Electrolyte leakage detector using insulation resistance and battery module including the electrolyte leakage detector

Abstract

The present invention relates to a battery module including an electrolyte leakage detector and an electrolyte leakage detector, the electrolyte leakage detector being provided at a lower portion of a pouch-type battery cell and detecting electrolyte leakage by measuring an insulation resistance or voltage of an external frame electrically connected to the electrolyte leakage detector.

Description

[Technical Field]

[0001] (Reference to Related Application) This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0126496, filed October 4, 2022, the entire contents of which are incorporated herein by reference.

[0002] (Technical field) The present invention relates to an electrolyte leakage detector using an insulation resistor and a battery module including such an electrolyte leakage detector, and more specifically to a detector disposed inside a battery module or a battery pack that detects electrolyte leaking from a battery cell using an insulation resistor, and a battery module or a battery pack including the detector. [Background technology]

[0003] A secondary battery is configured as a battery pack by connecting a plurality of battery cells in series and / or parallel to form a battery module according to the required output voltage or charge / discharge capacity, and further connecting these battery modules.

[0004] Pouch-type batteries, in which a stack-type or stack / folding-type electrode assembly is housed in a pouch-type battery case made of a laminate sheet, are also widely used in battery modules or battery packs due to advantages such as low manufacturing costs and high energy density.

[0005] Pouch-type batteries are typically manufactured by molding a laminate sheet including an outer coating layer, a metal barrier layer, and an inner adhesive layer into a battery case. An electrode assembly and an electrolyte are placed in a receiving portion of the laminate sheet and then sealed to form a pouch-type battery.

[0006] As shown in FIG. 1, a pouch-type battery 50 has an electrode assembly 20 housed in a housing 13 of a battery case 10, which is made up of a pouch-type lower section 11 and a pouch-type upper section 12. The electrode assembly 20 has positive and negative electrode tabs 21 and 22 welded to two electrode leads 31 and 32, respectively, which are exposed to the outside of the battery case 10. The outer periphery of the battery case 10 is sealed with a pair of insulating films 41 and 42 interposed between the upper and lower sections of the electrode leads 31 and 32.

[0007] 1 illustrates an example in which the positive and negative electrode tabs 21, 22 are positioned in the same direction. That is, in FIG. 1, the positive and negative electrode tabs 21, 22 are positioned only in the +x direction on a plane parallel to the yz plane of the electrode assembly 20. If the positive and negative electrode tabs 21, 22 are positioned in different directions on the electrode assembly 20, that is, if they are positioned in the +x and −x directions on a plane parallel to the yz plane of the electrode assembly 20 in FIG. 1, the folded edge of the battery case, i.e., the folded edge located on the y-axis in FIG. 1, is rotated counterclockwise and positioned on the x-axis.

[0008] Pouch-type batteries, in which electrode tabs are located on both sides of an electrode assembly, are often used in battery modules or battery packs. A battery cell assembly is formed by vertically arranging a plurality of pouch-type batteries, each having a positive electrode tab and a negative electrode tab on one side, and bus bars are disposed on both ends of the battery cell assembly to electrically connect the positive electrode tab and the negative electrode tab, or more specifically, the positive electrode lead and the negative electrode lead. The bus bars disposed on both ends of the battery cell assembly may be electrically connected to each other.

[0009] 2 is an exploded perspective view schematically illustrating the structure of a conventional battery module 100. Referring to FIG. 2, the battery module 100 includes a battery cell assembly 110 formed by stacking battery cells 111, each having electrode leads 112 disposed on both sides thereof; a bus bar frame 120 including a first vertical plate 121 and a second vertical plate 122 disposed on both sides of the battery cell assembly 110 corresponding to the positions of the electrode leads 112 of the battery cells 111, and an upper plate 123 connected to the first vertical plate 121 and the second vertical plate 122 and disposed on the top of the battery cell assembly 110; and a monoframe 130 formed in a square tube shape so that the battery cell assembly 110 with the bus bar frame 120 attached thereto can be inserted into an internal space. A side frame 140 is then coupled to the monoframe 130 to complete the battery module 100.

