The present disclosure relates to an electrode assembly and a battery cell including the same, and more particularly, to an electrode assembly with novel cooling structure and a battery cell including the same.
With the technology development and increased demand for mobile devices, demand for secondary batteries as energy sources has been rapidly increasing. In particular, a secondary battery has attracted considerable attention as an energy source for power-driven devices, such as an electric bicycle, an electric vehicle, and a hybrid electric vehicle, as well as an energy source for mobile devices, such as a mobile phone, a digital camera, a laptop computer and a wearable device.
In small mobile devices, one, or two, or three battery cells are used per device, while medium-or large-sized devices such as vehicles require high power and large capacity. Therefore, a medium-or large-sized battery module having a plurality of battery cells electrically connected to one another is used.
Since medium-or large-sized battery modules are preferably manufactured with as small a size and weight as possible, a prismatic battery, a pouch-type battery, or the like, which can be stacked with high integration and has a small weight relative to capacity, is mainly used as a battery cell of the medium-or large-sized battery modules. Such a battery module has a structure in which a plurality of cell assemblies including a plurality of unit battery cells are connected in series to obtain high output. Further, the battery cell includes positive and negative electrode current collectors, a separator, an active material, an electrolyte, and the like, and thus can be repeatedly charged and discharged through an electrochemical reaction between components.
Meanwhile, in recent years, amid the growing need for large-capacity structures including their utilization as an energy storage source, there is an increasing demand for battery packs having a multi-module structure formed by assembling a plurality of battery modules in which a plurality of secondary batteries are connected in series and/or in parallel.
Further, when a plurality of battery cells are connected in series or in parallel to form a battery pack, it is common to configure a battery module composed of at least one battery cell first and then configure a battery pack by using at least one battery module and adding other components.
Generally, when a secondary battery is heated over a standard operating temperature, the performance of the secondary battery may deteriorate, and in the worst case, there is also a risk of an explosion or ignition. In particular, a plurality of secondary batteries, that is, a battery module or a battery pack having battery cells can accumulate the heat emitted from the plurality of battery cells in a narrow space, which may raise the temperature of the battery module quickly and severely. In other words, a battery module including a large number of battery cells, and a battery pack equipped with such a battery module can obtain high output, but it is not easy to remove heat generated from the battery cells during charging and discharging. When the heat dissipation of the battery cell is not properly performed, deterioration of the battery cells is accelerated, the battery's lifespan is shortened, and the possibility of explosion or ignition increases.
Moreover, if a medium-or large-sized battery module is included in a battery pack for a vehicle, the battery module may be frequently exposed to direct sunlight and may be placed under high-temperature conditions, for example, in summer or in a desert.
Referring to
Referring to
Thus, conventionally, heat generated in the battery cells of a battery module was emitted only through a one-way path via the thermal conductive resin layer formed under the battery cell stack and the bottom part of the module frame. However, in recent years, the need for high capacity, high energy, rapid charging battery capabilities, and the like has continuously increased, the amount of current flowing through the busbar has increased, and the amount of heat generated from busbars, battery cells, and electrode leads has also increased. Such improvements result in difficulties cooling the heat generation using conventional methods.
Therefore, there is a need for a new structure for solving the heat generation problem of the battery cell, which occurs according to the needs of high capacity, high energy, rapid charging, and the like.
An object of the present disclosure is to provide a battery module that lowers battery cell temperature and thus improves cooling performance, and a battery pack including the same.
The objects of the present disclosure are not limited to the aforementioned objects, and other objects which are not mentioned herein should be clearly understood by those skilled in the art from the following detailed description and the accompanying drawing.
According to one embodiment of the present disclosure, there is provided a battery module comprising: a battery cell stack including a plurality of battery cells; a module frame that houses the battery cell stack; and a cooling pipe member formed between the upper part of the battery cell stack and the module frame, wherein the cooling pipe member comprises a first cooling pipe part and a second cooling pipe part.
The battery cell comprises a sealing part formed along a length direction of the battery cell, and the cooling pipe member may be formed to be adjacent to the sealing part.
The battery module according to the present embodiment is configured such that the sealing part may be located between the first cooling pipe part and the second cooling pipe part.
The sealing part may be folded at least once in one direction.
