This application claims the benefit of Korean Patent Application No. 10-2021-0005832 filed on Jan. 15, 2021 with the Korean Intellectual Property Office, the content of which is incorporated herein by reference in its entirety.
The present disclosure relates to a battery module and a battery pack including the same, and more particularly, to a battery module having enhanced safety and a battery pack including the same.
In modern society, as portable devices such as a mobile phone, a notebook computer, a camcorder and a digital camera has been daily used, the development of technologies in the fields related to mobile devices as described above has been activated. In addition, chargeable/dischargeable secondary batteries are used as a power source for an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (P-HEV) and the like, in an attempt to solve air pollution and the like caused by existing gasoline vehicles using fossil fuel. Therefore, the demand for development of the secondary battery is growing.
Currently commercialized secondary batteries include a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, and a lithium secondary battery. Among them, the lithium secondary battery has come into the spotlight because they have advantages, for example, hardly exhibiting memory effects compared to nickel-based secondary batteries and thus being freely charged and discharged, and having very low self-discharge rate and high energy density.
Such lithium secondary battery mainly uses a lithium-based oxide and a carbonaceous material as a cathode active material and an anode active material, respectively. The lithium secondary battery includes an electrode assembly in which a cathode plate and an anode plate, each being coated with the cathode active material and the anode active material, are arranged with a separator being interposed between them, and a battery case which seals and houses the electrode assembly together with an electrolytic solution.
Generally, the lithium secondary battery may be classified based on the shape of the exterior material into a can-type secondary battery in which the electrode assembly is mounted in a metal can, and a pouch-type secondary battery in which the electrode assembly is mounted in a pouch of an aluminum laminate sheet.
In the case of a secondary battery used for small-sized devices, two to three battery cells are arranged, but in the case of a secondary battery used for a middle- or large-sized device such as an automobile, a battery module in which a large number of battery cells are electrically connected is used. In such a battery module, a large number of battery cells are connected to each other in series or parallel to form a cell assembly, thereby improving capacity and output. One or more battery modules can be mounted together with various control and protection systems such as a BDU (battery disconnect unit), a BMS (battery management system) and a cooling system to form a battery pack.
Referring to
Referring to
When physical, thermal or electrical damage including overcharging occurs to the battery cell, the internal pressure of the battery cell 11 increases and exceeds a limit value of the fusion strength of the battery cell 11. In this case, the high-temperature heat, gas, and flame generated in the battery cell 11 can be discharged to the outside of the battery cell 11.
At this time, the high-temperature heat, gas and flame may be discharged through the openings 41H and 42H formed in the end plate 40. However, in the battery pack structure in which a plurality of battery modules 10 are arranged so that the end plates 40 face each other, the high-temperature heat, gas and flame ejected from the battery module 10 may affect the adjacent battery module 10. Thereby, the terminal busbar or the like formed on the end plate 40 of the adjacent battery module may be damaged, and high-temperature heat, gas and flame may enter the interior of the battery module 10 via the openings formed in the adjacent end plates 40 of the battery module 10 to damage other electrical components including the plurality of battery cells 11. In addition, this leads to heat propagation of the adjacent battery modules 10, which cause a chain ignition in the battery pack.
Therefore, there is a need to develop a technology capable of controlling high-temperature flames so that the influence on the adjacent battery module can be minimized when thermal propagation occurs in the battery module.
It is an object of the present disclosure to provide a battery module capable of controlling the discharge of a flame when an ignition phenomenon occurs in the battery module, and a battery pack including the same.
However, the problem to be solved by embodiments of the present disclosure is not limited to the above-described problems, and can be variously expanded within the scope of the technical idea included in the present disclosure.
According to one aspect of the present disclosure, there is provided a battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; and a module frame for housing the battery cell stack, wherein a vent is formed on at least one surface of the module frame, wherein the vent comprises a plurality of stacked layers, and wherein micropores are formed in each of the plurality of layers.
The plurality of layers may include a first layer and a second layer stacked in a first direction. The micropores formed in the first layer and the micropores formed in the second layer may be offset from each other in a second direction.
The plurality of layers may include a first layer and a second layer. A size of the micropores formed in the first layer and a size of the micropores formed in the second layer may be different from each other.
A diameter of the micropores formed in the first layer may be different from a diameter of the micropores formed in the second layer.
The plurality of layers may include a first layer and a second layer. The micropores formed in the first layer and the micropores formed in the second layer may be different from each other. The plurality of layers may include a first layer and a second layer. A density of the micropores formed in the first layer may be different than a density of the micropores formed in the second layer.
The plurality of layers may include a first layer and a second layer. A micropore group in which the micropores are gathered may be formed in each of the first layer and the second layer, and an arrangement form formed by the micropore group of the first layer may be different from an arrangement form formed by the micropore group of the second layer.
