Battery module and assembly method therefor

Abstract

The present disclosure relates to a battery module and an assembly method therefor, the battery module comprising: a plurality of battery cells stacked in one direction; a busbar electrically connected to the plurality of battery cells stacked in the one direction; a sensing unit electrically connected to the busbar in order to detect the voltage of the plurality of battery cells; and a sensing terminal unit provided between the sensing unit and the busbar so as to electrically connect the busbar and the sensing unit. The sensing terminal unit comprises: a coupling unit positioned so as to face at least a portion of the busbar; and a plurality of welding regions for coupling the coupling unit and the sensing terminal unit when the sensing terminal unit and the busbar are welded.

Description

Battery module and assembly method thereof

[0001] The present disclosure relates to a battery module and a method for assembling the same. More specifically, it relates to a battery module joined by welding and a method for assembling the same.

[0002] The battery module may include a sensing terminal for measuring the voltage and / or temperature of a plurality of battery cells included in the battery module.

[0003] Typically, sensing terminals and busbars, which are formed from dissimilar metals, utilize wire welding for electrical connection. However, the strength of the joint when welding dissimilar metals can be relatively low compared to when welding identical metals. Furthermore, the width of the wire-shaped weld bead formed during wire welding is relatively small compared to the length of the wire. Consequently, stress can be concentrated in the welded area when subjected to not only simple tensile or shear forces, but also bending or twisting. This can lead to problems such as damage to the sensing terminal or busbar.

[0004] Meanwhile, in order to improve the welding strength, the length of the pre-weld may be increased, but considering the limited size of the sensing terminal, there is a problem in that it is difficult to increase the welding length.

[0005] First, the present disclosure aims to solve the problem of improving the welding strength between the sensing terminal and the welding portion.

[0006] Second, the present disclosure aims to solve the problem of improving welding strength within the limited size of the sensing terminal.

[0007] Third, the present disclosure addresses the problem of ensuring close contact between the sensing terminal and the welding portion during welding.

[0008] Fourth, the present disclosure aims to solve the problem of reducing the scattering of spatter that may occur during welding.

[0009] Meanwhile, the battery module according to the present disclosure can be widely applied in green technology fields such as electric vehicles, battery charging stations, energy storage systems (ESS), and other battery-based photovoltaics and wind power generation. In addition, the battery module according to the present disclosure can be used in eco-friendly mobility, including electric vehicles and hybrid vehicles, to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0010] A battery module according to the present disclosure includes: a plurality of battery cells stacked along one direction; a bus bar electrically connected to the plurality of battery cells stacked along the one direction; a sensing unit electrically connected to the bus bar to detect a voltage of at least one battery cell among the plurality of battery cells; and a sensing terminal unit provided between the sensing unit and the bus bar to electrically connect the bus bar and the sensing unit; wherein the sensing terminal unit includes a coupling unit positioned to face at least a portion of the bus bar; and a plurality of welding regions coupling the coupling unit and the sensing terminal unit.

[0011] In addition, when welding the connecting portion and the bus bar, the battery module may form a plurality of welding beads on the outside of the connecting portion corresponding to the plurality of welding areas.

[0012] Additionally, a plurality of welding beads formed during welding corresponding to the plurality of welding areas may protrude outward from the joint.

[0013] Meanwhile, the plurality of welding beads may be positioned spaced apart from each other.

[0014] The plurality of welding regions may include a plurality of transverse welding regions arranged at a preset transverse interval along the one direction; and at least one longitudinal welding region arranged at a preset longitudinal interval in at least one of the plurality of transverse welding regions along the height direction of the bus bar.

[0015] And, the size of the horizontal spacing and the size of the vertical spacing may be the same.

[0016] Meanwhile, when welding the sensing terminal portion and the bus bar, a plurality of horizontal welding beads may be formed on the outside of the joint portion at the horizontal interval corresponding to the plurality of horizontal welding areas, and when welding the sensing terminal portion and the bus bar, at least one vertical welding bead may be formed on the outside of the joint portion at the vertical interval corresponding to the at least one vertical welding area.

[0017] Additionally, the plurality of welding areas may be arranged in a polygonal shape with each vertex being the center of the plurality of welding areas.

[0018] Alternatively, the plurality of welding areas may be arranged in a grid shape with the plurality of welding areas as vertices.

[0019] Meanwhile, the bus bar may include a first bus bar and a second bus bar provided on each side of the battery cell, and the sensing unit may include a first wire electrically connected to the first bus bar; and a second wire electrically connected to the second bus bar; and the sensing terminal unit may include a first sensing terminal connected to the first bus bar by welding; and a second sensing terminal connected to the second bus bar by welding; and the plurality of welding regions may include a plurality of first welding regions that are joined to each other when the first sensing terminal and the first bus bar are welded; and a plurality of second welding regions that are joined to each other when the second sensing terminal and the second bus bar are welded.

[0020] In addition, when welding the first sensing terminal and the first bus bar, a plurality of first welding beads can be formed on the outside of the first sensing terminal corresponding to the plurality of first welding areas, and when welding the second sensing terminal and the second bus bar, a plurality of second welding beads can be formed on the outside of the second sensing terminal corresponding to the plurality of second welding areas.

[0021] In addition, the plurality of first welding regions and the plurality of second welding regions may each include a plurality of transverse welding regions arranged at a preset transverse interval along the one direction; and at least one longitudinal welding region arranged at a preset longitudinal interval in at least one of the plurality of transverse welding regions along the height direction of the bus bar.

[0022] In addition, when welding the first sensing terminal and the first bus bar or when welding the second sensing terminal and the second bus bar, a plurality of transverse welding beads may be formed at the transverse intervals on the outer sides of the first sensing terminal and the second sensing terminal, corresponding to the plurality of transverse welding regions, and when welding the first sensing terminal and the first bus bar or when welding the second sensing terminal and the second bus bar, a plurality of longitudinal welding beads may be formed at the longitudinal intervals on the outer sides of the first sensing terminal and the second sensing terminal, corresponding to the plurality of longitudinal welding regions.

