Battery module having improved assembly structure of voltage sensing components and battery pack including the same

Abstract

A battery module according to the present application includes: a cell stack constituted by a plurality of battery cells stacked in one direction; and a sensing module arranged at a front or rear of the cell stack for voltage sensing and electrical connection of the battery cells, wherein the sensing module includes: a main frame formed to cover the front or rear of the cell stack and having a plurality of lead extraction holes through which electrode leads of the battery cells can be extracted; a plurality of bus bars arranged on the main frame to be spaced apart from each other in one direction; and a printed circuit board of a rigid material attached to the main frame and having a plurality of sensing tips provided to be attachable to and detachable from the corresponding bus bars.

Description

Technical Field

[0001] This disclosure relates to a battery module, and more particularly, to a battery module with an improved assembly structure of voltage sensing components, such as busbars, sensing elements, and connectors required for voltage sensing of individual battery cells.

[0002] This application claims priority to Korean Patent Application No. 10-2020-0149664, filed in Korea on November 10, 2020, the disclosure of which is incorporated herein by reference. Background Technology

[0003] Semi-permanent batteries that can convert electrical energy into chemical energy and can be repeatedly charged and discharged are called secondary batteries, in order to distinguish them from primary batteries that cannot be used again after one use.

[0004] Examples of rechargeable batteries include lithium-ion batteries, nickel-cadmium (Ni-Cd) batteries, lead-acid batteries, nickel-metal hydride (Ni-MH) batteries, zinc-air batteries, and alkaline manganese batteries. Among these, lead-acid and lithium-ion batteries are probably the most commercially viable rechargeable batteries.

[0005] In particular, lithium-ion batteries have recently been actively used as batteries for electric vehicles due to their advantages of high energy density, light weight, small size, excellent safety, low discharge rate, and long lifespan. For reference, lithium-ion batteries are generally classified into cylindrical, prismatic, and pouch batteries according to their manufacturing shape, and in addition to being used as batteries for electric vehicles, they can also be used as batteries for energy storage systems (ESS) and other electrical devices.

[0006] Currently, it may not be possible to obtain sufficient output from a single lithium-ion secondary battery (cell) to power an electric vehicle. In order to utilize secondary batteries as an energy source for electric vehicles, multiple lithium-ion battery cells should be connected in series and / or in parallel to form battery modules, and battery packs are typically constructed. These battery packs include a battery management system (BMS) for connecting the battery modules in series and functionally maintaining the battery modules, a cooling system, a battery disconnect unit (BDU), wiring harnesses, etc.

[0007] When the battery module is in Figure 1 When the location shown includes a pouch-type secondary battery cell, in order to connect the secondary battery cells in series and / or in parallel, the electrode leads 1a and 1b of the pouch-type secondary battery cell are welded to the busbar 3 located at the front or the front and rear of the battery module.

[0008] For voltage sensing of the secondary battery cells, a flexible printed circuit board (FPCB) 5 is connected to each busbar 3. The voltage information of the secondary battery cells is transmitted to the BMS (not shown) via connectors 7 mounted on the FPCB 5, and the BMS monitors the status of each secondary battery cell and controls charging and discharging based on the voltage information of the secondary battery cells.

[0009] In the battery module according to the prior art, each busbar 3 is laser-welded to the corresponding sensing terminal 5a of each FPCB to connect the FPCB 5 to the busbar 3. In this case, many soldering defects occur, and soldering quality management is difficult. During the above assembly process, the FPCB, which is typically more expensive than a printed circuit board (PCB), is often discarded due to soldering defects. Furthermore, the connector pins are soldered to the FPCB. In this case, the connector installation process is also difficult, and the connector, including the connector pins soldered to the FPCB, is considered susceptible to impact or vibration. Summary of the Invention

[0010] Technical issues

[0011] This disclosure is designed to address the problems of related technologies, and therefore aims to provide a battery module in which the assembly structure of the busbar, sensing element, and connector for voltage sensing is easier and more robust compared to related technologies.

[0012] It will be readily understood by those skilled in the art that other objects of this disclosure can be achieved by means of the means shown in the following description and claims, and combinations thereof.

