Battery device, energy storage device, power utilization device and battery device manufacturing method

Abstract

The invention discloses a battery device, an energy storage device, a power utilization device and a battery device manufacturing method, the battery device comprises a battery box and a plurality of battery monomers arranged in a closed space of the battery box, the battery box comprises a bottom plate, a frame and a top cover, and the top cover and the bottom plate are respectively connected to two opposite sides of the frame to form the closed space; the bottom plate comprises a first plate, a second plate and a third plate which are sequentially stacked, the second plate is arranged on the side, opposite to the closed space, of the first plate, a flow channel allowing heat exchange media to flow is formed between the first plate and the second plate, the third plate is arranged on the side, opposite to the first plate, of the second plate, and a buffering gap is formed between the third plate and the second plate. According to the battery device, the heat exchange plate is integrated to the bottom plate, the occupation of the heat exchange plate on the closed space in the battery box is reduced, so that the space for accommodating the single batteries is increased, and the heat exchange plate is integrated to the bottom plate, so that the overall height of the battery device is reduced, and the volume energy density of the battery device is improved. The invention has high volume energy density.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery device, an energy storage device, an electrical device, and a method for manufacturing a battery device. Background Art

[0002] New energy batteries are increasingly used in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are increasingly used in the field of energy storage. In new energy vehicles equipped with batteries, batteries can be used to provide power in whole or in part. In the field of energy storage, batteries can be installed in energy storage boxes or directly on the user side.

[0003] With the continuous development of battery technology, the industry continues to put forward higher requirements on the volume energy density of batteries. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a battery device, an energy storage device, an electrical device and a method for manufacturing a battery device with high volume energy density.

[0005] This application is implemented through the following technical solutions.

[0006] A first aspect of the present application provides a battery device, comprising a battery box and a plurality of battery cells arranged in a closed space of the battery box, wherein the battery box comprises a bottom plate, a frame and a top cover, wherein the top cover and the bottom plate are respectively connected to opposite sides of the frame to form the closed space; the bottom plate comprises a first plate, a second plate and a third plate stacked in sequence, wherein the second plate is arranged on a side of the first plate facing away from the closed space, a flow channel for heat exchange medium to flow is formed between the first plate and the second plate, and the third plate is arranged on a side of the second plate facing away from the first plate, and a buffer gap is formed between a portion of the third plate and a portion of the second plate.

[0007] In the embodiment of the present application, a flow channel for the heat exchange medium to flow is formed between the first plate and the second plate, so that the bottom plate also has a heat exchange function, that is, the heat exchange plate is integrated into the bottom plate, which reduces the occupation of the heat exchange plate in the enclosed space in the battery box, thereby increasing the space for accommodating the battery cells, and the heat exchange plate is integrated into the bottom plate, which compresses the overall height of the battery device, saves space in the height direction of the battery device, and improves the volume energy density of the battery device. By setting the third plate, the structural strength of the bottom plate is improved, the bearing and protection capacity of the bottom plate for the battery cells is improved, and the probability of the battery cells being damaged is reduced. In addition, since a buffer gap is formed between the third plate and the second plate, when the bottom plate is impacted, the buffer gap can play a buffering and energy absorption role, thereby improving the impact resistance and extrusion resistance of the bottom plate.

[0008] In some embodiments, the first plate, the second plate, and the third plate are connected as one body.

[0009] The first plate, the second plate and the third plate are connected as a whole, which is beneficial to further compressing the overall height of the battery device and also improves the overall structural strength of the bottom plate, thereby further improving the impact resistance and extrusion resistance of the bottom plate.

[0010] In some embodiments, the first plate, the second plate and the third plate are brazed together into one piece.

[0011] The first plate, the second plate and the third plate are connected as a whole through a brazing process, so that the formed bottom plate has better integrity. Compared with other connection methods (such as bolt connection or simple welding), integrated brazing can reduce stress concentration points at the connection parts. For example, if bolt connection is adopted, fatigue cracks may easily occur around the bolt hole due to stress concentration. When the bottom plate formed by integrated brazing is subjected to external forces such as the weight of the battery cell and vibration during use, the stress can be more evenly distributed on the entire structure, thereby improving the structural reliability of the bottom plate. Moreover, brazing forming makes the overall thickness of the bottom plate thinner, which is conducive to improving the volume energy density of the battery device. In addition, since the first plate is used to conduct heat during thermal management, integrated brazing forming makes the heat conduction less obstructed, and heat transfer can be performed more efficiently, thereby improving the battery performance and service life of the battery device.

[0012] In some embodiments, the buffer gap is filled with a buffer structure.

[0013] When the bottom plate is impacted or squeezed, the buffer structure filled in the buffer gap can play a role in buffering and energy absorption, thereby further improving the impact resistance and extrusion resistance of the bottom plate.

[0014] In some embodiments, a protective layer is attached to the surface of the third plate facing away from the second plate.

[0015] In this way, the protective layer is used to protect the surface of the third plate facing away from the second plate, thereby improving the wear resistance and impact resistance of the bottom of the battery device.

[0016] In some embodiments, a portion of the second plate is recessed toward the third plate to form a first groove with a notch toward the first plate, and the first plate closes the notch of the first groove to form the flow channel.

[0017] In this way, by forming the first groove on the second plate, the first plate closes the first groove to form a flow channel for the heat exchange medium to flow, so that the bottom plate also has a heat exchange function, which can adjust the temperature of the battery cell and control the temperature of the battery cell within an appropriate temperature range, thereby improving the performance of the battery device and extending the service life of the battery device.

[0018] In some embodiments, the portion of the second plate that is not recessed toward the third plate forms a recessed portion that is recessed toward the first plate relative to the bottom wall of the first groove, and the recessed portion abuts against the first plate.

[0019] By bringing the recessed portion into contact with the first plate, the contact area between the second plate and the first plate is increased, and the connection strength between the second plate and the first plate is increased, thereby improving the structural reliability of the bottom plate.

[0020] In some embodiments, the recessed portion includes an abutting portion and a spacing portion, the abutting portion abuts against a portion of the third plate, and a spacing is provided between the spacing portion and another portion of the third plate.

[0021] The abutting portion of the recessed portion abuts against the third plate, thereby increasing the contact area between the second plate and the third plate and improving the connection strength between the two, thereby improving the structural reliability of the bottom plate. In addition, a buffer gap is formed by a gap between the spacing portion of the recessed portion and the third plate, and the buffer gap can play a role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate.

[0022] In some embodiments, there is a distance between the bottom wall of the first groove and the third plate, a buffer gap is formed between the third plate and the bottom wall of the first groove and the spacer, and a buffer structure is filled in the buffer gap.

[0023] In this way, there is a distance between the bottom wall of the first groove and the third plate, so that the distance between the spacing part of the recessed part and the third plate is larger, thereby making the buffer gap formed between the third plate and the bottom wall of the first groove and the spacing part of the recessed part larger, so as to accommodate a larger buffer structure, thereby further improving the impact resistance and extrusion resistance of the bottom plate.

