Battery module insulation structure

Abstract

The present invention provides a battery module structure including an electrode assembly, a frame that is open at the top and houses the electrode assembly, a top plate that covers the top of the frame, a first insulating film attached to an inner surface of the frame including an inner surface of a side wall, and a second insulating film attached to the inner surface of the top plate.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0175923 filed on December 15, 2022, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

[0002] The present invention relates to a battery module including a battery cell stack and a housing enclosing the same, and having an insulating structure that insulates the battery cell stack and the housing from each other.

Background Art

[0003] Secondary batteries, which are highly applicable to a variety of products and have electrical characteristics such as high energy density, are commonly applied not only to portable devices but also to electric vehicles or hybrid vehicles driven by an electric drive source, power storage devices, and the like. These secondary batteries are not only characterized by the primary advantage of significantly reducing the use of fossil fuels, but also attract attention as a new energy source that is environmentally friendly and improves energy efficiency because they do not generate any by-products from the use of energy.

[0004] One or two or three battery cells are used per device for small mobile devices, while medium to large-sized devices such as automobiles require a high output and large capacity. Therefore, medium to large-sized battery modules in which a large number of battery cells are electrically connected are used.

[0005] Medium to large-sized battery modules are preferably manufactured with a small size and weight if possible, and thus square batteries, pouch-type batteries, etc., which can be stacked with a high degree of integration and have a low weight-to-capacity ratio, are mainly used as battery cells for medium to large-sized battery modules.

[0006] Figures 1 and 2 are exploded perspective and perspective views, respectively, showing the structure of a battery module. Referring to these drawings, a typical battery module may include a battery cell stack 1 formed by stacking multiple pouch-type battery cells, a frame 2 that is open at the top and houses the battery cell stack 1, and a top plate 3 that covers the top of the frame 2. The frame 2 and the top plate 3 may be made of an electrically conductive material such as metal and can be assembled by joining them together by methods such as welding.

[0007] On the other hand, if the frame 2 and the top plate 3 are made of an electrically conductive material such as metal, there is a risk that the frame 2 or the top plate 3 will short-circuit with the battery cell stack 1. These short circuits pose a risk of causing a fire by causing thermal runaway of the battery cell stack 1, and even if thermal runaway does not occur, they may prevent the battery module from performing at all or insufficiently. For this reason, it is preferable that the frame 2 and the top plate 3 are insulated from each other.

[0008] Figure 3 is a cross-sectional view of the battery module. Referring to this, a first insulating film 21 and a second insulating film 31 may be attached to the inner surfaces of the frame 2 and the top plate 3, respectively, to insulate them from the battery cell laminate 1. The first insulating film 21 and the second insulating film 31 may be attached at a predetermined distance from the boundary portion 4 where the frame 2 and the top plate 3 are joined to each other. This is to prevent the joining from becoming poor due to interference between the first insulating film 21 and the second insulating film 31 during the joining process of the frame 2 and the top plate 3 at the boundary portion 4, or to prevent the first insulating film 21 and the second insulating film 31 from being damaged by the heat generated during the welding process.

[0009] Figure 4 is a magnified view of the boundary portion of the battery module shown in Figure 3. Referring to this, at the boundary portion 4, the frame 2 and the top plate 3 are exposed to the side of the battery cell stack 1, which can cause a short circuit between the battery cell stack 1 and the boundary portion 4. These short circuits can occur when the battery cell stack 1 comes into contact with the boundary portion 4 due to current flow, and can also occur when the battery cell stack 1 has too short an insulating distance from the boundary portion 4. In this case, the insulating distance can be defined as the length of the shortest path taken by the current flowing between two objects that are far apart from each other. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The present invention was conceived against the background of the prior art described above, and aims to provide a battery module structure that ensures insulation performance between the frame and top plate and the battery cell stack.

[0011] Specifically, the present invention aims to provide a battery module structure in which the risk of the frame and top plate and the battery cell stack coming into contact with each other is eliminated or reduced, and the insulation distance between the frame and top plate and the battery cell stack is increased.

[0012] Another technical problem of the present invention is to provide a battery module structure that includes an insulating film that does not interfere with the joint between the frame and the top plate and is not damaged by the joint.

