Patent Application
20250183492
The present disclosure relates to a battery module, and a battery pack and a vehicle including the same, and more specifically, it relates to a battery module with enhanced safety, and a battery pack and a vehicle including the same.
Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are in the spotlight for their advantages of free charging and discharging due to almost no memory effect, a very low self-discharge rate, and a high energy density, compared to nickel-based secondary batteries.
These lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative electrode active materials, respectively. The lithium secondary batteries include an electrode assembly in which positive and negative electrode plates, coated with the positive and negative electrode active materials, respectively, are disposed with a separator therebetween, and an exterior case, i.e., a battery case, that seals and stores the electrode assembly with an electrolyte.
In general, lithium secondary batteries may be classified, depending on the shape of the exterior case, into can-type secondary batteries in which the electrode assembly is accommodated in a metal can and pouch-type secondary batteries in which the electrode assembly is accommodated in a pouch of an aluminum laminate sheet.
Recently, secondary batteries have been widely used in medium and large devices for driving and storing energy, such as electric vehicles and energy storage systems (ESSs), as well as in small devices such as portable electronic devices. In this case, a battery module may be configured such that multiple secondary batteries electrically connected to each other are stored inside a module case.
However, since the multiple battery cells or multiple battery modules described above are densely disposed in a narrow space, they may be vulnerable to a thermal event. In particular, when a thermal event occurs in any one battery cell, heat, flame, sparks, and the like may be generated. If this heat, or the like, is transferred to another battery cell, an explosive chain reaction such as thermal propagation (TP) may occur, which may lead to explosion or ignition in the battery module.
Additionally, battery cells, or the like, may experience swelling as they are used or under abnormal operating conditions (over-charge, over-discharge, exposure to high temperatures, electrical short circuit, or the like). In addition, this swelling or abnormal operating conditions may accelerate the thermal runaway.
Moreover, medium and large battery packs used in electric vehicles, or the like, include a large number of battery cells and battery modules to increase output and/or capacity, and there may be users, such as drivers nearby, so that the risk of a thermal chain reaction may increase more.
In particular, when mounting the battery module to a vehicle, it is usually installed in the lower part of the vehicle. In this case, if high-temperature gas is discharged upwards, it may cause great injury to the occupants.
Therefore, a battery module is required to be developed to delay heat transfer to other battery cells or battery modules and to suppress swelling when a thermal event occurs in a specific battery cell or battery module, thereby improving safety, and to discharge gas in a desired direction, in particular, in directions excluding the upward direction.
The present disclosure has been designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module capable of improving safety by delaying heat transfer and suppressing swelling, and a battery pack and a vehicle including the same.
In another aspect, the present disclosure provides a battery module capable of discharging gas in a desired direction, in particular, in directions excluding the upward direction.
In another aspect, the present disclosure provides a battery pack with improved stability by including such a battery module, and a vehicle including the same.
However, the technical problems that the present disclosure seeks to solve are not limited to the above-mentioned problems, and other problems not mentioned above will be clearly understood by those skilled in the art from the description of the disclosure described below.
According to one aspect of the present disclosure, there is provided a battery module that includes: a cell stack including a plurality of battery cells stacked in a first direction; a module case configured to accommodate the cell stack; a bus bar assembly including a bus bar terminal and a bus bar frame configured such that the bus bar terminal is seated on the bus bar frame, the bust bar assembly being configured to electrically connect the plurality of battery cells; and a cover member extending from one end of the bus bar frame in a second direction toward the cell stack so as to cover at least a portion of the cell stack, the second direction being perpendicular to the first direction, a length of the cover member in the second direction being less than a length of the cell stack in the second direction.
The cell stack may include at least one thermal barrier between a pair of battery cells of the plurality of battery cells.
Each of the plurality of battery cells may include an electrode lead. The bus bar frame may include: a bus bar seating portion on which the bus bar terminal is seated; an electrode lead through-hole through which the electrode lead of one of the battery cell passes; and a thermal barrier accommodation portion configured to accommodate the thermal barrier.
The cover member may include a first cell cover portion configured to cover at least a portion of an upper face of the cell stack.
The cover member may include a second cell cover portion configured to cover at least a portion of a side face of the cell stack.
