Patent Application
20230299383
This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0029158 filed in the Korean Intellectual Property Office on Mar. 5, 2021, the entire contents of which are incorporated herein by reference.
The present invention relates to a battery pack and a device including the same, and more specifically, it relates to a battery pack that minimizes heat propagation between adjacent battery modules and a device including the same.
A rechargeable battery with high applicability with ease according to product groups and electrical characteristics such as high energy density are universally applied to electric vehicles or hybrid vehicles driven by electric drive sources, as well as portable devices and power storage devices. Such a rechargeable battery is attracting attention as a new energy source for enhancing environmentally-friendly and energy efficiency in that it does not generate any by-products from the use of energy as well as the primary merit of dramatically reducing the use of fossil fuels.
A currently commercially available rechargeable battery includes a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, and a lithium rechargeable battery, and the lithium rechargeable battery is attracting attention for its merits of charging and discharging freely, a very low self-discharge rate, and high energy density because the memory effect hardly occurs compared to the nickel-based rechargeable battery.
In general, a lithium rechargeable battery can be classified into a cylindrical or prismatic rechargeable battery in which an electrode assembly is built into a metal can, and a pouch-type rechargeable battery in which an electrode assembly is built in a pouch of an aluminum laminate sheet, depending on the shape of the exterior material.
Recently, as the need for a large capacity rechargeable battery structure, including the use of rechargeable batteries as an energy storage source, increases, the demand for a battery pack with a medium-to-large module structure in which a plurality of rechargeable batteries are assembled in series or coupled in parallel battery modules is increasing. In such a battery module, a plurality of battery cells are coupled serially or in parallel to form a battery cell stack, thereby improving capacity and output. In addition, a plurality of battery modules may be mounted together with various control and protection systems such as a battery management system (BMS) and a cooling system to form a battery pack.
In particular, the battery pack has a structure in which a plurality of battery modules are combined, and thus in the case of overvoltage, overcurrent or overheating occurs in some battery modules, the safety and operation efficiency of the battery pack may be problematic. In particular, the capacity of the battery pack is gradually increasing to improve mileage, and as a result, the internal energy of the pack is also increased, and it is necessary to design a structure to satisfy the reinforced safety standards and to secure the safety of the vehicle and driver. For this purpose, particularly, the need for a structure that can prevent internal thermal runaway in advance and minimize the damage when it occurs is emerging.
Referring to
Here, referring to
Accordingly, unlike the conventional battery pack 10, it is necessary to develop a battery pack and a device including the same that prevent thermal runaway from occurring by preventing heat propagation between adjacent battery modules 11 from occurring.
The problem to be solved by the present invention relates to a battery pack that minimizes heat propagation between adjacent battery modules and a device including the same.
The problem to be solved by the present invention is not limited to the above-mentioned problems, and problems not mentioned can be clearly understood by a person of an ordinary skill in the technical field to which the present invention belongs from this specification and the attached drawing.
A battery pack an embodiment of the present invention includes: a pack frame in which a plurality of battery modules are mounted to be spaced apart from each other; and at least one insulating member positioned between a bottom surface of at least one of the plurality of battery modules and a bottom surface of the pack frame, wherein each battery module of the plurality of battery modules includes a battery cell stack where a plurality of battery cells are stacked, a module frame that accommodates the battery cell stack, and a heat sink that is positioned on a bottom portion of the module frame, the bottom portion of the module frame forms an upper plate of the heat sink, and the bottom portion of the module frame is in contact with refrigerant supplied in the heat sink.
The at least one insulating member is a pair of insulating members respectively positioned under each adjacent battery module among the plurality of battery modules.
The pair of insulating members may be spaced apart from each other.
The at least one insulating member may extend along a bottom surface of at least one battery module of the plurality of battery modules.
The at least one insulating member may have a larger size than the bottom surface of the at least one battery module.
The insulating member may have a same size as the bottom surface of the at least one battery module.
The at least one insulating member may have a larger size than the heat sink.
The at least one insulating member and the heat sink may have the same size.
The insulating member may be formed of an expanded polypropylene (EPP) foam.