[0013] The technical problems of the present invention are not limited to the purposes mentioned above. Other purposes and advantages of the present invention not mentioned can be understood from the following description and will be more clearly understood from the embodiments of the present invention. Furthermore, it will be readily understood that the purposes and advantages of the present invention can be achieved by the means and combinations thereof described in the claims. [Means for solving the problem]

[0014] To solve the above problems, the present invention provides a battery module structure comprising an electrode assembly, a frame that is open at the top and houses the electrode assembly, a top plate that covers the top of the frame, a first insulating film that adheres to the inner surface including the inner surface of the side wall of the frame, and a second insulating film that adheres to the inner surface of the top plate.

[0015] The battery module according to the present invention includes a structure for ensuring the insulating performance of the first insulating film and the second insulating film. In this specification, insulating performance means the function of preventing a short circuit from occurring when current flows between the frame and the top plate and the battery cell stack, and can be evaluated based on criteria such as contact interruption function, insulation distance securing function, and insulation damage prevention function. Insulation distance can be defined as the length of the shortest path taken by current flowing between two objects that are far apart from each other.

[0016] When the boundary is defined as the portion where the inner surface of the frame and the inner surface of the top plate are in contact with each other, the battery module may include a first overhang portion formed by folding the first insulating film inward from a first bend portion located a predetermined distance in the height direction from the boundary. By separating the first insulating film from the boundary by a predetermined distance, the possibility of the first insulating film interfering with the joint between the frame and the top plate can be reduced or eliminated, and if the frame and the top plate are welded to each other, damage to the first insulating film by welding heat can be prevented. The predetermined distance can be determined by considering the joining method between the frame and the top plate, and, if the joining method is welding, the welding heat, etc.

[0017] The first insulating film may include a third bent portion formed at the tip of the first overhang portion. The first insulating film may be folded inward at both the first bent portion and the third bent portion. Alternatively, the first insulating film may be folded inward at the first bent portion and outward at the third bent portion. The folding direction of the first insulating film at the third bent portion can be selected to a direction suitable for complicating the current path between the frame and the top plate and the battery cell stack, thereby increasing the insulation distance.

[0018] The battery module may include a second overhang portion formed by folding the second insulating film inward from a second bend portion located a predetermined distance in the width direction from the boundary portion. By separating the second insulating film from the boundary portion by a predetermined distance, the possibility of the second insulating film interfering with the joint between the frame and the top plate can be reduced or eliminated, and if the frame and the top plate are welded to each other, the second insulating film can be prevented from being damaged by welding heat. The predetermined distance can be determined by considering the joining method between the frame and the top plate, and, if the joining method is welding, the welding heat, etc.

[0019] The second insulating film may include a fourth bent portion formed at the tip of the second overhang portion. The second insulating film may be folded inward at both the second bent portion and the fourth bent portion. Alternatively, the second insulating film may be folded inward at the second bent portion and outward at the fourth bent portion. The folding direction of the second insulating film at the fourth bent portion can be selected to a direction suitable for complicating the current path between the frame and the top plate and the battery cell stack, thereby increasing the insulation distance.

[0020] The first insulating film and the second insulating film may be provided such that they overlap each other in a predetermined direction. In this case, the overlapping of the first insulating film and the second insulating film in a predetermined direction in a certain portion means that when a hypothetical straight line is drawn along the predetermined direction at a certain point on a portion of the first insulating film or the second insulating film, the hypothetical straight line passes through both the first insulating film and the second insulating film.

[0021] In this case, the first insulating film and the second insulating film may include portions that overlap each other in the height direction. Alternatively, the first insulating film and the second insulating film may include portions that overlap each other in the width direction. Alternatively, the first insulating film and the second insulating film may include portions that overlap each other in the thickness direction. By overlapping the first insulating film and the second insulating film, the battery cell laminate can be prevented from contacting the frame and the top plate.

[0022] The top plate may include a guide portion that extends along the boundary and protrudes downward. The guide portion can be formed integrally with the top plate.

[0023] The guide portion may include a tapered portion that guides the tip of the first overhang portion inward in the width direction as the top plate and the frame approach each other vertically. The first overhang portion can be guided to bend further inward by making oblique contact with the tapered portion as the frame and the top plate approach each other vertically. This further reduces the risk of the first insulating film interfering with the joint between the frame and the top plate.

[0024] The second insulating film may include a portion covering at least a part of the inner surface of the guide portion. In particular, the second insulating film may include a portion covering at least a part of the tapered portion. The cover may be by adhesion. That is, the second insulating film may include a portion adhering to at least a part of the tapered portion. At this time, preferably, the second insulating film may be provided so as to completely adhere to the tapered portion without including the second overhang portion. Thereby, it may be further facilitated that the tapered portion contacts the first insulating film obliquely.