[0013] Technical solution

[0014] According to embodiments of this disclosure, a battery module includes: a cell stack comprising a plurality of battery cells stacked in one direction; and a sensing module located on the front or rear of the cell stack for voltage sensing and electrical connection of the plurality of battery cells, wherein the sensing module includes: a main frame formed to cover the front or rear surface of the cell stack and including a plurality of lead holes through which electrode leads of the plurality of battery cells are extracted; a plurality of busbars located on the main frame and spaced apart from each other in one direction; and a printed circuit board formed of a rigid material, the printed circuit board including a plurality of sensing tips detachably disposed on corresponding busbars, and the printed circuit board being attached to the main frame.

[0015] The main frame may include: a busbar mounting portion recessed to correspond to each of the plurality of busbars; and a board mounting portion disposed above the busbar mounting portion and recessed to correspond to the printed circuit board.

[0016] Each of the plurality of sensing tips may include: a base soldered to the printed circuit board; and a connector extending from the base by a certain length and being attached to or detached from the busbar by rotating forward or backward.

[0017] The connector may include a bent end, wherein the busbar includes a slit, and the end of the connector is pressed into the slit.

[0018] The end of the connector may include one or more protrusions, which are formed in a convex shape.

[0019] The busbar can be configured in a frame shape to surround the outside of the lead hole.

[0020] The sensing module may further include a direct connector that is directly connected to the edge of the printed circuit board.

[0021] The direct connector may include: a connector housing, the connector housing including an upper plate portion and a lower plate portion, the upper plate portion contacting a surface of the printed circuit board, the lower plate portion contacting another surface of the printed circuit board and engaging with the edge of the printed circuit board; and connector terminals disposed in the connector housing and contacting wires disposed on the surface of the printed circuit board.

[0022] An empty space may be provided between a portion of the edge of the printed circuit board and the front surface of the main frame to connect the connector housing.

[0023] According to another aspect of this disclosure, a battery pack includes the battery module.

[0024] Beneficial effects

[0025] According to one aspect of this disclosure, a battery module can be provided in which the assembly structure of the busbar, sensing element, and connector for voltage sensing is easier and more robust compared to related technologies.

[0026] According to this disclosure, because a rigid printed circuit board is used as the sensing component, and the sensing tip of the rigid printed circuit board can be detachably squeezed into the busbar, the sensing tip and the busbar can be easily assembled and reprocessed when necessary.

[0027] Furthermore, according to this disclosure, because the assembly structure is configured such that the connector is not mounted but mechanically engaged with the printed circuit board, the connector can be more easily and securely assembled onto a rigid printed circuit board compared to the prior art.

[0028] The effects of this disclosure will become clearer through the following embodiments. It will also be readily understood that the effects of this disclosure can be achieved through the means and combinations thereof shown in the claims of this disclosure. Attached Figure Description

[0029] Figure 1 This is a partial perspective view of a portion of the front surface of a battery module according to the prior art.

[0030] Figure 2 This is a perspective view illustrating the structure of a battery module according to an embodiment of the present disclosure.

[0031] Figure 3 This is a perspective view of a sensing module according to an embodiment of the present disclosure.

[0032] Figure 4 It is a diagram. Figure 3 An exploded 3D view of the sensing module.

[0033] Figure 5 This is a view illustrating the state of the sensing tip and busbar before they are connected, according to an embodiment of the present disclosure.

[0034] Figure 6 This is a cross-sectional view illustrating the state after the sensing tip and busbar are connected according to an embodiment of the present disclosure.

[0035] Figure 7 yes Figure 6 A magnified view of a portion of the image.

[0036] Figure 8 This is an enlarged view illustrating an assembly structure between a rigid printed circuit board and a connector according to an embodiment of the present disclosure. Detailed Implementation

[0037] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before the description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure, on the basis of allowing the inventors to appropriately define the terminology for best interpretation. Therefore, the descriptions presented herein are merely preferred examples for illustrative purposes and are not intended to limit the scope of the present disclosure; thus, it should be understood that other equivalents and modifications can be made thereto without departing from the scope of the present disclosure.

