Battery Module, and Battery Pack and Vehicle Including the Same

A battery module includes a sub module including a cell stack assembly having a plurality of battery cells and a cooling fin interposed between adjacent battery cells; 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 a cooling liquid inlet; a rear sealing plate configured to cover an opening at the other longitudinal side of the module housing and having a cooling liquid outlet; and a sensing assembly configured to sense voltage of the battery cell.

TECHNICAL FIELD

The present disclosure relates to a battery module, and a battery pack and a vehicle including the battery module, and more specifically, to a battery module having a structure in which an insulating cooling liquid flowing into a module housing cools battery cells while flowing through a space between a cell wing portion of the battery cell and the module housing. A battery pack and a vehicle may include the battery module.

BACKGROUND ART

In the case of a battery module that uses indirect water cooling using a cooling water, the cooling performance is limited because the cooling water does not directly contact a battery cell, but rather indirectly contacts the battery cell through a module housing that houses the battery cell. In addition, because a cooling device such as a separate heatsink must be provided outside the module housing to form a flow path for cooling, the overall volume of the battery module is inevitably increased, which inevitably causes losses in terms of energy density.

In order to solve the problem of the indirect water-cooling method, a battery module having a cooling structure in which an insulating cooling liquid for cooling is directly introduced into the module housing to directly contact the battery cell is desired.

DISCLOSURE

Technical Problem

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 insulating cooling liquid is introduced into the battery module and directly contacts a battery cell to cause efficient cooling, such that the cooling liquid introduced into the battery module may flow smoothly.

In addition, the present disclosure is also directed to preventing a sensing line and a temperature sensor provided for sensing the voltage and temperature of the battery cell from being damaged by an insulating cooling liquid flowing inside the battery module, and enabling accurate temperature measurement.

However, the technical problems to be solved by the present disclosure are not limited to the above-described problems, and other problems not mentioned will be clearly understood by those skilled in the art from the present disclosure described below.

Technical Solution

A battery module according to an embodiment of the present disclosure comprises: a sub module including a cell stack assembly having a plurality of battery cells and a cooling fin interposed between adjacent battery cells; 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; a rear sealing plate configured to cover an opening at the other longitudinal side of the module housing and having an outlet; and a sensing assembly configured to sense voltage of the battery cell.

The sensing assembly may be disposed on a top of the sub module.

The sensing assembly may include a sensing line electrically connected to the plurality of battery cells and extending from one longitudinal end of the battery cells to the other longitudinal end.

The sensing line may be interposed between a cell body portion of the battery cell and a cell wing portion folded toward the cell body portion.

The sensing assembly may further include a temperature sensor mounted on the sensing line.

The temperature sensor may be interposed between a cell body portion of the battery cell and a cell wing portion folded toward the cell body portion.

The cooling fin may include a body contact portion interposed between adjacent battery cells, and a wing cover portion bent at any one of a top and bottom of the body contact portion to cover a cell wing portion of the battery cell.

The sub module may include 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.

The front bus bar frame assembly and the rear bus bar frame assembly may have a plurality of cooling liquid holes formed at a position corresponding to a cooling liquid flow path formed between the module housing and the cell wing portion of the battery cell and between the wing cover portion and the cell wing portion of the battery cell.

An insulating cooling liquid introduced into the module housing through the inlet may pass through the cooling liquid hole formed in the front bus bar frame assembly and flow to the cooling liquid flow path.

The insulating cooling liquid passing through the cooling liquid flow path may pass through the cooling liquid hole formed in the rear bus bar frame assembly and be discharged to the outside of the module housing through the outlet.

A battery pack and a vehicle according to an embodiment of the present disclosure to solve the above problem comprises the battery module according to the present disclosure.

Advantageous Effects

According to one aspect of the present disclosure, the insulating cooling liquid flows into the battery module and directly contacts the battery cell, and the cooling liquid introduced into the battery module may flow smoothly, thereby causing efficient and rapid cooling.