[0025] When the second insulating film is provided to cover a part of the guide portion and the first insulating film is bent and guided inward along the guide portion, the first insulating film and the second insulating film overlap each other, whereby the contact between the frame and the top plate and the battery cell laminate can be blocked.

[0026] As described above, the first insulating film and the second insulating film can increase the insulation distance between the frame and the top plate and the battery cell laminate by being bent or overlapping each other.

[0027] When the length of the shortest path taken by the current flowing between the surface of the battery cell laminate and the inner surface of the frame is defined as the first insulation distance, the first insulation distance may be larger than the shortest distance between the surface of the battery cell laminate and the inner surface of the frame. That is, by providing the first insulating film and the second insulating film, the insulation distance between the frame and the battery cell laminate can be increased.

[0028] At this time, the first insulation distance may be 1.5 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the frame. For example, when the component in the width direction of the length of the first overhang portion is 1.5 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the frame, the first insulation distance becomes 2 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the frame.

[0029] Alternatively, at this time, the first insulation distance may be 2 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the frame. For example, when the component in the width direction of the length of the first overhang portion is 2 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the frame, the first insulation distance becomes 2 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the frame.

[0030] When the length of the shortest path taken by the current flowing between the surface of the battery cell laminate and the inner surface of the top plate is defined as the second insulation distance, the second insulation distance may be greater than the shortest distance between the surface of the battery cell laminate and the inner surface of the top plate. That is, by providing the second insulating film and the second insulating film, the insulation distance between the top plate and the battery cell laminate can be increased.

[0031] At this time, the second insulation distance may be 1.5 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the top plate. For example, when the component in the height direction of the length of the second overhang portion is 1.5 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the top plate, the second insulation distance becomes 1.5 times or more the shortest distance between the surface of the battery cell laminate and the inner surface of the top plate.

[0032] Alternatively, the second insulation distance may be twice or more the shortest distance between the surface of the battery cell stack and the inner surface of the top plate. For example, if the height component of the length of the second overhang is twice or more the shortest distance between the surface of the battery cell stack and the inner surface of the top plate, the second insulation distance will be twice or more the shortest distance between the surface of the battery cell stack and the inner surface of the top plate.

[0033] The present invention also provides a battery pack that houses the battery module and a structure for an automobile that houses the battery pack.

[0034] Due to their high voltage and / or high capacity, multiple battery modules can be housed within a single pack frame to form a battery pack. These multiple battery modules can be connected in parallel or series by pack busbars included in the battery pack, and the connected unit as a whole can have a high voltage and capacity. The battery pack can be installed in an electric vehicle powered by a secondary battery. The battery pack can provide power to the vehicle via a motor installed in the vehicle. The detailed structures of these battery packs and vehicles are known to the ordinary technician and will not be described in detail elsewhere in this specification. [Effects of the Invention]

[0035] The present invention can provide a battery module structure in which the insulation distance between the frame and top plate and the battery cell stack is increased.

[0036] The present invention can provide a battery module structure in which direct contact between the frame and top plate and the battery cell stack is prevented.

[0037] The present invention provides a battery module structure that has improved insulation performance and does not interfere with or damage the joint between the frame and the top plate, by including an overhang portion in which the insulating film is folded inward.

[0038] The present invention can provide a battery module structure in which, during the assembly process of the frame and top plate, the first insulating film and the second insulating film are guided to effectively overlap each other without interfering with the joints.

[0039] In addition, the present invention can achieve various other effects, which will be explained in each embodiment, or, in cases where such effects can be easily inferred by an ordinary engineer, such explanations will be omitted. [Brief explanation of the drawing]

[0040] [Figure 1] This is an exploded perspective view showing the structure of the battery module. [Figure 2] This is a perspective view showing the structure of a battery module. [Figure 3] This is a cross-sectional view of a battery module. [Figure 4] Figure 3 is a magnified view of the boundary area of ​​the battery module. [Figure 5] This is a cross-sectional view of a battery module according to Embodiment 1 of the present invention. [Figure 6] This is a magnified view of the boundary area of ​​the battery module shown in Figure 5. [Figure 7] This is a cross-sectional view of a battery module according to Embodiment 2 of the present invention. [Figure 8] This is a magnified view of the boundary area of ​​the battery module shown in Figure 7. [Figure 9] This is a cross-sectional view showing the top plate and frame of the battery module according to Embodiment 3 of the present invention before they are assembled together. [Figure 10]This is a cross-sectional view showing the top plate and frame of the battery module according to Embodiment 3 of the present invention after they have been assembled together. [Figure 11] This is a magnified view of the boundary area of ​​the battery module shown in Figure 9. [Figure 12] This is a magnified view of the boundary area of ​​the battery module shown in Figure 10. [Figure 13] This figure shows a battery pack containing a battery module according to the present invention. [Figure 14] This diagram shows a car with the battery pack shown in Figure 13 installed inside. [Modes for carrying out the invention]