[0010] The bus bars 126 are disposed on the first vertical plate 121 and the second vertical plate 122. The bus bars 126 are used to connect the plurality of battery cells 111 in series or in parallel. The bus bars 126 are conductors with low impedance and high current capacity, and a plurality of bus bars 126 are arranged side by side in the direction in which the plurality of battery cells 111 are stacked, thereby connecting the battery cells 111 in series or in parallel.

[0011] Although the bus bar 126 has a plate-like structure with a uniform thickness, it is not limited thereto and may be modified to have various structures that allow electrical connection.

[0012] In addition to pouch-type batteries, cylindrical or prismatic batteries can also be used to form battery modules or battery packs. After multiple cylindrical or prismatic batteries are vertically arranged, bus bars can be placed on the upper and / or lower surfaces where the electrodes are located.

[0013] After the battery cells 111 and the bus bars 126 are connected, a separate case for fixing them may be provided on the outside.

[0014] When pouch-type batteries, cylindrical batteries, and prismatic batteries are used in battery modules or battery packs, electrolyte leakage from battery cells can cause various problems. Electrolyte leakage can not only degrade the electrical performance of the battery module or battery pack, but can also lead to corrosion, short circuits, and fire risks. In battery modules containing multiple battery cells, early detection of these issues is crucial due to safety concerns.

[0015] Patent Document 1 relates to an apparatus and method for detecting leakage of battery cell electrolyte to protect a battery pack. Patent Document 1 discloses a device including an electrolyte absorbing member attached to the outside of a battery cell to absorb electrolyte leaking from the battery cell and to have conductive properties as a result of this electrolyte absorption, a power supply connected to both ends of the electrolyte absorbing member to apply power, a resistor connected between the electrolyte absorbing member and the power supply, a sensing unit that detects whether current flows through the resistor, and a control unit that, when the sensing unit detects that current flows through the resistor, melts a fuse on a charge / discharge path of the battery pack to cut off the charge / discharge current.

[0016] Although Patent Document 1 has the feature of being able to protect a battery module or a battery pack by detecting leaked electrolyte, the overall structure is very complicated, as it absorbs the electrolyte and detects whether current is flowing, etc. In particular, the electrolyte absorbing member must be separately attached to the outside of each battery cell, and the multiple additional members occupy space, which results in a problem of low energy density.

[0017] Patent Document 2 relates to a battery module and a battery pack including the battery module, in which a film-type sensor for detecting electrolyte leakage is attached to both sides of a bus bar frame slit. The exterior of the film-type sensor is provided with an insulating coating layer, which is made of a material that reacts with and dissolves in an organic solvent, i.e., the electrolyte.

[0018] In Patent Document 2, when electrolyte leaks, the electrolyte moves to the lower end due to gravity, so unless a certain amount of electrolyte leaks, it is difficult to detect the leakage.In fact, there is a problem that the leaking electrolyte flows out between the slits, making early detection difficult.

[0019] Furthermore, electrical connections are required for each individual position where the sensor is attached, which requires a complex structure and can cause interference with the bus bar due to the electrical connections.

[0020] Patent Document 3 relates to a device for detecting electrolyte leakage in a battery module / pack, in which a conducting wire parallel to a strip containing a wiring portion is buried in the bottom of the battery module / pack, a wire window is formed to induce a capillary effect, and in the event of electrolyte leakage, both conducting wires are short-circuited, and the presence of battery leakage is determined by reading the electrical resistance.

[0021] In the case of Patent Document 3, the wiring for detecting the electrolyte is embedded in a separate bottom plate, but it can only detect when the amount of leaked electrolyte exceeds a predetermined amount. Patent Document 3 states that it can only detect when the amount of leaked electrolyte exceeds 8 ml.

[0022] Patent Document 3 is difficult to apply to battery modules or packs that use pouch-type batteries. Because the bottom of a pouch-type battery is connected without a separate seal, the only areas where electrolyte can leak are the sides or top. If electrolyte leaks to the top, the battery cells are stacked vertically, the gaps between them are very narrow, and pads may be provided between them. Therefore, unless the amount is large, the electrolyte that leaks to the top cannot flow to the bottom plate and dries before it reaches the bottom plate.