The sealing part may be folded a plurality of times in one direction, and the sealing part folded a plurality of times may be arranged in parallel to the side surface part of the module frame.
The sealing part comprises a first portion, a second portion and a third portion that are connected to each other, and the first portion, the second portion and the third portion may be arranged in parallel to each other.
The sealing part further comprises a first connecting part and a second connecting part, and a length of the first portion may be formed longer than a length of the first connecting part.
The first cooling pipe part and the second cooling pipe part are connected to each other, and a cooling flow path may be formed along the first cooling pipe part and the second cooling pipe part.
The first cooling pipe part and the second cooling pipe part may be formed in parallel to the longitudinal direction of the battery cell.
The first cooling pipe part and the second cooling pipe part form one cooling pipe unit, and the cooling pipe member may comprise a plurality of cooling pipe units.
The cooling pipe member further comprises a coolant inflow part and a coolant outflow part, and the first cooling pipe part may be connected to the coolant inflow part, and the second cooling pipe part is connected to the coolant outflow part.
The battery module further comprises end plates that cover the front and rear surfaces of the battery cell stack, wherein the coolant inflow part and the coolant outflow part may be formed adjacent to the end plate.
The battery module further comprises a thermally conductive resin layer formed between the upper part of the battery cell stack and the module frame, wherein the cooling pipe member may be in contact with the thermally conductive resin layer.
The battery module according to another embodiment of the present disclosure may further comprise a cooling pipe member that is formed between the lower part of the battery cell stack and the module frame.
According to yet another embodiment of the present disclosure, there is provided a battery pack comprising the above-mentioned battery module.
A battery module according to embodiments of the present disclosure includes a cooling pipe member formed between a battery cell stack and a module frame, thereby capable of effectively cooling a battery cell whose temperature rises in a high current and rapid charging environment. In addition, the internal temperature deviation of the battery module can be minimized, thereby improving the stability of the battery module.
The effects of the present disclosure are not limited to the effects mentioned above and additional other effects not described above will be clearly understood from the description of the appended claims by those skilled in the art.
Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily ascertain them. The present disclosure may be modified in various different ways, and is not limited to the embodiments set forth herein.
Portions that are irrelevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals designate like elements throughout the description.
Further, in the drawings, the size and thickness of each element are arbitrarily illustrated for convenience of description, and the present disclosure is not necessarily limited to those illustrated in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for clarity. In the drawings, for convenience of description, the thicknesses of a part and an area are exaggerated.
Further, it will be understood that when an element such as a layer, film, region, or plate is referred to as being “on” or “above” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, it means that other intervening elements are not present. Further, a certain part being located “above” or “on” a reference portion means the certain part being located above or below the reference portion and does not particularly mean the certain part “above” or “on” toward an opposite direction of gravity.
Further, throughout the description, when a portion is referred to as “including” or “comprising” a certain component, it means that the portion can further include other components, without excluding the other components, unless otherwise stated.
Further, throughout the description, when a directional limitation is referred to as “planar”, it means that a target portion is viewed from the upper side, and when a directional limitation is referred to as “cross-sectional”, it means that a target portion is viewed from the side of a cross section cut vertically.
The terms “first,” “second,” etc. are used to explain various components, but the components should not be limited by the terms. These terms are only used to distinguish one component from the other component.
Now, the battery module according to the present disclosure will be described with reference to
Referring to
The battery cell 110 is preferably a pouch-type battery cell, and can be formed in a rectangular sheet-like structure. For example, referring to
The battery cell 110 can be produced by joining both ends 114a and 114b of a cell case 114 and one side part connecting them when an electrode assembly (not shown) is housed in a cell case 114. In other words, the battery cell 110 according to the present embodiment has a total of three sealing parts 114sa, 114sb and 114sc, wherein the sealing part s 114sa, 114sb and 114sc have a structure that is sealed by a method such as heat sealing, and the remaining other side part may be composed of a connecting part 115. In particular, the sealing parts 114sa, 114sb, and 114sc may include a sealing part 114sc formed in the longitudinal direction of the battery cell and sealing part s 114sa and 114sb formed in the width direction of the battery cell. The sealing part 114sc formed in the longitudinal direction of the battery cell is not limited to the shape shown in
The connecting part 115 may extend long along one edge of the battery cell 110, and a bat-ear 110p may be formed at the end of the connecting part 115. Further, while the cell case 114 is sealed with the protruding electrode leads 111 and 112 being interposed therebetween, a terrace part 116 may be formed between the electrode leads 111 and 112 and the cell main body 113. That is, the battery cell 110 may include a terrace part 116 formed to extend from the cell case 114 in the direction in which the electrode leads 111 and 112 protrude.
