Battery module with improved safety

Abstract

To provide a battery module configured to improve safety when a thermal event occurs inside the battery module, and a battery pack and a vehicle including the same.SOLUTION: The present invention discloses a battery module, etc., configured to improve safety when a thermal event occurs inside a battery module. The battery module according to an aspect of the present invention includes a cell assembly having a plurality of battery cells electrically connected to each other via electrode leads, a module case that houses the cell assembly in an internal space, and a cover member attached to a side of the cell assembly from which the electrode leads protrude in the internal space of the module case.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2021-0181113 filed on December 16, 2021 and Korean Patent Application No. 10-2022-0166952 filed on December 2, 2022, and all the contents disclosed in the specifications and drawings of those applications are incorporated herein by reference.

[0002] The present invention relates to a battery, and more particularly, to a battery module with improved safety, a battery pack including the same, and an automobile.

Background Art

[0003] [[ID=十六]]In recent years, the demand for portable electronic products such as notebook computers, video cameras, and mobile phones has been rapidly increasing, and as the commercialization of robots, electric vehicles, etc. has been in full swing, research on high-performance secondary batteries that can be repeatedly charged and discharged has been actively conducted.

[0004] …… Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, etc. Among them, lithium secondary batteries have attracted attention because they can be freely charged and discharged because they hardly have a memory effect compared to nickel-based secondary batteries, have a very low self-discharge rate, and have a high energy density.

[0005] This type of lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate coated with such a positive electrode active material and a negative electrode active material are arranged with a separator interposed therebetween, and an exterior material that encloses the electrode assembly together with an electrolytic solution, that is, a battery case.

[0006] Generally, lithium-ion secondary batteries can be broadly classified into two types based on the shape of their casing: can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in an aluminum laminate sheet pouch.

[0007] Recently, secondary batteries are widely used not only in small devices such as portable electronic devices, but also in medium and large devices such as electric vehicles and energy storage systems (ESS) for propulsion and energy storage. Multiple such secondary batteries can be electrically connected and housed together inside a module case to form a single battery module. Furthermore, multiple such battery modules can be connected to form a single battery pack.

[0008] However, when multiple secondary batteries (battery cells) or multiple battery modules are densely packed into a small space, they can be vulnerable to thermal events. In particular, if an event such as thermal runaway occurs in one battery cell, high-temperature gases, flames, and heat may be generated. If such gases, flames, and heat are transferred to other battery cells contained within the same battery module, there is a risk of an explosive chain reaction such as thermal propagation. Such a chain reaction can cause accidents such as fires and explosions not only in the battery module in question, but also in other battery modules.

[0009] Furthermore, in the case of medium to large battery packs, such as those found in electric vehicles, numerous battery cells and modules are included to increase output and / or capacity, which can significantly increase the risk of thermal chain reactions. Moreover, in the case of battery packs installed in electric vehicles, there may be users such as drivers around. Therefore, if a thermal event occurring in a particular battery cell or module cannot be properly controlled and a chain reaction occurs, it could cause not only significant property damage but also loss of life.

[0010] In particular, in conventional battery modules, an insulating cover may be located where the electrode leads of each battery cell are situated to ensure insulation between the electrode leads and the module case. However, these insulating covers are primarily made of injected plastic and have a problem of being susceptible to flames. Therefore, if flames or vent gases emitted from a particular battery cell are directed towards the insulating cover, the insulating cover will melt and will not be able to properly protect the weld between adjacent electrode leads.

[0011] Furthermore, if the internal ejection generated as the battery cell ignites—that is, the residue left behind as the battery cell and busbar housing melt—directs towards the electrode leads, it could cause an internal short circuit. Also, if the electrode leads become loose during the venting process, they could come into contact with other unconnected electrode leads, potentially causing an internal short circuit. Moreover, the area where the electrode leads are located, i.e., the terrace portion of the battery cell, is a relatively large space, making it highly likely that flames and venting gases will concentrate and flow into it. For this reason, there is concern that the flames and gases could cause thermal runaway in other battery cells.

[0012] Furthermore, module terminals and connector terminals are often located in the same areas as electrode leads, and vent gases and flames can be discharged to the outside of the battery module through gaps or voids formed in these module and connector terminals. In this case, the likelihood of thermal runaway propagation between battery modules increases. [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] Therefore, the present invention was devised to solve the above-mentioned problems, and aims to provide a battery module configured to improve safety when thermal events occur inside the battery module, as well as a battery pack and an automobile including the same.

[0014] However, the technical problems that this invention aims to solve are not limited in any way to those described above, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0015] A battery module according to one aspect of the present invention for achieving the above objective includes a cell assembly comprising a plurality of battery cells electrically connected to each other via electrode leads, a module case housing the cell assembly in its internal space, and a cover member bonded to the side of the cell assembly on which the electrode leads protrude within the internal space of the module case.

[0016] Here, at least a portion of the cover member can be bonded to the electrode leads of a plurality of battery cells arranged in the cell assembly.

[0017] Furthermore, the module case may include a main frame with at least one of its front and rear sides open, and an end plate connected to the open portion of the main frame.

[0018] Furthermore, the cell assembly may be configured such that the electrode lead is positioned on the end plate side, and the cover member may be interposed between the electrode lead of the cell assembly and the end plate.

[0019] Furthermore, the cover member may be configured in a film shape having an adhesive layer on the surface of a base material layer.

[0020] Furthermore, the cover member may be configured in a form filled in the side portion where the electrode lead protrudes in the cell assembly.

[0021] Furthermore, the cover member may be filled between the seal portions of adjacent battery cells.

[0022] Furthermore, the cover member may be filled as a whole from the upper end to the lower end in front of or behind the cell assembly.

[0023] Furthermore, the cover member may be configured such that the upper end and the lower end are bent in the direction of the cell assembly.

[0024] Furthermore, the cover member may be configured to cover as a whole from the upper end to the lower end of the electrode leads of the plurality of battery cells.

[0025] Furthermore, the module case may have vent holes formed in at least one of the upper part and the lower part.