[0023] In Patent Document 3, the battery must be embedded separately in the bottom plate and must be provided with a capillary-like structure. If the battery is embedded longitudinally as in Patent Document 3, it is virtually impossible to detect leakage of the pouch-type battery at an early stage.

[0024] If electrolyte leaks from both sides of a pouch-type battery, i.e., from the portions where the electrode tabs protrude, the electrolyte will leak down to the lower end of the bus bar frame, and a considerable amount of electrolyte must leak in order for it to flow to the separate bottom plate.

[0025] Patent Document 3 also mentions multiple cases in which the strip-shaped detection groove is located in the center of the bottom plate or along the battery electrodes in the battery module, directly below the electrodes. However, Patent Document 3 first limits the shape of the strip-shaped detection groove. In the case of a pouch-type battery, since both side electrodes must first be connected to the bus bar frame, the strip-shaped detection groove in Patent Document 3 can only be located below the bus bar frame. In this case, early detection of trace amounts is impossible. Patent Document 3 also limits the minimum detectable amount to more than 8 ml.

[0026] It can be seen that early detection is impossible for pouch-type batteries in either the examples of Patent Document 3 or when it is placed under the electrodes. Considering that Patent Document 3 describes that the strip-shaped detection grooves are arranged in the longitudinal direction, directly above the electrodes, or that multiple grooves are arranged, this appears to be in consideration of the use of cylindrical battery cells.

[0027] Patent Document 4 relates to an electricity storage device that can detect abnormalities (electrolyte leakage) in electricity storage elements at an early stage. In Patent Document 4, the electricity storage device includes a plurality of electricity storage elements that contain electrolyte and are charged and discharged, and a holder that maintains each of the plurality of electricity storage elements in an insulated state within a predetermined plane (within the YZ plane). The holder has a conductive member exposed to the outside of the holder, and the conductive member is positioned in the direction of movement of the electrolyte leaking from each electricity storage element. The conductive member is connected to a sensor that detects the conductive state and non-conductive state of the conductive member.

[0028] Patent Document 4 measures insulation resistance and detects electrolyte leakage, but can only detect leakage of electrolyte in large amounts.

[0029] Thus, to date, there has been no technology provided that i) can detect minute amounts of electrolyte leakage early, ii) has a simple structure, and iii) can be applied without interfering with the configuration of conventional devices. [Prior art documents] [Patent documents]

[0030] [Patent Document 1] Korean Patent No. 10-1383599 [Patent Document 2] Korean Patent Publication No. 10-2021-0108269 [Patent Document 3] Chinese Patent Publication No. 111337201 [Patent Document 4] Japanese Patent Application Laid-Open No. 2014-63663 Summary of the Invention [Problem to be solved by the invention]

[0031] The present invention has been made to solve the above problems, and aims to provide an electrolyte leakage detector and a battery module including the same, which i) can detect a small amount of electrolyte leakage early, ii) has a simple structure, and iii) can be applied without interfering with the configuration of a conventional device. [Means for solving the problem]

[0032] To achieve the above-mentioned object, a battery module according to the present invention includes battery cells, vertical plates including bus bars to which electrodes of the battery cells are electrically coupled, and an outer frame surrounding the outer sides of the vertical plates and the battery cells, and further includes one or more electrical connecting parts that pass through the vertical plates and are electrically connected to the outer frame, and a sensing part that measures the insulation resistance or voltage of one of the terminal electrodes of the battery module and the outer frame.

[0033] In addition, in the battery module according to the present invention, the vertical plate may include a vertical support portion disposed vertically, a portion of the vertical support portion having a shape of a plurality of slits cut vertically, electrode grooves through which electrodes of the battery cells pass, a bus bar coupled to the electrodes that have passed through the electrode grooves, and a horizontal band-shaped lower end support portion coupled along a lower periphery of the vertical support portion.