[0023] Meanwhile, the bus bar includes a plurality of bus bar plates that electrically connect a preset number of battery cells among the plurality of battery cells by grouping them, and the plurality of bus bar plates can be arranged along the one direction.

[0024] In addition, the sensing terminal section may be provided in multiple units so as to correspond one-to-one to the plurality of bus bar plates.

[0025] Meanwhile, the sensing unit may include a flexible printed circuit board (FPCB).

[0026] Meanwhile, a method for assembling a battery module according to the present disclosure includes a busbar connecting step of stacking the plurality of battery cells along the one direction and then connecting them to the busbar; a sensing unit arranging step of arranging the sensing unit on the plurality of battery cells connected to the busbar; a jig arranging step of moving a welding jig toward a connecting portion positioned to face at least a portion of the busbar among the sensing terminal portions and bringing the sensing unit into contact with the connecting portion; and a welding step of welding the connecting portion and the busbar using the welding jig. In addition, the welding step may weld the connecting portion and the busbar such that a plurality of joining areas to be joined by the welding are arranged at a preset interval.

[0027] In addition, the method for assembling the battery module may further include a jig separation step of separating the welding jig from the joint after the welding step is completed.

[0028] In addition, the method for assembling the battery module may further include, prior to the jig arrangement step, a positioning step of overlapping at least a portion of the bus bar and the joint portion for welding the joint portion and the bus bar.

[0029] First, the present disclosure improves the welding strength between the sensing terminal and the welding portion, so that it can withstand bending or twisting.

[0030] Second, the present disclosure improves welding strength within a limited welding area of ​​the sensing terminal, thereby enabling stable measurement of battery cell voltage without damage even from external vibration or impact.

[0031] Third, the present disclosure can apply pressure between the sensing terminal and the welding portion during welding.

[0032] Fourth, the present disclosure can prevent the scattering of spatter and prevent the welding area of ​​the sensing terminal and the bus bar from being warped during welding.

[0033] Figure 1 is an example of a battery module described in the present disclosure.

[0034] Figure 2 is an example of a busbar assembly including a busbar and a busbar frame.

[0035] Fig. 3 is an example of a sensing unit according to the present disclosure.

[0036] Figure 4 is an example of disassembling a busbar frame, busbar, and sensing terminal.

[0037] Fig. 5(a) illustrates an example of a combined busbar frame, busbar, and sensing terminal. Fig. 5(b) is an enlarged view of multiple welding beads formed on the joint during welding.

[0038] Figure 6 illustrates a sensing unit, a sensing terminal unit, and a welding jig.

[0039] Figure 7 illustrates an example of a welding jig pressurizing a joint and a bus bar for welding.

[0040] Figures 8(a) to 8(c) schematically illustrate the shapes of various multiple welding beads formed at the joint.

[0041] Figure 9 is a flow chart schematically illustrating an example of a method for assembling a battery module.

[0042] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. The configuration of the device and the control method described below are only intended to illustrate embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. Reference numerals used throughout the specification represent identical components.

[0043] The battery cell described herein refers to a secondary battery that can be used by charging and discharging electric energy. For example, it may refer to a lithium secondary battery or a lithium-ion battery. As another example, it may refer to an all-solid-state battery. Taking a lithium secondary battery as an example, the main components of the battery cell may include a cathode, an anode, a separator, and an electrolyte. The battery cell may further include a lead tab that is connected to the anode and the anode, respectively, for electrical connection to the outside, and protrudes outward from the pouch.

[0044] Meanwhile, the battery module described herein refers to a battery assembly in which one or more battery cells are bundled together and then placed in a case to protect them from external shock, heat, vibration, etc. The battery assembly is connected to a busbar assembly housed inside via an external connection line to supply electricity to the outside or receive electricity from the outside and store it in the battery cells.

[0045] And, a battery pack is a set of battery modules assembled in a preset number to achieve the final desired voltage or power.

[0046] Fig. 1 is an example of a battery module (200) described in the present disclosure. The battery module (200) includes a plurality of battery cells (110) stacked along one direction (e.g., Y direction), a bus bar (151) electrically connected to the plurality of battery cells (110) stacked along the one direction, a sensing unit (191) electrically connected to the bus bar (151) to detect a voltage of at least one battery cell (110) among the plurality of battery cells (110), and a sensing terminal unit (195, see Fig. 4) provided between the sensing unit (191) and the bus bar (151) to electrically connect the bus bar (151) and the sensing unit (191).

[0047] The sensing terminal portion (195) includes a connecting portion (196, see FIG. 5) positioned to face at least a portion of the bus bar (151) and a plurality of welding areas (180, see FIG. 4) that connect the connecting portion (196) and the sensing terminal portion (195). The plurality of welding areas (180) are areas where the sensing terminal portion (195) and the bus bar (151) are connected by welding.

[0048] Specific examples of the above welding include ultrasonic welding using ultrasonic waves or laser welding using lasers.

[0049] The battery cell (110) may include a main body (115) that stores or generates electric energy and lead tab portions (111, 112) that protrude outward from the main body and are electrically connected to the bus bar (151). The lead tab portions each have a positive pole and a negative pole and may protrude in the same direction toward one side of the main body (115). Referring to FIG. 1, the battery cell (110) according to the present disclosure may include a first lead tab portion (111) and a second lead tab portion (112) in which the lead tab portions (111, 112) protrude in opposite directions.

[0050] The above plurality of battery cells (110) may be pouch-type secondary batteries, but are not limited thereto, and may also be square or cylindrical.

[0051] The above plurality of battery cells (110) are stacked in one direction, and then the lead tab portions (111, 112) of each of the plurality of battery cells (110) are electrically connected to a bus bar (151) to form a single cell stack (100).

[0052] The main body (115) may include a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. Specifically, the main body (115) may include an electrode assembly (not shown). The electrode assembly is a power generation device in which a separator is alternately arranged between the positive electrode plate and the negative electrode plate, and the separator is wound in a spiral shape by positioning it between the positive electrode plate and the negative electrode plate.