Each of the plurality of battery cells may include an electrode assembly, a pouch case, and an electrode lead.
The pouch case may include: an accommodation portion configured to accommodate the electrode assembly; and a sealing portion extending outwards by a predetermined length from the perimeter of the accommodation portion.
The sealing portion may include a terrace portion through which the electrode lead extends.
The first cell cover portion may cover an area corresponding to the terrace portion in the cell stack.
The battery module may include a pad between the first cell cover portion and the cell stack.
The pad may be configured such that a surface thereof seated on the cell stack has a shape corresponding to a surface of the cell stack.
The pad may have a thickness corresponding to a space between the first cell cover portion and the cell stack.
The pad may include an elastic material.
The elastic material may be a polyurethane (PU) material.
The cell stack may include at least one thermal barrier between a pair of battery cells of the plurality of battery cells, and a portion of the thermal barrier extends beyond the pair of battery cells and into the pad.
The cell stack may be configured such that the plurality of battery cells is stacked horizontally in an upright state.
The cover member may cover an upper face of the cell stack.
The module case may have a venting portion that is disposed at at least one of a lower face, a front face, or a rear face of the cell stack.
The venting portion may be configured such that gas generated from at least one of the plurality of battery cells is discharged to outside the battery module when the gas escapes through the terrace of the pouch case.
The bus bar frame may have a guide portion configured to guide gas generated from the at least one of the plurality of battery cells to the venting portion.
A thickness of the guide portion in the second direction decreases towards the venting portion.
The venting portion may be disposed adjacent to the terrace portion.
A material of the cover member includes mica or SUS material.
A battery pack according to the present disclosure may include the battery module according to the present disclosure.
A vehicle according to the present disclosure may include a battery pack according to the present disclosure.
According to one aspect of the present disclosure, when gas is generated from a battery cell, the gas is prevented from moving in a particular direction. In particular, if the cover member covers the upper face of the cell stack, the gas is prevented from moving upwards, thereby guiding movement of the gas in a desired direction to be discharged. Therefore, in the case where the battery module is mounted to the lower part of the vehicle, it is possible to prevent high-temperature gas from being discharged upwards and causing significant injury to the occupants.
According to another aspect of the present disclosure, it is possible to delay or prevent a thermal chain reaction in which flame and/or heat generated in a thermal event occurring in a specific battery cell transfers to other adjacent battery cells. Additionally, the thermal barrier is able to absorb or suppress the pressure generated by swelling of the specific battery cell.
According to another aspect of the present disclosure, the thermal barrier is able to be accommodated in the thermal barrier accommodation portion and stably fixed. Therefore, the thermal barrier is able to effectively absorb or suppress the pressure generated by swelling of the specific battery cell.
According to another aspect of the present disclosure, if gas or flame occurs in the terrace portion of the battery cell, the gas or flame can be surely suppressed and prevented from moving to the upper side of the cell stack. In addition, when injecting resin, or the like, onto the surface of the cell stack, it is possible to prevent the resin from overflowing into the space between the cell stack and the cover member.
According to another aspect of the present disclosure, the module case can be stably supported by the thermal barrier. In addition, the cell stack and the module case can be easily fixed by injecting resin into the space between the protrusion formed on the top of the battery cell and the adjacent protrusions.
According to another aspect of the present disclosure, gas or flame generated from the terrace portion of the battery cell can be discharged to the outside of the battery module through the venting portion. In addition, gas or flame can be discharged more effectively by the guide portion.
Hereinafter, exemplary aspects of the present disclosure will be described in detail with reference to the accompanying drawings. The accompanying drawings illustrate an exemplary aspect of the present disclosure and, together with the detailed description below, serve to provide further understanding of the technical idea of the present disclosure, and thus, the present disclosure is not construed as being limited to the drawings. The same reference numerals indicate the same elements. In addition, in the drawings, the thickness, proportions, and dimensions of elements are exaggerated for effective explanation of technical content.
It should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation.
Although terms indicating directions such as up, down, left, right, front, and back are used in this specification, it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.
Therefore, the configurations proposed in the aspects and drawings of this specification indicate only exemplary aspects of the present disclosure and do not represent all technical ideas of the present disclosure, so it should be understood that various equivalents and modifications could be made thereto at the time of filing the application.