[0034] In addition, in the battery module according to the present invention, the electrical connection portion may include at least one vertical connection portion that penetrates the lower end support portion and is electrically connected to one end of the outer frame, and an upper surface connection portion that is electrically connected to the vertical connection portion and is exposed to or disposed on an upper surface of the lower end support portion.

[0035] In addition, in the battery module according to the present invention, the electrical connection part may include at least one outer frame connection part electrically connected to one end of the outer frame, and an upper surface connection part electrically connected to the outer frame connection part and exposed to or disposed on an upper surface of the lower end support part.

[0036] In addition, in the battery module according to the present invention, the upper surface connectors may be spaced apart from the battery cells without contacting them.

[0037] In addition, in the battery module according to the present invention, when electrolyte leaks from the battery cells, the upper connection parts can be electrically connected to the battery cells by the leaked electrolyte.

[0038] In addition, in the battery module according to the present invention, the top connection part may be located below where the electrodes of the battery cells are disposed.

[0039] In addition, in the battery module according to the present invention, the top connector and the vertical connector may be made of a conductive material.

[0040] In the battery module according to the present invention, the upper surface connecting portion may be a thin metal strip and may be disposed on the upper surface of the lower end support portion on which the electrodes of the battery cells are disposed.

[0041] In addition, in the battery module according to the present invention, the vertical connectors may be located and fixed to one or both sides of the top connector.

[0042] In the battery module according to the present invention, the upper surface connecting parts may be circular and spaced apart from each other on the upper surface of the lower end support part on which the electrodes of the battery cells are disposed.

[0043] In addition, in the battery module according to the present invention, the outer frame connector may be an electric wire that electrically connects the upper connector and the outer frame.

[0044] The method for detecting electrolyte according to the present invention is a method for detecting electrolyte by measuring the insulation resistance or voltage of the outer frame and determining that electrolyte has leaked if the measured resistance or voltage is outside a reference range.

[0045] The present invention can also be provided as a configuration in which the above-mentioned problems to be solved are combined in any desired manner. [Effects of the Invention]

[0046] As described above, the present invention provides an electrolyte leakage detector and a battery module including such an electrolyte leakage detector that: i) can detect even a small amount of electrolyte leakage early; ii) has a relatively simple structure since it is only necessary to measure the insulation resistance or voltage of the external frame; and iii) can be applied without interfering with the configuration of a conventional device. [Brief explanation of the drawings]

[0047] [Figure 1] FIG. 1 is an exploded perspective view of a pouch-type battery according to the prior art. [Figure 2] FIG. 1 is an exploded perspective view schematically illustrating the structure of a battery module according to the prior art. [Figure 3] 1 is a perspective view of a pouch-type battery cell to be mounted in a battery module according to a preferred embodiment of the present invention; [Figure 4]2 is a schematic view of the inner side of the vertical plate of the battery module according to the present invention; FIG. [Figure 5] 2 is a schematic view of the outer side of the vertical plate of the battery module according to the present invention; FIG. [Figure 6] 1 is a schematic diagram showing a battery module including an outer frame according to the present invention; [Figure 7] 2 is a side view of an electrical connection according to an embodiment of the present invention; FIG. [Figure 8] FIG. 10 is a schematic plan view of an electrical connection portion according to yet another embodiment of the present invention. [Figure 9] 10A and 10B are diagrams showing a sensing unit for measuring the insulation resistance of an outer frame according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0048] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person skilled in the art to easily carry out the present invention. However, when describing the operation principle of a preferred embodiment of the present invention in detail, if it is determined that a detailed description of related well-known functions or configurations may unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0049] Furthermore, throughout the drawings, the same reference numerals are used for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0050] Hereinafter, an electrolyte leakage detector and a battery module including the electrolyte leakage detector according to the present invention will be described with reference to the accompanying drawings.