[0041] The aforementioned objectives, features, and advantages will be described in detail below with reference to the accompanying drawings, so that a person with ordinary skill in the art to which the present invention pertains can easily implement the technical concept of the present invention. In describing the present invention, if a specific description of known technology according to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0042] Although terms such as "first," "second," etc., are used to indicate various components, these components are not limited by these terms. These terms are simply used to distinguish one component from another, and unless otherwise specified, the first component may also be the second component.

[0043] In the entire specification, unless otherwise stated, each component may be singular or plural.

[0044] In the following, the placement of any configuration "above (or below)" a component or "above (or below)" a component means not only that the configuration is placed in contact with the upper (or lower) surface of the component, but also that other configurations may be interposed between the component and any configuration placed on (or below) it.

[0045] Furthermore, if it is stated that one component is “linked,” “joined,” or “connected” to another component, it should be understood that the components may be directly linked or connected to each other, but other components may also be “interposed” between them, or each component may be “linked,” “joined,” or “connected” through other components.

[0046] As used herein, singular expressions include plural expressions unless otherwise explicitly stated in the context. Terms such as “composed of” or “including” in this application should not be interpreted as necessarily including all of the multiple components or stages described in the specification, but rather as including some of the components or stages, or including further components or stages.

[0047] In the entire specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or greater and D or less unless otherwise specified.

[0048] The present invention provides a battery module structure comprising: an electrode assembly formed by stacking a plurality of pouch-type battery cells; a frame that is open at the top and houses the electrode assembly; a top plate that covers the top of the frame; a first insulating film that adheres to the inner surface including the inner surface of the side wall of the frame; and a second insulating film that adheres to the inner surface of the top plate.

[0049] The battery module according to the present invention includes a structure for ensuring the insulating performance of the first insulating film and the second insulating film. In this specification, insulating performance means the function of preventing a short circuit from occurring when current flows between the frame and the top plate and the battery cell stack, and can be evaluated based on criteria such as contact interruption function, insulation distance securing function, and insulation damage prevention function. Insulation distance can be defined as the length of the shortest path taken by current flowing between two objects that are far apart from each other.

[0050] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

[0051] [Example 1] Figures 1 and 2 are exploded perspective and perspective views, respectively, showing the structure of a battery module. Referring to these drawings, the battery module may include a battery cell stack 1, a frame 2, and a top plate 3.

[0052] The battery cell laminate 1 may be formed by stacking pouch-type battery cells. However, the battery cell laminate 1 is not limited to this, and may be an assembly of various electrodes or battery cells, regardless of its name.

[0053] The battery cell stack 1 may be housed in the frame 2. The frame 2 can be formed in an open shape at the top. The frame 2 may be made of an electrically conductive material. The frame may be made of a metal material.

[0054] The upper part of the frame 2 may be covered by the top plate 3. The top plate may be made of an electrically conductive material. The top plate 3 may be made of a metal material.

[0055] The frame 2 and the top plate 3 may be joined to each other. Hereinafter, the portion where the frame 2 and the top plate 3 are joined to each other will be referred to as the boundary portion. Here, the boundary portion is the inner boundary formed between the frame 2 and the top plate 3 when the frame 2 and the top plate 3 are joined to each other, and may refer to the corresponding portion on the frame 2 or the corresponding position on the top plate 3.

[0056] In this embodiment, the frame 2 and the top plate 3 may be made of metal, and the joining may be done by welding. Steps may be provided on the inner side of the upper ends of both side walls of the frame 2, recessed to interlock with the top plate 3. In this case, the boundary refers to the innermost end of the step and the corresponding part on the top plate 3.

[0057] Figure 5 is a cross-sectional view of a battery module according to Embodiment 1 of the present invention, and Figure 6 is a magnified view of the boundary portion of the battery module in Figure 5. Referring to these drawings, the battery module may include one or more insulating films that insulate the frame 2 and the top plate 3 from the battery cell laminate 1. The insulating film may be made of an insulating material or coated with an insulating material. The insulating film may have a predetermined elasticity.

