <NUM> and the stud <NUM> and the space between the inner surface of the terminal spacer <NUM> and the stud <NUM>.

Referring to <FIG> and <FIG> and <FIG> and <FIG>, the front end plate <NUM> covers the front sealing plate <NUM> and is fixed to the module housing <NUM>. The rear end plate <NUM> covers the rear sealing plate <NUM> and is fixed to the module housing <NUM>.

The front end plate <NUM> includes a terminal exposing portion 500a for exposing the connection portion <NUM> of the external terminal <NUM> to the outside of the front end plate <NUM> and an inlet exposing portion 500b for exposing the inlet P1 to the outside of the front end plate <NUM>. The rear end plate <NUM> includes an outlet exposing portion 600b for exposing the outlet P2 to the outside of the rear end plate <NUM>.

When the front end plate <NUM> and the rear end plate <NUM> are applied, a gasket (not shown) may be interposed in the coupling portion between the front end plate <NUM> and the module housing <NUM> and in the coupling portion between the rear end plate <NUM> and the module housing <NUM> in order to prevent the insulation cooling liquid from leaking.

Meanwhile, a battery pack and a vehicle according to an embodiment of the present disclosure include the battery module according to the present disclosure as described above. The battery pack includes at least one battery module according to the present disclosure and a pack housing for accommodating the at least one battery module. The battery module may be fastened to the pack housing through a fastening hole H formed in the front end plate <NUM> and/or the rear end plate <NUM>. That is, the fastening hole H may provide a space into which a fastening means such as a bolt for fastening the pack housing and the battery module is inserted. Meanwhile, if the battery pack includes a plurality of battery modules, the plurality of battery modules may be fastened to each other through the fastening hole H formed in the front end plate <NUM> and/or the rear end plate <NUM>.

Claim 1:
A battery module, comprising:
a sub module (<NUM>) including a cell stack assembly (<NUM>) having a plurality of battery cells (<NUM>) and a channel spacer (<NUM>) interposed between adjacent battery cells (<NUM>), a front bus bar frame assembly (120A) coupled to one longitudinal side of the cell stack assembly (<NUM>), and a rear bus bar frame assembly (120B) coupled to the other longitudinal side of the cell stack assembly (<NUM>);
a module housing (<NUM>) configured to accommodate the sub module (<NUM>);
a front sealing plate (<NUM>) configured to cover an opening at one longitudinal side of the module housing (<NUM>) and having an inlet (P1) for introducing an insulation cooling liquid; and
a rear sealing plate (<NUM>) configured to cover an opening at the other longitudinal side of the module housing (<NUM>) and having an outlet (P2) for discharging the insulation cooling liquid,
wherein the front bus bar frame assembly (120A) includes:
a bus bar frame (<NUM>); and
a plurality of bus bars (<NUM>) fixed on the bus bar frame (<NUM>) and coupled to electrode leads (111a) of the battery cells (<NUM>) and,
characterized in that
the battery module further comprises a pair of terminal assemblies (<NUM>) having an external terminal (<NUM>) located at an outer side of the front sealing plate (<NUM>) and a stud (<NUM>) provided through the front sealing plate (<NUM>) to electrically connect the external terminal (<NUM>) and the battery cell (<NUM>).