[0026] In addition to these, the battery module according to the present invention may further include a vent unit disposed outside the portion where the vent hole is formed in the module case and configured to allow the vent gas discharged from the vent hole to move.

[0027] Also, a battery pack according to another aspect of the present invention for achieving the above object includes the battery module according to the present invention.

[0028] Furthermore, an automobile according to still another aspect of the present invention for achieving the above object includes a battery module according to the present invention.

Advantages of the Invention

[0029] According to the present invention, even if a thermal event occurs inside the battery module, the safety of the battery module can be ensured at a certain level or higher.

[0030] In particular, according to one aspect of the present invention, when flames or vent gases are generated from a specific cell inside the battery module, the direction of the flames or vent gases can be controlled.

[0031] Furthermore, according to one embodiment of the present invention, it is possible to suppress or block the flames or vent gases from heading toward the electrode lead side.

[0032] Therefore, it is possible to prevent the internal discharge products from adhering to the electrode leads due to the flames or vent gases ejected from a specific battery cell, or to prevent internal short circuits or the like from occurring due to damage or floating of the electrode leads.

[0033] Also, according to such an embodiment of the present invention, since high-temperature gases, flames, etc. do not flow into the electrode lead side of the cell assembly, it is possible to prevent the propagation of thermal runaway between the battery cells.

[0034] Furthermore, according to such an embodiment of the present invention, it is possible to suppress or block the outflow of flames or vent gases into the voids, holes, etc. formed in the module terminals and connector terminals existing in the portion of the module case where the electrode leads are located. Therefore, in this case, it is possible to more effectively prevent the propagation of thermal runaway to other battery modules.

[0035] In addition to these, the present invention may have various other effects, which will be described in the section for each embodiment, or the description of effects that can be easily inferred by a person skilled in the art will be omitted.

[0036] The drawings accompanying this specification illustrate preferred embodiments of the present invention and are intended to further illustrate the technical idea of ​​the invention along with the content of the invention; therefore, the present invention shall not be construed as being limited only to what is shown in the drawings. [Brief explanation of the drawing]

[0037] [Figure 1] This is a schematic perspective view showing the assembled configuration of a battery module according to one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view of some of the components of the battery module. [Figure 3] This is a partial perspective view of the configuration in Figure 2, showing some of the components further broken down. [Figure 4] This is a front view of some of the components in Figure 2. [Figure 5] This is a partial perspective view schematically showing some components of a battery module according to another embodiment of the present invention. [Figure 6] This is a top view of the components of Figure 5. [Figure 7] This is a cross-sectional view taken along the line A3-A3' in Figure 5. [Figure 8] This is a magnified view of section A4 in Figure 7. [Figure 9] This is an enlarged view of section A6 in Figure 7. [Figure 10] This diagram schematically shows some components of a battery module according to yet another embodiment of the present invention, disassembled. [Figure 11] This figure schematically shows the cross-sectional configuration of the battery module in its connected state. [Figure 12]This diagram schematically shows some components of a battery module according to yet another embodiment of the present invention, disassembled. [Figure 13] Figure 12 is a perspective view of the battery module configuration, including its components, as seen from below. [Figure 14] This is a cross-sectional view taken along the line A10-A10' in Figure 13. [Modes for carrying out the invention]

[0038] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in this specification and in the claims are not to be interpreted in their usual or dictionary sense, but rather in a sense and concept corresponding to the technical idea of ​​the present invention, in accordance with the principle that the inventor himself may appropriately define the concept of terms in order to best describe the invention. Therefore, it should be understood that the embodiments described herein and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be a variety of equivalents and modifications that can be substituted thereat the time of this application.

[0039] Figure 1 is a schematic perspective view of the assembled configuration of a battery module according to one embodiment of the present invention; Figure 2 is an exploded perspective view of some components of the battery module of Figure 1; Figure 3 is a partial perspective view of a configuration in which some components of Figure 2 are further exploded; and Figure 4 is a front view of some components of Figure 2.

[0040] Referring to Figures 1 to 4, the battery module according to the present invention includes a cell assembly 100, a module case 200, and a cover member 300.

[0041] The cell assembly 100 may comprise a plurality of battery cells 110, where each battery cell 110 may represent a secondary battery. A secondary battery may comprise an electrode assembly, an electrolyte, and a battery case. In particular, the battery cells 110 arranged in the cell assembly 100 may be pouch-type secondary batteries. However, other forms of secondary batteries, namely cylindrical batteries and prismatic batteries, may also be used in the cell assembly 100 of the present invention.

[0042] Multiple secondary batteries can form a cell assembly 100 by stacking them on top of each other. For example, multiple secondary batteries can be stacked so that they are arranged horizontally (in the X-axis direction in the figure) with each battery standing upright in the vertical direction (in the Z-axis direction in the figure).

[0043] Each battery cell 110 may be equipped with electrode leads 111. In this case, the electrode leads 111 may be located at both ends of each battery cell 110, or at one end. Multiple battery cells 110 may be electrically connected to each other in series and / or in parallel via the electrode leads 111. In this case, the electrode leads 111 of each battery cell 110 may be in contact with each other and directly connected, or they may be indirectly connected via busbars or the like. On the other hand, a secondary battery in which the electrode leads 111 protrude in both directions is sometimes called a bidirectional cell, and a secondary battery in which the electrode leads 111 protrude in one direction is sometimes called a unidirectional cell. In Figure 2, etc., a configuration in which the electrode leads 111 protrude in both forward and backward directions is shown. However, the present invention is not limited in any way by such specific types or forms of secondary batteries, and various forms of secondary batteries already known at the time of filing of the present invention may be used in the cell assembly 100 of the present invention.

[0044] As shown in Figure 2, the module case 200 may be configured to accommodate the cell assembly 100 by forming an internal space, i.e., an empty space inside. Furthermore, the module case 200 may be configured in the shape of a rectangular parallelepiped, as shown in Figures 1 and 2. The cell assembly 100 can be accommodated in the internal space of such a rectangular parallelepiped.