[0058] The first insulating film 21 may be attached to the inner surface of the frame 2. Specifically, the first insulating film 21 may be attached to the inner surface of the frame 2, including the inner surfaces of both side walls of the frame 2. The first insulating film 21 can have a first bent portion 211, which is separated from the boundary portion 4 by a predetermined distance in the height direction, as the boundary of its attachment area. The first insulating film 21 can be folded inward at the first bent portion 211 to form a first overhang portion 212. The first overhang portion 212 may be provided extending from the first bent portion 211 without being attached to the inner surface of the frame 2. The predetermined distance can be determined by considering the joining method between the frame and the top plate, and, if the joining method is welding, the welding heat, etc.

[0059] The second insulating film 31 may be attached to the inner surface of the top plate 3. Specifically, the second insulating film 31 may be attached to the inner surface of the top plate 3, including the inner surfaces of both side walls of the top plate 3. The second insulating film 31 can have a second bent portion 311, which is separated from the boundary portion 4 by a predetermined distance in the width direction, as the boundary of its attachment area. The second insulating film 31 can be folded inward at the second bent portion 311 to form a second overhang portion 312. The second overhang portion 312 may be provided extending from the second bent portion 311 without being attached to the inner surface of the top plate 3. The predetermined distance can be determined by considering the joining method between the frame and the top plate, and, if the joining method is welding, the welding heat, etc.

[0060] The battery module according to this embodiment may include the first insulating film 21 and the second insulating film 31. The first insulating film 21 can adhere to the inner surfaces of both side walls of the frame 2 and can be folded inward from a first bent portion 211 located a predetermined distance in the height direction from the boundary portion 4 to form the first overhang portion 212. The second insulating film 31 can adhere to the inner surface of the top plate 3 and can be folded inward from a second bent portion 311 located a predetermined distance in the width direction from the boundary portion 4 to form the second overhang portion 312.

[0061] According to this embodiment, the first insulating film 21 and the second insulating film 31 are attached at a predetermined distance from the boundary portion 4, so they do not interfere with the joining of the frame 2 and the top plate 3. As a result, the frame 2 and the top plate 3 can have sufficient joining strength as designed. Furthermore, as described above, by attaching the first insulating film 21 and the second insulating film 31 at a distance from the boundary portion 4, it is also possible to prevent damage to the first insulating film 21 and the second insulating film 31 from the welding heat generated when the frame 2 and the top plate 3 are welded together.

[0062] Furthermore, according to this embodiment, the first overhang portion 212 and the second overhang portion 312 extend inward and are placed on the shortest path from the battery cell stack 1 to the frame 2 and the top plate 3, which can complicate the path through which current flows from the battery cell stack 1 to the frame 2 and the top plate 3, and potentially increase the insulation distance.

[0063] The first insulating film 21 and the second insulating film 31 may be provided such that they overlap each other in a predetermined direction. In this case, the overlapping of the first insulating film 21 and the second insulating film 31 in a predetermined direction in a certain portion means that when a virtual straight line is drawn along the predetermined direction at a certain point on a portion of the first insulating film 21 or the second insulating film 31, the virtual straight line passes through both the first insulating film 21 and the second insulating film 31.

[0064] In this case, the first insulating film 21 and the second insulating film 31 may include portions that overlap each other in the height direction. Alternatively, the first insulating film 21 and the second insulating film 31 may include portions that overlap each other in the width direction. Alternatively, the first insulating film 21 and the second insulating film 31 may include portions that overlap each other in the thickness direction.

[0065] The first insulating film 21 and the second insulating film 31 in this embodiment may include portions that overlap each other in the height, width, and thickness directions. In this case, the overlapping portions may be parts of the first overhang portion 212 and the second overhang portion 312, respectively. That is, when imaginary straight lines are drawn in the height, width, and thickness directions at a certain point on the first overhang portion 212, each of these imaginary straight lines may pass through a certain point on the second overhang portion 312.

[0066] According to this embodiment, the superposition of the first insulating film 21 and the second insulating film 31 can block contact between the battery cell laminate 1 and the frame 2 and the top plate 3, making the current flow path from the battery cell laminate 1 to the frame 2 and the top plate 3 more complex and increasing the insulation distance.

[0067] As described above, the first insulating film 21 and the second insulating film 31 can be folded or overlapped with each other as described above to increase the insulating distance between the frame 2 and the top plate 3 and the battery cell laminate 1.