[0053] Additionally, the electrode assembly may be arranged in a stacked manner in which the positive electrode plate, the separator, and the negative electrode plate are sequentially stacked.

[0054] The first lead tab portion (111) and the second lead tab portion (112) may be connected to the positive and negative electrodes, respectively, and may protrude for connection to the outside. The first lead tab portion (111) and the second lead tab portion (112) may be provided as terminals for connection to another battery cell (110) or an external device, for example, terminals for electrical connection to a bus bar assembly (150), and may be provided as positive and negative tabs, respectively.

[0055] If the first lead tab portion (111) and the second lead tab portion (112) are a positive tab and a negative tab, respectively, the first lead tab portion (111) and the second lead tab portion (112) will be electrically connected to the positive plate and the negative plate, respectively. The first lead tab portion (111) and the second lead tab portion (112) may protrude in a direction perpendicular to the stacking direction (Y direction) in which the plurality of battery cells (110) are stacked.

[0056] The first lead tab portion (111) and the second lead tab portion (112) can be formed of different materials having excellent electrical conductivity.

[0057] Meanwhile, the cell stack (100) may include a bus bar (151) located on the outside of the first lead tab portion (111) and the second lead tab portion (112) and electrically connected to the first lead tab portion (111) and the second lead tab portion (112).

[0058] Additionally, the cell stack (100) may further include a bus bar frame (152, see FIG. 2) that supports the bus bar (151) and faces the bus bar (151). The bus bar frame (152) is made of an insulating material and may electrically insulate between the main body (115) and the bus bar (151).

[0059] Meanwhile, the above bus bar (151) and the above bus bar frame (152) may be combined and referred to as a bus bar assembly (150).

[0060] That is, the busbar assembly (150) may be provided to electrically connect the plurality of battery cells (110) to the outside. For example, it may further include a first busbar (1511, see FIG. 2) electrically connected to each of the first lead tab portions (111) of the plurality of battery cells (110) and a first busbar frame (1521, see FIG. 2) supporting the first busbar (1511), a second busbar (1512, see FIG. 2) electrically connected to each of the second lead tab portions (112) of the plurality of battery cells (110) and a second busbar frame (1522, see FIG. 2) supporting the second busbar (1512).

[0061] Meanwhile, the battery module (200) includes a sensing unit (191) provided to measure the voltage of the plurality of battery cells (110) and a sensing terminal unit (195) that electrically connects the sensing unit (191) and the bus bar (151). The voltage of the plurality of battery cells (110) refers to the voltage applied to the plurality of battery cells (110) during charging and discharging.

[0062] The sensing unit (191) and the sensing terminal unit (195) can measure the total voltage of the plurality of battery cells (110), the individual voltage of each of the plurality of battery cells (110), or the voltage of some grouped battery cells (110) of the plurality of battery cells (110).

[0063] Accordingly, the sensing unit (191) will be electrically connected to at least one battery cell (110).

[0064] Additionally, the sensing unit (191) and the sensing terminal unit (195) can also measure the temperature of the plurality of battery cells (110).

[0065] Meanwhile, the sensing unit (191) and the sensing terminal unit (195) may be referred to as a sensing unit (190).

[0066] As described above, the bus bar (151) may include a first bus bar (1511) and a second bus bar (1512) that correspond to lead tab portions protruding from both sides of the main body (115) and extend in one direction (Y direction) in which the plurality of battery cells are stacked from each side of the main body (115).

[0067] At this time, the sensing unit (191) can electrically interconnect the first bus bar (1511) and the second bus bar (1512), and the sensing terminal unit (195) can include a first sensing terminal (1951, see FIG. 4) connecting the first bus bar (1511) and the sensing unit (191) and a second sensing terminal (not shown) connecting the second bus bar (1512) and the sensing unit (191). The second sensing terminal is the same as the first sensing terminal (1951) except for the connection position, and is therefore omitted.

[0068] The above sensing unit (191) may further include an external connection terminal (193) for connection with an external control unit, such as a BMS (Battery Management System).

[0069] Meanwhile, the sensing unit (191) may include a flexible printed circuit board (FPCB) formed of a flexible material for efficient use of a narrow space. Accordingly, the sensing unit (191) may be positioned on the upper portion of the cell stack (100), and the battery module (200) may include a plate-shaped support unit (194) to support the sensing unit (191).

[0070] The support member (194) is positioned between the sensing member (191) and the cell stack (100), and can be connected to the bus bar frame (152). The support member (194) can disperse external force applied to the sensing member (191) using the bus bar frame (152).

[0071] Referring to FIG. 1, the support member (194) connects the first bus bar frame (1521) and the second bus bar frame (1522) and may be located on the upper side of the cell stack (100).

[0072] Meanwhile, the battery module (200) may further include a module case (not shown) that accommodates the cell stack (100). The module case protects the cell stack (100) and may expose terminal portions (1913, 1914, see FIG. 2) for electrically connecting the cell stack (100) to the outside to the outside of the module case.

[0073] Figure 2 is an example of a busbar assembly (150) including a busbar (151) and a busbar frame (152).

[0074] The above bus bar assembly (150) may be provided for electrical connection between a plurality of battery cells (110) and the outside.

[0075] The above busbar assembly (150) may include a first busbar (1511) and a second busbar (1512) that extend along the direction in which the plurality of battery cells (110) are stacked and are electrically connected to the first lead tab portion (111) or the second lead tab portion (112) of each of the plurality of battery cells (110) located on both sides of the plurality of battery cells (110), a first busbar frame (1521) that supports the first busbar (1511), and a second busbar frame (1522) that supports the second busbar (1512).

[0076] The plurality of battery cells (110) will be connected in series or parallel so as to generate a preset target voltage in one battery module (200). Accordingly, the positions of the first lead tab portion (111) and the second lead tab portion (112) of each of the plurality of battery cells (110) in the cell stack (100) may not all be positioned in the same direction.

[0077] For example, if the first lead tab portion (111) has a positive pole and the second lead tab portion (112) has a negative pole, the positions of the first lead tab portion (111) and the second lead tab portion (112) in some battery cells (110) may be arranged opposite to the positions of the remaining battery cells (110).