[0038] These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Accordingly, for clarity, the thickness and dimensions of each element shown in the drawings may be exaggerated, omitted, or drawn schematically. Accordingly, the dimensions of each element do not perfectly reflect the actual dimensions or ratios.

[0039] Figure 2 This is a perspective view illustrating the structure of a battery module according to an embodiment of the present disclosure. Figure 3 This is a perspective view of a sensing module according to an embodiment of the present disclosure. Figure 4 It is a diagram. Figure 3 An exploded 3D view of the sensing module.

[0040] refer to Figures 2 to 4 A battery module according to an embodiment of the present disclosure includes a cell stack 100, a sensing module 200, a front cover 300, and a rear cover 400.

[0041] The cell stack 100 can be a group of battery cells 110. For example, the cell stack 100 can be formed by standing the battery cells 110 upright in the vertical direction and stacking the battery cells in the horizontal direction. The battery cell 110 refers to a pouch-type battery cell 110. In this embodiment, the battery cell 110 is a bidirectional leaded pouch-type battery cell, in which the positive electrode lead and the negative electrode lead are positioned opposite to each other.

[0042] The pouch-type battery cell 110 includes an electrode assembly, an electrolyte solution, and a pouch casing for encapsulating the electrode assembly and the electrolyte solution. The electrode assembly has a structure in which a positive electrode plate, a separator, and a negative electrode plate are repeatedly stacked, and each of the positive and negative electrode plates includes an electrode terminal. Inside the pouch casing, one or more electrode terminals are connected to electrode leads 111, and the electrode leads 111 extend to the outside of the pouch casing to functionally serve as electrode terminals of the battery cell 110.

[0043] The bag housing used to seal and contain the electrode assembly and electrolyte solution may include a thin metal film, such as an aluminum film, to complement electrochemical performance and improve heat dissipation of the electrode assembly and electrolyte solution. The aluminum film may be located between an inner adhesive layer and an insulating layer formed of an insulating material to ensure electrical insulation.

[0044] The sensing module 200 is installed on the front and rear of the cell stack 10 where the electrode leads 111 of each cell 110 are located.

[0045] The sensing module 200 for electrical connection of battery cell 110 and voltage and temperature sensing includes a main frame 210, multiple busbars 220, a printed circuit board 230 and a direct connector 240.

[0046] The main frame 210, as a plate-shaped structure, can have an area corresponding to the front (or rear) of the unit stack 100, and can be configured to cover the front (or rear) surface of the unit stack 100. The main frame 210 can be formed by injection molding from an insulating material such as plastic.

[0047] The front (or rear) of the cell stack 100 can be covered by the main frame 210, and the electrode leads 111 of each cell 110 can be extracted through multiple lead holes 213 formed in the main frame 210 and can be soldered to the corresponding busbar 220.

[0048] According to this embodiment, the main frame 210 includes a busbar mounting portion 211, a board mounting portion 212, and a connector connection portion O on its front surface. The busbar mounting portion 211, the board mounting portion 212, and the connector connection portion O are configured for connection and separation between the busbar 220 and the sensing tip 231 described below, stable mounting of the rigid printed circuit board 230, and ensuring connection space for the direct connector 240.

[0049] Busbar mounting portions 211 are arranged at the central portion of the main frame 210 in the left-right direction, and are recessed to correspond to the shape of the busbar 220 to be installed. That is, the busbar mounting portions 211 have a width and depth corresponding to the width and thickness of the busbar 220. Each busbar 220 corresponding to the busbar mounting portion 211 is inserted, so that no stepped portion is formed between the surface of the main frame 210 and the surface of the busbar 220. In other words, when the busbar 220 is inserted into the busbar mounting portion 211, the busbar 220 does not protrude beyond the surface of the main frame 210.

[0050] The board mounting portion 212, where the printed circuit board 230 will be assembled, can be positioned above or below the busbar mounting portion 211. In this embodiment, the board mounting portion 212 is formed directly above the busbar mounting portion 211. The board mounting portion 212 is recessed to correspond to the shape of the printed circuit board 230. That is, the board mounting portion 212 has a width and depth corresponding to the width and thickness of the printed circuit board 230. Similar to the busbar mounting portion 211, the printed circuit board 230 is inserted into the board mounting portion 212, thereby preventing the formation of a stepped portion between the surface of the main frame 210 and the surface of the printed circuit board 230. When the printed circuit board 230 is inserted into the board mounting portion 212, the printed circuit board 230 can be secured by using bolts B or by using adhesive or tape instead of bolts.