[0068] When the length of the shortest path taken by the current flowing between the surface of the battery cell stack 1 and the inner surface of the frame 2 is defined as the first insulation distance, the first insulation distance may be greater than the shortest distance between the surface of the battery cell stack 1 and the inner surface of the frame 2. That is, by providing the first insulating film 21 and the second insulating film 31, the insulation distance between the frame 2 and the battery cell stack 1 can be increased.

[0069] In this case, the first insulation distance may be 1.5 times or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the frame 2. For example, if the widthwise component of the length of the first overhang portion 212 is 1.5 times or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the frame 2, the first insulation distance will be 2 times or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the frame 2.

[0070] Alternatively, the first insulation distance may be twice or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the frame 2. For example, if the widthwise component of the length of the first overhang portion 212 is twice or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the frame 2, the first insulation distance will be twice or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the frame 2.

[0071] When the length of the shortest path taken by the current flowing between the surface of the battery cell stack 1 and the inner surface of the top plate 3 is defined as the second insulation distance, the second insulation distance may be greater than the shortest distance between the surface of the battery cell stack 1 and the inner surface of the top plate 3. That is, by providing the second insulating film 31, the insulation distance between the top plate 3 and the battery cell stack 1 can be increased.

[0072] In this case, the second insulation distance may be 1.5 times or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the top plate 3. For example, if the height component of the length of the second overhang portion 312 is 1.5 times or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the top plate 3, the second insulation distance will be 1.5 times or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the top plate 3.

[0073] Alternatively, the second insulation distance may be twice or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the top plate 3. For example, if the height component of the length of the second overhang portion 312 is twice or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the top plate 3, the second insulation distance will be twice or more the shortest distance between the surface of the battery cell stack 1 and the inner surface of the top plate 3.

[0074] In this embodiment, the first overhang portion 212 and the second overhang portion 312 can each form a 45-degree angle with the frame 2 and the top plate 3, respectively. In this case, the first overhang portion 212 and the second overhang portion 312 can each have a length of 1.5 to 2 times or more the shortest distance between the battery cell stack 1 and the frame 2, and the shortest distance between the battery cell stack 1 and the top plate 3, respectively.

[0075] In this embodiment, the widthwise component of the first overhang portion 212 and the heightwise component of the second overhang portion 312 may be 1.5 times or more the shortest distance between the battery cell stack 1 and the frame 2, and the shortest distance between the battery cell stack 1 and the top plate 3, respectively. In this case, the first insulation distance and the second insulation distance may be 1.5 times or more the shortest distance between the battery cell stack 1 and the frame 2, and the shortest distance between the battery cell stack 1 and the top plate 3, respectively.

[0076] [Example 2] In the following, explanations of parts of this embodiment that are not described in detail elsewhere are the same as in Embodiment 1.

[0077] Figure 7 is a cross-sectional view of a battery module according to Embodiment 2 of the present invention, and Figure 8 is a magnified view of the boundary portion of the battery module in Figure 7. Referring to these drawings, the first insulating film 21 and / or the second insulating film 31 may include a third bent portion 213 and / or a fourth bent portion 313 formed by folding again at the tip of the first overhang portion 212 and / or the second overhang portion 312.

[0078] The first insulating film 21 may include a third bent portion 213 formed at the tip of the first overhang portion 212.

[0079] The first insulating film 21 may be folded in the same direction at the first bent portion 211 and the third bent portion 213, or it may be folded in different directions at the first bent portion 211 and the third bent portion 213. That is, the first insulating film 21 may be folded inward at both the first bent portion 211 and the third bent portion 213, or it may be folded inward at the first bent portion 211 and outward at the third bent portion 213. The bending direction of the first insulating film 21 at the third bent portion 213 can be selected to a direction suitable for complicating the current path between the frame 2 and the top plate 3 and the battery cell laminate 1, thereby increasing the insulation distance.

[0080] The second insulating film 31 may include a fourth bent portion 313 formed at the tip of the second overhang portion 312.

[0081] The second insulating film 31 may be folded in the same direction at the second bent portion 311 and the fourth bent portion 313, or it may be folded in different directions at the second bent portion 311 and the fourth bent portion 313. That is, the second insulating film 31 may be folded inward at both the second bent portion 311 and the fourth bent portion 313, or it may be folded inward at the second bent portion 311 and outward at the fourth bent portion 313. The bending direction of the second insulating film 31 at the fourth bent portion 313 can be selected to a direction suitable for complicating the current path between the frame 2 and the top plate 3 and the battery cell laminate 1, thereby increasing the insulation distance.