[0078] Referring to FIG. 2, in the present disclosure, for convenience, the direction in which the external connection terminal (193) is located is set as the front (F) and the opposite side as the rear (R).

[0079] The above busbar assembly (150) may include a busbar (151) extending along the direction in which the plurality of battery cells (110) are stacked to electrically connect the plurality of battery cells (110) to the outside, and a busbar frame (152) that is provided to face the busbar (151) and supports the busbar (151).

[0080] Specifically, referring to FIGS. 1 and 2, the busbar assembly (150) includes a first busbar (1511) and a second busbar (1512) extending along the stacked direction of the plurality of battery cells (110) on both sides of the plurality of battery cells (110) to be connected to the lead tab portions of either the first lead tab portion (111) or the second lead tab portion (112) positioned on both sides of the plurality of battery cells (110), a first busbar frame (1521) extending along the stacked direction of the plurality of battery cells (110) and positioned to face the first busbar (1511) and supporting the first busbar (1511), and a second busbar frame (1521) extending along the stacked direction of the plurality of battery cells (110) and positioned to face the second busbar (1512) and supporting the second busbar (1512). It may include a second busbar frame (1522).

[0081] The first bus bar frame (1521) may include a first insertion hole (not shown) extending along the height direction of the battery module (200) so that either the first lead tab portion (111) or the second lead tab portion (112) may be inserted. After either the first lead tab portion (111) or the second lead tab portion (112) is inserted, it will be electrically connected to the first bus bar (1511) through the first insertion hole.

[0082] The above first bus bar frame (1521) may be formed of an insulating material. This is to electrically insulate between the main body (115) and the first bus bar (1511).

[0083] The first bus bar (1511) is electrically connected to one of the first lead tab portions (111) or the second lead tab portion (112), and may include a plurality of first bus bar plates (1511a) arranged parallel to the first bus bar frame (1521).

[0084] That is, the plurality of first bus bar plates (1511a) may be arranged along the direction in which the plurality of battery cells (110) are stacked to form the first bus bar (1511). Each of the plurality of first bus bar plates (1511a) may have a plate shape.

[0085] Any one of the plurality of first busbar plates (1511a) may include a first through-hole (1513) penetrating through the first busbar plate (1511a). Either the first lead tab portion (111) or the second lead tab portion (112) may be inserted into the first through-hole (1513) to be electrically connected to the first busbar (1511).

[0086] As described above, the arrangement of the first lead tab portion (111) and the second lead tab portion (112) may vary in order to connect the plurality of battery cells (110) in series or parallel. Accordingly, each of the plurality of first bus bar plates (1511a) may have an electrically different polarity.

[0087] The second bus bar frame (1522) may include a second insertion hole (not shown) extending along the height direction of the battery module (200) so that the other lead tab portion of the first lead tab portion (111) or the second lead tab portion (112) is inserted. After the other lead tab portion of the first lead tab portion (111) or the second lead tab portion (112) is inserted, it will be electrically connected to the second bus bar (1512) through the second insertion hole.

[0088] Likewise, the second bus bar frame (1522) may be formed of an insulating material. This is to electrically insulate between the main body (115) and the second bus bar (1512).

[0089] The second bus bar (1512) is electrically connected to one of the first lead tab portion (111) or the second lead tab portion (112), and may include a plurality of second bus bar plates (1521a) arranged parallel to the second bus bar frame (1522).

[0090] That is, the plurality of second bus bar plates (1521a) may be arranged along the direction in which the plurality of battery cells (110) are stacked to form the second bus bar (1512). Each of the plurality of second bus bar plates (1521a) may have a plate shape.

[0091] Any one of the second busbar plates (1511a) among the plurality of second busbar plates (1521a) may include a second through-hole (1514) penetrating through the second busbar plate (1521a). One of the first lead tab portion (111) or the second lead tab portion (112) will be inserted into the second through-hole (1514) to be electrically connected to the second busbar (1512).

[0092] The first bus bar (1511) and the second bus bar (1512), the first bus bar plate (1511a) and the second bus bar plate (1521a), and the first bus bar frame (1521) and the first bus bar frame (1521) may be positioned in opposite directions with the main body (115) interposed therebetween.

[0093] As described above, the arrangement of the first lead tab portion (111) and the second lead tab portion (112) may vary in order to connect the plurality of battery cells (110) in series or parallel. Accordingly, each of the plurality of second bus bar plates (1521a) may have an electrically different polarity.

[0094] Considering that the material of the first busbar frame (1521) is a polymer material with electrical insulation, and the first busbar (1511) is a metal material with excellent electrical conductivity, the first busbar frame (1521) and the first busbar (1511) can be joined by a method called thermal bonding. Alternatively, the first busbar (1511) may be inserted in advance and joined during the injection molding of the first busbar plate (1511a). However, the present invention is not limited thereto, and the joining method of the first busbar frame (1521) and the first busbar (1511) may use a different method.

[0095] Likewise, considering that the material of the second busbar frame (1522) is a polymer material having electrical insulation properties and the second busbar (1512) is a metal material having excellent electrical conductivity, the second busbar frame (1522) and the second busbar (1512) can be joined by a method called thermal bonding. Alternatively, the second busbar (1512) can be pre-inserted and joined during the injection molding of the second busbar plate (1521a). However, the present invention is not limited thereto, and the joining method of the second busbar frame (1522) and the second busbar (1512) can also use other methods.

[0096] Meanwhile, the busbar assembly (150) may further include a first terminal portion (1931) that electrically connects the first busbar (1511) to the outside for electrical connection with the outside, and a second terminal portion (1932) that electrically connects the second busbar (1512) to the outside.

[0097] Figure 3 is an example of a sensing unit (191) according to the present disclosure.

[0098] Specifically, the sensing unit (191) may include a first wire (1911) and a second wire (1912) extending along the direction in which the plurality of battery cells (110) are stacked. The material of the first wire (1911) and the second wire (1912) may have flexibility. This is to efficiently utilize the compact space inside the module case (not shown). That is, the first wire (1911) and the second wire (1912) may be bent as needed to correspond to the shape of the compact space.

