The present disclosure relates to a battery module and a battery pack including the same, and a manufacturing method of the same, and more particularly, to a battery module having improved productivity, a battery pack including the same, and a manufacturing method of the same.
In modern society, as portable devices such as a mobile phone, a notebook computer, a camcorder and a digital camera is used daily, 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, there is a growing 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, exhibiting low 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 a 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, each being coated with the positive electrode active material and the negative electrode 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 electrolyte 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 built into a metal can, and a pouch-type secondary battery in which the electrode assembly is built into a pouch of an aluminum laminate sheet.
Two to three battery cells are arranged in secondary batteries used for small-sized devices, but in the case of a secondary battery used for a medium- 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. In addition, 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.
As illustrated in
The battery cell stack 20 is formed by stacking a plurality of battery cells 11 in one direction, so that the electrode lead 11L can protrude in a direction perpendicular to the one direction in which the battery cells 11 are stacked.
The housing 30 may be made of a material having a predetermined strength to protect the battery cell stack 20 from external impacts, and the like, and is structurally formed by connecting the upper frame 31 and the lower frame 32. The corresponding edges of the upper frame 31 and the lower frame 32 may be welded together.
Each of the end plates 40 may be located in the protruding direction of the electrode lead 11L with respect to the battery cell stack 20, and each of a pair of busbar frames 50 may be located between the battery cell stack 20 and the respective end plate 40. Corresponding corners of the housing he 30 and each of the end plates 40 can be welded to each other.
As illustrated in
Meanwhile, it is necessary to measure the voltage information and temperature information of the battery cell and transmit it to the BMS (Battery Management System) to prevent ignition or explosion of the battery module 10. The conventional battery module 10 includes a low voltage (LV) sensing assembly 60 and thus, can transmit voltage information of a battery cell to the BMS. Specifically, the LV sensing assembly 60 is connected to the busbar 51 via a joining member 61 to measure the voltage of each battery cell, and the measured value can be transmitted to an external BMS via a connector. That is, the conventional battery module 10 can implement a low voltage (LV) connection by transmitting voltage information via the busbar 51 and the LV sensing assembly 60. Here, the LV connection means a sensing connection for sensing and controlling the voltage of the battery cell.
Taken together, the conventional battery module 10 joins the electrode leads 11L of each stacked battery cell to the busbar 51 to realize an HV connection, and the LV sensing assembly 60 can be connected to the busbar 51 to which the electrode lead 11L is joined to realize an LV connection. Further, the busbar frame 50 can be formed to mount such a busbar 51 .
However, the battery module 10 requires many parts to realize such an HV connection and an LV connection, and has a drawback that a complicated series of manufacturing processes is required.
It is an objective of the present disclosure to provide a battery module having improved productivity by improving the conventional HV connection structure and LV connection structure, a battery pack including the same and a manufacturing method of the same.
However, the problem to be solved by the 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 embodiment of the present disclosure, there is provided a battery module comprising: a battery cell stack in which a plurality of battery cells including electrode leads are stacked; a first sensing block and a second sensing block that cover the front surface and the rear surface of the battery cell stack in which the electrode leads protrude, respectively; and an elastic member that covers both side surfaces of the first sensing block, the second sensing block, and the battery cell stack, wherein at least two of the electrode leads is bent and joined after passing through a slit in the first sensing block or a slit in the second sensing block to form an electrode lead assembly, and wherein the elastic member covers the electrode lead assembly.
The elastic member may be continuously connected along both side surfaces of the first sensing block, the second sensing block, and the battery cell stack.
The upper surface and the lower surface of the battery cell stack may be exposed.
The battery module may include an LV (Low Voltage) sensing assembly for transmitting voltage information of the battery cell, wherein the LV sensing assembly may be located in at least one of the first sensing block and the second sensing block.
The LV sensing assembly may be connected to the electrode lead assembly.
The LV sensing assembly may include an LV connector; a connection member that connects the LV connector and the electrode lead assembly; and a joining plate located at one end of the connection member and joined to the electrode lead assembly.
The connection member may be a flexible printed circuit board (FPCB) or a flexible flat cable (FFC).