Such a battery cell 110 may be combined with a plurality of other battery cells 110, and the plurality of battery cells 110 may be stacked to be electrically connected to each other, thereby forming a battery cell stack 120. Particularly, as shown in
When charge and discharge of the battery cell 110 is repeatedly performed, heat is generated. A large amount of heat is generated in a portion adjacent to the electrode leads 111 and 112. Since a lot of heat may be generated in the electrode leads 111 and 112 along with the cell main body 113 due to charging and discharging, a novel structure for cooling the battery cell 110 may be required.
The conventional battery module lacked cooling efficiency due to the space occupied by the sealing part of the battery cell, and the conventional battery module did not properly utilize space when applying a thermally conductive resin layer to an upper part.
Therefore, referring to
Referring to
More specifically, the sealing part 114sc may be formed into a scroll shape either having at least one folding part by being folded at least once or having a plurality of folding parts by being folded a plurality of times. That is, it may have a single folding structure that is folded at least once or a double folding structure that is folded a plurality of times. The scroll shape described herein may indicate that the direction in which the sealing part 114sc is folded a plurality of times is formed in one direction so that the cross section of the sealing part 114sc has a rolled or spiral shape having a folding part.
Further, by being folded as above, the edge part located at the outermost side of the sealing part 114sc may be located at the center of the scroll shape. The edge part located at the outermost side may mean an outermost edge region before the sealing part 114sc is folded. By forming a scroll shape as described above, the edge part located at the outermost side can be folded a plurality of times so as to be located in the center of the scroll shape. The edge part located at the outermost side may correspond to the third portion 114sc3 of the sealing part 114sc that is folded a plurality of times.
By being folded a plurality of times in one direction as above, the sealing part 114sc can minimize the space occupied compared to a conventional sealing part. In particular, the space occupied by the sealing part can be minimized, thereby minimizing the heat transfer resistance.
The sealing part 114sc may include a first connecting part 114sc4 that connects the first portion 114sc1 and the second portion, and a second connecting part 114sc5 that connects the second portion 114sc2 and the third portion 114sc3.
If the length of the first connecting part 114sc4 of the sealing part 114sc is defined as the horizontal length of the sealing part 114sc and the length of the first portion 114sc1 is defined as the vertical length of the sealing part 114sc, the length of the first portion 114sc1 is formed longer than the length of the first connecting part 114sc4, and thus, a vertical length of the sealing part 114sc may be formed longer than a horizontal length of the sealing part 114sc. Thereby, the region occupied by the sealing part 114sc in the upper part of the battery cell stack 120 is minimized, so that cooling performance can be improved, and also the sealing part 114sc is fixedly formed in a cooling pipe structure described below.
The module frame 200 includes a U-shaped frame 300 which is opened at its upper, front, and rear surfaces and covers the lower part and both side parts of the battery cell stack 120, and an upper plate 400 that covers the upper part of the battery cell stack 120. At this time, the U-shaped frame 300 may include a bottom part 300a supporting the lower part of the battery cell stack 120, and side surface parts 300b each extending upward from both ends of the bottom part 300a. However, the module frame 200 is not limited thereto, and can be replaced with a frame having another shape such as an L-shaped frame or a mono-frame surrounding the cell stack 120 except the front and rear surfaces. The cell stack 120 housed inside the module frame 200 can be physically protected through the module frame 200.
The upper plate 400 can cover the opened upper side surface of the module frame 200. The end plate 150 can cover the front and rear surfaces of the cell stack 120 that are opened in the module frame 200. The end plate 150 can be weld-coupled with the front and rear end edges of the upper plate 400 and the front and rear end edges of the module frame 200. The end plate may include a front end plate 151 and a rear end plate 152.