[0045] The cover member 300 may be disposed in the internal space of the module case 200 together with the cell assembly 100. In particular, the cover member 300 may be bonded to the side of the cell assembly 100. Furthermore, the cell assembly 100 may be configured such that the electrode leads 111 protrude in a specific direction, and the cover member 300 may be bonded to the side of the portion of the cell assembly 100 from which the electrode leads 111 protrude.

[0046] For example, referring to Figures 2 and 3, the cell assembly 100 may have six sides (top, bottom, front, rear, left, and right) in a configuration in which multiple battery cells 110 are stacked. In this case, the electrode leads 111 may be arranged on the cell assembly 100 in a configuration that protrudes from specific sides of the cell assembly 100, namely the front and rear sections, as shown in the figures. In this case, the cover member 300 may be bonded to the front and rear sections of the cell assembly 100 where the electrode leads 111 are located.

[0047] The cover member 300 may consist solely of an adhesive material, or it may be configured to include both an adhesive and a non-adhesive material. The cover member 300 may maintain its adhesive properties, or it may be configured to lose its adhesive properties as the adhesive material hardens while it is bonded. Here, "adhesion" may include tackiness.

[0048] According to this embodiment of the present invention, the portion of the cell assembly 100 in which the multiple electrode leads 111 are joined and fixed to each other can be stably maintained. In particular, although the multiple electrode leads 111 can be joined and fixed to each other in a welded form, since the cover member 300 is bonded to the cell assembly 100 in the portion where the electrode leads 111 are located, the welded state of the multiple electrode leads 111 can be stably maintained. Therefore, even if vent gas or flames are generated from a specific battery cell 110 among the various battery cells 110 included in the cell assembly 100, the electrode leads 111 can be protected by the cover member 300. Furthermore, since the welded state and position of the electrode leads 111 can be kept constant by the cover member 300, it is possible to suppress the movement of the electrode leads 111 due to the ejection pressure of vent gas or the pressure of flames. In addition, according to the above embodiment, even if a discharge in the form of molten internal components is ejected from a specific battery cell 110, it is possible to prevent such discharge from adhering to the electrode leads 111 toward the electrode leads 111. Therefore, it is possible to effectively prevent short circuits from occurring inside the battery module, particularly on the electrode lead side, due to the movement of the electrode lead 111 or the adhesion of ejected material.

[0049] Furthermore, according to the above implementation configuration, it is possible to suppress the flow of gases, flames, and discharges ejected from the battery cell 110 in the direction of the electrode lead 111. Therefore, it becomes possible to more effectively prevent the propagation of thermal runaway through the terrace portion where the electrode lead 111 is located in the cell assembly 100.

[0050] In particular, at least a portion of the cover member 300 can be bonded to the electrode leads 111 of a plurality of battery cells 110 arranged in the cell assembly 100.

[0051] For example, as shown in Figures 2 and 3, the electrode leads 111 of the multiple battery cells 110 included in the cell assembly 100 can be connected to each other by means of welding or other methods. In this case, the cover member 300 can be attached in direct contact with the electrode leads 111 of at least some of the battery cells 110. Furthermore, the cover member 300 can be bonded to all of the electrode leads 111 of the battery cells 110 as a whole.

[0052] For example, as shown in Figures 2 to 4, the cover member 300 may be configured to cover the outer surface of the electrode lead 111 by being bonded to at least the outer surface of the electrode lead 111. For example, the electrode lead 111 may be positioned on the front side (in the -Y axis direction in the figures) of the cell assembly 100, and the cover member 300 may be configured to be bonded to the front surface of such front electrode lead 111.

[0053] According to this embodiment of the present invention, the electrode leads 111 arranged in the cell assembly 100 can be directly bonded to the cover member 300. Therefore, it is possible to more effectively prevent ejecta (such as molten particles) from the battery cell 110 from coming into contact with the surface of the electrode leads 111, particularly the outer surface (the front or rear surface). In this case, it is also possible to more effectively restrict the movement of the electrode leads 111 due to gas, flames, etc. Therefore, it is possible to more effectively prevent internal short circuits and the like from occurring on the electrode lead 111 side of the battery module.

[0054] The cover member 300 may be configured adjacent to or in contact with the electrode lead 111. Therefore, the cover member 300 may be made of an electrically insulating material or may contain an electrically insulating material. Furthermore, since the cover member 300 is bonded to the outer surface of the electrode lead 111, it may contain an adhesive or tacky material. The adhesive or tackiness of the cover member 300 may be maintained continuously or may change depending on temperature and other factors.

[0055] The cover member 300 may include various resins and various phase change materials (PCMs) that are already known at the time of filing of the present invention. In particular, the cover member 300 may consist of a thermal conductive material applied to the lower part of the cell assembly 100 inside the battery module, or may be equipped with such a thermal conductive material. For example, the cover member 300 may be equipped with a thermal interface material (TIM) such as thermal grease, thermal paste, or thermal compound. The cover member 300 may also be equipped with a fire extinguishing substance. For example, the cover member 300 may be equipped with calcium carbonate.

[0056] Furthermore, the battery module according to the present invention may further comprise a busbar assembly 400, as shown in Figures 2 and 3. The busbar assembly 400 may be configured to support the electrode leads 111, facilitate the connection of the electrode leads 111 to each other, and enable sensing of voltage and other parameters from the electrode leads 111. In particular, the busbar assembly 400 may comprise a module busbar 410 and a busbar housing 420, as shown in Figure 3.

[0057] Here, the module busbar 410 may be made of an electrically conductive material, i.e., a metallic material. The module busbar 410 may also be configured to electrically connect two or more electrode leads 111 together, or to be connected to one or more electrode leads 111 to transfer sensing information to a control unit such as a Battery Management System (BMS).