The heat sink may be coupled with the bottom portion of the module frame, and includes a lower plate where a recess portion is formed, and a refrigerant may flow between the recess portion and the bottom portion of the module frame.
A protrude pattern may be formed in the recess portion.
A device according to another embodiment of the present invention includes the above-described battery pack.
According to the embodiments, in the battery module of the embodiment of the present invention includes the heat sink that is positioned on the bottom portion of the module frame, and the insulating member is positioned between the bottom surface of the battery module and the bottom surface of the pack frame such that heat propagation between adjacent battery modules can be minimized.
The effect of the present invention is not limited to the above-mentioned effects, and the effects not mentioned will be clearly understood by a person of an ordinary skill in the technical field to which the present invention belongs from this specification and the accompanying drawings.
Hereinafter, with reference to the accompanying drawing, various embodiments of the present invention will be described in detail such that a person of an ordinary skill can easily practice it in the technical field to which the present invention belongs. The present invention may be implemented in several different forms and is not limited to the embodiments described herein. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
In the drawings, size and thickness of each element are arbitrarily illustrated for convenience of description, and the present invention is not necessarily limited to as illustrated in the drawings. In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In addition, in the drawing, for convenience of explanation, the thickness of some layers and regions is exaggerated.
In addition, unless explicitly described to the contrary, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
Further, throughout the specification, the phrase “on a plane” means viewing a target portion from the top, and the phrase “on a cross-section” means viewing a cross-section formed by vertically cutting a target portion from the side.
Hereinafter, a battery pack according to an embodiment of the present invention will be described.
A battery pack according to an embodiment of the present invention includes: a pack frame in which a plurality of battery modules are mounted to be spaced apart from each other; and an insulating member positioned between a bottom surface of the battery module and a bottom surface of the pack frame.
A pack frame 410 may be a lower housing on which a plurality of battery modules 100 are mounted, and may further include an upper cover (not shown) coupled to the pack frame 410 to cover an upper portion of the battery module 100. However, hereinafter, the upper cover (not shown) is omitted for convenience of explanation, but the battery pack 1000 of the present embodiment can be described assuming that a generally-used upper cover (not shown) is coupled together therewith.
The pack frame 410 may be formed by including a bottom surface on which the plurality of battery modules 100 are disposed, and a side wall extending upward from an edge of the bottom surface. An upper cover (not shown) covering the upper portion of the battery module 100 is coupled to the pack frame 410 to protect the internal electric field. In this case, various control and protection systems such as a battery management system (BMS) and a cooling system may be mounted inside the pack frame 410 together with the battery module 100.
For example, the pack frame 410 may be made of a steel or aluminum material. More preferably, the pack frame 410 is made of a steel material having relatively low thermal conductivity compared to an aluminum material, and thus the level of heat energy transfer between adjacent battery modules 100 through the pack frame 410 can be reduced. However, the present invention is not limited thereto, and any material having sufficient rigidity is applicable to the pack frame 410.
The insulating member 250 may be positioned under the battery module 100. More specifically, in the plurality of battery modules 100, the insulating member 250 may be positioned under each battery module 100. That is, in the battery pack 1000 according to the present embodiment, the insulating member 250 may be disposed under each of the battery modules 100 mounted on the pack frame 410. That is, each battery module 100 may be individually or independently disposed on the insulating member 250.
In addition, the insulating members 250 respectively positioned under the adjacent battery modules 100 among the plurality of battery modules 100 may be spaced apart from each other. In other words, the insulating member 250 disposed under one battery module 100 may be spaced apart from the insulating member 250 disposed under the other adjacent battery module 100.
Accordingly, unlike the conventional battery pack 10 (refer to
The insulating member 250 may be positioned between the bottom surface of the battery module 100 and the bottom surface of the pack frame 410. In other words, in the present embodiment, it may have a structure in which the pack frame 410, the insulating member 250, and the battery module 100 are stacked in that order.
The insulating member 250 may extend along the bottom surface of the battery module 100. More specifically, the insulating member 250 may extend along the bottom surface of the heat sink 200 (refer to
As an example, the insulating member 250 may have a different size from that of the bottom surface of the battery module 100, but may have a larger size than that of the bottom surface of the battery module 100. As another example, the insulating member 250 may have the same size as the bottom surface of the battery module 100.
