Patent Application
20230080173
This application claims the benefit of Korean Patent Application No. 10-2020-0052250 filed on Apr. 29, 2020 with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
The present disclosure relates to a battery pack and a device including the same, and more particularly to a battery pack having improved safety, and a device 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, rechargeable 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, there is an increasing need for development of the secondary battery.
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 positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate respectively coated with the positive electrode active material and the negative electrode active material are disposed with a separator being interposed between them, and an exterior material, i.e., battery case, which seals and accommodates the electrode assembly together with an electrolyte.
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 embedded in a metal can, and a pouch-type secondary battery in which the electrode assembly is embedded in a pouch of an aluminum laminate sheet.
In the case of a secondary battery used for a small-sized device, two to three battery cells are arranged, but in the case of a secondary battery used for a medium to 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 plurality of battery cells are connected to each other in series or parallel to form a cell stack, thereby improving capacity and output. In addition, one or more battery modules may be mounted together with various control and protection systems such as a battery disconnect unit (BDU), a battery management system (BMS) and a cooling system to form a battery pack.
When a secondary battery rises higher than an appropriate temperature, the secondary battery may undergo performance deterioration, and in the worst case, may explode or catch fire. In particular, in a battery module or a battery pack provided with a plurality of secondary batteries, that is, battery cells, the temperature may rise more quickly and drastically due to buildup of heat emitted from the plurality of battery cells in a small space. In other words, in the case of a battery module in which a plurality of battery cells are stacked and a battery pack equipped with such a battery module, high output can be obtained, but it is not easy to remove heat generated from the battery cells during charging and discharging. If the heat dissipation of the battery cell is not properly performed, the deterioration of the battery cell will be accelerated and the life will be shortened, and the possibility of explosion or ignition will increase.
Moreover, a battery module included in a battery pack for vehicle is often exposed to direct sunlight and to be in a high-temperature condition such as the summer season or a desert region. Therefore, when configuring a battery module or a battery pack, it may be very important to stably and effectively ensure the cooling performance.
Referring to
At this time, in the conventional battery pack 10, the battery module 1 may be composed of two layers, and leakage of the refrigerant may occur from the refrigerant pipe 2 supplying the refrigerant to the battery module 1 located in the upper part. When the leaked refrigerant contacts the HV line 3 or LV line 4 located in the lower part of the refrigerant pipe 2, a short circuit may occur.
Further, in the conventional battery pack 10, since the LV line 4 is located at the edge close to the pack housing (not shown), there is a high possibility that a short circuit occurs when an external impact or vibration occurs
In the case of the short circuit due to refrigerant leakage or external impact, etc., since it can lead to explosion or ignition, it can be said that it is important to develop a battery pack with improved safety while having cooling performance.
An object of the present disclosure is to provide a battery pack having improved safety, and a device 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.
A battery pack according to the present disclosure includes: a plurality of battery modules, each battery module of the plurality of battery modules including a battery cell stack in which a plurality of battery cells are stacked in a first direction, a terminal bus bar connected to the plurality of battery cells, and a sensing assembly for measuring the temperature and voltage of the plurality of battery cells; a pack frame for storing the plurality of battery modules; at least one high voltage (HV) line connected to the terminal bus bar of the plurality of battery modules; at least one low voltage (LV) line connected to the sensing assembly of the plurality of battery modules; and a pack refrigerant pipe for supplying a refrigerant to the plurality of battery modules, wherein the at least one HV line and the at least one at least one LV line are located above the pack refrigerant pipe.
The battery pack may further include a pack refrigerant pipe housing for storing the pack refrigerant pipe.
The battery pack may further include a housing cover for covering an opened upper side of the pack refrigerant tube housing, and the at least one HV line and the at least one LV line may be located above the housing cover.
The plurality of battery modules may include a first battery module and a second battery module facing each other in the first direction.
The battery pack may further include a BDU (battery disconnect unit) module connected to the at least one HV line to control an electrical connection of the plurality of battery modules.
The at least one HV line connected to the BDU module may be located between the first battery module and the second battery module.
The battery pack may further include a BMS (battery management system) module that is connected to the at least one LV line to monitor and control an operation of the plurality of battery modules.
The at least one LV line connected to the BMS module may be located between the first battery module and the second battery module.
The battery pack may further include a module connector for connecting the sensing assembly and the at least one LV line.
The battery module may further include end plates located on open sides of the module frame, wherein an opening may be formed in at least one of the end plates, so that the terminal bus bar and the module connector are exposed, and the first battery module and the second battery module may each be composed of two modules, the two first battery modules being disposed so that the end plates face each other, and the two second battery modules being disposed so that the end plates face each other.