[0099] The first wire (1911) and the second wire (1912) may be connected to an external connection terminal (193) located at the front of the battery module (200). To this end, the sensing unit (191) may include a connector (1915) for connecting the first wire (1911) and the second wire (1912) to the external connection terminal (193).

[0100] The first wire (1911) may include a first connection portion (1913) for electrically connecting with the sensing terminal portion (195) (specifically, a first sensing terminal (1951)). Similarly, the second wire (1912) may include a second connection portion (1914) for electrically connecting with the sensing terminal portion (195) (specifically, a second sensing terminal (not shown)).

[0101] The first connecting portion (1913) and the second connecting portion (1914) may be provided in multiple numbers. FIG. 3 illustrates an example of an area (A1, B1, C1, D1) where the first connecting portion, which is provided in the same number as the plurality of sensing terminal portions (195) on the first wire (1911) to be connected one-to-one to each of the plurality of sensing terminal portions (195), is located. In addition, FIG. 3 illustrates an example of an area (A2, B2, C2 D2) where the second connecting portion, which is provided in the same number as the plurality of sensing terminal portions (195) on the second wire (1912) to be connected one-to-one to each of the plurality of sensing terminal portions (195), is located.

[0102] Meanwhile, the shapes of the first wire (1911) and the second wire (1912) may be asymmetrical to each other. This is because the positions of the first sensing terminal (1951) connected to the first bus bar (1511) and the second sensing terminal connected to the second bus bar (1512) may be different from each other.

[0103] Meanwhile, the number of the plurality of first sensing terminals (1951) will be the same as the number of the plurality of first connecting portions (1913). The number of the plurality of second sensing terminals will be the same as the number of the plurality of second connecting portions (1914).

[0104] In addition, the number of the first sensing terminals (1951) may be the same as the number of the plurality of first bus bar plates (1511a). One first sensing terminal (1951) may correspond one-to-one to one first bus bar plate (1511a). This is because some of the battery cells (110) coupled to one first bus bar plate (1511a) among the plurality of battery cells (110) are arranged in the same manner. Similarly, the number of the second sensing terminals may be the same as the number of the plurality of second bus bar plates (1521a).

[0105] Fig. 4 is an example of disassembling the busbar frame (152), the busbar (151), and the sensing terminal portion (195). Specifically, it is an example of disassembling the busbar frame (152), one of the plurality of first busbar plates (1511a), and one of the plurality of first sensing terminals (1951). Unless otherwise specified, the remaining first busbar plates (1511a), the remaining first sensing terminals (1951), the plurality of second busbar plates (1521a), and the plurality of second sensing terminals will be connected in the same manner, and therefore, a repeated description thereof will be omitted.

[0106] Referring to FIG. 4, the first busbar frame (1521) may further include a coupling protrusion (1527) protruding toward the first busbar (1511). By heat-welding the coupling protrusion (1527) after the first busbar (1511) comes into contact with the first busbar frame (1521), the first busbar (1511) and the first busbar frame (1521) may be fixed to each other.

[0107] Referring to Fig. 4, the first busbar plate (1511a) forming a part of the first busbar (1511) may include a through hole (not shown) penetrating the first busbar plate (1511a) at a position corresponding to the coupling protrusion (1527). After the coupling protrusion (1527) is inserted into the through hole, heat fusion will be performed to fix the first busbar plate (1511a) and the first busbar frame (1521) to each other.

[0108] Meanwhile, the battery module (200) includes a sensing unit (190) that electrically connects the sensing unit (191) and the bus bar (151) to measure the voltage applied to the plurality of battery cells (110).

[0109] Referring to FIG. 4, specifically, the battery module (200) may include a first sensing terminal (1951) that electrically connects the first connection portion (1913) and the first bus bar plate (1511a).

[0110] The first sensing terminal (1951) may be formed of a conductive material. In addition, the first bus bar plate (1511a) and the first connection portion (1913) provided on the first wire (1911) may be electrically connected. Accordingly, the sensing portion (191) may detect the voltage of the plurality of battery cells (110). Specifically, the number of the first sensing terminals (1951) may be the same as the number of the plurality of first bus bar plates (1511a).

[0111] Meanwhile, the sensing terminal portion (195) or the first sensing terminal (1951) may be joined to the first bus bar plate (1511a) through welding. Typically, welding may be performed by simple spot welding or line welding.

[0112] The direction of the conventional line welding may be parallel to the height direction of the battery module (200). In particular, since the length of the line welding is relatively longer than the width of the line welding, it can withstand external forces such as tensile force or shear force well, but has a weak problem with respect to twisting or bending.

[0113] To solve this, the battery module (200) according to the present disclosure may include a plurality of welding areas (180) that connect the sensing terminal portion (195) to the bus bar (151). To indicate the plurality of welding areas (180), FIG. 4 illustrates the first sensing terminal (1951) and the first bus bar plate (1511a) in a virtual circular shape. That is, the plurality of welding areas (180) refer to areas where the first sensing terminal (1951) and the first bus bar plate (1511a) are connected by welding.

[0114] Referring to FIG. 4, the battery module (200) may include a plurality of welding areas (180) for connecting the first bus bar plate (1511a) and the first sensing terminal (1951). Specifically, spot welding is used, but the plurality of welding areas (180) may be arranged in a grid shape or polygonal shape by contact welding.

[0115] Referring to FIG. 4, the plurality of welding areas (180) may include a plurality of transverse welding areas (181) arranged at a preset transverse interval along one direction in which the plurality of battery cells (110) are stacked, and at least one longitudinal welding area (182) arranged at a preset longitudinal interval in at least one of the plurality of transverse welding areas (181) along the height direction of the bus bar.

[0116] For example, referring to Fig. 4, the plurality of welding areas (180) may be arranged in three rows and three columns (3×3) and may be areas welded by spot welding. Fig. 4 illustrates an example in which the horizontal welding areas (181) are provided in three pieces and the vertical welding areas (182) are also provided in three pieces, but this may be modified in various ways.