[0058] Furthermore, the busbar housing 420 may be made of an electrically insulating material, i.e., a plastic material. In addition, the busbar housing 420 may be configured so that the module busbar 410 is mounted and fixed. Furthermore, the busbar housing 420 may have a slit formed in it, as shown by the part indicated by S1 in Figure 3. The module busbar 410 may be mounted on the outside, i.e., the front side, of the busbar housing 420. In this case, the electrode lead 111 may pass through the slit S1 of the busbar housing 420 and contact the module busbar 410 located on the outside. In particular, the electrode lead 111 may be coupled and fixed to the module busbar 410 individually or in a stack of two or more. In this case, methods such as laser welding or ultrasonic welding may be used as the coupling and fixing method between the electrode lead 111 and the module busbar 410, but in addition, various other fastening methods may be applied.

[0059] The cover member 300 can be attached to the electrode lead 111 with at least a portion located outside the busbar housing 420, i.e., on the front side. For example, as shown in Figures 2 to 4, the electrode lead 111 may be configured to be stacked with the module busbar 410 on the outside of the busbar housing 420, i.e., on the front side. In this case, the cover member 300 can be bonded to the outside of the electrode lead 111, i.e., on the front side. In this case, the cover member 300 can be bonded to the module busbar 410 and / or the busbar housing 420 together with the electrode lead 111. For example, the cover member 300 can be bonded to the front surface of the electrode lead 111, the module busbar 410 and the busbar housing 420. On the other hand, although not shown, the cover member 300 can also be deployed on the rear side of the cell assembly 100 and bonded to the rear electrode lead 111, the rear module busbar 410 and the rear surface of the busbar housing 420 on the rear side of the cell assembly 100.

[0060] Furthermore, the battery module according to the present invention may further include terminal terminals 500 and connector terminals 600.

[0061] Here, the terminal terminal 500 may have a positive terminal and a negative terminal. The terminal terminal 500 is made of an electrically conductive metallic material such as copper or aluminum and can function as a passage for charge and discharge currents by being connected to other components outside the battery module. The connector terminal 600 can also function as a passage for exchanging various information and signals of the cell assembly 100, such as the electrical characteristics of the cell assembly, i.e., the voltage of each battery cell 110 and the overall voltage of the cell assembly 100, with a control component such as a battery management system (BMS). Such terminal terminals 500 and connector terminals 600 are components that are widely deployed in battery modules, and a detailed explanation of them is omitted.

[0062] The terminal terminals 500 and connector terminals 600 may be located in the busbar housing 420, as shown in Figure 3 and other figures. However, the present invention is not necessarily limited to this configuration, and the terminal terminals 500 and connector terminals 600 may also be located in other parts besides the busbar housing 420.

[0063] In such an implementation, the cover member 300 may not be adhered to the terminal terminals 500 or the connector terminals 600. That is, the cover member 300 may be mainly adhered to parts other than the terminal terminals 500 and the connector terminals 600, and configured so that at least a portion of each of the terminal terminals 500 and the connector terminals 600 is exposed to the outside.

[0064] The module case 200 may include a main frame 210 and an end plate 220.

[0065] Here, the main frame 210 may be configured in a form in which at least one of the front or rear is open. In particular, as shown in Figure 2, the main frame 210 may be configured in a form in which the top, bottom, left, and right sides are closed, and the front and rear are open. In this case, the top, bottom, left, and right sides may each be configured as plates, and these four plates may be manufactured as an integrated tubular shape. A main frame 210 of this shape may be called a monoframe. That is, the main frame 210 comprises an upper plate, a lower plate, a left plate, and a right plate, and the internal space can be defined by these plates. The cell assembly 100 can be housed in the internal space of the main frame 210 defined in this way.

[0066] Furthermore, the end plates 220 may be configured to be coupled to the open portions of the main frame 210. For example, as shown in Figures 1 and 2, if the main frame 210 is configured as a monoframe with open front and rear ends, the end plates 220 may be positioned at the front and rear of the main frame 210, respectively, and coupled to the front and rear open portions of the main frame 210. In this case, the internal space of the main frame 210 can be defined at the front and rear by the end plates 220, thereby closing the internal space as a whole.

[0067] In such an implementation, the cell assembly 100 may be configured such that the electrode leads 111 of each battery cell 110 are located on the end plate 220 side. That is, referring to Figure 2, each of the multiple battery cells 110 arranged in the cell assembly 100 may be a pouch-type secondary battery and may be configured in an upright position. That is, the wide surface of the housing portion of each battery cell 110 faces left to right, and the seal portion surrounding the housing portion of each battery cell 110 may be located above, below, in front of, and behind the housing portion. The electrode leads 111 may be located on the front and rear sides of each battery cell 110. The multiple battery cells 110 may be arranged horizontally, particularly in the left to right direction (X-axis direction). Therefore, it can be said that the terrace portion where the electrode leads 111 are located in the seal portion of each battery cell 110 is located on the front and rear sides.

[0068] At least a portion of the cover member 300 may be interposed between the electrode leads 111 of the cell assembly 100 and the end plate 220. That is, at least a portion of the cover member 300 may be located outside (forward or backward) of the electrode leads 111 of each battery cell 110. The cover member 300 is bonded to the electrode leads 111, and the outer surface of the cover member 300 may face the end plate 220.

[0069] This embodiment prevents vent gases and flames emitted from a specific battery cell 110 from heading toward the end plate 220. Furthermore, since the cover member 300 adhered to the electrode lead 111 prevents direct contact between the electrode lead 111 and the end plate 220, there is no need for conventional insulating covers in the form of injection-molded materials, i.e., injection covers, that were included in battery modules. In other words, conventionally, an injection cover in a form physically separated from the electrode lead 111 and the end plate 220 was required for electrical insulation. Moreover, if such an injection cover melted in the presence of flames or gases, it could adhere to the electrode lead and cause internal short circuits. However, according to the above embodiment of the present invention, since the insulating cover adhered to the electrode lead 111 is interposed between the electrode lead 111 and the end plate 220, it becomes possible to remove the conventional injection cover.