[0024] In some embodiments, the cushioning structure comprises a foam structure.

[0025] The foam structure can play a good role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate. In addition, the foam structure has a low density and light weight, which is conducive to the lightweight of the battery device. In addition, the foam structure has a good thermal insulation effect, which can reduce the amount of heat or cold energy in the heat exchange medium in the flow channel that diffuses outward through the second plate and the third plate, reducing energy dissipation, thereby helping to improve the thermal management performance of the bottom plate for the battery cell.

[0026] In some embodiments, the foam structure includes at least one of polystyrene foam, polyethylene foam, and polyurethane foam.

[0027] The foam is easy to obtain and inexpensive, which is beneficial to cost saving. It can also play a good role in buffering and energy absorption, thereby improving the impact resistance and extrusion resistance of the bottom plate.

[0028] In some embodiments, the cushioning structure comprises a rubber structure.

[0029] The rubber structure is elastic and can play a good role in buffering and energy absorption, thereby improving the impact resistance and extrusion resistance of the base plate.

[0030] In some embodiments, the rubber structure is made of natural rubber; and / or the rubber structure is made of synthetic rubber, and the synthetic rubber includes nitrile rubber and / or silicone rubber.

[0031] The buffer structure made of the above materials can play a good role in buffering and energy absorption, thereby improving the impact resistance and extrusion resistance of the bottom plate.

[0032] In some embodiments, a bottom wall of the first groove abuts against the third plate, and a buffer gap is formed between the third plate and the spacer.

[0033] In this way, by abutting the third plate against the bottom wall of the first groove, the contact area between the second plate and the third plate is increased, the connection reliability between the two is improved, and thus the structural reliability of the bottom plate is improved. In addition, a buffer gap is formed between the third plate and the spacer of the recessed portion, and when the bottom plate is impacted, the buffer gap can play a role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate.

[0034] In some embodiments, a portion of the third plate protrudes toward the second plate to form a protrusion, and the protrusion extends into the abutting portion and abuts against an inner wall of the abutting portion.

[0035] In this way, by providing the protruding portion, part of the third plate abuts against the inner wall of the abutting portion, thereby increasing the contact area between the third plate and the second plate, improving the connection strength between the two, and improving the structural reliability of the bottom plate.

[0036] In some embodiments, a protective layer is attached to the surface of the third plate facing away from the second plate.

[0037] In this way, the protective layer is used to protect the surface of the third plate facing away from the second plate, thereby improving the wear resistance and impact resistance of the bottom of the battery device.

[0038] In some embodiments, the portion of the third plate protruding toward the second plate is further formed with a second groove with a notch facing away from the second plate, and a portion of the protective layer is filled in the second groove.

[0039] Part of the protective layer is filled in the second groove, so that the protective layer is locally thickened, which can improve the protective effect and improve the wear resistance and impact resistance of the bottom of the battery device.

[0040] In some embodiments, the protective layer includes at least one of a polyurea coating, an epoxy resin coating, a polyvinyl chloride coating, and a polyurethane coating.

[0041] The provision of the above coating improves the wear resistance and impact resistance of the bottom of the battery device.

[0042] In some embodiments, the first plate, the second plate, and the third plate are all made of aluminum plates.

[0043] Aluminum has a low density, which makes the bottom plate light, which is beneficial to the lightweight of the battery device, and the low cost of aluminum helps to reduce the cost of the battery device. In addition, aluminum has good thermal conductivity. The first plate is made of aluminum, which is beneficial to improve the heat conduction between the heat exchange medium and the battery cell, and improve the thermal management performance of the battery device.

[0044] In some embodiments, the first plate is an aluminum plate, the second plate is a steel-aluminum composite plate, and the third plate is a steel plate, wherein the steel-aluminum composite plate includes an aluminum layer and a steel layer connected by rolling, the aluminum layer is connected to the aluminum plate, and the steel layer is connected to the steel plate.

[0045] The steel plate has high strength and good toughness, strong impact resistance and durability. Therefore, the second plate is made of steel-aluminum composite plate and the third plate is made of steel plate, which improves the durability of the bottom plate.

[0046] In some embodiments, the first plate is an aluminum plate, the second plate is an aluminum-titanium composite plate, and the third plate is a titanium alloy plate, wherein the aluminum-titanium composite plate includes an aluminum layer and a titanium layer connected by rolling, the aluminum layer is connected to the aluminum plate, and the titanium layer is connected to the titanium alloy plate.

[0047] The titanium alloy plate has high strength and good toughness, strong impact resistance and durability. Therefore, the second plate adopts aluminum-titanium composite plate and the third plate adopts titanium alloy plate, which improves the durability of the bottom plate.

[0048] A second aspect of the present application provides an energy storage device, which includes a plurality of battery devices provided in the first aspect, and the battery devices are used to store or provide electrical energy.

[0049] Since the energy storage device includes the above-mentioned battery device, the battery device has a high volume energy density, and therefore, the energy storage device has a high volume energy density.

[0050] A third aspect of the present application provides an electrical device, which includes a plurality of battery devices provided in the first aspect, and the battery devices are used to store or provide electrical energy.

[0051] Since the electric device includes the battery device described above, the battery device has a high volume energy density, and therefore the electric device has a high volume energy density.

[0052] A fourth aspect of the present application provides a method for manufacturing a battery device, comprising: Make the base plate; Provide a frame, a top cover and multiple battery cells; Connecting the frame to the bottom plate to form a box having an opening on one side; Installing a plurality of the battery cells into the box through the opening; Seal the top cover on the opening of the box body; The bottom plate includes a first plate, a second plate and a third plate stacked in sequence, the second plate is arranged on the side of the first plate facing away from the top cover, a flow channel for heat exchange medium to flow is formed between the first plate and the second plate, the third plate is arranged on the side of the second plate facing away from the first plate, and a buffer gap is formed between a portion of the third plate and a portion of the second plate.

[0053] In the embodiment of the present application, a flow channel for the heat exchange medium to flow is formed in the bottom plate, so that the bottom plate also has a heat exchange function, that is, the heat exchange plate is integrated into the bottom plate, which reduces the occupation of the heat exchange plate in the enclosed space in the battery box, thereby increasing the space for accommodating battery cells. In addition, the heat exchange plate is integrated into the bottom plate, which compresses the overall height of the battery device, saves space in the height direction of the battery device, and improves the volume energy density of the battery device.

[0054] In some embodiments, the manufacturing of the base plate includes: Forming the first plate, the second plate and the third plate respectively by stamping; The first plate, the second plate and the third plate are stacked in sequence and brazed as a whole.