According to another embodiment of the present disclosure, there is provided a battery pack comprising: the above-mentioned battery module; a housing that houses the battery module; and a thermal conductive resin layer that is located between the battery module and the bottom part of the housing, wherein the elastic member is opened in its lower part, so that the lower surface of the battery cell stack is exposed.
The lower surface of the battery cell stack may be in contact with the thermal conductive resin layer.
According to yet another embodiment of the present disclosure, there is provided a method for manufacturing a battery module, the method comprising the steps of: stacking a plurality of battery cells including electrode leads to manufacture a battery cell stack; arranging a first sensing block and a second sensing block to cover the front surface and the rear surface of the battery cell stack in which the electrode leads protrude, respectively; passing the electrode lead via a slit in the first sensing block or a slit in the second sensing block and then joining at least two of the electrode leads to each other to form an electrode lead assembly; and arranging an elastic member to cover both side surfaces of the first sensing block, the second sensing block, and the battery cell stack, wherein the elastic member covers the electrode lead assembly.
The elastic member may be continuously connected along both side surfaces of the first sensing block, the second sensing block, and the battery cell stack.
An LV (Low Voltage) sensing assembly for transmitting voltage information of the battery cell may be located in at least one of the first sensing block and the second sensing block.
The method for manufacturing a battery module may further include a step of connecting the LV sensing assembly and the electrode lead assembly.
The LV sensing assembly may include an LV connector; a connection member that connects the LV connector and the electrode lead assembly; and a joining plate located at one end of the connection member and joined to the electrode lead assembly, and in the step of connecting the LV sensing assembly and the electrode lead assembly, the joining plate may be joined to the electrode lead assembly.
According to embodiments of the present disclosure, the joint between the electrode leads and the joint between the electrode leads and the LV sensing assembly are integrally formed, instead of removing the conventional busbar, so that the HV connection and the LV connection can be performed at the same time, and thus, productivity improvement can be expected.
Additionally, since the use of busbars is unnecessary, there is an advantage that the weight of the battery module is reduced and the manufacturing unit price is lowered.
Further, the HV connection and LV connection are performed on the sensing block, wherein by arranging an elastic member covering the sensing block, protection and fixation of the sensing block becomes possible.
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 the embodiments. 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 arranged on or below a reference portion, and does not necessarily mean being arranged 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.
As illustrated in
First, the battery cell 110 is preferably a pouch-type battery cell, and can be formed in a rectangular sheet-like structure. The battery cell 110 according to the present embodiment includes protruding first and second electrode leads 111 and 112. Specifically, the battery cell 110 according to the present embodiment has a structure in which first and second electrode leads 111 and 112 face each other with respect to the cell main body 113 and protrude from one end part 114a and the other end part 114b, respectively. More specifically, the first and second electrode leads 111 and 112 are connected to an electrode assembly (not shown), and protrude from the electrode assembly (not shown) to the outside of the battery cell 110. The first and second electrode leads 111 and 112 have different polarities from each other, and as an example, one of them may be a cathode lead 111, and the other one may be the anode lead 112. That is, the cathode lead 111 and the anode lead 112 may protrude in mutually opposite directions with respect to one battery cell 110.
Meanwhile, the battery cell 110 can be produced by joining both end parts 114a and 114b of a cell case 114 and one side part 114c and connecting them in a state in which 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, wherein the sealing parts have a structure that is sealed by a method such as heat-sealing, and the remaining other side part may be composed of a connection part 115. The cell case 114 may be composed of a laminated sheet including a resin layer and a metal layer.
A plurality of battery cells 110 may be included, and the plurality of battery cells 110 can be stacked to be electrically connected to each other, thereby forming a battery cell stack 200. Particularly, as shown in
Next, the first sensing block and the second sensing block according to the present embodiment will be described in detail with reference to
As illustrated in
The first sensing block 410 and the second sensing block 420 may include a material having electrical insulation, and as an example, it may include a plastic material, a polymer material, or a composite material. Further, the first sensing block 410 and the second sensing block 420 may have a kind of basket shape, and can be configured to cover the front surface and the rear surface of the battery cell stack 200, respectively.