[0070] In the above-described configuration, the main frame 210 may be made of a metal material such as aluminum or stainless steel (SUS). Similarly, the end plate 220 may also be made of a metal material, like the main frame 210. In particular, the end plate 220 may be made of the same material as the main frame 210. According to the present invention, since a cover member 300 made of an electrically insulating material can be attached to the outside of the electrode leads 111 of the cell assembly 100, electrical insulation between the cell assembly 100 and the end plate 220 can be maintained even if the end plate 220 is made of a metal material that has electrical conductivity. Alternatively, at least a part of the module case 200 may be made of a non-metallic material such as plastic.

[0071] The cover member 300 may be configured in the form of a film. In particular, the cover member 300 may be made of a polymer material and comprises a base layer having a thin sheet-like structure, wherein an adhesive layer may be provided on at least one surface of such base layer, i.e., the inner surface. For example, referring to the configuration in Figure 3, in the case of a cover member 300 located on the front side of the cell assembly 100, the adhesive may be applied to the rear surface of the base layer.

[0072] Here, the cover member 300 may have a thin thickness of 0.5 mm to 1 mm. However, the thickness of such a cover member 300 can be appropriately designed to other forms depending on various situations and conditions, such as the type, form, and size of the battery cell 110 and the material of the cover member 300.

[0073] Furthermore, the cover member 300 may be configured in a folded shape that encloses the outside of the cell assembly 100. For example, as shown in parts A2 and A2' in Figures 2 and 3, the cover member 300 may be configured in a shape where both horizontal ends are folded. These folded portions may be folded toward the outer surfaces of the two battery cells 110 located on the outermost side of the horizontally stacked cell assembly 100. In particular, the folded portions at both horizontal ends of the cover member 300 may be bonded to the outside of the cell assembly 100. That is, the left and right folded portions of the cover member 300, as shown in parts A2 and A2' in Figures 2 and 3, may be bonded to the left and right surfaces of the cell assembly 100, respectively.

[0074] According to this embodiment of the present invention, the bonding force between the cover member 300 and the cell assembly 100 is improved, preventing deformation of the position and shape of the cover member 300 even when vent gas or flames are generated. Therefore, the protective effect of the cover member 300 on the electrode leads 111 is further improved. Furthermore, according to the above embodiment, by narrowing or eliminating the gap between the cover member 300 and the cell assembly 100, the movement of vent gas or flames to the front and rear sides of the cell assembly 100 can be suppressed even more effectively.

[0075] The cover member 300 can be configured in such a way that it is filled into the side portion of the cell assembly 100 where the electrode leads 111 protrude. This will be explained in more detail with reference to Figures 5 to 7 and others.

[0076] Figure 5 is a schematic partial perspective view showing some components of a battery module according to another embodiment of the present invention. Figure 6 is a top view relating to the components of Figure 5. Furthermore, Figure 7 is a cross-sectional view taken along the line A3-A3' in Figure 5. On the other hand, for the various embodiments included in this specification, including this embodiment, detailed explanations will be omitted for parts that are identical or similar to the descriptions of other embodiments, and the explanation will focus on the differences.

[0077] Referring to Figures 5 to 7, the cell assembly 100 may be configured such that electrode leads 111 protrude from its front side. A module case 200, in particular an end plate 220, may be located on the front side of such a cell assembly 100. In this configuration, the cover member 300 may be configured to be filled into and bonded to the front side of the cell assembly 100.

[0078] For example, the cover member 300 may be configured to fill at least a portion of the space between the front side of the cell assembly 100 and the end plate 220. In this case, the cover member 300 may be initially injected or applied as a viscous and fluid adhesive to fill at least a portion of the space between the front side of the cell assembly 100 and the end plate 220, and then configured to harden. In another example, the cover member 300 may be configured to remain viscous or fluid after being injected or applied to the front side of the cell assembly 100 without hardening.

[0079] In particular, the cover member 300 can be filled between the sealing portions of adjacent battery cells 110. This will be explained in more detail with further reference to Figure 8.

[0080] Figure 8 is an enlarged view of section A4 of Figure 7.

[0081] Referring to Figure 8, the electrode leads 111 of each battery cell 110 included in the cell assembly 100 may protrude forward. In this case, each battery cell 110 may have a sealing portion with the electrode leads 111 interposed therein, with the terrace portion located forward as indicated by T. A gap may be formed between the sealing portions of each battery cell 110, that is, between the terrace portions T of each battery cell 110, as shown by A5. In this case, the cover member 300 may fill the space between the sealing portions of adjacent battery cells 110, that is, the space between the terrace portions of adjacent battery cells 110.

[0082] Furthermore, using one seal section (terrace section) as a reference, the cover member 300 can be filled on the left and right sides of each seal section. Although not shown in Figure 8, the cover member 300 can also be filled on the top and bottom of each seal section. In this case, the cover member 300 can be said to be configured to enclose all of the top, bottom, left, and right portions of the seal section (terrace section).

[0083] According to this configuration of the present invention, when the internal pressure in a particular battery cell 110 increases due to conditions such as thermal runaway, it is possible to prevent rupture on the terrace side where the electrode leads 111 are located. Therefore, it is possible to more effectively prevent vent gas or flames from being directly ejected or exposed on the end plate 220 side. Furthermore, according to the above embodiment, the movement of the terrace is firmly prevented by the cover member 300, thereby restricting the movement of the electrode leads 111 located on the terrace.

[0084] In particular, the cover member 300 is located in front of and / or behind the cell assembly 100, but may be configured to fill the entire area from the top end to the bottom end.

[0085] For example, as shown in Figure 5, the cover member 300 located on the front side of the cell assembly 100 can be filled as a whole from the top end to the bottom end of the cell assembly 100. That is, the filling component between the terraces, such as the part indicated as A5 in Figure 8, can be configured to extend in an elongated manner from the top end to the bottom end of the cell assembly 100.

[0086] Furthermore, the cover member 300 may be configured such that its upper and lower ends are bent in the direction of the cell assembly 100. That is, the cover member 300 may be filled up to the surface of the upper end of the cell assembly 100, as shown in part B1 in Figure 5, and may have a shape that is bent onto the surface of the upper end of the cell assembly 100. In this case, the cover member 300 may be bonded to the upper surface of the cell assembly 100. The cover member 300 may be interposed between the upper surface of the cell assembly 100 and the inner surface (lower surface) of the module case 200.