A busbar frame 130 can be formed between the end plate 150 and the front and rear surfaces of the battery cell stack 120. The busbar frame 130 can cover the portion of the battery cell stack 120 exposed from the module frame 200. The plurality of busbars 160 mounted to the busbar frame 130 are formed protrusively from the battery cells 110, and can be connected with the electrode leads 111 and 112 mounted on the busbar frame 130. A slot through which the electrode leads 111 and 112 pass may be formed in the busbar 160. Therefore, the electrode leads 111 and 112 and the busbar 160 passing through the slot of the busbar 160 may contact each other.
The battery module 100 according to the present embodiment further includes a first thermal conductive resin layer 310 located between the lower surface of the battery cell stack 120 and the bottom part of the module frame 200, that is, the bottom part 300a of the frame member 300, wherein the first thermal conductive resin layer 310 may play a role of transferring heat generated in the battery cell 110 to the bottom of the battery module 100 and fixing the battery cell stack 120.
The battery module 100 according to the present embodiment may further include a second thermally conductive resin layer 320 formed between the upper part of the battery cell stack 120 and the upper part of the module frame 200, that is, the upper plate 400. Therefore, the heat generated in the battery cell 110 can be transferred even through the upper part of the module frame 200 via the second thermally conductive resin layer 320.
The battery module 100 according to the present embodiment includes a heat transfer path to the upper part of the module frame 200 through the second thermally conductive resin layer 320, rather than a one-way path through the bottom part of the module frame 200, thereby causing an improvement in the cooling performance. The first thermally conductive resin layer 310 and the second thermally conductive resin layer 320 may be formed by a method of applying and curing a thermal resin. Therefore, the first thermally conductive resin layer 310 and the second thermally conductive resin layer 320 are illustrated in a plate shape, but in the process of applying and then curing the thermally conductive resin, they can be freely deformed in accordance with the shape of other components.
A conventional battery module was configured to discharge the heat generated in the battery cells through the thermal conductive resin layer formed at a lower part of the battery cell. However, a problem exists in that the heat generated in the battery cells cannot be efficiently cooled only by the thermally conductive resin layer formed under the battery cell stack and the cooling structure through the one-way path via the bottom part of the module frame.
Therefore, there is a need for a structure that can effectively cool the heat in a situation where the battery cells generate a large amount of heat in a short period of time due to the flow of a high current, such as rapid charging.
The cooling pipe member 500 of the battery module 100 according to the present embodiment will be described in more detail with reference to the previously listed figures and
Referring to
Referring to
The first cooling pipe part 510 and the second cooling pipe part 520 may be connected to each other. Therefore, a cooling flow path may be formed along the first cooling pipe part 510 and the second cooling pipe part 520. Further, the first cooling pipe part 510 and the second cooling pipe part 520 may be formed in parallel to the longitudinal direction of the battery cell 110. Therefore, the cooling flow path formed along the first cooling pipe part 510 and the second cooling pipe part 520 may also be formed in parallel to the longitudinal direction of the battery cell 110. A coolant or cooling water may flow through the cooling flow path formed in parallel to the longitudinal direction of the battery cell 110. That is, the upper surface of the battery cell stack 120 can be cooled by the coolant or cooling water flowing along the first cooling pipe part 510 and the second cooling pipe part 520.
The first cooling pipe part 510 and the second cooling pipe part 520 may form one cooling pipe unit. The cooling pipe unit may include a state in which the first cooling pipe part 510 and the second cooling pipe part 520 are connected to each other. Therefore, the cooling pipe unit may include a cooling flow path that is formed along the first cooling pipe part 510 and the second cooling pipe part 520. The cooling pipe member 500 includes a plurality of cooling pipe units, and thereby may include a plurality of first cooling pipe parts 510 and a plurality of second cooling pipe parts 520. That is, the cooling pipe member 500 can be formed with a plurality of cooling pipe units, and therefore, include a plurality of cooling flow paths. In some cases, the cooling pipe units may be repeated so that the cooling flow paths are connected to each other to form one cooling flow path.