The plurality of layers may be metal sheets.
The plurality of layers may be press-fitted at high temperature and high pressure to form the vent.
The module frame may include a ceiling, a bottom and side surface covering an upper surface, a lower surface and side surfaces of the battery cell stack, respectively. At least one of the ceiling, the bottom and the side surfaces may include the vent.
The battery module may further include a first end plate and a second end plate that cover a front surface and a rear surface of the battery cell stack, respectively. At least one of a terminal busbar opening through which a terminal busbar is exposed and a module connector opening through which a module connector is exposed may be formed in at least one of the first end plate and the second end plate.
The plurality of layers may be arranged apart from each other at a predetermined interval.
The module frame may include an upper frame and a lower frame, and the upper frame and the lower frame may be joined by a method in which edges corresponding to each other are welded.
The plurality of layers mat be a first layer and a second layer. The micropores formed in the first layer may have a different shape than the micropores formed in the second layer.
The plurality of layers may be a first layer and a second layer. The micropores formed in the first layer may be formed in a first pattern and the micropores formed in the second layer may be formed in a second pattern different than the first pattern.
According to embodiments of the present disclosure, a plurality of layers in which micropores are formed are configured in a venting structure, and when an ignition phenomenon occurs in the battery module, the high-temperature gas can be quickly discharged to the outside, and the high-temperature flame can be suppressed. Thereby, it is possible to prevent a flame from being applied to the battery module that is adjacent to the battery module in which the ignition phenomenon has occurred, thereby minimizing the damage.
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 carry out 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 some layers and regions are exaggerated.
In addition, 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, the word “on” or “above” means disposed on or below a reference portion, and does not necessarily mean being disposed on the upper end of the reference portion toward the 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 referred to as “planar”, it means when a target portion is viewed from the upper side, and when referred to as “cross-sectional”, it means when a target portion is viewed from the side of a cross section cut vertically.
Referring to
First, referring to
Meanwhile, the battery cell 110 can be manufactured by joining both end parts 114a and 114b of the cell case 114 and one side part 114c connecting them, in a state in which the 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, the sealing parts 114sa, 114sb and 114sc have a structure sealed by a method such as heat fusion, and the remaining other side part may be formed of a connection part 115. The cell case 114 may be formed of a laminated sheet containing a resin layer and a metal layer.
In addition, the connection part 115 may extend long along one edge of the battery cell 110, and a protrusion part 110p of the battery cell 110 called a bat-ear may be formed at an end part of the connection 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 includes a terrace part 116 formed to extend from the cell case 114 in a protruding direction of the electrode leads 111 and 112.
The battery cell 110 may be composed by a plurality of numbers, and the plurality of battery cells 110 may be stacked so as to be electrically connected to each other, thereby forming a battery cell stack 120. Referring to
Meanwhile, the module frame 200 can be opened in the protruding direction of the electrode leads 111 and 112 (x-axis direction, −x-axis direction), and a first end plate 410 and a second end plate 420 may be located on opened both sides of the module frame 200, respectively. The first end plate 410 can be joined to the module frame 200 while covering the first busbar frame 310, and the second end plate 420 can be joined to the module frame 200 while covering the second busbar frame (not shown). That is, a first busbar frame 310 may be located between the first end plate 410 and the battery cell stack 120, and a second busbar frame (not shown) may be located between the second end plate 420 and the battery cell stack 120. Further, an insulating cover 800 (see
The first end plate 410 and the second end plate 420 are located so as to cover the one surface and the other surface of the battery cell stack 120, respectively. The first end plate 410 and the second end plate 420 can protect the first busbar frame 310 and various electrical components connected thereto from external impacts. For this purpose, they must have a predetermined strength and may include a metal such as aluminum. Further, the first end plate 410 and the second end plate 420 may be joined to a corresponding edge of the module frame 200 by a method such as welding, respectively.
The first busbar frame 310 can be located on one surface of the battery cell stack 120 to cover the battery cell stack 120 and at the same time, guide the connection between the battery cell stack 120 and external devices. Specifically, at least one of a busbar, a terminal busbar, and a module connector may be mounted onto the first busbar frame 310. Particularly, at least one of a busbar, a terminal busbar, and a module connector may be mounted onto a surface opposite to the surface of the first busbar frame 310 facing the battery cell stack. As an example,
The electrode lead 111 of the battery cells 110 is bent after passing through a slit formed in the first busbar frame 310 and can be joined to the busbar 510 or the terminal busbar 520. The battery cells 110 constituting the battery cell stack 120 may be connected in series or in parallel by the busbar 510 or the terminal busbar 520. Further, the battery cells 110 can be electrically connected to an external device or circuit through the terminal busbar 520 exposed to the outside of the battery module 100.