[0051] In this configuration, the surface of the busbar 220 and the surface of the printed circuit board 230 are on the same plane. In this case, the busbar 220 and the sensing tip 231 can be easily connected, which will be described in detail below.

[0052] The connector connection part O is a recessed portion at the edge of the board mounting part 212. Because the connector connection part O is provided, a certain space can be ensured between the edge of the printed circuit board 230 and the main frame 210, and the direct connector 240 can be connected through this space to engage with the edge of the printed circuit board 230.

[0053] Because the electrode leads 111 of the battery cell 110 lack sufficient mechanical rigidity, a busbar 220 is used for stable electrical connection of the battery cell 110. The busbar 220 can be formed of copper, aluminum, or a coating metal thereof.

[0054] Multiple busbars 220 can be secured by being properly inserted into the busbar mounting portion 211 of the main frame 210. Although not shown, the busbars 220 can also be secured using adhesive, hooks, or bolts.

[0055] In this embodiment, six busbars 220 are arranged at equal intervals on the front main frame 210 of the unit stack 100, and five busbars (not shown) are arranged at equal intervals on the rear main frame 210 of the unit stack 100. The busbars 220 can be formed in any of various shapes, such as straight bars, U-shaped shapes, or quadrilateral frame shapes.

[0056] Since the busbar 220 with a quadrilateral frame shape can be mounted on the main frame 210 to surround the outside of the lead hole 213, the electrode leads 111 can be pulled out from the lead hole 213, and then some of the electrode leads 111 can be soldered to the left side of the quadrilateral frame and the remaining electrode leads can be soldered to the right side of the quadrilateral frame, so a large number of electrode leads 111 can be easily soldered.

[0057] Accordingly, in this embodiment, a busbar 220 with a quadrilateral frame shape is used. Two of the busbars 220 serve as the positive and negative electrode terminals of the battery module. For this purpose, the shapes of the positive electrode terminal T1 and the negative electrode terminal T2 are added to the first busbar 220 and the sixth busbar 220, which are the outermost busbars on the front main frame 210.

[0058] In this configuration, the positive electrode leads of the first group of battery cells 110 are soldered to the first busbar 220 of the front main frame 210, and the negative electrode leads of the first group of battery cells 110 are soldered together with the positive electrode leads of the second group of battery cells 110 to the first busbar 220 of the rear main frame 210. Next, the negative electrode leads of the second group of battery cells 110 and the positive electrode leads of the third group of battery cells 110 are soldered to the second busbar 220 of the front main frame 210. In this manner, the negative electrode leads of the last group of battery cells 110 are soldered to the sixth busbar 220 of the front main frame 210. (The Nth group of battery cells 110 refers to one or more battery cells 110 bundled together.) In this case, all the battery cells 110 constituting the cell stack 100 can be connected in series and / or in parallel via multiple busbars 220.

[0059] As described above, the battery cells 110 are connected in series via busbars 220 in groups or bundles. In this case, the voltage of each battery cell 110 connected in series can be determined by measuring the voltage at each busbar 220.

[0060] The printed circuit board 230 can be used as a sensing component for sensing the voltage at each busbar 220. Because the printed circuit board 230 can transmit a large amount of signal or power while occupying a small space in the battery module, it can be effectively used as a voltage sensing component.

[0061] In the prior art, flexible printed circuit boards (FPCBs) capable of three-dimensional (3D) wiring have been widely used as sensing components. However, FPCBs are susceptible to impact and are expensive, and as described in the background section, laser soldering should be performed when the FPCB is attached to busbar 220. Accordingly, this disclosure uses a printed circuit board 230 made of a rigid material that can be securely attached to the main frame 210, instead of an FPCB.