[0117] Since it is sufficient if there is at least one of the above-mentioned transverse welding area (181) and the above-mentioned longitudinal welding area (182), the above-mentioned plurality of welding areas (180) can be variously modified, such as 4 rows and 2 columns, or 2 rows and 5 columns. In addition, the above-mentioned plurality of welding areas (180) can also be arranged in the shape of a polygon, such as a triangle, pentagon, or star, which cannot be expressed in rows and columns.

[0118] That is, the plurality of welding areas (180) may be arranged in a polygonal shape with each vertex being the center of the plurality of welding areas (180). Alternatively, the plurality of welding areas (180) may be arranged in a grid shape with the plurality of welding areas (180) as vertices.

[0119] The size of the above horizontal gap and the size of the above vertical gap may be the same. This is to better withstand external force applied in any direction.

[0120] Fig. 5(a) illustrates an example of a combination of the busbar frame (152), the busbar (151), and the sensing terminal portion (195). The sensing terminal portion (195) can be electrically connected to the sensing portion (191) and the busbar (151).

[0121] Specifically, FIG. 5(a) illustrates an example of the first busbar frame (1521), the first busbar plate (1511a), and the first sensing terminal (1951). The first sensing terminal (1951) can be electrically connected to the first wire (1911) and the first busbar plate (1511a).

[0122] At least a part of the sensing terminal portion (195) may be positioned to overlap with the bus bar (151), and at least another part of the sensing terminal portion (195) may be positioned to overlap with the sensing portion (191). Specifically, at least a part of the first sensing terminal (1951) may be positioned to overlap with the first bus bar plate (1511a), and another part of the first sensing terminal (1951) may be positioned to overlap with the first wire (1911).

[0123] At least a portion of the sensing terminal portion (195) may be positioned to face the bus bar (151) and may include a coupling portion (196) coupled with the bus bar (151). Specifically, at least a portion of the first sensing terminal (1951) may be positioned to face the first bus bar plate (1511a) and may include a coupling portion (196) coupled with the first bus bar plate (1511a).

[0124] After the above-mentioned joining portion (196) is brought into contact with the first busbar plate (1511a), the joining portion (196) may be joined to the first busbar plate (1511a) by welding the plurality of welding areas (180). That is, the joining portion (196) and the first busbar plate (1511a) may be joined to each other by spot welding the plurality of welding areas (180). Therefore, at this time, a plurality of welding beads (170) may be formed on the outside of the joining portion (196) by welding the plurality of welding areas (180).

[0125] Since the above-described plurality of welding beads (170) are formed by the melting of the welding material or the base material used during welding, the positions of the above-described plurality of welding beads (170) will be formed at positions corresponding to the above-described plurality of welding areas (180). The above-described plurality of welding beads (170) may be spaced apart from each other and arranged in a polygonal or angular shape, similar to the above-described plurality of welding areas (180).

[0126] The above-described plurality of welding beads (170) may be circular in shape. If the above-described plurality of welding areas (180) are located between the joint portion (196) and the first bus bar plate (1511a), the above-described plurality of welding beads (170) will be formed to be exposed to the outside of the joint portion (196).

[0127] Fig. 5(b) is an enlarged view of a plurality of welding beads (170) formed on the joint (196) during welding. Of course, the positions and spacing of the plurality of welding areas (180) can also be inferred through this.

[0128] Referring to FIG. 4, the battery module (200) may include a plurality of welding areas (180) for connecting the first bus bar plate (1511a) and the first sensing terminal (1951). Specifically, spot welding is used, but the plurality of welding areas (180) may be arranged in a grid shape or polygonal shape by contact welding.

[0129] Referring to FIG. 5(b), the plurality of welding beads (170) may include a plurality of transverse welding beads (171) arranged at a preset transverse interval (L1) along one direction in which the plurality of battery cells (110) are stacked, and at least one longitudinal welding bead (172) arranged at a preset longitudinal interval (L2) from at least one transverse welding bead (171) among the plurality of transverse welding beads (171) along the height direction of the bus bar.

[0130] For example, referring to Fig. 5(b), the plurality of welding beads (170) are arranged in three rows and three columns (3×3), and such an arrangement can be formed by spot welding. Fig. 4 illustrates an example in which the transverse welding beads (171) are provided in three pieces and the longitudinal welding beads (172) are also provided in three pieces, but this can be modified in various ways. That is, depending on how the plurality of welding areas (180) are arranged, the arrangement of the corresponding plurality of welding beads (170) will also vary.

[0131] Since at least one of the above-described transverse welding beads (171) and the above-described longitudinal welding beads (172) is sufficient, the plurality of welding beads (170) can be variously modified, such as 4 rows and 2 columns, or 2 rows and 5 columns. In addition, the plurality of welding beads (170) can also be arranged in a polygonal shape, such as a triangle, pentagon, or star, which cannot be expressed in rows and columns.

[0132] That is, the plurality of welding beads (170) may be arranged in a polygonal shape with each vertex being the center of the plurality of welding beads (170). Alternatively, the plurality of welding beads (170) may be arranged in a grid shape with the plurality of welding beads (170) as vertices.

[0133] As with the above-mentioned plurality of welding areas (180), the size of the transverse spacing (L1) of the above-mentioned plurality of welding beads (170) and the size of the longitudinal spacing (L2) may be the same.

[0134] Fig. 6 illustrates the sensing unit (191), the sensing terminal unit (195), and the welding jig (130). Specifically, at least a portion of the first bus bar plate (1511a) and the first sensing terminal (1951), for example, the coupling unit (196), may be electrically connected to each other. In addition, another portion of the first wire (1911) and the first sensing terminal (1951) may be connected to the first wire (1911).

[0135] In particular, the battery module (200) may include a plurality of welding areas (180) in which the bus bar (151) and the sensing terminal portion (195) or the first bus bar plate (1511a) and the first sensing terminal (1951) are joined by welding. The plurality of welding areas (180) will be located on a surface of the joining portion (196) facing the first bus bar plate (1511a). In addition, the joining portion (196) may include a plurality of welding beads (170) formed during welding corresponding to the arrangement of the plurality of welding areas (180) on the outside of the joining portion (196).