[0087] Furthermore, the cover member 300 may be filled to the surface of the lower end of the cell assembly 100 and have a shape that is folded over the surface of the lower end of the cell assembly 100, as shown in part B2 in Figure 5. In this case, the cover member 300 may be bonded to the lower surface of the cell assembly 100. The cover member 300 may be interposed between the lower surface of the cell assembly 100 and the inner surface (upper surface) of the module case 200.

[0088] According to this embodiment of the present invention, the movement of vent gas, flames, etc., towards the electrode lead 111 side of the cell assembly 100 can be suppressed even more effectively. That is, in the above embodiment, the space between the front and / or rear sides of the cell assembly 100 and the end plate 220 is narrowed. In addition, the cover member 300 can block the movement of vent gas, flames, etc., discharged to the center of the upper or lower end of the cell assembly 100 towards the end plate 220 side. Therefore, according to this embodiment, various problems caused by the movement of flames and vent gases to the part where the electrode lead 111 is located or towards the end plate 220 side can be prevented even more effectively.

[0089] Furthermore, this configuration improves the coupling between the cover member 300 and the cell assembly 100. Additionally, the above configuration allows the cover member 300 to provide even more robust protection to the electrode leads 111 of the battery cell 110.

[0090] Furthermore, the cover member 300 can be filled horizontally between the body of each battery cell 110 and the busbar assembly 400. For example, referring to Figure 8, the housing portion in each battery cell 110 where the electrode assembly is housed and the busbar assembly 400 can be arranged to be separated by a predetermined distance in the front-to-back direction (Y-axis direction in the figure). In this case, the cover member 300 can be filled in such a form, interposed between the housing portion of the battery cell 110 and the busbar assembly 400, particularly the busbar housing 420. In this case, the cover member 300 can be said to be filled (located) between the housing portion of each battery cell 110 and the electrode leads 111.

[0091] The cover member 300 may also be located horizontally outside the electrode lead 111. This will be explained in more detail with reference to Figure 9, along with Figure 7.

[0092] Figure 9 is an enlarged view of section A6 in Figure 7.

[0093] Referring to Figures 7 and 9, the cover member 300 may be located outside the electrode leads 111. More specifically, the electrode leads 111 may be located on the front side of the cell assembly 100, with different electrode leads 111 in contact with each other. In this case, the electrode leads 111 may be in contact with the module busbar 410 and welded together with the module busbar 410. In such a configuration, the cover member 300 may be located outside the electrode leads 111, i.e., on the front side, as shown in the portion indicated by A7 in Figure 9.

[0094] In this case, the cover member 300 can prevent the electrode lead 111 from being exposed to the outside. Furthermore, the end plate 220 may be located outside the electrode lead 111. Therefore, according to the above embodiment, the cover member 300 can be interposed between the electrode lead 111 and the end plate 220. Thus, if the cover member 300 is made of an electrically insulating material, it is possible to prevent an electrical short circuit between the electrode lead 111 and the end plate 220, even if the end plate 220 is made of a metal material.

[0095] Furthermore, the cover member 300 can be interposed between the electrode leads 111. For example, adjacent electrode leads 111 can be separated from each other, as shown in the portion indicated by A8 in Figure 9. In this case, the cover member 300 can be filled between the electrode leads 111. With this configuration, it becomes possible to more effectively prevent movement of the electrode leads 111 and unintentional contact between them.

[0096] Furthermore, in the above-described embodiment, the cover member 300 may be located outside the busbar assembly 400. That is, referring to the embodiment in Figure 9, the cover member 300 may be located in front of the busbar assembly 400 (towards the Y-axis direction).

[0097] Furthermore, the cover member 300 may be configured to fill both the inside and outside of the busbar assembly 400 together. For example, the cover member 300 may fill both the inside (rear side) and the outside (front side) of the busbar assembly 400, as shown in Figures 7 to 9.

[0098] According to this embodiment of the present invention, the busbar assembly 400, to which the electrode leads 111 are welded, can be securely protected and fixed by the cover member 300. In particular, the busbar housing 420 may be formed from a plastic material, but damage or melting of such a busbar housing 420 due to flames or high-temperature vent gases can be more reliably prevented. In this case, the placement (filling) of the cover member 300 around the busbar assembly 400 can reduce the empty space in the area where the busbar assembly 400 is located. Therefore, in this case, even if flames or vent gases are generated from the cell assembly 100, the safety of the battery module can be more reliably guaranteed.

[0099] On the other hand, if a cover member 300 is provided around the busbar assembly 400, the cover member 300 may be configured not to enclose the terminal terminals 500 or connector terminals 600. That is, as shown in the various drawings mentioned above, the terminal terminals 500 and connector terminals 600 may be configured to be exposed to the outside. This is because such terminal terminals 500 and connector terminals 600 need to be exposed to the outside of the module case 200 and connected to other external components.

[0100] In particular, if the cover member 300 is configured to be filled into the side of the cell assembly 100, a fluid adhesive material for forming the cover member 300 may be injected into the module case 200 in which the cell assembly 100 is housed. In this case, if the fluid adhesive material is injected both in front of and behind the busbar assembly 400, the area around the terminal terminals 500 and connector terminals 600 provided on the top of the busbar assembly 400, especially the top, may be configured so that the adhesive material is not filled. For example, the busbar housing 420 may be equipped with a guide structure such as a partition to prevent the adhesive material for the cover member 300 from flowing around the terminal terminals 500 and connector terminals 600.

[0101] In addition, various structures and manufacturing methods can be applied to ensure that the terminal terminals 500 and connector terminals 600 are not completely enclosed by the cover member 300 but are exposed to the outside.

[0102] The cover member 300 may be configured to cover the electrode leads 111 of the multiple battery cells 110 from their upper ends to their lower ends as a whole.