Referring to
The cell stack 100 may include a plurality of battery cells 110 stacked in at least one direction. Here, each battery cell 110 may refer to a secondary battery. The secondary battery may include an electrode assembly, an electrolyte, and a battery case. In particular, the cell stack 100 may be configured such that a plurality of pouch-type secondary batteries are arranged side by side in the horizontal direction while their wide surfaces face each other in an upright state.
The battery cell 110 may include an electrode assembly, a pouch case, and an electrode lead 113. The pouch case may include an accommodation portion 111 for accommodating the electrode assembly and a sealing portion 112 extending outwards by a predetermined length from the perimeter of the accommodation portion 111. The accommodation portion 111 may correspond to approximately the middle portion of the pouch case, and the sealing portion 112 may be a portion that is heat-sealed along the perimeter of the accommodation portion 111 in order to seal the accommodation portion 111. The pouch case may include an upper case and a lower case, and the pouch case may be sealed by heat-sealing the edge of the upper case and the edge of the lower case in contact with each other. A terrace portion T may be an area located in a direction in which the electrode lead 113 extends to the outside of the pouch case.
The terrace portion T has an area where the electrode lead 113 is interposed between the upper case and the lower case, so the sealing force thereof may be structurally lower than that of the remaining area of the sealing portion 112. An empty space may be formed between the terrace portion T and the electrode assembly. This empty space may function as a gas collection space where gas generated inside the battery cell 110 is collected. Therefore, when gas is generated inside the battery cell 110, the gas may be collected in the gas collection space, and gas venting due to rupture of the sealing portion 112 according to an increase in internal pressure may more likely occur in the terrace portion T.
The module case 200 may be configured to accommodate the cell stack 100. The module case 200 may be configured to have an accommodation space capable of accommodating the cell stack 100. The module case 200 may have an approximately square pillar shape. The module case 200 may include a case body 210 comprised of walls constituting respective surfaces, and a pair of end covers 220 covering the front and back of the cell stack 100.
The bus bar assembly 400 may include a plurality of bus bar terminals 410 and a bus bar frame 420. Each bus bar terminal 410 may be connected to adjacent electrode leads 113. The bus bar frame 420 may be configured such that each bus bar terminal 410 is seated thereon. The bus bar frame 420 may include an electrically insulating material to be insulated from the bus bar terminals 410. The bus bar frame 420 may include a polymer material, such as plastic. In the case where the battery cell 110 is a bidirectional battery cell 110, the bus bar assembly 400 may be provided as a pair of bus bar assemblies located at opposite ends of the battery module 10 where the electrode leads 113 are provided. In the case where the battery cell 110 is a unidirectional battery cell 110, the bus bar assembly 400 may be located at one end where the electrode leads 113 are provided.
The cover member 500 may extend from one end of the bus bar frame 420 toward the cell stack 100 so as to cover at least a portion of the cell stack 100. The cover member 500 may extend from the upper end (the end located in the +Z-axis direction) of the bus bar frame 420 toward the cell stack 100 (in the −Y-axis direction). The cover member 500 may be made of a mica or SUS material. The cover member 500 may be configured such that the surface of an electrically conductive body is coated with an electrically insulating material.
According to this configuration of the present disclosure, when gas is generated from the battery cell 110, the gas is suppressed from moving through the cover member 500. In the case where the cover member 500 covers the upper surface of the cell stack 100, since gas is prevented from moving upwards, the gas may be guided in a desired direction to be discharged. Therefore, in the case where the battery module 10 is mounted to a lower part of the vehicle, it is possible to prevent high-temperature gas from being discharged upwards and causing significant injury to the occupants.
Referring back to
At least one thermal barrier 120 may be disposed among a plurality of battery cells 110. The thermal barrier 120 may be disposed between two adjacent battery cells 110. The thermal barrier 120 may be configured in a plate shape. In the case where a plurality of pouch-type battery cells 110 is stacked in the left and right directions in an upright state, the thermal barrier 120 may be interposed between two adjacent cells in an upright state while opposite surfaces thereof facing in the left and right directions.