The first busbar frame 310 may include an electrically insulating material. The first busbar frame 310 restricts the busbar 510 or the terminal busbar 520 from making contact with the battery cells 110, except for the portion where the busbar 510 or the terminal busbar 520 is joined to the electrode leads 111, thereby preventing the occurrence of a short circuit.
Meanwhile, as described above, the second busbar frame may be located on the other surface of the battery cell stack 120, and at least one of the busbar, terminal busbar, and module connector may be mounted onto the second busbar frame. An electrode lead 112 can be joined to such a busbar.
An opening in which at least one of the terminal busbar and the module connector is exposed can be formed in the first end plate 410 according to the present embodiment. The opening may be a terminal busbar opening or a module connector opening. In one example, as shown in
Referring to
The first end plate 410 and the second end plate 420 shown in
Next, a venting part according to an embodiment of the present disclosure will be described in detail with reference to
Referring to
The module frame 200 may include a ceiling part 201, a bottom part 202, and both side surface parts 203. Here, the ceiling part 201 means a surface in the z-axis direction that covers the upper surface of the battery cell stack 120, the bottom part 202 means a surface in the −z-axis direction that covers the lower surface of the battery cell stack 120, and the both side surface parts 203 refer to surfaces in the y-axis and −y-axis directions each covering both side surfaces of the battery cell stack 120.
In
Such a venting part 200V includes a plurality of layers 200L, and micropores 210H and 220H are formed in each of the plurality of layers 200L. That is, in the present embodiment, the venting part 200V may refer to one surface of the module frame 200 including the plurality of layers 200L in which the micropores 210H and 220H are formed.
More specifically, the plurality of layers 200L may include a first layer 210 and a second layer 220, and micropores 210H and 220H may be formed in each of the first layer 210 and the second layer 220. For convenience of explanation, only two layers of the first layer 210 and the second layer 220 are shown, but additional layers such as a third layer and a fourth layer may be included as needed. Meanwhile, the number of micropores 210H and 220H formed in each of the plurality of layers 200L is not particularly limited, and can vary depending on the size and density of the micropores 210H and 220H described later.
The plurality of layers 200L may be a metal sheet in which micropores 210H and 220H are formed, and the plurality of layers 200L may be press-fitted at high temperature and high pressure to form a venting part 200V.
As described above, when a high-temperature gas or flame is generated from the battery cell 110, a high-temperature gas or flame is immediately discharged through the terminal busbar opening 410H or the module connector opening 420H, which may damage adjacent battery modules. In particular, if the flame is discharged directly, the flame may also spread to adjacent battery modules, which may lead to a chain ignition and explosion.
Thus, micropores 210H and 220H are formed in the venting part 200V according to the present embodiment, which makes it possible to prevent the high-temperature flame from being directly discharged while the high-temperature gas is rapidly discharged to the outside. That is, the plurality of micropores 210H and 220H can play a role like a kind of mesh screen and suppress the flame from being discharged to the outside. Further, since the micropores 210H and 220H having a fine size are formed rather than a simple through hole, the effect of increasing the heat transfer area of the module frame 200 can be obtained. That is, the amount of gas discharged can be increased, and the rate of temperature rise in the battery module 100 due to heat dissipation to the outside of the battery module 100 can be reduced.
Further, in the venting part 200V according to the present embodiment, the first layer 210 and the second layer 220 in which the micropores 210H and 220H are formed are composed of a plurality of layers rather than a single layer. Each time the flame generated inside passes through each of the plurality of layers 200L, the flame intensity may be lowered by heat dissipation. That is, the venting part 200V according to the present embodiment can have a flame extinguishing function that effectively suppresses the flame without deteriorating the gas discharge function.
Further, as the plurality of layers 200L are arranged apart from each other at a predetermined interval, it is possible to reduce the frequency at which sparks inside the battery module 100 are directly exposed to the outside. Therefore, it is possible to prevent the heat and flame between the battery modules 100 from being transferred in the battery pack or device.
Further, since it is composed of a plurality of layers rather than a single layer, the path through which the flame is discharged can be set more complicatedly. As the flame discharge path becomes complicated, it is possible to effectively block the flame with a strong straight advancing tendency, and the flame intensity may be lowered every time it passes through each of the plurality of layers 200L. That is, the venting part 200V according to the present embodiment can have a further enhanced flame extinguishing function.
Meanwhile, in
Next, a venting part according to modified embodiments of the present disclosure will be described.
Referring to
Specifically, the plurality of layers 200La may include a first layer 210a and a second layer 220a. At this time, in a state in which the first layer 210a and the second layer 220a are stacked, the micropores 210Ha formed in the first layer 210a and the micropores 220Ha formed in the second layer 220a may be arranged so as to be displaced from each other. As shown
In this manner, by setting the micropores formed in each layer to be displaced from each other based on the state in which the layers are stacked, the path through which the flame is discharged can be set more complicatedly. In particular, considering the nature of flames or sparks that have a strong straight advancing tendency and burst out instantaneously, the path formed by the micropores is implemented so as not to be in a straight line, an attempt was made to effectively regulate the discharge of flames instead of having an effect on gas discharge. The venting part 200Va according to the present embodiment can have a further enhanced flame extinguishing function.