According to another aspect of the present disclosure, the sensing line and the temperature sensor provided for sensing the voltage and temperature of the battery cell may be prevented from being damaged by the insulating cooling liquid flowing inside the battery module, and accurate temperature measurements may be taken by the temperature sensor by minimizing the influence of the insulating cooling liquid in measuring the temperature of the battery cell.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS.1,2and4, the battery module according to an embodiment of the present disclosure includes a sub module100, a module housing200, a front sealing plate300, a rear sealing plate400and a sensing assembly800. The battery module may further include a front end plate500and/or a rear end plate600and/or a pair of terminal assemblies700in addition to the above-described components.

Referring toFIGS.2to9, the sub module100includes a cell stack assembly110.

The sub module100includes a front bus bar frame assembly120A and a rear bus bar frame assembly120B in addition to the cell stack assembly110.

The cell stack assembly110includes a plurality of battery cells111. In addition, the cell stack assembly110may further include at least one cooling fin112interposed between adjacent battery cells111and/or at least one buffer pad113interposed between the adjacent battery cells111. The plurality of battery cells111are stacked approximately in a vertical standing form on a surface parallel to the X-Y plane to form a single cell stack assembly110. When the cell stack assembly110includes the cooling fin112and/or the buffer pad113, the cooling fin112and/or the buffer pad113are also stacked in a vertical standing form approximately perpendicular to the surface parallel to the X-Y plane together with the plurality of battery cells111to form a single cell stack assembly110.

The battery cell111may be a pouch-type battery cell having a pair of electrode leads111adrawn out in opposite directions along the longitudinal direction (parallel to the X-axis).

Referring toFIGS.7to9, the cooling fin112includes a body contact portion112ainterposed between the battery cells111adjacent to each other, and a wing cover portion112bbent at any one of the top and bottom of the body contact portion112ato cover the cell wing portion W of the battery cell111. The cooling fin112may further include a pair of fixing portions112cformed at both ends in the longitudinal direction (parallel to the X-axis) of the wing cover portion112b.

As shown inFIG.7, when the battery cell111is of a pouch type, an area in which an electrode assembly (not shown) is accommodated may be defined as the cell body portion B, and a region elongated along the longitudinal direction (parallel to the X-axis) of the battery module in the sealing area formed around the cell body portion B may be defined as the cell wing portion W.

The body contact portion112ais interposed between the cell body portions B of the pair of adjacent battery cells111and is in direct contact with the cell body portions B of the battery cells111. The body contact portion112arapidly conducts heat generated from the cell body portion B of the battery cell111in the width direction of the cooling fin112, that is, in the height direction (parallel to the Z-axis) of the battery module and directs the heat toward the wing cover portion112b. As such, the heat conducted toward the wing cover portion112bis transferred along the longitudinal direction (parallel to the X-axis) of the battery module by the insulating cooling liquid flowing through the cooling liquid flow path P formed between the cell wing portion W of the battery cell111and the wing cover portion112bof the cooling fin112, and is discharged to the outside of the battery module.

In addition to forming the cooling liquid flow path P as described above, the wing cover portion112bmay also perform the function of absorbing an external impact applied to the cell stack assembly110, such that the cell stack assembly110moves in the vertical direction (parallel to the Z-axis) within the module housing200. This impact absorption function of the wing cover portion112bmay help prevent damage to the sensing line810and the temperature sensor820interposed between the cell wing portion W and the cell body portion B (seeFIG.13). The sensing assembly800including the sensing line810and the temperature sensor820are described below.

The fixing portion112cis shaped to correspond to a guide rib121b, which is described below. As the fixing portion112cis coupled to the guide rib121b, the fixing portion112cguides the fastener between the cell stack assembly110, which includes the cooling fin112and the bus bar frame assemblies120A,120B.

The buffer pad113may be interposed between adjacent battery cells111to absorb volume expansion due to swelling of the battery cells111.