The thermal barrier 120 may be configured to block or delay the propagation of flame and/or heat. Additionally, the thermal barrier 120 may be configured to absorb or suppress pressure generated by swelling of the battery cell 110. The thermal barrier 120 may be made of a material that is resistant to high temperatures. The thermal barrier 120 may include materials such as mica, glass fiber-reinforced plastic (GFRP), or carbon fiber-reinforced plastic (CFRP).
According to this configuration of the present disclosure, it is possible to delay or prevent a thermal chain reaction in which flame and/or heat generated in a thermal event occurring in a specific battery cell 110 transfers to other adjacent battery cells 110. Additionally, the thermal barrier 120 is able to absorb or suppress the pressure generated by swelling of the battery cell 110.
Referring to
The bus bar terminal 410 may be seated on the bus bar terminal seating portion 421. The bus bar terminal seating portion 421 may be configured to be recessed to conform to the shape of the bus bar terminal 410 such that the bus bar terminal 410 may be seated thereon.
The electrode lead through-hole 422 may be configured to allow the electrode lead 113 to pass through the same. The electrode lead through-hole 422 may be a hole provided at a position approximately corresponding to the electrode lead 113. The electrode lead through-hole 422 may have a shape that approximately corresponds to the electrode lead 113. The electrode lead through-hole 422 may be, for example, an approximately rectangular hole. The electrode lead 113 may pass through the electrode lead through-hole 422 and may then be coupled to the bus bar terminal 410.
The thermal barrier accommodation portion 423 may accommodate the thermal barrier 120. The thermal barrier accommodation portion 423 may be a hole or groove formed approximately to conform to the height of the thermal barrier 120. The thermal barrier accommodation portion 423 may be a hole or groove in an approximately rectangular shape. The thermal barrier 120 may protrude to the outside of the bus bar frame 420 by extending beyond the hole-shaped thermal barrier accommodation portion 423. The thermal barrier 120 may be inserted into the thermal barrier accommodation portion 423, which may be configured as a groove formed on the inner surface of the bus bar frame 420.
According to this configuration of the present disclosure, the thermal barrier 120 may be accommodated inside the thermal barrier accommodation portion 423 and stably fixed. Therefore, the thermal barrier 120 may effectively absorb or suppress the pressure generated by swelling of the battery cell 110. In another aspect, according to this configuration of the present disclosure, the thermal barrier 120 may cover the entire area of the battery cell 110 in the longitudinal direction (direction parallel to the Y-axis), thereby preventing or delaying thermal propagation between the battery cells 110 adjacent to each other.
Referring back to
The first cell cover portion 510 may cover at least a portion of the upper face of the cell stack 100. The first cell cover portion 510 may cover the area corresponding to the terrace portion T of the battery cells 110 in the cell stack 100.
Referring back to
The second cell cover portion 520 may cover at least a portion of the side face of the cell stack 100. The second cell cover portion 520 may cover the area corresponding to the terrace portion T of the battery cells 110 in the cell stack 100. The second cell cover portion 520 may be provided on opposite side faces of the cell stack 100.
The cover member 500 may be connected to the bus bar frame 420. The cover member 500 may be connected to the bus bar frame 420 in various ways. For example, they may be connected to each other by bolting, hooking, insertion grooves and insertion protrusions, and the like. In addition, the bus bar frame 420 and the cover member 500 may be configured as one member.
According to this configuration of the present disclosure, if gas generated inside the battery cell 110 is discharged through the terrace portion T, the movement of the gas may be suppressed by the first cell cover portion 510 and/or the second cell cover portion 520, thereby guiding and discharge the gas in a desired direction. In particular, in the case where both the first cell cover portion 510 and the second cell cover portion 520 are provided, gas may be discharged only from the bottom.
Referring to
The pad 600 may be provided between the first cell cover portion 510 and the cell stack 100. The pad 600 may be attached to the surface of the first cell cover portion 510 facing the cell stack 100. The pad 600 may be configured such that the surface to be seated on the cell stack 100 has a shape corresponding to the surface of the cell stack 100. The pad 600 may have a thickness corresponding to the spacing between the first cell cover portion 510 and the cell stack 100. The lower surface of the pad 600 may be configured in a shape corresponding to a plurality of irregularities formed on the upper surface of the cell stack 100. The pad 600 may be configured to seal the space between the cell stack 100 and the cover member 500.
