Pouch battery assembly and battery pack

Abstract

The application relates to the technical field of lithium batteries, in particular to a soft package battery assembly and a battery pack. The soft package battery assembly comprises a battery monomer and a cooling frame; the battery monomer has a width direction; the battery monomer comprises a roll core, a tab and a cladding film; the cladding film comprises a cladding film main body and a top sealing edge, the cladding film main body clads the roll core, and the tab is led out from the top sealing edge; the cooling frame comprises a tab cooling pipe and two side cooling pipes; the tab cooling pipe extends along the width direction and is attached to the top sealing edge to cool the tab; the two ends of the tab cooling pipe are respectively connected to the two side cooling pipes, the two side cooling pipes are respectively located on the two sides of the battery monomer opposite to each other in the width direction and are attached to the cladding film main body to cool the roll core. According to the soft package battery assembly and the battery pack, the problem that the existing cooling form has poor cooling effect and does not consider cooling the tab area with the fastest temperature rise is solved.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a soft-pack battery assembly and battery pack. Background Technology

[0002] Currently, the cooling method for individual battery cells in pouch cells typically involves attaching a cooling plate to the large surface of the cell. However, in this method, because the heat-conducting surface of the cell core is along the thickness direction of the battery cell, which is the direction with the lowest thermal conductivity, the heat conduction speed is low and the cooling effect is poor.

[0003] Furthermore, current cooling methods do not consider cooling the tab region where the temperature rises the fastest. Summary of the Invention

[0004] The purpose of this application is to provide a soft-pack battery assembly and battery pack, thereby solving the problems of poor cooling effect of existing cooling methods and failure to consider cooling the tab area where the temperature rises the fastest.

[0005] According to a first aspect of this application, a pouch battery assembly is provided, the pouch battery assembly including a battery cell and a cooling frame; the battery cell has a width direction; the battery cell includes a core, tabs, and a covering film; the covering film includes a covering film body and a top seal, the covering film body covering the core, and the tabs extending from the top seal; the cooling frame includes a tab cooling tube and two side cooling tubes; the tab cooling tube extends along the width direction and fits against the top seal to cool the tabs; the two ends of the tab cooling tube are respectively connected to the two side cooling tubes, the two side cooling tubes are respectively located on opposite sides of the battery cell in the width direction and fit against the covering film body to cool the core.

[0006] In any of the above technical solutions, the coating film further includes two folded edges that are opposite to each other in the width direction; the side cooling pipe is disposed between the folded edges and the coating film body.

[0007] In any of the above technical solutions, a phase change material is further provided inside the electrode cooling tube; the phase change material can cool the electrode by absorbing heat through phase change.

[0008] In any of the above technical solutions, further, a liquid release hole is provided on the side of the tab cooling tube facing the top sealing edge; the liquid release hole is sealed by a sealing film, which is fusible under certain conditions; a cooling flame retardant bag is provided inside the tab cooling tube, the opening of the cooling flame retardant bag is fixed to the tab cooling tube to form a cooling flame retardant cavity with the sealing film, the interior of the cooling flame retardant cavity contains the phase change material and the flame retardant, and when the sealing film melts, the phase change material and the flame retardant are discharged from the liquid release hole.

[0009] In any of the above technical solutions, further, the surface of the liquid release hole is provided with a grid, and the inner side of the grid is sealed by the sealing film; the cooling flame retardant bag is elastic, and when the sealing film melts, the phase change material and the flame retardant are squeezed out by the cooling flame retardant bag.

[0010] In any of the above technical solutions, the battery cell further includes a length direction and a width direction that are perpendicular to each other; each of the side cooling pipes extends along the length direction, and each of the side cooling pipes includes an inlet end and an outlet end, and the working fluid flowing in each of the side cooling pipes is a coolant.

[0011] In any of the above technical solutions, further, there are two tabs and two top sealing edges; the two top sealing edges are respectively disposed at both ends of the battery cell, and the two tabs are respectively led out from the two top sealing edges; the cooling frame includes two tab cooling pipes and two side cooling pipes; each tab cooling pipe extends along the width direction and its two ends are respectively connected to the two side cooling pipes; the two tab cooling pipes are respectively attached to the two top sealing edges.