According to the embodiments of the present disclosure, by simplifying the arrangement of the HV and LV lines and arranging them in a stable position, the safety of the battery pack can be improved.
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 implement 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 specification.
Further, in the figures, 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 figures. In the figures, the thickness of layers, regions, etc. are exaggerated for clarity. In the figures, for convenience of description, the thicknesses of some layers and regions are shown to be 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 specification, when a portion is referred to as “including” a certain component, it means that the portion can further include other components, without excluding the other components, unless otherwise stated.
Further, throughout the specification, 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, the battery cell 110 may be a pouch-type battery cell. Such a pouch-type battery cell may be formed by storing an electrode assembly in a pouch case of a laminate sheet including a resin layer and a metal layer, and then heat-sealing the outer periphery of the pouch case. At this time, the battery cell 110 may be formed in a rectangular sheet-like structure.
The battery cells 110 may be composed of a plurality of cells, and the plurality of battery cells 110 are stacked so that they can be electrically connected to each other to form a battery cell stack 120. In particular, as shown in
The module frame 200 for storing the battery cell stack 120 may include an upper cover 220 and a U-shaped frame 210.
The U-shaped frame 210 may include a bottom portion 210a and two side portions 210b extending upward from both end parts of the bottom portion 210a. The bottom portion 210a may cover the lower surface (in the direction opposite to the z-axis) of the battery cell stack 120, and the side portions 210b may cover both side surfaces (the x-axis direction and the direction opposite to the same) of the battery cell stack 120.
The upper cover 220 may be formed in a single plate-shaped structure that wraps the lower surface wrapped by the U-shaped frame 210 and the remaining upper surface (z-axis direction) excluding the both side surfaces. The upper cover 220 and the U-shaped frame 210 can be joined by welding or the like in a state in which the corresponding corner portions are in contact with each other, thereby forming a structure that covers the battery cell stack 120 vertically and horizontally. The battery cell stack 120 may be physically protected via the upper cover 220 and the U-shaped frame 210. For this purpose, the upper cover 220 and the U-shaped frame 210 may include a metal material having a predetermined strength.
Meanwhile, although not specifically shown, the module frame 200 according to the modified embodiment may be a mono frame in the form of a metal plate in which the upper surface, the lower surface, and both sides are integrated. That is, it is not a structure in which the U-shaped frame 210 and the upper cover 220 are combined with each other, but a structure in which the upper surface, the lower surface, and both sides are integrated by being manufactured by extrusion molding.
The end plate 400 may be formed so as to be located on both open sides (y-axis direction and the direction opposite to the same) of the module frame 200 corresponding to each other to cover the battery cell stack 120. The end plate 400 may physically protect the battery cell stack 120 and other electrical equipment from external impact.
The battery module 100 may include a heat sink 300 located below the bottom portion 210a of the module frame 200, wherein a refrigerant may supply to the heat sink 300 via a cooling port 500 and the refrigerant may discharge from the heat sink 300. Specifically, the cooling port 500 may include a refrigerant injection port 500a and a refrigerant discharge port 500b located apart from each other. The pack refrigerant pipe 600 may include a pack refrigerant supply pipe and a pack refrigerant discharge pipe, and the refrigerant injection port 500a and the refrigerant discharge port 500b may be connected to the pack refrigerant supply pipe and the pack refrigerant discharge pipe, respectively.
The module frame 200 according to the present embodiment may include a module frame protrusion 211 formed so that the bottom portion 210a of the module frame 200 extends and passes through the end plate 400. At this time, the refrigerant flown in and discharged by the cooling port 500 connecting to the upper surface of the module frame protrusion 211 can be supplied to a heat sink 300 via the module frame protrusion 211 and discharged from the heat sink 300.
Specifically, the cooling port 500 according to the present embodiment includes a refrigerant injection port 500a for supplying a refrigerant to the heat sink 300 and a refrigerant discharge port 500b for discharging the refrigerant from the heat sink 300, and the refrigerant injection port 500a and the refrigerant discharge port 500b may be respectively connected to a pack refrigerant pipe 600. The module frame protrusion 211 may include a first module frame protrusion and a second module frame protrusion which are located apart from each other on one side of the module frame 200. The refrigerant injection port 500a may be disposed on the first module frame protrusion, and the refrigerant discharge port 500b may be disposed on the second module frame protrusion.
With the configuration as above, the pack refrigerant pipe 600 may supply a refrigerant to the battery module 100 or discharge the refrigerant from the battery module 100.
In the following, the terminal bus bar 710 and the sensing assembly 730 will be described in detail with reference to
Referring to
Specifically, the battery module 100 may include a bus bar frame 700 located in the protruding direction of the electrode lead 111 protruding out from the battery cell 110. A terminal bus bar 710, a bus bar 720, a sensing assembly 730, and a module connector 740 may be mounted on the bus bar frame 700.