The front bus bar frame assembly120A and the rear bus bar frame assembly120B are coupled to both longitudinal sides (extending in a direction parallel to the X axis) of the cell stack assembly110, so that a plurality of battery cells111are electrically connected.

The front bus bar frame assembly120A and the rear bus bar frame assembly120B have substantially the same structure except that the front bus bar frame assembly120A is provided with the inner terminal123and the rear bus bar frame assembly120B is not provided with the inner terminal123. Accordingly, a detailed description of the specific structure of the rear bus bar frame assembly120B will be omitted for brevity, and a detailed description of the specific structure of the front bus bar frame assembly120A will be intensively described.

Referring toFIGS.4to10, the front bus bar frame assembly120A includes a bus bar frame121and a plurality of bus bars122. In addition, the front bus bar frame assembly120A may further include a pair of inner terminals123. The bus bar frame121covers one side of the cell stack assembly110in the longitudinal direction (parallel to the X-axis).

The bus bar frame121includes a plurality of cooling liquid holes121a. The cooling liquid hole121afunctions as a passage so that the insulating cooling liquid introduced into the module housing200through the inlet P1provided in the front sealing plate300may flow toward the cell stack assembly110through the bus bar frame121.

As shown inFIGS.7and8, the cooling liquid flow path P is formed between the module housing200and the cell wing portion W. In an embodiment in which the cell stack assembly110of the present disclosure includes the cooling fin112, the cooling liquid flow path P may be formed between the wing cover portion112band the cell wing portion W, in addition to being formed between the module housing200and the cell wing portion W. Accordingly, for smooth supply and discharge of the insulating cooling liquid, the cooling liquid hole121amay be formed between the module housing200and the cell wing portion W. The cooling liquid hole121amay also be formed at a position corresponding to the cooling liquid flow path P formed between the wing cover portion112band the cell wing portion W.

The insulating cooling liquid introduced toward the cell stack assembly110through the cooling liquid hole121aformed in the front bus bar frame assembly120A flows toward the rear bus bar frame assembly120B through the cooling liquid flow path P in a direction along the arrow illustrated inFIGS.5and6. The insulating cooling liquid that has flowed to the rear bus bar frame120B flows toward the rear sealing plate400through the cooling liquid hole121aformed in the rear bus bar frame120B, and is emitted out of the battery module through an outlet P2provided in the rear sealing plate400. In this process, the insulating cooling liquid comes into direct contact with the electrode lead111aof the battery cell111and the cell wing portion W to cool the battery cell111.

The bus bar122is fixed on the bus bar frame121and is coupled to the electrode lead111adrawn out through a lead slit formed in the bus bar frame121to electrically connect the plurality of battery cells111.

The inner terminal123is fixed on the bus bar frame121and is coupled to the electrode lead111aof the battery cell111located at the outermost battery cell111among the battery cells111provided in the cell stack assembly110. The inner terminal123functions as a high potential terminal. The inner terminal123located at one side of the longitudinal direction (parallel to the Y-axis) of the bus bar frame121functions as a positive electrode high potential terminal, and the inner terminal123located at the other longitudinal side of the bus bar frame121functions as a negative electrode high potential terminal. The inner terminal123is electrically connected to an outer terminal710. Such a connection is shown inFIGS.11and12and is described below.

Referring toFIGS.5to10, the bus bar frame121of the front bus bar frame assembly120A and the bus bar frame121of the rear bus bar frame assembly120B include a plurality of guide ribs121bformed on the top and bottom along the longitudinal direction (parallel to the Y-axis). The guide rib121bis shaped to extend in the direction toward the cell stack assembly110. The guide rib121bis formed at a position corresponding to the fixing portion112cof the cooling fin112.