[0012] In any of the above technical solutions, both of the top sealing edges extend along the length direction and are located in the middle of the coating film body; there are two cooling racks, which are symmetrically arranged.

[0013] In any of the above technical solutions, further, both of the top sealing edges extend along the length direction and are located on one side of the covering film body; the cooling rack is one.

[0014] According to a second aspect of this application, a battery pack is provided, including a pouch battery assembly as described above.

[0015] In any of the above technical solutions, the battery pack further includes a plurality of battery cells, which are arranged along the length direction; and the plurality of cooling racks are connected in sequence.

[0016] According to the soft-pack battery assembly of this application, the soft-pack battery assembly includes a battery cell and a cooling rack. The battery cell has a width direction and includes a core, tabs, and a covering film. The covering film includes a covering film body and a top seal edge. The covering film body covers the core, and the tabs extend from the top seal edge.

[0017] The cooling rack includes a tab cooling pipe and two side cooling pipes. The tab cooling pipe extends along the width direction and fits against the top seal edge to cool the tab. The two ends of the tab cooling pipe are respectively connected to two side cooling pipes. The two side cooling pipes are located on opposite sides of the battery cell in the width direction and fit against the coating film body to cool the core.

[0018] Based on the above technical features, the beneficial effects of this application are as follows:

[0019] The tab cooling pipe in the cooling rack of this application extends along the width direction and fits against the top seal edge to cool the tab area where the temperature rises the fastest.

[0020] Furthermore, the two side cooling pipes are located on opposite sides of the battery cell in the width direction and are attached to the main body of the coating film to cool the core. Compared with the large-area cooling method in the prior art (the heat conduction surface of the battery cell core is in the thickness direction, and the heat conduction speed is low), the cooling effect of this application is more obvious (the heat conduction rate of the battery cell core in the width direction is high, so the cooling effect is more obvious).

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This invention provides a schematic diagram of the structure of a pouch battery assembly according to the first embodiment of the present application.

[0024] Figure 2 Show Figure 1 A partial structural schematic diagram of the AA cross-section;

[0025] Figure 3 Show Figure 1 A partial structural schematic diagram of the BB cross-section;

[0026] Figure 4This invention provides a schematic diagram of the structure of a pouch battery assembly according to a second embodiment of the present application.

[0027] Figure 5 Show Figure 4 A partial structural schematic diagram of the AA cross-section;

[0028] Figure 6 Show Figure 4 A partial structural schematic diagram of the BB cross-section;

[0029] Figure 7 A schematic diagram of the structure of the release hole in an embodiment of this application is shown;

[0030] Figure 8 A schematic diagram of the structure of a cooling flame-retardant bag according to an embodiment of this application is shown;

[0031] Figure 9 A schematic diagram showing the connection of multiple pouch battery assemblies according to an embodiment of this application is provided.

[0032] Icons: 101-Core; 102-Taper; 103-Taper area of ​​cell; 104-Covering film body; 105-Top sealing edge; 106-Folded edge; 200-Cooling rack; 201-Taper cooling pipe; 2011-Release hole; 202-Side cooling pipe; 300-Covering film; 400-Connecting pipe; 500-Cooling flame-retardant bag; 600-Sealing film; X-Length direction; Y-Width direction; Z-Thickness direction. Detailed Implementation

[0033] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0034] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0035] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0036] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0037] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0038] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.

[0039] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0040] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0041] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0042] The first aspect of this application provides a pouch battery assembly, thereby solving the problems of poor cooling effect of existing cooling methods and failure to consider cooling the tab area where the temperature rises the fastest.

[0043] The following will refer to Figures 1 to 9 Detailed description of the pouch battery assembly according to some embodiments of this application.

[0044] like Figure 1 and Figure 2 As shown, the soft-pack battery assembly of this application includes a battery cell and a cooling rack 200. The battery cell has a width direction Y and includes a core 101, tabs 102, and a covering film 300. The covering film 300 includes a covering film body 104 and a top sealing edge 105. The covering film body 104 covers the core 101, and the tabs 102 extend from the top sealing edge 105.