[0136] In general, for welding, the bus bar (151) and the joint (196) need to be in close contact before and during welding. In addition, it is also necessary to prevent spatter generated during welding from flying. To this end, the battery module (200) may be pressurized by a welding jig when welding the joint (196) and the bus bar (151).

[0137] The above welding jig (130) may include a welding body (133) that presses the sensing terminal portion (195) to bring the sensing terminal portion (195) into close contact with the bus bar (151) during welding, a welding through hole (131) that penetrates the welding body (133), and a jig fastening hole (132) for fixing the welding body (133).

[0138] Since the portion corresponding to the plurality of welding areas (180) among the joint portions (196) is exposed through the welding through hole (131), the worker can weld the joint portion (196) and the bus bar (151), or the joint portion (196) and the first bus bar plate (1511a) through the welding through hole (131).

[0139] Fig. 7 illustrates an example in which the welding jig (130) applies pressure to the joint portion (196) and the bus bar (151) for welding. Specifically, Fig. 7 illustrates an example in which the welding jig (130) applies pressure to the joint portion (196) of the first sensing terminal (1951) and the first bus bar plate (1511a) before separating the welding jig (130) after welding.

[0140] For welding, the welding jig (130) can be pressed so that the joint portion (196) and the first busbar plate (1511a) are in close contact. A worker can access multiple welding areas (180) through the welding through-hole (131) to weld the joint portion (196) and the first busbar plate (1511a).

[0141] The plurality of welding beads (170) will be formed corresponding to the positions of the plurality of welding areas (180). By checking the shape and number of the plurality of welding beads (170), it will be possible to check whether welding has been performed properly.

[0142] Figures 8(a) to 8(c) schematically illustrate the shapes of a plurality of welding beads (170) formed at the joint (196). In addition, the positions of a plurality of welding areas (180) corresponding thereto can also be indirectly identified through these figures.

[0143] Fig. 8(a) illustrates an example in which multiple welding beads (170) are formed and arranged in 4 rows and 2 columns. This is because multiple welding areas (180) are arranged in the same shape. Fig. 8(b) illustrates an example in which multiple welding beads (170) are formed and arranged in a + shape. This is because multiple welding areas (180) are arranged in the same + shape. Fig. 8(c) illustrates an example in which multiple welding beads (170) are formed and arranged in a triangular shape. This is because multiple welding areas (180) are arranged in a triangular shape.

[0144] Therefore, the arrangement shape of the plurality of welding beads (170) may vary depending on the arrangement shape of the plurality of welding areas (180).

[0145] Figure 9 is a flow chart schematically illustrating an example of a method for assembling a battery module (200).

[0146] The method for assembling a battery module (200) according to the present disclosure includes a busbar connection step (S100) of stacking the plurality of battery cells (110) along the one direction and then connecting them to the busbar (151); a sensing unit arrangement step (S200) of arranging the sensing unit (191) on the plurality of battery cells (110) coupled with the busbar (151); a jig arrangement step (S500) of bringing the welding jig (130) into contact with the coupling portion (196) to pressurize the coupling portion (196) and the busbar (151), and a welding step (S700) of welding the plurality of welding areas through a welding through-hole (131) penetrating the welding jig (130).

[0147] The above busbar connection step (S100) refers to a step of stacking the plurality of battery cells (110) along the one direction and then electrically connecting the plurality of battery cells (110) and the busbar (151). In the busbar connection step (S100), the plurality of battery cells (110) will be connected in series or parallel via the busbar (151).

[0148] The assembly method according to the present disclosure may proceed to the sensing unit arrangement step (S200) after the bus bar connection step (S100). In the sensing unit arrangement step (S200), a constant sensing unit (191) may be arranged on one surface of the plurality of battery cells (110). Preferably, the sensing unit (191) may be positioned on the upper portion of the plurality of battery cells (110).

[0149] In the above jig arrangement step (S500), the welding jig (130) can be moved toward the joint portion (196). When the joint portion (196) and the first bus bar plate (1511a) are in contact, after the welding jig (130) comes into contact with the joint portion (196), the welding jig (130) can press the joint portion (196) and the first bus bar plate (1511a).

[0150] Accordingly, the method for assembling the battery module (200) may further include, prior to the jig arrangement step (S500), a positioning step (S300) of overlapping a portion of the sensing terminal portion (195) and the bus bar (151), specifically, the first sensing terminal (1951) and the first bus bar plate (1511a). Through the positioning step (S300), a portion of the coupling portion (196) may overlap the bus bar (151) or the first bus bar plate (1511a).

[0151] Through the above welding step (S700), the method of assembling the battery module (200) can form a plurality of welding beads on the outside of the joining portion (196) by welding a plurality of welding areas (180) among the overlapping portions of the joining portion (196) and the first bus bar plate (1511a).

[0152] The above-described plurality of welding areas (180) may be arranged at preset intervals as described above. Accordingly, after the welding step (S700), the above-described plurality of welding beads (170) may be positioned corresponding to the above-described plurality of welding areas (180) and exposed to the outside.

[0153] Preferably, the plurality of welding areas (180) may be arranged at the intervals along the direction in which the plurality of battery cells (110) are stacked or along the height direction of the bus bar (151).

[0154] Thereafter, the method for assembling the battery module (200) may further include a jig separation step (S900) of separating the welding jig (130) from the joint (196) or the cell stack (100) after the welding step (S700). This is because the welding jig (130) is an auxiliary device for welding.

[0155] Since the welding of the joint portion (196) and the first busbar plate (1511a) is performed inside the welding through hole (131), the welding jig (130) can reduce the scattering of spatter during welding. In addition, the portion where the joint portion (196) and the first busbar plate (1511a) overlap can be more effectively pressurized.