[0103] For example, as shown in Figure 5, a cover member 300 may be provided to cover the electrode lead 111 located on the front side of the busbar housing 420, so as to cover the entire electrode lead 111 from its upper end to its lower end.

[0104] In particular, the cover member 300 can be configured to completely cover the entire electrode lead 111 arranged in the cell assembly 100 in the vertical direction. That is, the cover member 300 can be configured to cover the electrode lead 111 as a whole. For example, as shown in Figures 2, 4, and 5, if the cover member 300 is arranged on the front side of the cell assembly 100, it can be configured so that the entire outer surface of the electrode lead 111 located on the front side of the cell assembly 100, i.e., the front surface, is not exposed to the front. Therefore, as shown in Figure 4, when the cell assembly 100 is viewed from the front, the electrode lead 111 can be completely enclosed by the cover member 300 and not exposed to the outside.

[0105] According to this embodiment of the present invention, the outside of the electrode lead 111, i.e., the front side, can be more securely protected and fixed by the cover member 300. Therefore, it is possible to more effectively prevent foreign matter, such as molten particles, from adhering to the outside of the electrode lead 111, and to prevent the electrode lead 111 from moving. Furthermore, as shown in the various drawings above, when multiple battery cells 110 are stacked in the left-right direction, vent gas and flames generated in a particular battery cell 110 are likely to flow into the electrode lead 111 side from the top or bottom. Therefore, if the cover member 300 covers the entire electrode lead 111 from its top end to its bottom end, as in the above embodiment, the protective effect on the electrode lead 111 is further improved.

[0106] Figure 10 is a schematic diagram showing some components of a battery module according to yet another embodiment of the present invention in an exploded view. Figure 11 is a schematic diagram showing the cross-sectional configuration of the battery module of Figure 10 when it is assembled. For example, Figure 11 schematically shows the cross-sectional configuration along the A9-A9' arrow in the assembled battery module of Figure 10.

[0107] Referring to Figures 10 and 11, a vent hole may be formed in the module case 200, as indicated by H. The vent hole H may be configured to penetrate the module case 200. In such a configuration, if vent gas is generated and ejected from the cell assembly 100 housed in the internal space of the module case 200, the vent gas can be discharged to the outside of the module case 200 through the vent hole H.

[0108] In particular, the cell assembly 100 may be configured such that a plurality of battery cells 110 are stacked in the left-right direction inside the module case 200, as shown in the various drawings mentioned above. In this case, the vent holes H may be formed on the upper and / or lower sides of the module case 200. That is, the module case 200 may include an upper plate and a lower plate, and the vent holes H may be formed in such upper and lower plates. Furthermore, as shown in Figure 10, the vent holes H may be configured to extend in an elongated shape in the left-right direction, which is the stacking direction of the battery cells 110, in the upper and lower plates.

[0109] According to this embodiment of the present invention, vent gas and flames ejected from the cell assembly 100 can be smoothly discharged to the outside of the module case 200 through the vent holes H. Therefore, the effect of the present invention in preventing vent gas and flames from being directed toward the electrode leads 111 located on the front and rear sides of the cell assembly 100 by the cover member 300 is further enhanced.

[0110] Furthermore, as in the embodiment described above, when multiple battery cells 110 are arranged in the left-right direction and the front and rear sides, i.e., the terrace side, of each battery cell 110 are bonded by the cover member 300, vent gas can be discharged from each battery cell 110 in an upward or downward direction. In this case, as in the embodiment described above, when the vent holes H are formed in the upper and / or lower part of the module case 200, vent gas and the like can easily be directed towards the vent holes H without being directed towards the electrode leads 111.

[0111] Thus, in an embodiment in which the module case 200 is provided with vent holes H, the battery module according to the present invention may further include a vent unit 700, as shown in Figures 10 and 11.

[0112] The vent unit 700 may be positioned on at least one side of the module case 200 so that the vent gas can move. In particular, the vent unit 700 may be positioned on the outside of the module case 200. Furthermore, the vent unit 700 may be configured to be attached to at least the portion of the module case 200 in which the vent hole H is formed. As shown in Figures 10 and 11, if the vent hole H is located at the top, the vent unit 700 may be attached to the top of the module case 200.

[0113] Furthermore, the vent unit 700 may have a vent channel formed inside. That is, as shown by the arrow in Figure 11, the vent unit 700 may be configured so that the vent gas discharged from the vent hole H flows into the internal space, i.e., the vent channel, and can move within the vent channel. In addition, the vent unit 700 may have an outlet formed on at least one side so that the internal vent gas is discharged to the outside. The vent unit 700 may be made of a metallic material such as aluminum or steel.

[0114] According to this embodiment of the present invention, by controlling the path of the vent gas discharged from the module case 200 of the battery module, including its discharge direction and position, damage to users and other equipment caused by high-temperature vent gas can be eliminated or reduced. Furthermore, according to the above embodiment, by bending the vent gas discharge path through the vent unit 700, fire-inducing factors such as flames and sparks can be more effectively suppressed from being discharged to the outside of the battery module. In this case, various forms of blocking structures for blocking substances such as flames and sparks can be arranged inside the vent unit 700. Moreover, according to this embodiment of the present invention, the normal configuration of the battery module, that is, the structure of the module case 200 and the cell assembly 100 arranged inside it, can be maintained without significant changes, and the vent unit 700 can be attached or welded to the outside, making it possible to control various aspects of the vent gas with a relatively simple manufacturing process and a simple structure.

[0115] Figure 12 is a schematic diagram showing some components of a battery module according to yet another embodiment of the present invention in an exploded view. Figure 13 is a perspective view of the battery module configuration, including the components of Figure 12, viewed from below. Figure 14 is a cross-sectional view taken along the line A10-A10' in Figure 13. This embodiment will be described focusing on the differences from the embodiments described above.