[0045] Specifically, such as Figure 2 As shown, the electrode tab 102, the core 101, and the covering film 300 (aluminum-plastic film shell) are assembled through processes such as ultrasonic welding, heat sealing, and edge folding 106. The electrode tab area 103 is formed at the ultrasonic welding point between the electrode tab 102 and the core 101. Figure 3 As shown, the heat-sealed edges on both sides of the covering film 300 are folded to form aluminum-plastic film folded edges 106.

[0046] like Figure 1 and Figure 2As shown, the cooling rack 200 includes a tab cooling pipe 201 and two side cooling pipes 202. The tab cooling pipe 201 extends along the width direction Y and is attached to the top sealing edge 105 to cool the tab area 103 of the battery cell. The two ends of the tab cooling pipe 201 are respectively connected to the two side cooling pipes 202. The two side cooling pipes 202 are located on opposite sides of the battery cell in the width direction Y and are attached to the coating film body 104 to cool the core 101. In this embodiment, the connection between the side cooling pipes 202 and the coating film body 104 is preferably achieved by using thermally conductive adhesive.

[0047] In summary, the tab cooling pipe 201 in the cooling rack 200 of this application extends along the width direction Y and fits against the top seal edge 105 to cool the tab area 103 of the cell with the fastest temperature rise, thereby avoiding local overheating of the battery and causing safety risks.

[0048] Furthermore, the two side cooling pipes 202 are located on opposite sides of the battery cell in the width direction Y, and are attached to the coating film body 104 to cool the core 101, which is different from the large-area cooling method in the prior art (e.g., see reference). Figure 3 The heat-conducting surface of the battery cell winding 101 is in the thickness direction Z, and the heat conduction speed is low. Therefore, the cooling effect of this application is more obvious (because the heat conduction rate of the battery cell winding 101 in the width direction Y is high, so the cooling effect is more obvious).

[0049] It is also worth mentioning that some existing technologies, in order to solve the problem of poor cooling effect of large-area cooling methods, attach the cooling plate to one side of the battery cell (excluding the large area). However, in this form, since there are folded edges on both sides of the battery cell, these folded edges will block the connection between the battery cell and the cooling plate. Therefore, the above-mentioned cooling method has low thermal conductivity and poor cooling effect.

[0050] Therefore, in the embodiments of this application, such as Figure 3 As shown, the side cooling pipe 202 of this application can be disposed between the folded edge 106 and the coating film body 104 to solve the above-mentioned problems.

[0051] Specifically, such as Figure 3 As shown, the heat-sealed edges on both sides of the covering film 300 are folded to form aluminum-plastic film folded edges 106 (i.e., Figure 3 In the middle, there are two opposing folds 106 in the width direction Y). A side cooling pipe 202 is disposed between the folds 106 and the coating film body 104, and is adhered to the coating film body 104 by thermally conductive adhesive to cool the core 101. In this way, the side cooling pipe 202 avoids the fold area of ​​the battery 106 and is close to the side of the battery, improving cooling efficiency.

[0052] The following section will describe in detail the specific cooling process of the tab cooling pipe 201 and the side cooling pipe 202.

[0053] In the embodiments of this application, such as Figure 7 and Figure 8 As shown, the tab cooling tube 201 has multiple liquid release holes 2011 on the side facing the top sealing edge 105. The liquid release holes 2011 are sealed by a sealing film 600. The sealing film 600 is fusible under certain conditions (for example, the melting point of the sealing film 600 is between 120 and 180°C), preferably a PE film.

[0054] like Figure 8 As shown, a cooling flame retardant bag 500 is provided inside the tab cooling tube 201. The cooling flame retardant bag 500 is elastic. The opening of the cooling flame retardant bag 500 is fixed to the inner wall around the liquid release hole 2011 of the tab cooling tube 201 to form a cooling flame retardant cavity with the sealing film 600. The cavity contains a mixture of phase change material and flame retardant, for example, the ratio of phase change material to flame retardant is between 1:1 and 1:3.