[0051] The basic structure of the battery module according to the present invention is similar to that of a conventional battery module using pouch-type batteries. FIG. 2 is an exploded perspective view schematically illustrating the structure of a conventional battery module. Compared to the case of FIG. 2, the pouch-type battery may be modified to have electrodes disposed on only one side as shown in FIG. 1, and the bus bar frames may not be connected to each other at their upper ends. Even in the case of a pouch-type battery having electrodes disposed on both sides, the configuration is not limited to the bus bar frame 120 of FIG. 2, and any configuration may be used as long as the bus bars on both sides are electrically connected. Furthermore, the monoframe 130 and side frame 140 of FIG. 2 are merely examples, and may be modified to any configuration as long as they can function as an outer case surrounding the battery module.

[0052] FIG. 3 is a perspective view of a battery cell mounted in a battery module according to an embodiment of the present invention.

[0053] As shown in FIG. 3, a pouch-type battery or battery cell 60 includes an upper cell casing 62, a lower cell casing 61, electrode assemblies (not shown) housed inside the upper and lower cell casings, sealing portions 65 at the upper and lower ends of the cell casing, a pair of electrode tabs (not shown), a pair of electrode leads consisting of a positive electrode lead 66 and a negative electrode lead 67, one side of which is electrically connected to the electrode tab and the other side of which protrudes outside the cell casing, and an insulating film (not shown).

[0054] In detail, the cell case upper part 62 and the cell case lower part 61 are provided with pocket-like spaces for accommodating the electrode assembly.

[0055] The cell case uses a laminate sheet consisting of an outer coating layer, a metal layer, and an inner coating layer to form a space capable of housing the electrode assembly.

[0056] The inner coating layer must have insulating and electrolytic resistance properties because it is in direct contact with the electrode assembly, and must also have sealing properties to seal against the outside. That is, the sealing portions where the inner layers are thermally bonded together must have excellent adhesive strength.

[0057] The material for such an inner coating layer may be selected from polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, which have excellent chemical resistance and sealing properties, polyurethane resins, and polyimide resins, but is not limited thereto. Polypropylene is preferred because of its excellent mechanical properties such as tensile strength, rigidity, surface hardness, and impact strength, as well as chemical resistance.

[0058] The metal layer in contact with the inner coating layer corresponds to a barrier layer that prevents moisture and various gases from penetrating into the battery from the outside, and a suitable material for such a metal layer is an aluminum thin film, which is lightweight yet has excellent formability.

[0059] The outer surface of the metal layer is provided with an outer coating layer, which may be made of a heat-resistant polymer having excellent tensile strength, moisture-proof properties, and air-proof properties to protect the electrode assembly and ensure heat resistance and chemical resistance, such as, but not limited to, nylon or polyethylene terephthalate.

[0060] The electrode assemblies housed inside the upper cell case 62 and the lower cell case 61 can be classified into a stack type electrode assembly in which a plurality of electrodes are stacked, a jelly roll type electrode assembly in which a separator is interposed between a positive electrode and a negative electrode and the electrode is wound up, a lamination / stack type electrode assembly in which a plurality of unit cells are stacked, and a stack / folding type electrode assembly in which a unit cell is positioned on a separator sheet and the electrode is wound up.

[0061] To manufacture the lamination / stack type electrode assembly or stack / folding type electrode assembly, a unit cell is prepared. The unit cell may be a mono-cell in which a separator is interposed between a positive electrode and a negative electrode, or a bi-cell in which a positive electrode, a negative electrode, and a positive electrode, or a negative electrode, a positive electrode, and a negative electrode, are stacked and a separator is interposed between the positive electrode and the negative electrode.

[0062] The electrode assembly according to the present invention may have a stacked structure of anode / separator / cathode / separator / anode. It goes without saying that the number of cathodes and anodes constituting the electrode assembly may be freely set. A lamination / stack type electrode assembly in which a plurality of unit cells are laminated may also be used. The electrode assembly structure may be applied to all electrode assemblies described herein.

[0063] The positive and negative electrodes of the electrode assembly are provided with a positive electrode tab and a negative electrode tab, respectively, and these paired tabs are connected to the positive electrode lead 66 and the negative electrode lead 67, respectively, by spot welding or the like, and are arranged to protrude to the outside of the cell case by a predetermined length.