Referring to
The first cooling pipe part 510 is connected to the coolant inflow part 530, and the second cooling pipe part 520 may be connected to the coolant outflow part 540. The first cooling pipe part 510 is connected to the coolant outflow part 540, and the second cooling pipe part 520 is connected to the coolant inflow part 530, so that they can also be cross-connected to each other. Therefore, the battery module 100 according to the present embodiment may be configured such that a coolant is flowed in through the coolant inflow part 530, the battery cell 110 is cooled through the first cooling pipe part 510 and the second cooling pipe part 520, and then the coolant is discharged to the outside of the battery module 100 through the coolant outflow part 540. In addition, a flow of the cooling flow path flowing through the inflow and outflow of the coolant may be formed.
Referring to
Further, the cooling pipe member 500 may be formed to be adjacent to the sealing part 114sc. In particular, the sealing part 114sc may be located between the first cooling pipe part 510 and the second cooling pipe part 520 of the cooling pipe member 500. Therefore, there exists good space utilization by the sealing part 114sc, and the stability of the battery module can be improved due to the cooling effect of the battery cell 110 through the cooling pipe member 500. In particular, the sealing part 114sc is located between the first cooling pipe part 510 and the second cooling pipe part 520, so that the sealing part 114sc can be stably fixed.
Next, a battery module according to another embodiment of the present disclosure will be described with reference to
Referring to
The battery module 100 according to the present embodiment includes not only a first cooling pipe member 500 formed between the upper part of the battery cell stack 120 and the module frame 200, but also a second cooling pipe member 600 formed between the lower part of the battery cell stack 120 and the module frame 200, thereby capable of forming an additional cooling path.
The second cooling pipe member 600 may be in contact with the first thermally conductive resin layer 310. Further, the second cooling pipe member 600 may include a first cooling pipe part 610 and a second cooling pipe part 620, and may include a coolant inflow part 630 and a coolant outflow part 640.
The coolant inflow part 630 and the coolant outflow part 640 may be formed adjacent to the rear end plate 152, and more specifically, they may be formed adjacent to the lower part of the rear end plate 152.
The battery module 100 according to the present embodiment includes a first cooling pipe member 500 and a second cooling pipe member 600, thereby capable of forming a plurality of cooling flow paths for cooling the upper and lower parts of the battery cell stack 120. Therefore, not only can the heat generation problem of the battery cells 110 be solved, but also the safety factor of the battery module 100 can be improved.
Next, the sealing part included in the battery module according to another embodiment of the present disclosure will be further described with reference to
In the battery module 100 according to the present embodiment, the length of the sealing part 114sc extending toward the upper part of the module frame 200 (i.e., a vertical length of the sealing part 114sc) is equal to or longer than the length extending along the upper part of the battery cell 110 (i.e., a horizontal length of the sealing part 114sc), and also the sealing part 114sc may have various shapes other than the sealing part 114sc of
In one example, as shown in
In another example, as shown in
In another example, as shown in
The battery cell 110 of the present embodiment can also include other various shapes of the sealing part 114sc. Thus, the battery cell 110 of the present embodiment can increase the degree of heat transfer between the upper part of the sealing part 114sc and the second thermally conductive resin layer 320, and improve the cooling performance of the second thermally conductive resin layer 320 for the battery cell 110.
Next, a battery pack according to yet another embodiment of the present disclosure will be described.
A battery pack according to the present embodiment comprises the above-mentioned battery module. In addition, the battery pack of the present disclosure may have a structure in which one or more of the battery modules according to the present embodiment are gathered, and packed together with a battery management system (BMS) and a cooling device that control and manage battery's temperature, voltage, etc.
The battery pack can be applied to various devices. Such a device can be applied to a vehicle such as an electric bicycle, an electric vehicle, or a hybrid vehicle, but the present disclosure is not limited thereto, and is applicable to various devices that can use a battery module, which is also falls under the scope of the present disclosure.
Although the invention has been illustrated and described above with reference to preferred embodiments thereof, the scope of the present disclosure is not limited to specific embodiments described above, and numerous other modifications can be made by those skilled in the art, without departing from the spirit and scope of the principles of the invention described in the appended claims. Further, these modifications should not be understood individually from the technical spirit or perspective of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0009946 | Jan 2022 | KR | national |
The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2022/019764 filed on Dec. 7, 2022, which claims the benefit of Korean Patent Application No. 10-2022-0009946 filed on Jan. 24, 2022, the entire contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/019764 | 12/7/2022 | WO |