As an example, the insulating member 250 may have a different size from the size of the heat sink 200 (
Accordingly, the contact area of the insulating member 250 with the bottom surface of the battery module 100, that is, the heat sink 200 (
For example, the insulating member 250 may be made of a foaming material such as expanded polypropylene (EPP) foam. However, the insulating member 250 is not limited thereto, and it can be any material as long as it has excellent thermal insulation properties.
Accordingly, with the above configuration, the insulating member 250 can prevent the bottom surface of the battery module 100, that is, the heat sink 200 (see
Referring to
The battery cell 111 is preferably a pouch-type battery cell. For example, the battery cell 111 may be manufactured by accommodating an electrode assembly in a pouch case of a laminate sheet including a resin layer and an inner layer, and then heat-sealing a sealing portion of the pouch case. The battery cell 111 may be formed in a rectangular sheet-type structure. Such a battery cell 111 may be provided in plural, and a plurality of battery cells 111 are stacked to be electrically connected to each other to form the battery cell stack 112.
The module frame 114 may include an upper cover 115 and a U-shaped frame 116. Here, the U-shaped frame 116 may include a bottom portion and two side portions extending upward from both ends of the bottom portion. In this case, the bottom portion may cover the lower surface of the battery cell stack 112, and the side portion may cover the side surface of the battery cell stack 112. The upper cover 115 and the U-shaped frame 116 may be joined by welding or the like in a state in which corresponding edge portions are in contact with each other to form a structure that covers the upper, lower, left, and right sides of the battery cell stack 112. For this, the upper cover 115 and the U-shaped frame 116 may be made of a metal material having predetermined strength. However, the module frame 114 is not limited thereto, and may be a mono frame in the form of a metal plate in which upper and lower surfaces and both sides are integrated.
The end plate 120 may be positioned on an open first side (x-axis direction) and a second side (the opposite direction of the x-axis) of the module frame 114 to cover the front and rear surfaces of the battery cell stack 112. Accordingly, the end plate 120 can physically protect the battery cell stack 112 and other electrical equipment from external impact.
Meanwhile, although not specifically illustrated, a bus bar frame on which a bus bar is mounted and an insulating cover for electrical insulation may be positioned between the battery cell stack 112 and the end plate 120.
Referring to
Specifically, the cooling port 150 according to the present embodiment includes a refrigerant injection port for supplying refrigerant to the heat sink 200 and a refrigerant discharge port for discharging refrigerant from the heat sink 200. The module frame protrude portion 116a may include a first module frame protrude portion and a second module frame protrude portion positioned to be spaced apart from each other on one side of the module frame 114, and the refrigerant injection port may be disposed on the first module frame protrude portion and the refrigerant discharge port may be disposed on the second module frame protrude portion.
Hereinafter, referring to
A bottom portion of the module frame 114 may form an upper plate of the heat sink 200, and the bottom portion of the module frame 114 may contact the refrigerator supplied in the heat sink 200.
The heat sink 200 may be positioned under the module frame 114. More specifically, the heat sink 200 may include a lower plate 210 that forms the skeleton of the heat sink 200 and is directly coupled to the bottom portion of the module frame 114 by welding and the like, and a recess portion 240 that is a path through which the refrigerant flows.
The heat sink 200 may include a heat sink protrude portion 200P protruding from one side of the heat sink 200 to a portion where the module frame protrude portion 116a is positioned. Here, the heat sink protrude portion 200P and the module frame protrude portion 116a may be directly coupled to each other by a method such as welding.
The recess portion 240 of the heat sink 200 corresponds to a portion in which the lower plate 210 is recessed downward. A cross-section of the recess portion 240, cut vertically in the x-z plane based on a direction in which the refrigerant flow path extends may be a U-shaped tube, and the bottom portion of the module frame 114 may be positioned on an open upper side of the U-shaped tube. As the heat sink 200 is in contact with the bottom portion of the module frame 114, a space between the recess portion 240 and the bottom portion of the module frame 114 becomes a region through which refrigerant flows, that is, a flow path for refrigerant. Accordingly, the bottom portion of the module frame 114 can be in direct contact with the refrigerant.