[0116] Referring to Figures 12 to 14, the cover member 300 may be substantially the same as that in Figure 5, and may be configured to cover the sides of the cell assembly 100, particularly the front and / or rear sides of the cell assembly 100 where the electrode leads 111 are located. However, unlike in Figure 5, the cover member 300 may not completely cover the entire side of the cell assembly 100, but rather may be configured not to completely cover a portion of the side of the cell assembly 100.

[0117] More specifically, as shown in the portion indicated by B3 in Figures 12 and 14, the cover member 300 may be configured not to cover the lower part of the side of the cell assembly 100. Furthermore, as shown in Figures 12 and 14, the cover member 300 may be configured to be separated from the side of the cell assembly 100 by a predetermined distance in the horizontal direction (front-to-back direction, Y-axis direction). In this case, the cover member 300 can be said to be configured to cover the horizontal outer side of the cell assembly 100, but to be open in the downward direction without covering it.

[0118] With this implementation configuration, it becomes possible to control vent gas and the like through the portion not covered by the cover member 300, i.e., portion B3. In other words, when vent gas or flame is generated from the cell assembly 100, such vent gas and the like can be guided downwards, as indicated by the arrows in Figure 14.

[0119] In this case, the module case 200 may have a vent hole formed on its lower side, as shown by H' in Figures 13 and 14. Such a vent hole H' may be provided in a position that communicates with the uncovered portion (unfilled portion) B3 of the cover member 300, as shown in Figure 14. Furthermore, this embodiment can be applied even more effectively in an implementation where the battery module is placed on the pack case, and a component for guiding vent gas or the like is provided on the bottom surface side of the pack case, that is, on the part of the pack case that is in contact with the lower side of the battery module.

[0120] According to this embodiment of the present invention, it becomes easier to realize directional venting, in which vent gases and flames formed inside the battery module are directed in a specific direction, i.e., towards the lower side of the battery module. Furthermore, according to the above embodiment, it is possible to more effectively prevent vent gases and flames from being directed towards the module terminals located on the upper front or rear side of the battery module.

[0121] Furthermore, in yet another embodiment of the present invention, the venting direction may be controlled by adjusting the amount (filling ratio) of the cover member 300. For example, in the embodiment shown in Figures 12 to 14, the cover member 300 is arranged to be filled as a whole on the front and rear sides of the cell assembly 100, but the amount of cover member 300 in part B3 may be configured to be less than in other parts. In this case, it becomes possible to guide vent gas or the like to the part of the cover member 300 that is filled less.

[0122] On the other hand, while the embodiments shown in Figures 12 to 14 describe a configuration in which the vent gas is guided to the lower side of the battery module, embodiments in which the vent gas is guided to the other side of the battery module, i.e., the upper side, are also available.

[0123] The battery pack according to the present invention may include one or more of the battery modules according to the present invention as described above. In addition to such battery modules, the battery pack according to the present invention may further include various other components, such as battery management systems (BMS), busbars, pack cases, relays, current sensors, and other battery pack components that are known at the time of filing the application of the present invention.

[0124] The battery module according to the present invention can be applied to automobiles such as electric vehicles and hybrid vehicles. That is, an automobile according to the present invention may include the battery module or battery pack according to the present invention. In addition to such battery modules or battery packs, an automobile according to the present invention may further include various other components included in the automobile. For example, an automobile according to the present invention may further include, in addition to the battery module according to the present invention, a vehicle body, a motor, an electronic control unit (ECU) or other control devices, etc.

[0125] Furthermore, the battery module according to the present invention can be applied to an energy storage system (ESS). That is, the energy storage system according to the present invention may include the battery module or battery pack according to the present invention.

[0126] On the other hand, while directional terms such as up, down, left, right, front, and back have been used in this specification, these terms are used merely for ease of explanation, and it will be obvious to those skilled in the art that they may vary depending on the position of the object in question, the observer's position, etc.

[0127] Although the present invention has been described above with reference to limited embodiments and drawings, it goes without saying that the present invention is not limited thereto, and that various modifications and variations can be made by persons with ordinary skill in the art to which the present invention pertains, within the equivalent scope of the technical concept and claims of the present invention. [Explanation of Symbols]

[0128] 100 cell assembly 110 battery cells 111 Electrode Leads 200 Module Case 210 Main frame, 220 End Plate 300 Cover component 400 Busbar Assembly 410 module busbar, 420 Busbar Housing 500 Terminal Connectors 600 connector terminals 700 Vent Unit

Claims

1. A cell assembly comprising multiple battery cells electrically connected to each other via electrode leads, A module case that houses the cell assembly in its internal space, In the internal space of the module case, a cover member is bonded to the side of the cell assembly from which the electrode leads protrude, A battery module comprising, The cover member is made of a material having insulating and adhesive or tacky properties, and is configured in the cell assembly to be filled in the side portion where the electrode leads protrude. The module case comprises a battery module having a main frame with at least one of its front and rear sides open, and an end plate coupled to the open portion of the main frame.

2. The battery module according to claim 1, wherein at least a portion of the cover member is bonded to the electrode leads of a plurality of battery cells arranged in the cell assembly.

3. The cell assembly has the electrode leads positioned on the end plate side, The battery module according to claim 1, wherein the cover member is interposed between the electrode leads of the cell assembly and the end plate.

4. The battery module according to claim 1, wherein the cover member is filled between the sealing portions of adjacent battery cells.

5. The battery module according to claim 1, wherein the cover member fills the entire cell assembly from its upper end to its lower end, either in front of or behind the cell assembly.

6. The battery module according to claim 5, wherein the upper and lower ends of the cover member are bent in the direction of the cell assembly.

7. The battery module according to claim 1, wherein the cover member covers the electrode leads of the plurality of battery cells from the upper end to the lower end as a whole.

8. The battery module according to claim 1, wherein the module case has vent holes formed in at least one of its upper and lower parts.

9. The battery module according to claim 8, further comprising a vent unit disposed outside the portion of the module case in which a vent hole is formed, wherein the vent gas discharged from the vent hole is movable.

10. A battery pack comprising a battery module according to any one of claims 1 to 9.

11. An automobile comprising a battery module according to any one of claims 1 to 9.

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