[0062] As in Figure 3 and Figure 4 As shown, the printed circuit board 230 formed of a rigid material according to an embodiment of the present disclosure may include a plurality of sensing tips 231 detachably disposed on the busbar 220 and wires 232 configured to transmit signals from each sensing tip 231, and may be fixedly attached to the board mounting portion 212. In this case, because the printed circuit board 230 is formed of a rigid material, the printed circuit board 230 may be securely fixed to the board mounting portion 212 using bolts B.

[0063] Each of the plurality of sensing tips 231 may include: a base 231a that is soldered to a printed circuit board 230; and a connector 231b that extends from the base 231a by a certain length and is attached to or detached from the busbar 220 by rotating forward or backward.

[0064] Moreover, as in Figure 5 As shown, the connector 231b includes an end portion 231c that is bent at an angle of approximately 90°. The busbar 220 includes a slit 221, which is formed by cutting to a certain depth in the thickness direction. The slit 221 is formed at a position where the end portion 231c of the connector 231b can be inserted when the sensing tip 231 is rotated.

[0065] In these constructions, such as in Figure 6 As shown, by rotating the connection portion 231b of the sensing tip 231 while the busbar 220 and the printed circuit board 230 are attached to the main frame 210, the end portion 231c of the connection portion 231b can be squeezed and fitted into the slit 221 of the busbar 220.

[0066] As described above, the busbar 220 and the printed circuit board 230 are respectively located on the busbar mounting portion 211 and the board mounting portion 212, such that the surface of the busbar 220 and the surface of the printed circuit board 230 are on the same plane. Accordingly, when the end 231c of the connector 231b is inserted into the slit 221 of the busbar 220 by rotating the connector 231b of the sensing tip 231, the remaining portion of the connector 231b can be tightly attached in a manner parallel to the surface of the connector 231b.

[0067] Furthermore, the sensing tip 231 may include at least one protrusion 231d formed in a convex shape on the end 231c of the connecting portion 231b. (See reference) Figure 7 According to this embodiment, the sensing tip 231 includes a protrusion 231d on the end 231c of the connector 231b, which is either non-flat or convex. When the end 231c of the connector 231b is inserted into the slit 221 of the busbar 220, a portion of the protrusion 231d collides with and is compressed against the inner wall surface of the slit 221. In this case, a restoring force is applied to the protrusion 231d, thereby strongly maintaining contact between the inner wall surface of the slit 221 and the protrusion 231d.

[0068] Furthermore, in order to allow one end of the end 231c of the connecting portion 231b to be stuck outside the slit 221, one end of the end 231c of the connecting portion 231b may have an annular shape 231e, so that the connecting portion 231b is not easily separated from the slit 221.

[0069] In this configuration, when the sensing tip 231 and the busbar 220 are connected, the connection can be performed easily and quickly, and the disconnection can be performed when necessary. Therefore, compared with laser welding between the sensing tip 231 and the busbar 220, it is also possible to replace only one of the busbar 220 and the printed circuit board 230.

[0070] The direct connector 240 can be used to transmit voltage information of the battery cell 110 sensed by the sensing tip 231 of the printed circuit board 230 to the battery management system (BMS) (not shown).

[0071] As in Figure 8 As shown, the direct connector 240 according to an embodiment of the present disclosure can be configured to be directly connected to the edge of the printed circuit board 230.

[0072] In detail, the direct connector 240 may include: a connector housing that is inserted into and engages with the printed circuit board 230; a plurality of connector terminals disposed within the connector housing; and a plurality of cables 244 that are connected one-to-one to the plurality of connector terminals and extend to the outside.

[0073] The connector housing includes: an upper plate portion 241a and a lower plate portion 241b, which form a space for accommodating connector terminals; and a latch portion 242 and a board holding lead 243, which form a locking device for the printed circuit board 230.

[0074] The upper plate portion 241a and the lower plate portion 241b can form the body of the connector housing. The upper plate portion 241a and the lower plate portion 241b are formed such that: the front portions are spaced apart from each other by the thickness of the printed circuit board 230 so as to be inserted into the edge of the printed circuit board 230 at a certain depth, and the rear portions are connected to each other to form a whole.