The fixing portion112chaving a shape corresponding to the guide rib121bis formed at both ends of the wing cover portion112bof the cooling fin112in the longitudinal direction (parallel to the X-axis). The movement of the cooling fin112in the vertical direction (parallel to the Z-axis) and longitudinal direction (parallel to the X-axis) is restricted by the guide rib121band the fixing portion112c. Accordingly, when the front bus bar frame assembly120A and the rear bus bar frame assembly120B are coupled to the cell stack assembly110, the coupling position may be guided, thereby increasing the convenience of assembly.

Referring toFIGS.1to6, the module housing200accommodates a sub module100including the cell stack assembly110, the front bus bar frame assembly120A, and the rear bus bar frame assembly120B. The module housing200has at least two sides, at least on of the two sides being open in the longitudinal direction (parallel to the X-axis).

Referring toFIGS.5,6,11and12, the front sealing plate300covers the opening formed at one side of the module housing200in the longitudinal direction (parallel to the X-axis). The front sealing plate300has a cooling liquid inlet P1for inflow of the insulating cooling liquid. To prevent the insulating cooling liquid from leaking, a gasket G may be interposed between the edge surface of the front sealing plate300and the inner surface of the module housing200(seeFIG.12).

The front sealing plate300is provided with a pair of terminal holes300athrough which components for electrical connection between the inner terminal123provided in the front bus bar frame assembly120A and the outer terminal710may pass. The terminal hole300ais formed at a position on the front sealing plate300corresponding to the inner terminal123.

Referring toFIG.6, the rear sealing plate400covers the opening of the module housing200at an opposite side of the module relative to the front sealing plate300in the longitudinal direction (parallel to the X-axis), and has a cooling liquid outlet P2for discharging the insulating cooling liquid. Like the front sealing plate300, a gasket G may be interposed between the edge surface of the real sealing plate400and the inner surface of the module housing200to prevent the insulating cooling liquid from leaking.

The front sealing plate300and rear sealing plate400may be made of an insulating resin for electrical insulation.

Referring toFIGS.11and12, the terminal assembly700includes an outer terminal710positioned on the outside of the front sealing plate300and a stud720electrically connecting the outer terminal710and the battery cell111. The stud720is fixed to the inner terminal123. The stud720may penetrate the inner terminal123and be fixed to the inner terminal123by press-fitting. The stud720fixed to the inner terminal123is drawn out through the terminal hole300aformed in the front sealing plate300and coupled with the outer terminal710.

The terminal assembly700may further include a ring-shaped terminal spacer730inserted into the terminal hole300aformed in the front sealing plate300. The terminal spacer730may be made of a metal material. In embodiments where the terminal spacer730is provided, the stud720passes through the terminal spacer730.

The terminal assembly700may further include a fastening nut740for fastening the outer terminal710to the stud720. The fastening nut740is fastened to the stud720, which penetrates the terminal spacer730and the fastening portion712of the outer terminal710so that the fastening portion712of the outer terminal710is tightly fixed to the terminal spacer730. Accordingly, the inner terminal123and the outer terminal710are electrically connected to each other through the terminal spacer730.

The terminal assembly700may further include a first O-ring750that covers the outer circumference of the terminal spacer730and is interposed between the inner surface of the front sealing plate300and the inner terminal123. Referring toFIGS.11and12, the first O-ring750prevents the insulating cooling liquid introduced into the space between the front sealing plate300and the bus bar frame121from leaking to the outside of the front sealing plate300through the space between the inner surface of the terminal hole300aand the terminal spacer730.

In addition, the terminal assembly700may further include a second O-ring760positioned around the stud720, which is press-fitted into the inner terminal123and exposed to the space between the inner terminal123and the bus bar frame121, and is interposed between the inner terminal123and the bus bar frame121. The second O-ring760prevents the insulating cooling liquid introduced into the space between the front sealing plate300and the bus bar frame121from leaking to the outside of the front sealing plate300through the space between the inner terminal123and the stud720and the space between the inner surface of the terminal spacer730and the stud720.