[0055] The first plate, the second plate and the third plate are connected as a whole through a brazing process, so that the formed bottom plate has better integrity. Compared with other connection methods (such as bolt connection or simple welding), integrated brazing can reduce stress concentration points at the connection parts. For example, if bolt connection is adopted, fatigue cracks may easily occur around the bolt holes due to concentration. When the bottom plate formed by integrated brazing is subjected to external forces such as the weight of the components above the bottom plate and vibration during use, the stress can be more evenly distributed on the entire structure, thereby improving the structural reliability of the bottom plate. Moreover, brazing molding makes the overall thickness of the bottom plate thinner, which is conducive to improving the volume energy density of the battery device. In addition, since the first plate is used to conduct heat during thermal management, integrated brazing molding makes the heat conduction less obstructed, and heat transfer can be performed more efficiently, thereby improving the battery performance and service life of the battery device.

[0056] Effects of the Invention The present application provides a battery device, an energy storage device, an electrical device and a method for manufacturing a battery device having a high volume energy density. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings: Figure 1 is a schematic structural diagram of a vehicle according to one or more embodiments; Figure 2 is a perspective exploded schematic diagram of a battery device according to one or more embodiments; Figure 3 is a schematic diagram of a three-dimensional structure of a battery cell according to one or more embodiments; Figure 4 is a schematic diagram of a three-dimensional exploded structure of a battery cell according to one or more embodiments; Figure 5 is a schematic three-dimensional structural diagram of a partial structure of a battery device according to one or more embodiments; Figure 6 is a schematic diagram of a three-dimensional structure of a box of a battery device according to one or more embodiments; Figure 7 is a top view of a casing of a battery device according to one or more embodiments; Figure 8 for Figure 7 Sectional view at AA in the middle; Fig. 9 for Figure 7 Sectional view at the middle BB; Fig.10 A partial schematic diagram of a structure of a base plate according to one or more embodiments; Fig.11 is a partial schematic diagram of another structure of a base plate according to one or more embodiments; Fig.12 is a flow chart of a method for manufacturing a battery device according to one or more embodiments; Fig.13 The present invention is a flow chart of manufacturing a base plate in a method for manufacturing a battery device according to one or more embodiments.

[0058] Description of Reference Numerals 1000 vehicle; 100 battery device; 200 controller; 300 motor; 1 battery cell; 11 shell; 111 end cover; 112 shell; 12 electrode assembly; 120 pole ear; 13 electrode terminal; 14 pressure relief mechanism; 2 battery box; 20 flow channel; 21 top cover; 22 box body; 23 frame; 231 side beam; 232 cross beam; 24 bottom plate; 241 first plate; 242 second plate; 2421 first groove; 2423 recessed portion; 2423a abutting portion; 2423b spacer portion; 243 third plate; 2431 protruding portion; 2432 second groove; 244 buffer gap; 245 buffer structure; 245a foam structure; 246 protective layer; 25 second fastener; 26 first fastener. DETAILED DESCRIPTION

[0059] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions.

[0061] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0062] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0063] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0064] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0065] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0066] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0067] Below, this application is described in detail.

[0068] At present, new energy batteries are increasingly used in life and industry. New energy batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0069] The inventors of the present application discovered that the heat exchange plate used for thermal management of the battery pack is generally arranged in the battery box, placed between the bottom plate of the battery box and the battery cell. The heat exchange plate and the bottom plate are arranged separately, so that the battery pack occupies a relatively large space in the height direction, affecting the volume energy density of the battery pack.

[0070] The inventors of the present application have discovered through research that integrating the heat exchange plate into the base plate so that the base plate also has a water cooling function can reduce the space occupied by the battery pack in the height direction, thereby increasing the volume energy density of the battery pack.

[0071] Based on this design concept, the inventor of the present application designed a battery device, which includes a battery box and a plurality of battery cells arranged in a closed space of the battery box. The battery box includes a bottom plate, a frame and a top cover. The top cover and the bottom plate are respectively connected to opposite sides of the frame to form a closed space. The bottom plate is formed with a flow channel for the flow of heat exchange medium.

[0072] This design integrates the heat exchange plate used for thermal management of the battery device with the bottom plate, thereby reducing the occupation of the heat exchange plate in the enclosed space in the battery box, thereby increasing the space for accommodating battery cells. In addition, the heat exchange plate is integrated with the bottom plate, which compresses the overall height of the battery device, saves space in the height direction of the battery device, and improves the volume energy density of the battery device.

[0073] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, in parallel or in mixed connection through a busbar component.

[0074] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0075] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0076] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0077] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0078] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0079] In some embodiments, the battery box can be used as part of the chassis structure of the vehicle. For example, part of the battery box can become at least a part of the floor of the vehicle, or part of the battery box can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0080] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0081] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0082] A battery cell includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, which is disposed between the negative electrode and the positive electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and released back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0083] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0084] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0085] As an example, the positive electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium or silver, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0086] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523), LiNi0.5Co At least one of 0.25Mn0.25O2 (also referred to as NCM211), LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi0.8Co0.15Al0.05O2) and modified compounds thereof. The modified compound refers to a substance obtained by modification means such as doping or coating on the basis of the above substances.

[0087] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a foamed nickel, a foamed copper, a foamed aluminum, a foamed alloy, or a foamed carbon. When the foamed metal is used as the positive electrode, the positive electrode active material may not be disposed on the surface of the foamed metal, but of course, the positive electrode active material may also be disposed. As an example, the positive electrode active material is filled or / and deposited in the foamed metal.

[0088] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0089] As an example, the negative electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium or silver, etc., may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0090] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0091] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0092] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0093] In some embodiments, the negative electrode may be a foam metal. The foam metal may be foam nickel, foam copper, foam aluminum, foam alloy, or foam carbon, etc. When the foam metal is used as the negative electrode plate, the surface of the foam metal may not be provided with a negative electrode active material, but of course, a negative electrode active material may also be provided.

[0094] As an example, a negative electrode active material may be filled and / or deposited in the negative electrode current collector.

[0095] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0096] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using battery devices, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0097] The technical solutions described in the embodiments of the present application are applicable to various energy storage devices using battery devices, such as energy storage containers or energy storage cabinets.

[0098] In the following embodiments, for the convenience of description, the electric device of one embodiment of the present application is taken as a vehicle 1000 as an example for description. The following is a description with reference to the accompanying drawings.

[0099] Figure 1 is a schematic structural diagram of a vehicle 1000 according to one or more embodiments; The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended range vehicle. Figure 1 As shown, a battery device 100 is disposed inside the vehicle 1000, and the battery device 100 can be disposed at the bottom, head, or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000, for example, the battery device 100 can be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to power the motor 300, for example, for the starting, navigation, and working power requirements of the vehicle 1000 during driving.

[0100] In some embodiments of the present application, the battery device 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0101] Figure 2 is a perspective exploded schematic diagram of a battery device 100 according to one or more embodiments.

[0102] like Figure 2 As shown, the battery device 100 includes a battery box 2 and at least one battery cell 1. A closed space is provided in the battery box 2, and the at least one battery cell 1 is accommodated in the closed space.