[0156] The present disclosure may be implemented in various forms and modifications, and the scope of the invention is not limited to the embodiments described above. Therefore, if a modified embodiment includes elements of the claims of the present disclosure, it should be considered to fall within the scope of the present disclosure.

Claims

1. Multiple battery cells stacked along one direction; A bus bar electrically connected to the plurality of battery cells stacked along the above-described direction; A sensing unit electrically connected to the bus bar to detect the voltage of at least one battery cell among the plurality of battery cells; and A sensing terminal provided between the sensing unit and the bus bar to electrically connect the bus bar and the sensing unit; The above sensing terminal part a joint positioned so as to face at least a portion of the above bus bar; and A battery module characterized by including a plurality of welding areas that connect the above-mentioned joining portion and the above-mentioned sensing terminal portion.

2. In paragraph 1, When welding the above joint and the above bus bar, A battery module characterized in that a plurality of welding beads are formed on the outside of the joint corresponding to the plurality of welding areas.

3. In paragraph 1, A battery module characterized in that a plurality of welding beads formed during welding corresponding to the plurality of welding areas protrude outward from the joint.

4. In either paragraph 2 or paragraph 3, A battery module characterized in that the plurality of welding beads are positioned spaced apart from each other.

5. In paragraph 1, The above multiple welding areas are A plurality of transverse welding areas arranged at preset transverse intervals along the above direction; and A battery module characterized by comprising at least one longitudinal welding area arranged at a preset longitudinal interval in at least one of the plurality of transverse welding areas along the height direction of the bus bar.

6. In paragraph 5, A battery module characterized in that the size of the horizontal gap and the size of the vertical gap are the same.

7. In paragraph 5, When welding the sensing terminal and the bus bar, a plurality of transverse welding beads are formed on the outside of the joint at the transverse interval corresponding to the plurality of transverse welding areas. A battery module characterized in that, when welding the sensing terminal and the bus bar, at least one longitudinal welding bead is formed on the outside of the joint portion at the longitudinal interval corresponding to the at least one longitudinal welding area.

8. In paragraph 1, The above multiple welding areas are A battery module characterized in that it is arranged in a polygonal shape with the center of the plurality of welding areas as each vertex.

9. In paragraph 1, The above multiple welding areas are A battery module characterized in that the plurality of welding areas are arranged in a grid shape with the above-mentioned plurality of welding areas as vertices.

10. In paragraph 1, The above bus bar Including a first bus bar and a second bus bar provided on each side of the above battery cell, The above sensing part A first wire electrically connected to the first bus bar; and A second wire electrically connected to the second bus bar; The above sensing terminal part A first sensing terminal connected to the first bus bar by welding; and A second sensing terminal connected to the second bus bar by welding; The above multiple welding areas are A plurality of first welding areas that are joined to each other when welding the first sensing terminal and the first bus bar; and A battery module characterized by including a plurality of second welding areas that are joined to each other when welding the second sensing terminal and the second bus bar.

11. In paragraph 10, When welding the first sensing terminal and the first bus bar, a plurality of first welding beads are formed on the outside of the first sensing terminal corresponding to the plurality of first welding areas, A battery module characterized in that, when welding the second sensing terminal and the second bus bar, a plurality of second welding beads are formed on the outside of the second sensing terminal corresponding to the plurality of second welding areas.

12. In paragraph 10, The above plurality of first welding areas and the above plurality of second welding areas are each A plurality of transverse welding areas arranged at preset transverse intervals along the above direction; and A battery module characterized by comprising at least one longitudinal welding area arranged at a preset longitudinal interval in at least one of the plurality of transverse welding areas along the height direction of the bus bar.

13. In paragraph 12, Each of the above first sensing terminal and the above second sensing terminal When welding the first sensing terminal and the first bus bar or when welding the second sensing terminal and the second bus bar, a plurality of transverse welding beads are formed at the transverse intervals corresponding to the plurality of transverse welding areas on each outer side of the first sensing terminal and the second sensing terminal, A battery module characterized in that, when welding the first sensing terminal and the first bus bar or when welding the second sensing terminal and the second bus bar, a plurality of longitudinal welding beads are formed at the longitudinal interval corresponding to the plurality of longitudinal welding areas on each outer side of the first sensing terminal and the second sensing terminal.

14. In paragraph 1, The above bus bar A plurality of bus bar plates are included for electrically connecting a preset number of battery cells among the plurality of battery cells; The above multiple busbar plates A battery module characterized in that it is arranged along the above direction.

15. In paragraph 14, The above sensing terminal part A battery module characterized in that it is provided in multiple units so as to correspond one-to-one to the above multiple bus bar plates.

16. In paragraph 1, A battery module characterized in that the above-mentioned joint and the above-mentioned bus bar are pressurized by a welding jig during welding.

17. In paragraph 1, The above sensing part A battery module characterized by including a flexible printed circuit board (FPCB).

18. A method for assembling a battery module, comprising: a plurality of battery cells stacked along a direction; a bus bar electrically connected to the plurality of battery cells stacked along the direction; a sensing unit electrically connected to the bus bar to detect a voltage of at least one battery cell among the plurality of battery cells; and a sensing terminal unit provided between the sensing unit and the bus bar to electrically connect the bus bar and the sensing unit; A busbar connecting step of stacking the plurality of battery cells along the one direction and then connecting them to the busbar; A sensing unit arrangement step of arranging the sensing unit on the plurality of battery cells combined with the bus bar; A jig arrangement step of moving a welding jig toward a joint positioned to face at least a portion of the bus bar among the sensing terminals and contacting the joint; and A welding step of welding the joint and the bus bar using the welding jig; The above welding step is A method for assembling a battery module, characterized in that the joint portion and the bus bar are welded so that a plurality of joint areas joined by the welding are arranged at preset intervals.

19. In paragraph 18, A method for assembling a battery module, characterized in that it further includes a jig separation step for separating the welding jig from the joint after the above welding step is completed.

20. In paragraph 18, A method for assembling a battery module, characterized in that, prior to the jig arrangement step, it further includes a positioning step of overlapping at least a portion of the bus bar and the joint portion for welding the joint portion and the bus bar.

Images