The bus bar 720 takes a charge of a function for electrically connecting the battery cells 110 included in the battery cell stack 120. The electrode lead 111 of the battery cell 110 may be curved after passing through a slit formed in the bus bar frame 700, and connected with the bus bar 720. Accordingly, the battery cells 110 may be connected in series or in parallel.
The terminal bus bar 710 is connected with the electrode lead 111 of the battery cell 110, one end of which is exposed to the outside of the battery module 100, and thus, it can take a charge of a function for connecting the battery cell 110 electrically connected via the bus bar 720 to the outside. The terminal bus bar 710 may be connected to an HV line 800 described later to be electrically connected to another battery module 100 or connected to a battery disconnect unit (BDU) module.
The connection method of the electrode lead 111 and the bus bar 720 or the connection method of the electrode lead 111 and the terminal bus bar 710 are not particularly limited, and a method such as welding may be applied.
The sensing assembly 730 can include sensors to measure the temperature or voltage of the battery cell 110.
In the following, the HV line 800 and the LV line 900 will be described in detail with reference to
Referring to
Each battery modules 100 may be electrically connected to each other via an HV line 800, and finally connected to the BDU module 1200 via the HV line 800. The BDU module 1200 is a module that is disposed between the battery module 100 and an inverter, and includes a relay, a resistor, and the like. The BDU module 1200 plays a role of stably supplying or breaking battery power to a power system of a vehicle, and thus protecting the power system of the vehicle when a fault current occurs.
Each battery module 100 is connected to the BMS module 1300 via a LV line 900, so that the measured temperature or voltage data of the battery cell 110 inside the battery module 100 may be transmitted to the BMS module 1300. The BMS module 1300 plays a role of managing the temperature or voltage of each battery module 100 based on the measured temperature or voltage data. Meanwhile, in
At this time, as shown in
Further, the battery pack 1000 according to the present embodiment may further include a pack refrigerant pipe housing 610 for storing the pack refrigerant pipe 600 and a housing cover 620 for covering the opened upper side of the pack refrigerant pipe housing 610. The pack refrigerant pipe housing 610 and the housing cover 620 may be connected along the pack refrigerant pipe 600. The refrigerant leaked from the pack refrigerant pipe 600 may penetrate into the inside of plural components constituting the battery pack 1000 to cause a fire or explosion. The pack refrigerant pipe housing 610 and the housing cover 620 according to the present embodiment are connected along the pack refrigerant pipe 600, and it is possible to prevent the leaked refrigerant from penetrating into the inside of other components.
Meanwhile, as described above, in the conventional battery pack 10 shown in
Referring back to
Further, the HV line 800 connected to the BDU module 1200 may be disposed between the first battery module 100a and the second battery module 100b, and the LV line 900 connected to the BMS module 1300 may be disposed between the first battery module 100a and the second battery module 100b. That is, the HV line 800 and the LV line 900 are located in the center of the plurality of battery modules 100 so that they are not greatly affected by external shocks or the like. Therefore, the possibility of occurrence of a short circuit with respect to the HV line 800 and the LV line 900 can be reduced, and the insulation performance and safety of the battery pack 1000 can be improved.
Meanwhile, referring again to
Specifically, the heat sink 300 is formed under the module frame 200, and the heat sink 300 may include a lower plate 310 which forms the framework of the heat sink 300 and is directly joined to the bottom portion 210a of the module frame 200 by welding or the like, and a recessed portion 340 which is a path through which the refrigerant flows. Further, the heat sink 300 may include a heat sink protrusion 300P which protrudes from one side of the heat sink 300 to a portion where the module frame protrusion 211 is located.
The heat sink protrusion 300P and the module frame protrusion 211 may be directly joined to each other by welding or the like.
The recessed portion 340 of the heat sink 300 corresponds to a portion in which the lower plate 310 is recessed and formed on the lower side. The recessed portion 340 may have a structure in which a cross section cut perpendicularly to the xz plane or yz plane with respect to the direction in which the refrigerant flow path extends is a U-shaped tube and the bottom portion 210a may be located on the opened upper side of the U-shaped tube. While the heat sink 300 is in contact with the bottom portion 210a, the space between the recessed portion 340 and the bottom portion 210a becomes a region through which the refrigerant flows, that is, a refrigerant flow path. Therefore, the bottom portion 210a of the module frame 200 may come into direct contact with the refrigerant.