The pad 600 may include an elastic material. The pad 600 may include a polyurethane (PU) material.
According to this configuration of the present disclosure, when gas or flame generated inside the battery cell 110 is discharged through the terrace portion T, it is possible to suppress and prevent the gas or flame from moving to the upper face of the cell stack 100. Additionally, in the case where resin, or the like, is injected onto the surface of the cell stack 100, the resin may be prevented from overflowing into the space between the cell stack 100 and the cover member 500.
Referring to
The protrusion 121 may protrude from one end of the thermal barrier 120 toward the module case 200. The protrusion 121 may extend from the upper end of the thermal barrier 120 to the module case 200. The protrusion 121 may extend along the longitudinal direction (direction parallel to the Y-axis) of the battery cell 110. The protrusion 121 may extend along the longitudinal direction (direction parallel to the Y-axis) of the battery cell 110 to have the same length as the thermal barrier 120.
According to this configuration of the present disclosure, the module case 200 may be stably supported by the thermal barrier 120. In addition, resin may be injected into the space between the protrusion 121, the top of the battery cell 110, and an adjacent protrusion 121 to facilitate fixation between the cell stack 100 and the module case 200. In particular, in the case where the protrusion 121 extends along the longitudinal direction (direction parallel to the Y-axis) of the battery cell 110 to have the same length as the thermal barrier 120, the pad 600 may have a groove formed to accommodate the protrusion 121, thereby maximizing the effect of preventing or delaying heat transfer between adjacent battery cells 110.
Referring back to
Hereinafter, a description will be made based on the case where the cell stack 100 includes a plurality of battery cells 110 stacked horizontally in an upright state and where the cover member 500 covers the upper face of the cell stack 100.
The venting portion 201 may be disposed at least one of the lower, front, and rear faces of the cell stack 100. The venting portion 201 may be disposed at the front and/or rear sides of the module case 200 such that the gas or flame emitted through the electrode lead through-hole 422 and/or the thermal barrier accommodation portion 423 of the bus bar frame 420 may be discharged. The venting portion 201 may be disposed at the bottom of the module case 200. The venting portion 201 may be disposed adjacent to the terrace portion T.
The venting portion 201 may be configured to discharge gas emitted from at least one of the plurality of battery cells 110 to the outside of the battery module 10. The venting portion 201 may be configured in the form of a simple hole passing through the module case 200. In addition, it may be a specific device that is closed in a normal state, instead of completely open, and opened depending on a change in pressure or temperature, as well as the completely open hole. The venting portion 201 may be, for example, a one-way valve. The guide portion 424 may be configured to guide gas generated from at least one of the plurality of battery cells 110 to the venting portion 201. The guide portion 424 may be provided at the bottom of the bus bar frame 420. The thickness of the guide portion 424 may be reduced as it is closer to the venting portion 201. The guide portion 424 may be configured such that the space between the bus bar frame 420 and the terrace portion T widens as it is closer to the venting portion 201.
According to this configuration of the present disclosure, gas or flame generated in the terrace portion T of the battery cell 110 may be discharged to the outside of the battery module 10 through the venting portion 201. Additionally, gas or flame may be discharged more effectively by the guide portion 424.
Referring to
Referring to
As described above, although the present disclosure has been described based on exemplary aspects with reference to the accompanying drawings, it is obvious to those skilled in the art will that various modified aspects may be implemented within the technical scope of the present disclosure. Therefore, the scope of the present disclosure should be construed according to the claims described to include various modifications.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0167608 | Dec 2022 | KR | national |
| 10-2023-0043199 | Mar 2023 | KR | national |
This application is a bypass continuation of PCT/KR2023/018008, filed on Nov. 9, 2023, and claims priority to Korean Patent Application No. 10-2022-0167608, filed on Dec. 5, 2022, and Korean Patent Application No. 10-2023-0043199, filed on Mar. 31, 2023, the disclosures of which are explicitly incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2023/018008 | Nov 2023 | WO |
| Child | 19048056 | US |