[0103] In some embodiments of the present application, the battery box 2 may include a top cover 21 and a box body 22. The top cover 21 and the box body 22 are buckled together to form a closed space inside the battery box 2 to accommodate the battery cells 1. The closed space here means covering or closing, which may be sealed or unsealed.

[0104] The box body 22 may be a hollow structure with one end open, and the top cover 21 may be a plate-like structure, and the top cover 21 covers the open side of the box body 22, so that the top cover 21 and the box body 22 define a closed space together; the top cover 21 and the box body 22 may also be hollow structures with one side open, and the open side of the top cover 21 covers the open side of the box body 22. Of course, the battery box 2 formed by the top cover 21 and the box body 22 may be in various shapes, such as a cylinder, a cuboid, etc.

[0105] In the battery device 100, there can be multiple battery cells 1, and the multiple battery cells 1 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that the multiple battery cells 1 are both connected in series and in parallel. The multiple battery cells 1 can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 1 is placed in the closed space formed by the box body 22 and the top cover 21; of course, the battery device 100 can also be a battery module formed by connecting multiple battery cells 1 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and are contained in the closed space formed by the box body 22 and the top cover 21. The battery device 100 can also include other structures. For example, the battery device 100 can also include a busbar component for realizing electrical connection between the multiple battery cells 1.

[0106] In the embodiment of the present application, the battery cell 1 may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0107] The battery cell 1 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0108] As an example, the battery cell 1 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.

[0109] Figure 3 is a schematic diagram of a three-dimensional structure of a battery cell according to one or more embodiments; Figure 4 It is a schematic diagram of a three-dimensional exploded structure of a battery cell according to one or more embodiments.

[0110] A battery cell 1 refers to the smallest unit that makes up a battery. Figure 3 and Figure 4The battery cell 1 includes a housing 11, an electrode assembly 12 and other functional components. The housing 11 includes an end cap 111 and a shell 112. The shell 112 has a receiving space and an opening. The electrode assembly 12 is disposed in the receiving space. The end cap 111 closes the opening of the shell 112.

[0111] The end cap 111 refers to a component that covers the opening of the shell 112 to isolate the internal environment of the battery cell 1 from the external environment. Without limitation, the shape of the end cap 111 can be adapted to the shape of the shell 112 to match the shell 112. Optionally, the end cap 111 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 111 is not easily deformed when squeezed and collided, so that the battery cell 1 can have a higher structural strength and the safety performance can also be improved. The electrode terminal 13 is electrically connected to the electrode assembly 12 for outputting or inputting electrical energy of the battery cell 1.

[0112] In some embodiments of the present application, the end cap 111 may also be provided with a pressure relief mechanism 14 for releasing the internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold value. The material of the end cap 111 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments of the present application, an insulating member may also be provided on the inner side of the end cap 111, and the insulating member may be used to isolate the electrical connection components in the housing 112 from the end cap 111 to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber, etc.

[0113] The shell 112 is a component used to cooperate with the end cap 111 to form the internal environment of the battery cell 1, wherein the formed internal environment can be used to accommodate the electrode assembly 12, the electrolyte and other components. The shell 112 and the end cap 111 can be independent components, and an opening can be set on the shell 112, and the internal environment of the battery cell 1 is formed by covering the opening with the end cap 111 at the opening. Without limitation, the end cap 111 and the shell 112 can also be integrated. Specifically, the end cap 111 and the shell 112 can form a common connection surface before other components are put into the shell, and when the interior of the shell 112 needs to be encapsulated, the end cap 111 is covered with the shell 112. The shell 112 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 112 can be determined according to the specific shape and size of the electrode assembly 12. The material of the shell 112 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0114] The electrode assembly 12 is a component in the battery cell 1 where electrochemical reactions occur. One or more electrode assemblies 12 may be contained in the housing 112. The electrode assembly 12 is mainly formed by winding or stacking positive and negative electrode sheets, and an isolation member is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 120. The positive tab and the negative tab may be located together at one end of the main body or at both ends of the main body, respectively. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tab 120 connects the electrode terminal 13 to form a current loop.

[0115] Figure 5 is a schematic three-dimensional structural diagram of a partial structure of a battery device according to one or more embodiments; Figure 6 is a schematic diagram of a three-dimensional structure of a box of a battery device according to one or more embodiments; Figure 7 is a top view of a casing of a battery device according to one or more embodiments; Figure 8 for Figure 7 Sectional view at AA in the middle; Fig. 9 for Figure 7 Sectional view at the middle BB; Fig.10 A partial schematic diagram of a structure of a base plate according to one or more embodiments; Fig.11 is a partial schematic diagram of another structure of a base plate according to one or more embodiments; Fig.12 is a flow chart of a method for manufacturing a battery device according to one or more embodiments; Fig.13 The present invention is a flow chart of manufacturing a base plate in a method for manufacturing a battery device according to one or more embodiments.

[0116] like Figure 2 , Figures 5 to 8 As shown, the first aspect of the present application provides a battery device 100, which includes a battery box 2 and a plurality of battery cells 1 arranged in a closed space of the battery box 2, the battery box 2 includes a top cover 21 and a box body 22, the box body 22 includes a bottom plate 24 and a frame 23, the top cover 21 and the bottom plate 24 are respectively connected to opposite sides of the frame 23 to form a closed space; the bottom plate 24 is formed with a flow channel 20 for the flow of heat exchange medium.

[0117] The heat exchange medium includes a liquid heat exchange medium or a gaseous heat exchange medium. The liquid heat exchange medium may be a polyol-based water-cooling liquid or a water-based coolant such as ethylene glycol coolant or glycerol water-cooling liquid. The gaseous heat exchange medium may be air, ammonia, nitrogen, hydrogen, carbon dioxide or alcohol vapor.

[0118] By forming a flow channel 20 for the flow of heat exchange medium in the bottom plate 24, the bottom plate 24 also has a heat exchange function. The bottom plate 24 with the heat exchange medium flowing can cool the battery cell 1 when the temperature of the battery cell 1 increases, and can also heat the battery cell 1 when the temperature of the battery cell 1 decreases. One end of the flow channel 20 of the bottom plate 24 has an inlet for the heat exchange medium to enter, and the other end of the flow channel 20 has an outlet for the heat exchange medium to flow out. In the process of flowing through the flow channel 20, the heat exchange medium exchanges heat with the battery cell 1 to adjust the temperature of the battery cell 1. The bottom plate 24 controls the temperature of the battery cell 1 within an appropriate temperature range by controlling the temperature of the battery cell 1, thereby improving the performance of the battery device 100 and extending the service life of the battery device 100.

[0119] In the embodiment of the present application, a flow channel 20 for the flow of heat exchange medium is formed in the bottom plate 24, so that the bottom plate 24 also has a heat exchange function, that is, the heat exchange plate is integrated into the bottom plate 24, which reduces the occupation of the heat exchange plate in the enclosed space in the battery box 2, thereby increasing the space for accommodating the battery cell 1. In addition, the heat exchange plate is integrated into the bottom plate 24, which compresses the overall height of the battery device 100, saves space in the height direction of the battery device 100, and improves the volume energy density of the battery device 100.