In the following, in order to avoid repetition of the description, the first sensing block 410 shown in
As described above, electrode leads 111 and 112 may be located on the front surface and the rear surface of the battery cell stack 200. A slit 410S may be formed in the first sensing block 410, and the first sensing block 410 is arranged such that the electrode leads 111 and 112 can pass through the slit 410S. After passing through the slit 410S, at least two electrode leads 111 and 112 may be bent and joined to form an electrode lead assembly 110L. Similarly, a slit is formed in the second sensing block 420, and the electrode lead passes through the slit and then is bent to form an electrode lead assembly.
More specifically, the electrode leads 111 and 112 protruding in the same direction with respect to the adjacent battery cells 110 are bent in a direction perpendicular to the protruding direction of the electrode leads 111 and 112, and are joined to each other to form an electrode lead assembly 110L. Thereby, one surface of the electrode lead assembly 110L may be perpendicular to a direction (y-axis direction) in which the electrode leads 111 and 112 protrude from the battery cell 110. In this case, electrode leads having the same polarity may be joined to each other, or electrode leads having different polarities may be joined to each other. In other words, electrode leads having the same polarity may be joined to each other to realize a parallel connection between the battery cells 110, and electrode leads having different polarities may be joined to each other to realize a series connection between the battery cells 110. This can vary depending on the design of the battery module.
The electrode leads 111 and 112 of the battery cell 110 located outside the battery cell stack 200 may be connected to the terminal busbar 500. Unlike the conventional battery module 10 (see
The battery module 100 according to the present embodiment may include a low voltage (LV) sensing assembly 900 for transmitting voltage information of a battery cell. The LV sensing assembly 900 may be located in at least one of the first sensing block 410 and the second sensing block 420. Specifically, the LV sensing assembly 900 can be located on the opposite side of a surface facing the battery cell stack 200 among the first sensing block 410. Similarly, although not specifically shown in the figure, the LV sensing assembly 900 can be located on the opposite side of a surface facing the battery cell stack 200 among the second sensing block 420.
The LV sensing assembly 900 is for a low voltage (LV) connection, wherein the LV connection means a sensing connection for sensing and controlling a voltage of a battery cell. Voltage information and temperature information of the battery cell 110 can be transmitted to an external BMS (Battery Management System) via the LV sensing assembly 900. Such LV sensing assembly 900 can be connected to the electrode lead assembly 110L.
The LV sensing assembly 900 may include an LV connector 910, a connection member 920 for connecting the LV connector 910 and the electrode lead joined body 110L, and a joining plate 930 located at one end of the connection member 920 and joined to the electrode lead joined body 110L.
The LV connector 910 can be configured to transmit and receive signals to and from an external control device to control the plurality of battery cells 110. The connection member 920 may be a flexible printed circuit board (FPCB) or a flexible flat cable (FFC). Voltage and temperature information measured from the plurality of battery cells 110 may be transmitted to an external BMS (battery management system) via the connection member 920 and the LV connector 910. That is, the LV sensing assembly 900 including the LV connector 910 and the connection member 920 can detect and control phenomena such as overvoltage, overcurrent, and overheating of each battery cell 110. The joining plate 930 is located at one end of the connection member 920 and may be made of a metal material having electrical conductivity. By connecting such a joining plate 930 to the electrode leads 111 and 112, the connection member 920 and the electrode lead 111 can be electrically and physically connected. Specifically, one side of the joining plate 930 passes through the connection member 920 and is then bent to thereby be coupled with the connection member 920, and the other side of the joining plate 930 can be formed in a plate shape to be joined, particularly welded, to the electrode leads 111 and 112.
Meanwhile, as described above, the battery cells 110 may be stacked along the x-axis direction to form the battery cell stack 200, whereby the electrode leads 111 and 112 may protrude in the y-axis direction and the -y-axis direction, respectively. As described above, at least two electrode leads 111 and 112 may be bent and joined to form the electrode lead joined body 110L. The joining plate 930 of the LV sensing assembly 900 can be directly joined to the electrode lead joined body 110L to connect the LV sensing assembly 900 and the electrode leads 111 and 112 to each other.