[0075] When the connector housing is attached to the edge of the printed circuit board 230, the front side of the upper plate portion 241a contacts the front surface of the printed circuit board 230, and the front side of the lower plate portion 241b contacts the rear surface of the printed circuit board 230. The latch portion 242 and the board retaining lead 243 are additionally connected to the printed circuit board 230 to prevent movement of the direct connector 240. Insertion holes can be formed in the rear portions of the upper plate portion 241a and the lower plate portion 241b, and connector terminals can be individually inserted into these insertion holes.

[0076] Furthermore, in this embodiment, an empty space is provided between a portion of the edge of the printed circuit board 230 and the front surface of the main frame 210. This empty space corresponds to the connector connection portion O of the main frame 210. Because the lower plate portion 241b of the connector housing can be located in this empty space, the direct connector 240 can be connected to the edge of the printed circuit board 230 without being obstructed by the upper end of the main frame 210.

[0077] As described above, in the battery module according to this disclosure, because the sensing tip 231 of the printed circuit board 230 can be detachably press-fitted into the busbar 220, the sensing tip 231 and the busbar 220 can be easily assembled, and reprocessing can be performed when necessary. Moreover, because the assembly structure is formed such that the direct connector 240 is mechanically engaged with the printed circuit board 230, the connector can be installed more securely and easily compared to the prior art.

[0078] A battery pack according to this disclosure may include one or more battery modules according to this disclosure. Furthermore, in addition to the battery modules, the battery pack according to this disclosure may further include a battery pack housing for housing the battery modules and various means for controlling the charging and discharging of each battery module, such as a main BMS, a current sensor, and a fuse.

[0079] The battery module according to this disclosure can be applied to vehicles, such as electric vehicles or hybrid vehicles. That is, the vehicle may include the battery module according to this disclosure.

[0080] While one or more embodiments of this disclosure have been described with reference to examples and accompanying drawings, this disclosure is not limited thereto, and those skilled in the art will understand that various changes in form and detail may be made therein without departing from the scope of this disclosure as defined by the appended claims.

[0081] Those skilled in the art will understand that when directional terms such as up, down, left, right, front, and back are used, these terms are merely for ease of interpretation and can be varied depending on the position of the target object, the observer's position, etc.

Claims

1. A battery module, comprising: A cell stack, comprising multiple battery cells stacked in one direction; and A sensing module, located at the front or rear of the cell stack, is used for voltage sensing and electrical connection of the plurality of battery cells. The sensing module includes: The main frame is formed to cover the front or rear surface of the cell stack and includes a plurality of lead holes through which the electrode leads of the plurality of cell cells are extracted; Multiple busbars, located on the main frame and spaced apart from each other in one direction; and A printed circuit board, formed of a rigid material, includes multiple sensing tips detachably disposed on corresponding busbars, and is attached to the main frame. Each of the plurality of sensing tips includes: The base, which is soldered to the printed circuit board; and A connecting portion, which extends from the base by a certain length and is attached to or detached from the busbar by rotating forward or backward. The connecting portion includes a bent end. The busbar includes a slit, and the end of the connector is pressed and fitted into the slit.

2. The battery module according to claim 1, wherein, The main framework includes: Busbar mounting portion, the busbar mounting portion being recessed to correspond to each of the plurality of busbars; and A board mounting portion is disposed above the busbar mounting portion and is recessed to correspond to the printed circuit board.

3. The battery module according to claim 1, wherein, The end of the connector includes one or more protrusions, which are formed in a convex shape.

4. The battery module according to claim 1, wherein, The busbar is configured in a frame shape to surround the outside of the lead hole.

5. The battery module according to claim 1, wherein, The sensing module further includes a direct connector that is directly connected to the edge of the printed circuit board.

6. The battery module according to claim 5, wherein, The direct connector includes: a connector housing, the connector housing including an upper plate portion and a lower plate portion, the upper plate portion contacting a surface of the printed circuit board, the lower plate portion contacting another surface of the printed circuit board and engaging with the edge of the printed circuit board; and connector terminals disposed within the connector housing and contacting wires disposed on the surface of the printed circuit board.

7. The battery module according to claim 6, wherein, An empty space is provided between a portion of the edge of the printed circuit board and the front surface of the main frame to connect the connector housing.

8. A battery pack comprising a battery module according to any one of claims 1 to 7.

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