Although there is no particular limitation on a manufacturing method of the recess portion 240 of the heat sink 200, the U-shaped recess portion 240 with an open upper side may be formed by providing a structure in which a depression is formed with respect to the plate-shaped heat sink 200.
Such a recess portion 240 may be continued from one of the heat sink protrude portions 200P to another. The refrigerant supplied through the refrigerant injection port of the cooling port 150 passes between the module frame protrude portion 116a and the heat sink protrude portion 200P and then flows into the space between the recess portion 240 and the bottom portion of the module frame 114. Thereafter, the refrigerant moves along the recess portion 240, passes between the other module frame protrude portion 116a and the other heat sink protrude portion 200P, and is discharged through the refrigerant discharge port of the cooling ports 150.
In addition, the bottom portion of the module frame 114 may be joined by welding to a portion of the lower plate 210, in which the recess portion 240 of the heat sink 200 is not formed. Through the integrated cooling structure of the bottom portion of the module frame 114 and the heat sink 200, the present embodiment not only improves the cooling performance described above, but also supports the load of the battery cell stack 112 accommodated in the module frame 114 and reinforces the rigidity of the battery module 100. In addition, the lower plate 210 and the bottom portion of the module frame 114 are sealed through welding and the like, and thus refrigerant can flow without leakage in the recess portion 240 formed inside the lower plate 210.
For effective cooling, as shown in
Meanwhile, referring back to
In the case of a large-area battery module in which the number of stacked battery cells increases significantly compared to the prior art, such as the battery cell stack 112 according to the present embodiment, the refrigerant flow path may be formed wider, and thus the temperature deviation may be more severe. In particular, compared to the case in which approximately 12 to 24 battery cells are stacked in one battery module, the case in which approximately 32 to 48 battery cells are stacked in one battery module is included in a large-area battery module. In such a case, the protrude pattern 240D according to the present embodiment has the effect of substantially reducing the width of the cooling path, thereby minimizing the pressure drop and simultaneously reducing the temperature deviation between widths of the refrigerant path. Therefore, it is possible to implement a uniform cooling effect.
In the conventional battery pack shown in
On the other hand, in the battery pack 1000 according to the present embodiment, each battery module 100 implements a cooling integrated structure of the module frame 114 and the heat sink 200, and thus the heat transferred to the heat sink 200 in some battery module 100 can be prevented from being transmitted to a heat sink 200 of another battery module 100. Accordingly, although some of the heat caused by abnormal phenomena (CE) such as overvoltage, overcurrent, or overheating generated in some battery modules 100 is transmitted to the heat sink 200, the risk of heat propagation to the adjacent battery module 100 can be prevented.
In addition, the battery module 100 having the above-described integrated cooling structure is individually cooled, and thus the cooling efficiency of each battery module 100 may be further increased. In addition, through a structure in which the heat sink 200 is integrated with the bottom portion of the module frame 114, the space utilization rate on the battery module 100 and the battery pack 1000 on which the battery module 100 is mounted can be further improved. In addition, the height of the battery module 100 is reduced by removing the unnecessary cooling structure, and thus it possible to reduce costs and increase spatial utility. Furthermore, since the battery module 100 can be compactly disposed, the capacity or output of the battery pack 1000 including a plurality of the battery module 100 can be increased.
Referring to
In addition, it may further include a venting induction frame 300 disposed along edges of a plurality of battery module 100. More specifically, a plurality of battery modules 100 and the venting induction frame 300 may be mounted in the pack frame 410.
For example, at least one rupture portion 500 is formed on one side wall of the pack frame 410, and thus heat or flames generated thereinside can be discharged to the outside. In the present embodiment, although the two rupture portions 500 are formed on only one side of a pair of horizontal beams 320, it is not limited thereto and the rupture portion 500 is also provided on the other horizontal beam 320 or may be provided in the vertical beam 310, and the position and number of the rupture portions 500 can be appropriately selected as necessary.