[0120] In some embodiments of the present application, Figure 2 , Figures 5 to 7 As shown, the frame 23 includes a side beam 231 surrounding the bottom plate 24 and a cross beam 232 connected between the side beam 231 and the bottom plate 24. A receiving groove for receiving the battery cell 1 is formed between the side beam 231, the cross beam 232 and the bottom plate 24. The top cover 21 covers the notch of the receiving groove to form a closed space.

[0121] In some embodiments of the present application, Fig.10 and Fig.11 As shown, the bottom plate 24 includes a first plate 241 and a second plate 242 , and the first plate 241 and the second plate 242 are stacked to form a flow channel 20 therebetween.

[0122] One of the first plate 241 and the second plate 242 is provided with a groove extending along a curve or a straight line, and the other is a flat plate. The two are combined to form a flow channel. Alternatively, both the first plate 241 and the second plate 242 are provided with a groove extending along a curve or a straight line. When the two are combined, the grooves of the two are combined to form a flow channel.

[0123] In this way, a flow channel 20 is formed in the bottom plate 24 , so that the bottom plate 24 also has a heat exchange function, thereby compressing the overall height of the battery device 100 , saving space in the height direction of the battery device 100 , and improving the volume energy density of the battery device 100 .

[0124] In some embodiments of the present application, Fig.10 and Fig.11 As shown, the second plate 242 is arranged on the side of the first plate 241 facing away from the enclosed space, and the bottom plate 24 also includes a third plate 243 arranged on the side of the second plate 242 facing away from the first plate 241. The first plate 241, the second plate 242 and the third plate 243 are connected as a whole.

[0125] By providing the third plate 243 , the structural strength of the bottom plate 24 is improved, the bearing and protection capabilities of the bottom plate 24 for the battery cell 1 are improved, and the probability of the battery cell 1 being damaged is reduced.

[0126] In some embodiments of the present application, the first plate 241 , the second plate 242 , and the third plate 243 are integrally brazed.

[0127] The first plate 241, the second plate 242 and the third plate 243 are brazed as a whole, which means that the first plate 241, the second plate 242 and the third plate 243 are connected as a whole through a brazing process, so that the formed bottom plate 24 has better integrity. Compared with other connection methods (such as bolt connection or simple welding), the integral brazing can reduce the stress concentration points at the connection parts. For example, if bolt connection is adopted, stress may be concentrated around the bolt hole and fatigue cracks may occur easily. When the bottom plate 24 formed by integral brazing is subjected to external forces such as the weight of the battery cell 1 and the vibration during the driving of the vehicle, the stress can be more evenly distributed on the entire structure, thereby improving the structural reliability of the bottom plate 24. Moreover, the brazing formation makes the overall thickness of the bottom plate 24 thinner, which is conducive to improving the volume energy density of the battery device 100. In addition, since the first plate 241 is used to conduct heat during thermal management, the integral brazing formation makes the heat conduction less obstructed, and the heat transfer can be more efficiently performed, thereby improving the battery performance and service life of the battery device 100.

[0128] In some embodiments of the present application, Fig.11 As shown, a buffer gap 244 is formed between a portion of the third plate 243 and a portion of the second plate 242 .

[0129] In this way, when the bottom plate 24 is impacted, the buffer gap 244 can play a role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate 24 .

[0130] In some embodiments of the present application, Fig.11 As shown, the buffer gap 244 is filled with a buffer structure 245 .

[0131] When the bottom plate 24 is impacted or squeezed, the buffer structure 245 filled in the buffer gap 244 can play a role of buffering and absorbing energy, thereby improving the impact resistance and squeeze resistance of the bottom plate 24 .

[0132] In some embodiments of the present application, Fig.10 and Fig.11 As shown, a portion of the second plate 242 is recessed toward the third plate 243 to form a first groove 2421 with a notch facing the first plate 241 , and the first plate 241 closes the notch of the first groove 2421 to form a flow channel 20 .

[0133] In this way, by forming the first groove 2421 on the second plate 242, the first plate 241 closes the first groove 2421 to form a flow channel 20 for the heat exchange medium to flow, so that the bottom plate 24 also has a heat exchange function, and can adjust the temperature of the battery cell 1, and control the temperature of the battery cell 1 within an appropriate temperature range, thereby improving the performance of the battery device 100 and extending the service life of the battery device 100.

[0134] In some embodiments of the present application, Fig.10 and Fig.11 As shown, the portion of the second plate 242 that is not recessed toward the third plate 243 forms a recessed portion 2423 that is recessed toward the first plate 241 relative to the bottom wall of the first groove 2421 , and the recessed portion 2423 abuts against the first plate 241 .

[0135] “The portion of the second plate 242 that is not recessed toward the third plate 243” refers to the remaining portion of the second plate 242 except the first groove 2421, that is, the remaining portion of the second plate 242 except the first groove 2421 forms a recessed portion 2423 that is recessed toward the first plate 241 relative to the bottom wall of the first groove 2421.

[0136] Exemplarily, the second plate 242 is formed by stamping, and the first groove 2421 is formed by stamping while the recessed portion 2423 is also formed.

[0137] The first plate 241 and the second plate 242 are connected by abutting the recessed portion 2423 against the first plate 241 , so that a flow channel 20 is formed between the first groove 2421 and the first plate 241 , and the connection strength between the first plate 241 and the second plate 242 is high.

[0138] In some embodiments of the present application, Fig.10 and Fig.11 As shown, the recessed portion 2423 includes a contact portion 2423 a and a spacer portion 2423 b , the contact portion 2423 a contacts a portion of the third plate 243 , and a space is formed between the spacer portion 2423 b and another portion of the third plate 243 .

[0139] The abutting portion 2423a of the recessed portion 2423 abuts against the third plate 243, thereby increasing the contact area between the second plate 242 and the third plate 243 and improving the connection strength between the two, thereby improving the structural reliability of the bottom plate 24. In addition, a buffer gap 244 is formed by a gap between the spacing portion 2423b of the recessed portion 2423 and the third plate 243. The buffer gap 244 can play a role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate 24. In some embodiments of the present application, such as Fig.10 As shown, the bottom wall of the first groove 2421 abuts against the third plate 243, and a buffer gap 244 is formed between the third plate 243 and the spacer 2423b.

[0140] In this way, by abutting the third plate 243 against the bottom wall of the first groove 2421, the contact area between the second plate 242 and the third plate 243 is increased, the connection reliability between the two is improved, and thus the structural reliability of the bottom plate 24 is improved. In addition, a buffer gap 244 is formed between the third plate 243 and the spacer 2423b of the recessed portion 2423. When the bottom plate 24 is impacted, the buffer gap 244 can play a role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate 24.

[0141] In some embodiments of the present application, Fig.10 As shown, the bottom wall of the first groove 2421 abuts against the third plate 243 , and a buffer gap 244 is formed between the third plate 243 and the spacer 2423 b , and the buffer gap 244 is filled with a buffer structure 245 .