[0055] When the electrode tabs heat up during charging and discharging, the phase change material can cool the electrode tabs by absorbing heat through phase change. At the same time, when the thermal runaway of the battery cell reaches the melting point of the sealing film 600, the sealing film 600 melts, and the phase change material and flame retardant are discharged from the release hole 2011 under the pressure of the cooled flame retardant bag 500, suppressing further thermal runaway.

[0056] Furthermore, the surface of the release hole 2011 may also be provided with a grid, the inside of which is sealed by a sealing film 600. This prevents cold components inside the battery pack from forcibly damaging the sealing film 600.

[0057] In the embodiments of this application, such as Figure 1 As shown, the battery cell has a length direction X and a width direction Y that are perpendicular to each other. Each side cooling pipe 202 extends along the length direction X and includes an inlet end and an outlet end. The working fluid flowing in each side cooling pipe 202 is coolant.

[0058] That is, Figure 1 As shown, each side cooling pipe 202 is arranged independently, with liquid entering at one end and liquid exiting at the other end, and is not connected to the tab cooling pipe 201.

[0059] In the embodiments of this application, such as Figure 1 and Figure 4 As shown, there are two tabs 102 with opposite polarities, and two top seals 105, which are respectively located at both ends of the battery cell. The two tabs 102 are led out from the two top seals 105 respectively.

[0060] To address this, the cooling rack 200 includes two tab cooling pipes 201 and two side cooling pipes 202. Each tab cooling pipe 201 extends along the width direction Y and is connected to two side cooling pipes 202 at both ends. The two tab cooling pipes 201 are respectively attached to two top sealing edges 105.

[0061] The following section will use dual-pit soft-pack batteries and single-pit soft-pack batteries as examples to describe the installation method of the cooling rack 200.

[0062] like Figures 1-3 As shown, the cooling method for dual-pit pouch batteries is as follows:

[0063] like Figure 2 As shown, both top sealing edges 105 extend along the length direction X and are located in the middle of the covering film body 104, and are arranged symmetrically.

[0064] In this regard, such as Figure 2 and Figure 3 As shown, there are two cooling racks 200, which are symmetrically arranged. Among them, two tab cooling pipes 201 are sandwiched on both sides of the top sealing edge 105, and two side cooling pipes 202 are sandwiched on both sides of the folded edge 106.

[0065] For this purpose, the mass ratio of phase change material to flame retardant can be 1:1, and the materials selected are phase change paraffin and trichloropropyl phosphate.

[0066] like Figures 4-6 As shown, the cooling method for dual-pit pouch batteries is as follows:

[0067] like Figure 5 As shown, both top sealing edges 105 extend along the length direction X and are located on one side of the covering film body 104 (for example, the two top sealing edges 105 are located on the two end faces of the covering film body 104 respectively, and the two top sealing edges 105 are located on the same side), and are symmetrically arranged.

[0068] In this regard, such as Figure 5 and Figure 6 As shown, there is one cooling rack 200. Among them, the tab cooling pipe 201 is attached to one side of the top sealing edge 105, and the two side cooling pipes 202 are located inside the folded edge 106.

[0069] The mass ratio of phase change material to flame retardant can be 1:2, and the materials selected are phase change paraffin and tris(β-chloroethyl) phosphate.

[0070] According to a second aspect of this application, a battery pack is provided, including a pouch battery assembly as described above.

[0071] Furthermore, such as Figure 9As shown, the battery pack includes multiple battery cells arranged along the length direction X, and multiple cooling racks 200 are connected in sequence. Specifically, multiple side cooling pipes 202 are connected in sequence through connecting pipes 400, that is, multiple side cooling pipes 202 on one side independently enter and exit the coolant.

[0072] In summary, the tab cooling pipe 201 in the cooling rack 200 of this application extends along the width direction Y and fits against the top seal edge 105 to cool the tab area 103 of the cell with the fastest temperature rise, thereby avoiding local overheating of the battery and causing safety risks.

[0073] Furthermore, the two side cooling pipes 202 are located on opposite sides of the battery cell in the width direction Y, and are attached to the coating film body 104 to cool the core 101, which is different from the large-area cooling method in the prior art (e.g., see reference). Figure 3 The heat-conducting surface of the battery cell winding 101 is in the thickness direction Z, and the heat conduction speed is low. Therefore, the cooling effect of this application is more obvious (because the heat conduction rate of the battery cell winding 101 in the width direction Y is high, so the cooling effect is more obvious).