In addition, the venting induction frame 300 may be disposed along the entire edges of the plurality of battery modules 100. The venting induction frame 300 is formed in the shape of a tube along each side of the battery pack 1000, and a pair of vertical beams 310 and a pair of horizontal beams 320 are extended along the first direction (x-axis direction) and the second direction (y-axis direction), respectively, and they may be formed to be able to communicate as a whole.
With the above configuration, a passage is formed to communicate with the whole inside the square-shaped venting induction frame 300 formed of the vertical beam 310 and the horizontal beam 320. The passage communicates with the venting gate 121 and the rupture portion 500 of the battery module 100, and thus, when a thermal runaway occurs from the battery module 100, heat and flame are induced to the outside, thereby minimizing the influence on the surrounding battery module. In this case, the flame contained in the generated high-pressure venting gas is combusted while passing through the passage inside the venting induction frame 300 and can be discharged to the outside in a safer state. In addition, this venting induction frame 300 serves as a support frame to stably support the battery module 100, not during thermal runaway, to improve the stability of the battery pack 1000.
Hereinafter, a heat propagation path when issues such as overvoltage, overcurrent, or overheating occur in some battery modules in the battery pack will be described in detail.
Referring to
Here, heat generated in the battery module 100 in which the cell event CE has occurred may be transmitted through a heat energy movement path passing through the heat sink 200 and insulation member 250 included in the battery module 100.
More specifically, the heat generated in the battery module 100 in which the cell event CE has occurred may first be transferred to the heat sink 200. As described above, due to the integrated cooling structure of the bottom portion of the module frame 114 and the heat sink 200, each battery module 100 includes a heat sink 200 individually, and thus the heat transmitted from the battery cell stack 112 to the heat sink 200 is not transmitted to another adjacent battery module 100.
Accordingly, according to the present embodiment, due to the integrated cooling structure of the battery module 100, even though the cell event CE occurs in some battery modules 100 among a plurality of battery modules 100, heat propagation to the adjacent battery module 100 can be prevented.
In addition, some of the heat transmitted to the heat sink 200 of the battery module 100 may be transmitted to the insulation member 250. Here, the insulating member 250 may block some of the heat transmitted from the heat sink 200 of the battery module 100 while preventing the heat generated from the battery module 100 from being directly transmitted to the pack frame 410. That is, although a cell event CE occurs in some battery modules 100 among a plurality of battery modules 100 and relatively much heat energy is generated, heat energy transmitted to the pack frame 410 through the insulating member 250 is minimized, and the temperature rise of the adjacent battery module 100 can also be minimized.
In addition, as described above, as the insulating member 250 is individually separated from each other in the lower portion of the battery module 100, the heat transmitted to the insulating member 250 of the battery module in which the cell event CE has occurred is not directly transmitted to another battery module 100. More specifically, some of the heat transmitted to the insulating member 250 of the battery module 100 in which the cell event CE has occurred may be transmitted to the pack frame 410, and some of the heat transmitted to the pack frame 410 may be transmitted to an insulating member 250 of another adjacent battery module 100.
Accordingly, although some of the heat generated in the battery module 100 in which the cell event CE has occurred is transmitted to the other adjacent battery module 100, the heat transmitted from the pack frame 410 can effectively blocked by the insulating member 250 of another adjacent battery module 100.
Accordingly, in the present embodiment having the above heat propagation path, although a cell event CE occurs in some battery modules 100 among a plurality of battery modules 100, it is possible to effectively prevent heat propagation to other adjacent battery modules 100, there preventing a series of thermal runaway phenomena.
The battery pack described above may be applied to various devices. Such a device may be applied to transportation means such as an electric bicycle, an electric vehicle, a hybrid vehicle, and the like, but the present invention is not limited thereto, and is applicable to various devices that can use a battery module and a battery pack including the same and this is also included within the scope of the present invention.
Although the preferred embodiments of the present invention have been described in detail above, the right range of the present invention is not limited thereto, and various modifications and improvements of a person of ordinary skill in the art using the basic concept of the present invention defined in the following claims range also fall within the scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0029158 | Mar 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/002309 | 2/16/2022 | WO |