[0064] The insulating films are located on the upper and lower surfaces of the pair of electrode leads, more specifically, at the sealing portion 65 where the cell case upper portion 62 and the cell case lower portion 61 are heat-sealed. The insulating films prevent electricity generated in the electrode assembly from flowing to the cell case via the electrode leads and maintain a sealed state between the electrode leads and the cell case. The insulating film is preferably made of a non-conductive material that does not conduct electricity well. Typically, insulating tape, which is easily attached to the electrode leads and has a relatively thin thickness, is used, but is not limited to this.

[0065] In the drawings, the battery cell is shown as being bidirectional, with the positive electrode lead 66 and the negative electrode lead 67 located at opposite ends, but the present invention can also be applied to a non-uniform battery cell in which the pair of electrode leads are arranged in the same direction.

[0066] During the use of a battery module, repeated charging and discharging can cause separation of the heat-sealed sealing portion of a pouch-type battery, i.e., deterioration of the heat-sealed portion due to expansion pressure caused by gas generated by an irreversible reaction or repeated use of a high current such as during rapid charging can lead to leakage of the electrolyte.

[0067] In addition, electrolyte leakage can occur due to various reasons, such as the case being broken due to external impact or chemical corrosion.

[0068] Since the bottom surface of a pouch-type battery arranged vertically inside a battery module is connected without any separate sealing, the only areas where electrolyte can leak are the side or top surface of the pouch-type battery. If electrolyte leaks to the top surface, the battery cells are stacked vertically, the gaps between them are very narrow, and pads may be provided between them. Therefore, unless the amount is large, the electrolyte that leaks to the top surface cannot flow to the bottom plate and dries before it reaches the bottom plate.

[0069] If electrolyte leaks from both sides of a pouch-type battery, i.e., from the portions where the electrode tabs protrude, the electrolyte will leak down to the lower end of the bus bar frame, and a considerable amount of electrolyte must leak in order for it to flow to the separate bottom plate.

[0070] FIG. 4 is a schematic view of the inside of a vertical plate of a battery module according to the present invention, FIG. 5 is a schematic view of the outside of a vertical plate of a battery module according to the present invention, and FIG. 6 is a schematic view showing a battery module including a configuration in which electrodes of pouch-type cells are fastened to a vertical plate 200 and an external frame.

[0071] 4 to 6, vertical plates 200 are disposed on the left and right sides of the battery cell assembly in the battery module. In the vertical plates 200 in Figures 4 to 6, the circuit portion including bus bars for electrical connection is omitted.

[0072] The vertical plate 200 may include a vertically disposed vertical support portion 220, electrode grooves 240 formed by vertically cutting a number of slits in a portion of the vertical support portion 220 and through which electrodes of the pouch-type battery cells pass, a bus bar (not shown) coupled to the electrodes passing through the electrode grooves 240, and a horizontal band-shaped lower support portion 260 coupled along the lower periphery of the vertical support portion 220. The vertical plate 200 may be symmetrically positioned on one side or both sides depending on the shape and position of the electrodes of the battery cells.

[0073] The external frame 300 is a single frame that protects the vertical plate 200 and the pouch-type battery cells from the outside and may be composed of a mono-frame 310 and a side frame 320. The external frame 300 may be modified into various shapes, but is not limited thereto. Unlike the mono-frame 310 of FIG. 6, the external frame 300 may be configured as a metal frame, and the electrical connector 270 described below may be connected to such a frame-shaped external frame. In this case, a separate cover may also be provided. The lower end support 260 of the vertical plate 200 is fixed to the lower part of the external frame 300.

[0074] The electrical connection part 270 according to the present invention is disposed on the upper surface of the lower end support part 260. In Fig. 4, the electrical connection part 270 is simply shown by a black line.

[0075] Referring to FIG. 6, the electrical connection part 270 is electrically connected to the monoframe 310, and when electrolyte leaks from the battery cell, electricity is passed between the battery cell and the monoframe 310 through the electrical connection part 270.