[0142] In this way, by filling the buffer structure 245 in the buffer gap 244 , the impact resistance and extrusion resistance of the bottom plate 24 are improved.

[0143] In some embodiments of the present application, Fig.11 As shown, there is a distance between the bottom wall of the first groove 2421 and the third plate 243 , and a buffer gap 244 is formed between the third plate 243 and the bottom wall of the first groove 2421 and the spacer 2423 b of the recessed portion 2423 , and the buffer gap 244 is filled with a buffer structure 245 .

[0144] In this way, there is a distance between the bottom wall of the first groove 2421 and the third plate 243, so that the distance between the spacer 2423b of the recessed portion 2423 and the third plate 243 is larger, thereby making the buffer gap 244 formed between the third plate 243 and the bottom wall of the first groove 2421 and the spacer 2423b of the recessed portion 2423 larger, thereby being able to accommodate a larger buffer structure 245, thereby further improving the impact resistance and extrusion resistance of the bottom plate 24.

[0145] In some embodiments of the present application, Fig.11 As shown, the cushioning structure 245 includes a foam structure 245a.

[0146] The foam structure refers to a structure with a large number of micropores inside. The foam structure can play a good role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate 24. In addition, the foam structure has a low density and light weight, which is conducive to the lightweight of the battery device 100. In addition, the foam structure has a good heat insulation effect, which can reduce the amount of heat or cold energy in the heat exchange medium in the flow channel that diffuses outward through the second plate 242 and the third plate 243, reducing the dissipation of energy, thereby helping to improve the thermal management performance of the bottom plate 24 for the battery cell 1.

[0147] In some embodiments of the present application, the foam structure 245a includes at least one of polystyrene foam, polyethylene foam, and polyurethane foam.

[0148] The foam is easy to obtain and inexpensive, which is beneficial to cost saving. It can also play a good role in buffering and absorbing energy, thereby improving the impact resistance and compression resistance of the bottom plate 24.

[0149] In some embodiments of the present application, the buffer structure 245 includes a rubber structure.

[0150] The rubber structure refers to a structural member made of rubber material, which can be a solid structure or a foam structure made of rubber. The rubber structure is elastic and can play a good role in buffering and absorbing energy, thereby improving the impact resistance and extrusion resistance of the bottom plate 24.

[0151] In some embodiments of the present application, the rubber structure is made of natural rubber; and / or the rubber structure is made of synthetic rubber, and the synthetic rubber includes nitrile rubber and / or silicone rubber.

[0152] The buffer structure 245 made of the above-mentioned material can play a good role in buffering and energy absorption, thereby improving the impact resistance and extrusion resistance of the bottom plate 24.

[0153] In some embodiments of the present application, Fig.10 and Fig.11 As shown, a portion of the third plate 243 protrudes toward the second plate 242 to form a protruding portion 2431 , and the protruding portion 2431 extends into the abutting portion 2423 a of the recessed portion 2423 and abuts against the inner wall of the abutting portion 2423 a .

[0154] In this way, by setting the protrusion 2431, part of the third plate 243 is abutted against the inner wall of the abutment portion 2423a, thereby increasing the contact area between the third plate 243 and the second plate 242, improving the connection strength between the two, and improving the structural reliability of the bottom plate 24.

[0155] In some embodiments of the present application, Fig.10 and Fig.11 As shown, a protective layer 246 is attached to the surface of the third plate 243 facing away from the second plate 242 .

[0156] In this way, the protective layer 246 is used to protect the surface of the third plate 243 facing away from the second plate 242 , thereby improving the wear resistance and impact resistance of the bottom of the battery device 100 .

[0157] In some embodiments of the present application, a portion of the third plate 243 protruding toward the second plate 242 is further formed with a second groove 2432 with a notch facing away from the second plate 242 , and a portion of the protective layer 246 is filled in the second groove 2432 .

[0158] Exemplarily, the protrusion 2431 of the third plate 243 is formed by stamping, and the second groove 2432 is formed while the protrusion 2431 is formed.

[0159] Part of the protection layer 246 is filled in the second groove 2432 , so that the protection layer 246 is partially thickened, which can improve the protection effect and improve the wear resistance and impact resistance of the bottom of the battery device 100 .

[0160] In some embodiments of the present application, the protective layer 246 includes at least one of a polyurea coating, an epoxy resin coating, a polyvinyl chloride coating, and a polyurethane coating.

[0161] The provision of the above coating improves the wear resistance and impact resistance of the bottom of the battery device 100 .

[0162] For example, the surface of the protective layer 246 facing away from the third plate 243 is a plane, which improves the stability of the placement of the battery device 100. The protective layer 246 can be formed by spraying or brushing, but is not limited to this.

[0163] In some embodiments of the present application, the first plate 241 , the second plate 242 , and the third plate 243 are all made of aluminum plates.

[0164] Exemplarily, the first plate 241, the second plate 242 and the third plate 243 are all made of aluminum plates, and the first plate 241, the second plate 242 and the third plate 243 are brazed into one piece. The first plate 241, the second plate 242 and the third plate 243 are made of the same material, and the melting points of the three plates are basically the same, which can improve the brazing effect of the three plates. The material of the aluminum plate used by the first plate 241, the second plate 242 and the third plate 243 can be, but not limited to, 3003 aluminum.

[0165] Aluminum has a low density, which makes the bottom plate 24 light, which is beneficial to the lightweight of the battery device 100, and the cost of aluminum is low, which is beneficial to reducing the cost of the battery device 100. In addition, aluminum has good thermal conductivity, and the first plate 241 is an aluminum plate, which is beneficial to improve the heat conduction between the heat exchange medium and the battery cell 1, and improve the thermal management performance of the battery device 100.

[0166] In some embodiments of the present application, the first plate 241 is an aluminum plate, the second plate 242 is a steel-aluminum composite plate, and the third plate 243 is a steel plate, wherein the steel-aluminum composite plate includes an aluminum layer and a steel layer connected by rolling, the aluminum layer is connected to the aluminum plate, and the steel layer is connected to the steel plate.

[0167] The material of the aluminum plate used for the first plate 241 and the material of the aluminum layer used for the second plate 242 may be, but are not limited to, 3003 aluminum.

[0168] The steel plate has high strength and good toughness, and is impact-resistant and durable. Therefore, the second plate 242 is made of a steel-aluminum composite plate, and the third plate 243 is made of a steel plate, which improves the durability of the bottom plate 24.

[0169] Exemplarily, the first plate 241 is made of an aluminum plate, the second plate 242 is made of a steel-aluminum composite plate, and the third plate 243 is made of a steel plate, wherein the steel-aluminum composite plate includes an aluminum layer and a steel layer connected by rolling, the aluminum layer is connected to the aluminum plate, the steel layer is connected to the steel plate, and the first plate 241, the second plate 242, and the third plate 243 are brazed into one piece. The first plate 241 is connected to the aluminum layer of the second plate 242, and the melting points of the two are substantially the same, so the brazing effect of the two is good; the third plate 243 is connected to the steel layer of the second plate 242, and the melting points of the two are substantially the same, so the brazing effect of the two is good.