Referring toFIGS.1and2andFIGS.5and6, the front end plate500covers the front sealing plate300and is fixed to the module housing200. The rear end plate600covers the rear sealing plate400and is fixed to the module housing200.

The front end plate500includes a terminal exposing portion500afor exposing the connection portion711of the outer terminal710to the outside of the front end plate500, and an inlet exposing portion500bfor exposing the inlet P1to the outside of the front end plate500. The rear end plate600includes an outlet exposing portion600bfor exposing the cooling liquid outlet P2to the outside of the rear end plate600.

When the front end plate500and the rear end plate600are fixed to the module housing200of the battery module according to the present disclosure, a gasket for preventing the insulating cooling liquid from leaking may be applied to the coupling area between the front end plate500and the module housing200and the coupling area between the rear end plate600and the module housing200.

Referring toFIGS.4,7, and13, the sensing assembly800is disposed on the top of the sub module100and senses the voltage of the battery cell111. The sensing assembly800includes a sensing line810electrically connected to the plurality of battery cells111and extending from one end of the battery cell111in the longitudinal direction (parallel to the X-axis) to the other longitudinal end. The sensing line810is electrically connected to the battery cells111along both sides of the cell stack assembly110in the longitudinal direction (parallel to the X-axis). Coupling the sensing line810to the bus bar122causes the electrical connection between the sensing line810and the battery cell111. However, the present disclosure is not limited thereto, and the sensing line810may also be directly coupled to the electrode lead111aof the battery cell111.

The sensing line810may be interposed between the cell body portion B of the pouch-type battery cell111and the cell wing portion W folded toward the cell body portion B. This arrangement prevents the sensing line810from being damaged by the insulating cooling liquid flowing inside the battery module.

The sensing assembly800may additionally perform the function of sensing the temperature of the battery cell111in addition to sensing the voltage. To this end, the sensing assembly800may further include at least one temperature sensor820mounted on the sensing line810. The temperature sensor820may be disposed adjacent to an electrode lead111ahaving a large heat generation. Like the sensing line810, the temperature sensor820may be interposed between the cell body portion B of the battery cell111and the cell wing portion W folded toward the cell body portion B. This arrangement prevents the temperature sensor820from being damaged by the insulating cooling liquid flowing inside the battery module. In addition, this arrangement prevents or minimizes the contact between the temperature sensor820and the insulating cooling liquid so that the temperature of the battery cell111can be accurately sensed. Further, the sensing line810and the temperature sensor820may be additionally covered by the wing cover portion112bof the cooling fin112, and thus are further covered by the cell wing portion W.

The sensing assembly800may further include a printed circuit board (PCB)830electrically connected to the sensing line810in addition to the sensing line810. The PCB830may be fixed on the bus bar frame121. A connector assembly (not shown) may be mounted on the PCB830, and a control device such as a battery management system (BMS) (not shown) may be connected through this connector assembly. In this embodiment, the BMS may measure and/or receive information about the voltage, temperature, etc. of the battery cell111and control charging/discharging of the battery module in accordance with the information received.

A battery pack according to an embodiment of the present disclosure may include the battery module according to an embodiment of the present disclosure as described above. The battery pack may include additional components such as a pack housing and/or a battery management system (BMS) together with at least one battery module.

The battery module may be fastened to the pack housing through the fastening hole H formed in the front end plate500and/or the rear end plate600. That is, the fastening hole H may provide a space into which a fastener, such as a bolt for fastening the pack housing and the battery module, is inserted. In another embodiment, when 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 plate500and/or the rear end plate600.

A vehicle according to an embodiment of the present disclosure may include at least one battery module and/or the battery pack as described above. The vehicle according to an embodiment of the present disclosure may be, for example, a hybrid vehicle or an electric vehicle that operates by being powered by the battery module and/or the battery pack of the present disclosure.

DESCRIPTION OF REFERENCE NUMERALS