Referring to
Specifically, the plurality of layers 200Lb may include a first layer 210b and a second layer 220b, and the size of the micropores 210Hb formed in the first layer 210b and the size of the micropores 220Hb formed in the second layer 220b may be different from each other. As an example, the micropores 210Hb formed in the first layer 210b and the micropores 220Hb formed in the second layer 220b may be circular micropores as in the micropores 210H and 220H of
In this manner, by setting the micropores formed in each layer to have different sizes, the path through which the flame can be set more complicatedly. As the flame discharge path becomes more complex, it is possible to effectively block a flame with a strong straight advancing tendency, the venting part 200Vb according to the present embodiment can have a further enhanced flame extinguishing function.
Referring to
Specifically, the plurality of layers 200Lc may include a first layer 210c and a second layer 220c, and the micropores 210Hc formed in the first layer 210c and the micropores 220Hc formed in the second layer 220c may have different shapes. As an example, the micropores 210Hc formed in the first layer 210c may be circular, and the micropores 220Hc formed in the second layer 220c may be rectangular.
In this manner, by setting the micropores formed in each layer to have different shapes, the path through which the flame is discharged can be set more complicatedly. As the flame discharge path becomes complicated, it is possible to effectively block a flame with a strong straight advancing tendency. The venting part 200Vc according to the present embodiment may have a further increased flame-extinguishing function.
Referring to
Specifically, the plurality of layers 200Ld may include a first layer 210d and a second layer 220d, and the density of the micropores 210Hd formed in the first layer 210d and the density of the micropores 220Hd formed in the second layer 220d may be different from each other. As an example, when the first layer 210d is located outside the second layer 220d in the battery module as shown in
By setting the density of micropores formed in each layer to be different from each other in this way, the path through which the flame is discharged can be set more complicatedly. As the flame discharge path is more complicated, it is possible to effectively block a flame with a strong straight advancing tendency. The venting part 200Vd according to the present embodiment may have a further increased flame-extinguishing function.
Referring to
Specifically, the plurality of layers 200Le may include a first layer 210e and a second layer 220e, wherein an arrangement form formed by the micropore groups 210Ge and 210Ge′ of the first layer 210e may be different from an arrangement form formed by the micropore group 220Ge of the second layer 220e. As an example, the first layer 210e may have a form in which a rectangular micropore group 210Ge and an atypical micropore group 210Ge′ are combined, but the second layer 220e may be in the form of combining only the rectangular micropore group 220Ge. However, this is an exemplary structure, and various arrangement forms are possible when only the arrangement form of the micropore group between the layers is different.
In this manner, by setting the arrangement form of the micropore group formed by the micropores formed in each layer to be different from each other, the path through which the flame is discharged can be set more complicatedly. As the flame discharge path becomes complicated, it is possible to effectively block a flame with a strong straight advancing tendency. The venting part 200Ve according to the present embodiment may have a further enhanced flame extinguishing function.
Next, a module frame according to embodiments of the present disclosure will be described in detail with reference to
First,
Referring to
The upper frame 200U and the lower frame 200D are joined by a method in which the edges corresponding to each other are welded, so that the module frame 200 in which the venting part 200V is formed in the ceiling part 201 as shown in
Referring to
The upper frame (200U) and the lower frame (200D) are joined by a method in which the edges corresponding to each other are welded, so that a module frame 200′ in which venting parts 200V are formed on both side surfaces can be manufactured.
Although it is not specifically illustrated, the module frame in which the venting part 200V is formed at the bottom part can also be manufactured in a similar manner.
The terms representing directions such as the front side, the rear side, the left side, the right side, the upper side, and the lower side have been used in embodiments of the present disclosure, but the terms used are provided simply for convenience of description and may become different according to the position of an object, the position of an observer, or the like.
The one or more battery modules according to embodiments of the present disclosure described above can 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.
The battery module or the battery pack can be applied to various devices. For example, it can be applied to vehicle means such as an electric bike, an electric vehicle, and a hybrid electric vehicle, and may be applied to various devices capable of using a secondary battery, without being limited thereto.
The present disclosure has been described in detail with reference to exemplary embodiments thereof, but the scope of the present disclosure is not limited thereto and modifications and improvements made by those skilled in the part by using the basic concept of the present disclosure, which are defined in the following claims, also belong to the scope of the present disclosure.
Number | Date | Country | Kind |
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10-2021-0005832 | Jan 2021 | KR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/KR2022/000253 | 1/6/2022 | WO |