The method of joining the electrode leads 111 and 112 to form the electrode lead joined body 110L or the method of joining the electrode lead joined body 110L and the joining plate 930 is not particularly limited as long as electrical connection is possible, and as an example, welding can be performed. Further, the electrode leads 111 and 112 protruding in the +y-axis direction are mainly described, but with respect to for the electrode leads 111 and 112 protruding in the −y axis direction, the structure of the electrode lead joined body and the LV sensing assembly 900 can be formed similarly.
In the conventional battery module 10, the electrode lead 11L is joined to the busbar 51 for a HV connection, and separately from that, the LV sensing assembly 60 is connected to the busbar 51. On the other hand, in the battery module 100 according to the present embodiment, when the electrode lead assembly 110L is formed, the HV connection and the LV connection are not performed individually, but can be performed at once, so that productivity improvement can be expected. It has the advantage that the configuration of the busbar frame and the like can be removed and the battery module 100 of a more compact configuration can be manufactured.
In addition, the busbar or the busbar frame can be removed because the busbar is not necessary. Further, there is an advantage that the weight of the battery module 100 is lightened and the manufacturing unit price thereof is lowered because the conventional busbar frame 50 and the end plate 40 are replaced with first and second sensing blocks 410 and 420 and an elastic member 700 described later.
On the other hand, the first sensing block 410 and the second sensing block 420 according to the present embodiment guide the HV connection and LV connection of the battery module 100, and at the same time, have a predetermined strength, and therefore, can play a role of protecting the battery cells 110.
Next, the elastic member 700 will be described in detail.
As illustrated in
Meanwhile, as shown in
That is, the battery module including the first sensing block 410, the second sensing block 420, and the elastic member 700 according to the present embodiment can form a module-less structure in which the conventional housing 30 (see
Further, the upper part and the lower part of the elastic member 700 are open and thus, the upper surface and the lower surface of the battery cell stack 200 are exposed to the outside, and the cooling performance can be improved because it is more effective for heat dissipation than being surrounded by the housing. Here, the upper surface means a surface of the battery cell stack 200 in the +z-axis direction, and the lower surface means a surface of the battery cell stack 200 in the −z-axis direction.
The material of such an elastic member 700 is not particularly limited as long as it has a predetermined elastic force, and as an example, it may include at least one of a polymer composite material, a composite material such as fiber-reinforced plastic (FRB), and a metal alloy.
As illustrated in
The cooling fin 300 may include a metal material having high thermal conductivity. The specific material is not limited, and as an example, aluminum (Al) may be included. Cooling fins 300 having high thermal conductivity may be arranged between the battery cells 110 and directly attached to widen the cooling area. Thereby, the cooling performance is improved.
As described above, the lower part of the elastic member 700 is open and thus, the lower surface of the battery cell stack 200 is exposed to the outside, wherein the cooling fins 300 according to the present embodiment may protrude from the lower surface of the battery cell stack 200. Thereby, the cooling fins 300 according to the present embodiment may come into direct contact with a thermal conductive resin layer described later. The cooling fin 300 arranged between the battery cells 110 comes into direct contact with the thermal conductive resin layer, so that the heat discharge performance of the battery module can be maximized.
Meanwhile, as further illustrated in
Next, a battery pack according to an embodiment of the present disclosure will be described in detail with reference to
As illustrated in
The battery module 100 includes a battery cell stack 200, first and second sensing blocks 410 and 420, and an elastic member 700 as described above. Since the details of the battery module 100 overlaps with the contents described above, a further description will be omitted.
The battery pack 1000 may further include an upper cover 1200 for covering the housing 1100. That is, a plurality of battery modules 100 may be housed between the housing 1100 and the upper cover 1200.
The thermal conductive resin layer 1300 can be formed by applying a thermal conductive resin onto the bottom part 1110. Specifically, the thermal conductive resin is applied onto the bottom part 1110, the battery module 100 according to the present embodiment is located thereon, and then the thermal conductive resin is cured to form the thermal conductive resin layer 1300.