[0076] In a normal state where there is no electrolyte leakage, a certain distance is maintained between the electrical connector 270 and the battery cell, resulting in an insulated state, and the monoframe 310 is also insulated. However, if leakage occurs and electricity flows between the monoframe 310 and the battery cell, a leakage current may occur, which may result in a change in insulation resistance or voltage.

[0077] Specific embodiments of the electrical connection part 270 and a method for measuring the insulation resistance or voltage will be described in detail below with reference to FIGS.

[0078] FIG. 7 is a schematic side view of electrical connectors 270A and 270B according to one embodiment of the present invention, and FIG. 8 is a schematic plan view of electrical connectors 270A and 270C according to yet another embodiment of the present invention.

[0079] 7, the electrical connections 270A and 270B are formed by connecting the conductive upper connection portion 271A and the vertical connection portion 272A or by connecting the upper connection portion 271B and the outer frame connection portion 273, and maintain a certain distance from the battery cell without contacting it. The distance is preferably sufficient to ensure electrical connection when electrolyte leaks into the upper connection portions 271A and 271B. The upper connection portions 271A and 271B are located below the electrodes of the battery cell (e.g., battery cell 60 in FIGS. 3 and 6).

[0080] 7(a), the upper surface connector 271A is located on the upper surface of the lower end support part 260, and the upper surface connector 271A and the monoframe 310 are connected to each other via the vertical connector 272A. Meanwhile, since the vertical connector 272A must pass through the lower end support part 260 and be fixed to the monoframe 310, it may preferably be in the form of a bolt or a rivet, but is not limited thereto. The entire electrical connector 270A may also be in the form of a simple cylinder, unlike that shown in FIG. 7(a).

[0081] 7(b), as a form of the electrical connector 270B according to the modified embodiment of the present invention, the upper connector 271B is directly connected to the monoframe 310 via the outer frame connector 273 without the vertical connector 272A, and the form is not limited as long as it is an electric wire or a flexible flat cable (FFC) electrically connected to one side of the monoframe 310. Here, it is sufficient that the upper connector 271B is fixed to the lower end support 260 by being adhered.

[0082] FIG. 8 is a plan view showing the electrical connecting portion 270A located on the upper surface of the lower end support portion 260 of FIG.

[0083] 8(a), the upper surface connecting portion 271A is configured in the shape of a thin metal strip and is located on the upper surface of the lower end support portion 260, and both ends of the upper surface connecting portion 271A are fixed by the vertical connecting portions 272A. Here, the vertical connecting portion 272A is not particularly limited to a specific location as long as it is connected to the upper surface connecting portion 271A and electrically connected to the monoframe 310. In FIG. 8(a), the upper surface connecting portion 271A may be in a form separated into multiple portions, and each separated portion may have a vertical connecting portion 272A.

[0084] 8(b), the upper connecting portion 271C is formed integrally with the vertical connecting portion 272C, and at least one is disposed directly below the battery cell pouch. The upper connecting portion 271C may have various shapes, but a circular shape is preferred.

[0085] FIG. 9 shows a sensing unit 330 for measuring the insulation resistance or voltage of the monoframe 310 according to the present invention.

[0086] 9, the sensor 330 measures the insulation resistance or voltage between the monoframe 310, which is connected to ground, and the external electrode of the pouch-type battery cell. Before leakage occurs, a measurement of several hundred megaohms (Mohms) is made at 500V for 60 seconds. However, when the electrolyte 280 leaks, current flows between the upper connector 271 and the battery cell, resulting in a decrease in insulation resistance or an increase in voltage. Although not shown in FIG. 9, the sensor 330 that detects the insulation resistance or voltage may be included in the module BMS or the battery pack BMS.

[0087] In addition, if electrolyte 280 leaks from multiple pouch-type battery cells, a leakage current equal to the number of pouch-type battery cells that are conducting current is generated, further reducing the insulation resistance. The degree of electrolyte 280 leakage can be detected based on the reduced resistance value compared to the reference insulation resistance value.