[0074] Furthermore, a side cooling pipe 202 is disposed between the folded edge 106 and the coating film body 104, and is adhered to the coating film body 104 with thermally conductive adhesive to cool the core 101. In this way, the side cooling pipe 202 avoids the folded edge 106 area of ​​the battery and is in close contact with the side of the battery, thereby improving cooling efficiency.

[0075] Furthermore, the tab cooling pipe 201 can cool the tab area by absorbing heat through phase change material when the battery heat generation increases, making the overall battery temperature more uniform.

[0076] Furthermore, the tab cooling pipe 201 can suppress the spread of flame by releasing flame retardant when the battery experiences thermal runaway, and can suppress heat diffusion to a certain extent.

[0077] Furthermore, the use of the cooling rack 200 modules makes group connection convenient, allowing for easy series and parallel connections.

[0078] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the scope of the technology disclosed in this application, or make equivalent substitutions for some of the technical features. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application.

Claims

1. A pouch battery assembly, characterized in that, The pouch battery assembly includes individual battery cells and a cooling rack; The battery cell has a width direction; The battery cell includes a core, tabs, and a coating film; The covering film includes a covering film body and a top sealing edge. The covering film body covers the core, and the tab extends out from the top sealing edge. The cooling rack includes a tab cooling pipe and two side cooling pipes; The electrode cooling tube extends along the width direction and fits against the top sealing edge to cool the electrode. The two ends of the tab cooling tube are respectively connected to two side cooling tubes. The two side cooling tubes are located on opposite sides of the battery cell in the width direction and are attached to the coating film body to cool the core. The covering film also includes two folded edges that are opposite to each other in the width direction; The side cooling pipe is disposed between the folded edge and the covering film body; The electrode cooling tube is internally equipped with a phase change material; The phase change material can cool the tabs by absorbing heat through phase change; The electrode cooling tube has a liquid release hole on the side facing the top sealing edge; The liquid release hole is sealed by a sealing film, which is fusible under certain conditions; The electrode cooling tube is provided with a cooling flame retardant bag inside. The opening of the cooling flame retardant bag is fixed to the electrode cooling tube to form a cooling flame retardant cavity with the sealing film. The cooling flame retardant cavity contains the phase change material and the flame retardant. When the sealing film melts, the phase change material and the flame retardant are discharged from the release hole. The surface of the liquid release hole is provided with a grid, and the inner side of the grid is sealed by the sealing film; The cooling flame-retardant bag is elastic, and when the sealing film melts, the phase change material and the flame retardant are extruded by the cooling flame-retardant bag; The battery cell has a length direction and a width direction that are perpendicular to each other; Each of the side cooling pipes extends along the length direction, and each of the side cooling pipes includes an inlet end and an outlet end, and the working fluid flowing in each of the side cooling pipes is a coolant.

2. The soft-pack battery assembly according to claim 1, characterized in that, There are two electrode tabs and two top sealing edges; The two top sealing edges are respectively disposed at both ends of the battery cell, and the two tabs are respectively led out from the two top sealing edges; The cooling rack includes two of the tab cooling pipes and two of the side cooling pipes; Each of the tab cooling tubes extends along the width direction and is connected to two of the side cooling tubes at both ends; The two electrode cooling tubes are respectively attached to the two top sealing edges.

3. The soft-pack battery assembly according to claim 2, characterized in that, Both of the top sealing edges extend along the length direction and are located in the middle of the covering film body; There are two cooling racks, which are arranged symmetrically.

4. The soft-pack battery assembly according to claim 2, characterized in that, Both of the top sealing edges extend along the length direction and are located on one side of the covering film body; The cooling rack is one unit.

5. A battery pack, characterized in that, Includes a pouch cell battery assembly as described in any one of claims 1-4; the battery cell has a length direction perpendicular to the width direction; The battery pack includes a plurality of battery cells, which are arranged along the length direction; The multiple cooling racks are connected in sequence.

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