[0082] In this embodiment, the first insulating film 21 and the second insulating film 31 may each include the third bent portion 213 and the fourth bent portion 313. In this case, the first insulating film 21 may be folded in different directions at the first bent portion 211 and the third bent portion 213, and the second insulating film 31 may be folded in the same direction at the second bent portion 311 and the fourth bent portion 313. As a result, the tip of the first overhang portion 212 and the tip of the second overhang portion 312 may be folded in opposing directions, and the first overhang portion 212 and the second overhang portion 312 may interlock with each other.

[0083] According to this embodiment, the first overhang portion 212 and the second overhang portion 312 interlock or overlap each other again, making it possible to more reliably prevent contact between the battery cell stack 1 and the frame 2 and the top plate 3, and to further increase the insulation distance.

[0084] [Example 3] In the following, explanations of parts of this embodiment that are not described in detail elsewhere are the same as in Examples 1 and 2.

[0085] Figures 9 and 10 are cross-sectional views showing the top plate and frame of a battery module according to Embodiment 3 of the present invention before and after assembly, respectively, and Figures 11 and 12 are enlarged partial views showing the boundary portion of the battery module in Figures 9 and 10, respectively. Referring to these drawings, the top plate 3 may include a guide portion 32. The guide portion 32 may extend from the top plate 3 along the boundary portion 4 and be formed to protrude downward. The guide portion 32 may be formed integrally with the top plate 3.

[0086] The guide portion 32 may include a tapered portion 321. The tapered portion 321 can be formed in a shape that slopes downward and indents outward on the inner surface of the guide portion. The tapered portion 321 can make oblique contact with the first overhang portion 212 as the frame 2 and the top plate 3 approach each other vertically, thereby guiding the tip of the first overhang portion 212 inward in the width direction.

[0087] The second insulating film 31 may include a portion that covers at least a part of the inner surface of the guide portion 32. In particular, the second insulating film 31 may include a portion that covers at least a part of the tapered portion 321. The cover may be by adhesion. That is, the second insulating film 31 may include a portion that adheres to at least a part of the tapered portion 321. In this case, preferably, the second insulating film 31 may be provided completely attached to the tapered portion 321 without including the second overhang portion 312. This may make it even easier for the tapered portion 321 to come into oblique contact with the first insulating film 21.

[0088] In the battery module according to this embodiment, the top plate 3 may include a guide portion 32 that extends along the boundary portion 4 and protrudes downward. The guide portion 32 may be formed integrally with the top plate 3. The guide portion 32 may include a tapered portion 321 that is formed obliquely on its inner surface. The second insulating film 31 may extend to and adhere to a portion of the tapered portion 321.

[0089] According to this embodiment, the first overhang portion 212 is guided inward in the width direction by making oblique contact with the tapered portion 321, and the second insulating film 31 is attached up to the tapered portion 321. As a result, the first insulating film 21 and the second insulating film 31 overlap each other in the thickness direction, completely blocking contact between the battery cell laminate 1 and the frame 2 and the top plate 3, and significantly increasing the insulation distance.

[0090] Furthermore, according to this embodiment, the guide portion 32 guides the first overhang portion 212 inward in the width direction, further reducing the risk of the first insulating film 21 interfering with the joint between the frame 2 and the top plate 3. Since the second insulating film 31 adheres to the tapered portion 321, it cannot reach the outside of the guide portion 32 where the boundary portion 4 is located, and therefore cannot interfere with the joint between the frame 2 and the top plate 3. At this time, the risk of the first insulating film 21 and the second insulating film 31 being damaged by the welding heat between the frame 2 and the top plate 3 is also greatly reduced.

[0091] The present invention also provides a battery pack that houses the battery module and a structure for an automobile that houses the battery pack.

[0092] Figure 13 shows a battery pack containing the battery module according to the present invention, and Figure 14 shows an automobile containing the battery pack of Figure 13. Referring to these drawings, multiple battery modules (M) can be housed in a single pack frame to form a battery pack (P) due to their high voltage and / or high capacity. Multiple battery modules (M) can be connected in parallel or in series by pack busbars included in the battery pack (P), and the connected unit as a whole can have a high voltage and capacity. The battery pack (P) can be housed in an electric vehicle (V) powered by a secondary battery. The battery pack (P) can provide power to the automobile (V) by a motor housed in the automobile (V). The detailed structure of these battery packs and automobiles is known to the ordinary technician and will not be described in detail elsewhere in this specification.