The thermal conductive resin may include a thermal conductive adhesive material, and specifically, may include at least one of a silicone material, a urethane material, and an acrylic material. The thermal conductive resin is a liquid during application but is cured after application, so that it can fix a plurality of battery cells 110 constituting the battery cell stack 200. Further, it is possible to quickly transfer the heat generated in the battery module 100 to the bottom part 1110 and thus prevent the battery pack 1000 from overheating because the thermal conductive resin has excellent heat transfer properties.
As illustrated in
Further, the cooling fin 300 according to the present embodiment extends from the lower surface of the battery cell stack 200 to come into contact with the thermal conductive resin layer 1300. Since the lower surface of the battery cell stack 200 is exposed, the cooling fin 300 located between the battery cells 110 can come into direct contact with the thermal conductive resin layer 1300 on the bottom part 1110. The heat discharge performance can be maximized by configuring the cooling fins 300 facing the battery cells 110 so as to be in direct contact with the thermal conductive resin layer 1300.
Meanwhile, in the module-less structure in which the housing is removed, it is essential to fix the exposed battery cell 110 for structural safety. Therefore, in the battery pack 1000 according to the present embodiment, the structural safety can be supplemented because each battery cell 110 constituting the battery module 100 is fixed while being in contact with the thermal conductive resin layer 1300.
In addition, the unnecessary cooling structure can be removed, thereby reducing the cost. Further, since the number of parts in the height direction of the battery pack 1000 is reduced, the space utilization rate can be increased, so that the capacity or output of the battery module can be increased.
Next, a method for manufacturing the battery module 100 according to an embodiment of the present disclosure will be described in detail with reference to
As illustrated in
Side surface pads 600 may be arranged on both side surfaces of the battery cell stack 200 to supplement stiffness, and a cooling fin 300 may be arranged between the battery cells 110 for cooling and heat dissipation. In some cases, an adhesive member such as a double-sided tape may be arranged between the battery cell 110 and the side surface pad 600 or between the battery cell 110 and the cooling fin 300.
As illustrated in
At this time, the LV sensing assembly 900 may be located in at least one of the first sensing block 410 and the second sensing block 420. As described above, the LV sensing assembly 900 may include an LV connector 910, a connection member 920, and a bonding plate 930. The detailed contents are omitted to avoid a repetition of the description.
The method for manufacturing a battery module 100 according to an embodiment of the present disclosure includes a step of connecting the LV sensing assembly 900 and the electrode lead assembly 110L. Specifically, in the step of forming the electrode lead assembly 110L, the joining plate 930 of the LV sensing assembly 900 may be joined to the electrode lead assembly 110L together with the formation of the electrode lead assembly 110L. Welding can be applied to both the joining between the electrode leads 111 and 112 for forming the electrode lead assembly 110L and the joining between the electrode lead assembly 110L and the joining plate 930. By performing these two welding processes simultaneously, the productivity can be improved. That is, the HV connection and the LV connection can be simultaneously realized.
As illustrated in
Although the terms representing directions such as front, rear, left, right, upper and lower directions are used in the present embodiment, these are merely used for ease of explanation, and may differ depending on a position of an object, a position of an observer, or the like.
The one or more battery modules according to an embodiment of the present disclosure described above may be mounted together with various control and protection systems such as BMS (battery management system) and a cooling system to form a battery pack.
The battery module or the battery pack can be applied to various devices. Such a device can be applied to a vehicle means 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 secondary battery.
Although preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts of the present disclosure, which are defined in the appended claims, also falls within the scope of the present disclosure.
Number | Date | Country | Kind |
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10-2021-0003178 | Jan 2021 | KR | national |
This application is a US national phase of international application No. PCT/KR2022/000274 filed on Jan. 7, 2022, and claims the benefit of priority from Korean Patent Application No. 10-2021-0003178 filed on Jan. 11, 2021, the contents of which are incorporated by reference in their entirety as if fully set forth herein.
Filing Document | Filing Date | Country | Kind |
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PCT/KR2022/000274 | 1/7/2022 | WO |