[0170] In some embodiments of the present application, the first plate 241 is an aluminum plate, the second plate 242 is an aluminum-titanium composite plate, and the third plate 243 is a titanium alloy plate, wherein the aluminum-titanium composite plate includes an aluminum layer and a titanium layer connected by rolling, the aluminum layer is connected to the aluminum plate, and the titanium layer is connected to the titanium alloy plate.

[0171] The material of the aluminum plate used for the first plate 241 and the material of the aluminum layer used for the second plate 242 may be, but are not limited to, 3003 aluminum.

[0172] The titanium alloy plate has high strength and good toughness. The titanium alloy plate is impact-resistant and durable. Therefore, the second plate 242 is made of an aluminum-titanium composite plate and the third plate 243 is made of a titanium alloy plate, which improves the durability of the bottom plate 24.

[0173] Exemplarily, the first plate 241 is made of an aluminum plate, the second plate 242 is made of an aluminum-titanium composite plate, and the third plate 243 is made of a titanium alloy plate, wherein the aluminum-titanium composite plate includes an aluminum layer and a titanium layer connected by rolling, the aluminum layer is connected to the aluminum plate, the titanium layer is connected to the titanium alloy plate, and the first plate 241, the second plate 242 and the third plate 243 are brazed into one piece. The first plate 241 is connected to the aluminum layer of the second plate 242, and the melting points of the two are basically the same, so the brazing effect of the two is good; the third plate 243 is connected to the titanium layer of the second plate 242, and the melting points of the two are similar, so the brazing effect of the two is good.

[0174] In some embodiments of the present application, Fig. 9 As shown, the bottom plate 24 is connected to the surface of the side beam 231 facing away from the top cover 21 through the first fastener 26. The first fastener 26 includes but is not limited to a flow drill screw.

[0175] Exemplarily, the first fastener 26 passes through the third plate 243, the second plate 242, and the first plate 241 and is connected to the side beam 231. Exemplarily, a portion of the third plate 243 and a portion of the second plate 242 exceed the circumferential edge of the first plate 241, and the first fastener 26 passes through the portion of the third plate 243 and the second plate 242 that exceeds the first plate 241 and is connected to the side beam 231. Exemplarily, a portion of the third plate 243 exceeds the circumferential edge of the second plate 242 and the first plate 241, and the first fastener 26 passes through the portion of the third plate 243 that exceeds the second plate 242 and the first plate 241 and is connected to the side beam 231.

[0176] In some embodiments of the present application, the bottom plate 24 is connected to the surface of the side beam 231 facing away from the top cover 21 by welding. The welding method includes but is not limited to friction welding.

[0177] Exemplarily, the first plate 241 and the second plate 242 are both connected to the side beam 231 by friction welding.

[0178] In some embodiments of the present application, Fig. 9 As shown, the bottom plate 24 is connected to the surface of the cross beam 232 facing away from the top cover 21 through the second fastener 25. The second fastener 25 includes but is not limited to a flow drill screw.

[0179] Exemplarily, the second fastener 25 passes through the third plate 243, the second plate 242 and the first plate 241 and is connected to the crossbeam 232. The second fastener 25 avoids the position of the flow channel 20 of the bottom plate 24.

[0180] A second aspect of the present application provides an energy storage device, which includes a plurality of battery devices 100 provided in the first aspect, and the battery devices 100 are used to store or provide electrical energy.

[0181] Since the energy storage device includes the battery device 100 described above, and the battery device 100 has a high volume energy density, the energy storage device also has a high volume energy density.

[0182] A third aspect of the present application provides an electrical device, which includes a plurality of battery devices 100 provided in the first aspect, and the battery devices 100 are used to store or provide electrical energy.

[0183] Since the electric device includes the battery device 100 described above, the battery device 100 has a high volume energy density, and therefore the electric device has a high volume energy density.

[0184] like Fig.12 As shown, the fourth aspect of the present application provides a method for manufacturing a battery device, the manufacturing method comprising: S1, making the base plate; S2, providing the frame, top cover and multiple battery cells; S3, connecting the frame to the bottom plate to form a box body with an opening on one side; S4, installing a plurality of battery cells into the box through the opening; S5, sealing the top cover to the opening of the box body.

[0185] The bottom plate 24 is formed with a flow channel 20 for the heat exchange medium to flow.

[0186] The embodiment of the present application forms a flow channel 20 for the flow of heat exchange medium in the bottom plate 24, so that the bottom plate 24 also has a heat exchange function, that is, the heat exchange plate is integrated into the bottom plate 24, which reduces the occupation of the heat exchange plate in the closed space in the battery box 2, thereby increasing the space for accommodating the battery cell 1, and the heat exchange plate is integrated into the bottom plate 24, which compresses the overall height of the battery device 100, saves space in the height direction of the battery device 100, and improves the volume energy density of the battery device 100.

[0187] In some embodiments of the present application, Fig.13 As shown, a base plate 24 is manufactured, including: S11, forming a first plate, a second plate and a third plate respectively by stamping; S12, stacking the first plate, the second plate and the third plate in sequence and brazing them as a whole.

[0188] A flow channel 20 is formed between the first plate 241 and the second plate 242 , a buffer gap 244 is formed between the second plate 242 and the third plate 243 , and a buffer structure 245 is filled in the buffer gap 244 .

[0189] The first plate 241, the second plate 242 and the third plate 243 are brazed as a whole, which means that the first plate 241, the second plate 242 and the third plate 243 are connected as a whole through a brazing process, so that the formed bottom plate 24 has better integrity. Compared with other connection methods (such as bolt connection or simple welding), the integral brazing can reduce the stress concentration points at the connection parts. For example, if bolt connection is adopted, stress may be concentrated around the bolt hole and fatigue cracks may occur easily. When the bottom plate 24 formed by integral brazing is subjected to external forces such as the weight of the components above the bottom plate 24 and the vibration during the driving of the vehicle, the stress can be more evenly distributed on the entire structure, thereby improving the structural reliability of the bottom plate 24. In addition, the brazing molding makes the overall thickness of the bottom plate 24 thinner, which is conducive to improving the volume energy density of the battery device 100. In addition, since the first plate 241 is used to conduct heat during thermal management, the integral brazing molding makes the heat conduction less obstructed, and the heat transfer can be more efficiently performed, thereby improving the battery performance and service life of the battery device 100.

[0190] Specific examples of some embodiments of the present application are described below with reference to the accompanying drawings.