[0093] The embodiments described above should be understood to be illustrative and not limiting in all respects, and the scope of the present invention is indicated more by the claims described below than by the detailed description above. The meaning and scope of the claims described below, as well as any modifications and deformable forms conceived from their equivalent concepts, should be interpreted as being included within the scope of the present invention.

[0094] As described above, the present invention has been explained with reference to the illustrative drawings. However, the present invention is not limited to the embodiments and drawings disclosed herein, and it is natural that various modifications can be made by an ordinary person within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention are not explicitly described and explained while embodiments of the present invention have been described above, it is natural that predictable effects from such configurations should also be acknowledged. [Explanation of Symbols]

[0095] 1. Battery cell stack 2 frames 21 First insulating film 211 1st bend 212 First Overhang Section 213 3rd bend 3. Top plate 31. Second insulating film 311 2nd bending section 312 Second Overhang Section 313 4th bend 32 Guide section 321 Tapered section 4. Boundary M Battery Module P Battery Pack V Automobile X-length direction Y width direction Z (height direction)

Claims

1. Battery cell stack, The top is open and the frame houses the stack of battery cells, A top plate that covers the upper part of the aforementioned frame, A first insulating film that adheres to the inner surface including the inner surface of the side wall of the frame, and This includes a second insulating film that adheres to the inner surface of the top plate, When the boundary is defined as the portion where the inner surface of the frame and the inner surface of the top plate come into contact with each other, The first insulating film is folded inward from a first bent portion that is separated by a predetermined distance in the height direction from the boundary portion, forming a first overhang portion and The second insulating film includes at least one of the second overhang portions formed by folding inward from a second bent portion located a predetermined distance in the width direction from the boundary portion, Battery module.

2. Including a third bent portion formed at the tip of the first overhang portion, The battery module according to claim 1.

3. The bending directions of the first bending portion and the third bending portion of the first insulating film are different from each other. The battery module according to claim 2.

4. The bending directions of the first bending portion and the third bending portion of the first insulating film are the same. The battery module according to claim 2.

5. Including a fourth bent portion formed at the tip of the second overhang portion, A battery module according to any one of claims 1 to 4.

6. The bending directions of the second bending portion and the fourth bending portion of the second insulating film are different from each other. The battery module according to claim 5.

7. The bending directions of the second bending portion and the fourth bending portion of the second insulating film are the same. The battery module according to claim 5.

8. The first insulating film and the second insulating film include portions that overlap each other in the height direction. The battery module according to claim 1.

9. The first insulating film and the second insulating film include portions that overlap each other in the width direction. The battery module according to claim 1.

10. The first insulating film and the second insulating film include portions that overlap each other in the thickness direction. The battery module according to claim 1.

11. The top plate includes a guide portion that extends along the boundary and protrudes downward, The guide portion includes a tapered portion that guides the tip of the first overhang portion inward in the width direction as the top plate and the frame move closer to each other vertically. The battery module according to claim 1.

12. The second insulating film includes a portion that covers at least a part of the inner surface of the guide portion. The battery module according to claim 11.

13. The second insulating film includes a portion that covers at least a part of the tapered portion, The battery module according to claim 11.

14. The second insulating film includes a portion that adheres to at least a part of the tapered portion. The battery module according to claim 13.

15. When the length of the shortest path taken by the current flowing between the surface of the battery cell stack and the inner surface of the frame is defined as the first insulation distance, The first insulation distance is greater than the shortest distance between the surface of the battery cell stack and the inner surface of the frame. The battery module according to claim 1.

16. The first insulation distance is 1.5 times or more the shortest distance between the surface of the battery cell stack and the inner surface of the frame. The battery module according to claim 15.

17. The first insulation distance is at least twice the shortest distance between the surface of the battery cell stack and the inner surface of the frame. The battery module according to claim 16.

18. When the length of the shortest path taken by the current flowing between the surface of the battery cell stack and the inner surface of the top plate is defined as the second insulation distance, The second insulation distance is greater than the shortest distance between the surface of the battery cell stack and the inner surface of the top plate. The battery module according to claim 1.

19. The second insulation distance is 1.5 times or more the shortest distance between the surface of the battery cell stack and the inner surface of the top plate. The battery module according to claim 18.

20. The second insulation distance is at least twice the shortest distance between the surface of the battery cell stack and the inner surface of the top plate. The battery module according to claim 19.

21. Includes the battery module described in claim 1, Battery pack.

22. Includes the battery pack described in claim 21, car.

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