The method of manufacturing the recessed portion 340 of the heat sink 300 is not particularly limited, but by providing a structure formed by being recessed with respect to a plate-shaped heat sink 300, a U-shaped recessed portion 340 with an opened upper side may be formed.
The recessed portion 340 may be connected from one of the heat sink protrusions 300P to the other. The refrigerant supplied through the refrigerant injection port 500a passes between the first module frame protrusion and the heat sink protrusion 300P, and is first flown in the space between the recessed portion 340 and the bottom portion 210a. Thereafter, the refrigerant moves along the recessed portion 340, passes between the second module frame protrusion and the heat sink protrusion 300P, and is discharged through the refrigerant discharge port 500b.
Meanwhile, although not shown, a thermally conductive resin layer containing a thermally conductive resin may be located between the bottom portion 210a of the module frame 200 and the battery cell stack 120 in
The thermally conductive resin may include a thermally conductive adhesive material, and specifically, may include at least one of a silicone material, a urethan material, and an acrylic material. The thermally conductive resin is a liquid during application but is cured after application, and thus, can perform the role of fixing one or more battery cells 110 constituting the battery cell stack 120. Further, since the thermally conductive resin has excellent thermal conductivity properties, heat generated from the battery cell 110 can be quickly transferred to the lower side of the battery module.
The battery module 100 according to the present embodiment implements an integrated cooling structure of the module frame 200 and the heat sink 300 to further improve cooling performance. Since the bottom portion 210a of the module frame 200 plays a role of corresponding to the upper plate of the heat sink 300, the integrated cooling structure can be implemented. The cooling efficiency due to direct cooling is increased, and through a structure in which the heat sink 300 is integrated with the bottom portion 210a of the module frame 200, it is possible to further improve the space utilization rate on the battery module 100 and the battery pack 1000 in which the battery module 100 is mounted
Specifically, the heat generated from the battery cell 110 can be transferred to the outside of the battery module 100 through a thermally conductive resin layer (not shown) located between the battery cell stack 120 and the bottom portion 210a, the bottom portion 210a of the module frame 200, and the refrigerant. By removing the conventional unnecessary cooling structure, the heat transfer path can be simplified and the air gap between respective layers can be reduced, so that the cooling efficiency or performance can be enhanced. In particular, since the bottom portion 210a is composed of an upper plate of the heat sink 300 and the bottom portion 210a comes into direct contact with the refrigerant, there is an advantage that more direct cooling through the refrigerant can be performed.
Further, the height of the battery module 100 is reduced through the removal of the unnecessary cooling structure, so that cost can be reduced and space utilization rate can be increased. Furthermore, since the battery module 100 may be disposed in a compact manner, the capacity or output of the battery pack 1000 including a plurality of battery modules 100 may be increased.
Meanwhile, the bottom portion 210a of the module frame 200 may be weld-joined to a portion of the lower plate 310 of the heat sink 300 in which the recessed portion 340 is not formed. Since the present embodiment has the integrated cooling structure of the bottom portion 210a of the module frame 200 and the heat sink 300, it has the effect of not only improving the cooling performance described above, but also supporting the load of the battery cell stack 120 hosed in the module frame 200 and reinforcing the rigidity of the battery module 100. In addition, the lower plate 310 and the bottom portion 210a of the module frame 200 are sealed through welding, etc., so that the refrigerant can flow without leakage in the recessed portion 340 formed inside the lower plate 310.
For effective cooling, as shown in
A protruding pattern 340D may be formed in the recessed portion 340 of the heat sink 300 according to the present embodiment.
In the case of a large-area battery module in which the number of stacked battery cells is increased significantly compared to the conventional case, such as the battery cell stack 120 according to the present embodiment, the width of the refrigerant flow path may be formed wider, the temperature deviation may be more severe. In the large-area battery module, it may include a case in which approximately 32 to 48 battery cells are stacked in one battery module compared to a case in which approximately 12 to 24 battery cells are stacked in one battery module in the past. In this case, since the protrusion pattern 340D according to the present embodiment may have the effect of substantially reducing the width of the cooling passage, the pressure drop can be minimized, and at the same time, the temperature deviation between the widths of the refrigerant flow path can be reduced. Therefore, a uniform cooling effect can be realized.
Meanwhile, the refrigerant is a medium for cooling, and is not particularly limited, but may be cooling water.
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 the present embodiment, but the terms used are provided simply for convenience of description and may become different according to the location of an object or an observer.
The battery module or the battery pack can be applied to various devices. For example, it can be applied to transportation 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.
100: battery module
600: pack refrigerant pipe
710: terminal bus bar
730: sensing assembly
800: HV line
900: LV line
1200: BDU module
1300: BMS module
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0052250 | Apr 2020 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2021/004398 | 4/8/2021 | WO |