[0088] Although certain parts of the present invention have been described in detail above, it will be apparent to those skilled in the art that such specific descriptions are merely preferred embodiments and do not limit the scope of the present invention. It is obvious to those skilled in the art that various changes and modifications are possible within the scope and technical spirit of the present invention, and it goes without saying that such changes and modifications fall within the scope of the appended claims. [Explanation of symbols]

[0089] 10 Battery case 11 Pouch type lower part 12 Pouch-type upper part 13 Storage section 20 Electrode assembly 21, 22 Electrode tabs 31, 32, 66, 67 Electrode leads 41, 42 Insulating film 50, 60 pouch type battery / battery cell 61 Cell case bottom 62 Cell case top 65 Sealing part 100 battery modules 110 Battery cell assembly 111 Pouch-type battery / battery cell 112 Electrode Lead 120 Busbar Frame 121 1st vertical plate 122 2nd vertical plate 123 Upper Plate 126 Busbar 130 Monoframe 140 Side Frame 200 vertical board 220 Vertical support 240 Electrode groove 260 Lower end support part 270, 270A, 270B, 270C Electrical Connections 271A, 271B, 271C Top connection part 272A, 272C Vertical connection 273 External frame connection 280 Electrolyte 300 External Frame 310 Monoframe 320 Side Frame 330 Sensing part

Claims

1. A battery cell; a vertical plate including a bus bar to which the electrodes of the battery cells are electrically coupled; an outer frame surrounding the vertical plate and the exterior of the battery cell; A battery module, one or more electrical connection portions that penetrate the vertical plate and are electrically connected to the outer frame; a sensing unit for measuring an insulation resistance or a voltage between one of the terminal electrodes of the battery module and the outer frame, When an electrolyte leaks from the battery cell, the electrical connection part is electrically connected to the battery cell by the leaked electrolyte. Battery module.

2. The vertical plate is a vertical support disposed vertically; a plurality of slits formed in a vertical direction in a portion of the vertical support portion, the slits forming electrode grooves through which the electrodes of the battery cells pass; a bus bar coupled to the electrode that has passed through the electrode groove; a lower end support portion connected along a lower periphery of the vertical support portion and having a horizontal band shape; The battery module according to claim 1 .

3. The electrical connection at least one vertical connection portion that penetrates the lower end support portion and is electrically connected to one end of the outer frame; an upper surface connection portion electrically connected to the vertical connection portion and disposed on an upper surface of the lower end support portion; The battery module according to claim 2 .

4. The electrical connection At least one outer frame connection portion electrically connected to one end of the outer frame; an upper surface connection portion electrically connected to the outer frame connection portion and disposed on an upper surface of the lower end support portion; The battery module according to claim 2 .

5. The battery module according to claim 3 , wherein the upper surface connectors are spaced apart from the battery cells and do not come into contact with the battery cells.

6. The battery module of claim 3 , wherein the upper connection portion is electrically connected to the battery cell by the leaked electrolyte when the electrolyte of the battery cell leaks.

7. The battery module according to claim 3 , wherein the upper surface connectors are located below the electrodes of the battery cells.

8. The battery module of claim 3 , wherein the top connection portion and the vertical connection portion are made of a conductive material.

9. The battery module according to claim 3 , wherein the upper surface connecting portion is a thin metal strip and is disposed on the upper surface of the lower end support portion on which the electrodes of the battery cells are disposed.

10. The battery module of claim 3 , wherein the vertical connector is located on one or both sides of the top connector and fixed thereto.

11. The battery module according to claim 3 , wherein the upper surface connecting parts are circular and spaced apart from each other on the upper surface of the lower end support part on which the electrodes of the battery cells are arranged.

12. The battery module according to claim 4 , wherein the outer frame connecting portion is an electric wire that electrically connects the upper surface connecting portion and the outer frame.

13. A method for detecting electrolyte leakage from a battery cell using the battery module according to claim 1, comprising: measuring the insulation resistance or voltage of the outer frame, and determining that the electrolyte is exposed if the measured insulation resistance decreases or the measured voltage increases compared to a reference value; method.

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