[0191] As a specific example, a battery pack (battery device 100) is provided, including a battery box (battery box 2) and a plurality of battery cells (battery cells 1) accommodated in the battery box. The bottom plate (bottom plate 24) of the battery box includes a temperature averaging plate (first plate 241), a flow channel plate (second plate 242) and a bottom plate (third plate 243) arranged in sequence. The temperature averaging plate (first plate 241), the flow channel plate (second plate 242) and the bottom plate (third plate 243) are all made of 3003 aluminum plate and brazed into an integral body. A portion of the flow channel plate is recessed toward the bottom plate to form a first groove (first groove 2421) with a notch facing the temperature averaging plate. The temperature averaging plate closes the notch of the first groove to form a flow channel (flow channel 20), so that the bottom plate also has a heat exchange function, that is, the heat exchange plate is integrated into the bottom plate, which reduces the occupation of the heat exchange plate in the enclosed space in the battery pack, thereby increasing the space for accommodating the battery cells. In addition, the heat exchange plate is integrated into the bottom plate, which compresses the overall height of the battery pack, saves space in the height direction of the battery pack, and improves the volume energy density of the battery pack.

[0192] Furthermore, the portion of the flow channel plate (second plate 242) that is not recessed toward the bottom plate (third plate 243) forms a recessed portion (recessed portion 2423) that is recessed toward the temperature averaging plate relative to the bottom wall of the first groove, and the recessed portion abuts against the temperature averaging plate, so that the temperature averaging plate closes the notch of the first groove, thereby forming a flow channel (flow channel 20). The bottom surface of the bottom plate is sprayed with a polyvinyl chloride coating or a polyurea coating, etc.

[0193] There is a gap between part of the recessed portion (spacer 2423b) and the bottom plate, another part of the recessed portion (abutment portion 2423a) abuts against the bottom plate, and the bottom wall of the first groove (first groove 2421) abuts against the bottom plate, so that a gap (buffer gap 244) is formed between part of the recessed portion (spacer 2423b) and the bottom plate.

[0194] As another specific example, for ease of understanding, only the differences between this example and the first example are described. The difference is that there is a spacing between the bottom wall of the first groove (first groove 2421) and the bottom plate, and a gap (buffer gap 244) is formed between the bottom plate and the bottom wall of the first groove and the recessed portion (spacer 2423b), and the gap is filled with buffer material (buffer structure 245).

[0195] As another specific example, for ease of understanding, only the differences between this example and the first example are described. The differences are that the temperature equalizing plate is made of 3003 aluminum plate, the flow channel plate is made of steel-aluminum composite plate, and the bottom plate is made of steel plate, wherein the steel-aluminum composite plate includes a 3003 aluminum layer and a steel layer connected by rolling, the 3003 aluminum layer is brazed with the 3003 aluminum plate, and the steel layer is brazed with the steel plate.

[0196] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way.

Claims

1. A battery device, characterized in that: The invention comprises a battery box and a plurality of battery cells arranged in a closed space of the battery box. The battery box includes a bottom plate, a frame and a top cover, wherein the top cover and the bottom plate are respectively connected to opposite sides of the frame to form the closed space. The bottom plate includes a first plate, a second plate and a third plate stacked in sequence, the second plate is arranged on the side of the first plate facing away from the closed space, a flow channel for heat exchange medium to flow is formed between the first plate and the second plate, the third plate is arranged on the side of the second plate facing away from the first plate, and a buffer gap is formed between a portion of the third plate and a portion of the second plate.

2. The battery device according to claim 1, characterized in that: The first plate, the second plate and the third plate are connected as one body.

3. The battery device according to claim 1, characterized in that: The first plate, the second plate and the third plate are integrally brazed.

4. The battery device according to claim 1, characterized in that: The buffer gap is filled with a buffer structure.

5. The battery device according to claim 1, characterized in that: A protective layer is attached to the surface of the third plate facing away from the second plate.

6. The battery device according to claim 1, characterized in that: A portion of the second plate is recessed toward the third plate to form a first groove facing the first plate, and the first plate closes the groove of the first groove to form the flow channel.

7. The battery device according to claim 6, characterized in that: The portion of the second plate that is not recessed toward the third plate forms a recessed portion that is recessed toward the first plate relative to the groove bottom wall of the first groove, and the recessed portion abuts against the first plate.

8. The battery device according to claim 7, characterized in that: The recessed portion includes a contact portion and a spacing portion. The contact portion contacts a portion of the third plate, and a spacing is provided between the spacing portion and another portion of the third plate.

9. The battery device according to claim 8, characterized in that: There is a distance between the bottom wall of the first groove and the third plate, a buffer gap is formed between the third plate, the bottom wall of the first groove and the spacer, and a buffer structure is filled in the buffer gap.

10. The battery device according to claim 9, characterized in that: The cushioning structure includes a foam structure.

11. The battery device according to claim 10, characterized in that: The foam structure includes at least one of polystyrene foam, polyethylene foam and polyurethane foam.

12. The battery device according to claim 9, characterized in that: The buffer structure includes a rubber structure.

13. The battery device according to claim 12, characterized in that The rubber structure is made of natural rubber; and / or The rubber structure is made of synthetic rubber, and the synthetic rubber includes nitrile rubber and / or silicone rubber.

14. The battery device according to claim 8, characterized in that The bottom wall of the first groove abuts against the third plate, and a buffer gap is formed between the third plate and the spacer.

15. The battery device according to claim 8, characterized in that: A portion of the third plate protrudes toward the second plate to form a protruding portion, and the protruding portion extends into the abutting portion and abuts against an inner wall of the abutting portion.

16. The battery device according to claim 15, characterized in that: A protective layer is attached to the surface of the third plate facing away from the second plate.

17. The battery device according to claim 16, characterized in that: The portion of the third plate protruding toward the second plate is further formed with a second groove with a notch facing away from the second plate, and a portion of the protective layer is filled in the second groove.

18. The battery device according to claim 16, characterized in that: The protective layer includes at least one of a polyurea coating, an epoxy resin coating, a polyvinyl chloride coating, and a polyurethane coating.

19. The battery device according to any one of claims 1 to 18, characterized in that: The first plate, the second plate and the third plate are all made of aluminum plates.

20. The battery device according to any one of claims 1 to 18, characterized in that: The first plate is made of aluminum plate, the second plate is made of steel-aluminum composite plate, and the third plate is made of steel plate. The steel-aluminum composite plate includes an aluminum layer and a steel layer connected by rolling, wherein the aluminum layer is connected to the aluminum plate, and the steel layer is connected to the steel plate.

21. The battery device according to any one of claims 1 to 18, characterized in that: The first plate is made of aluminum plate, the second plate is made of aluminum-titanium composite plate, and the third plate is made of titanium alloy plate. The aluminum-titanium composite plate comprises an aluminum material layer and a titanium material layer connected by rolling, wherein the aluminum material layer is connected to the aluminum plate, and the titanium material layer is connected to the titanium alloy plate.

22. An energy storage device, characterized in that: The energy storage device comprises a plurality of battery devices according to any one of claims 1 to 21, and the battery devices are used to store or provide electrical energy.

23. An electrical device, characterized in that: The electrical device comprises a plurality of battery devices according to any one of claims 1 to 21, wherein the battery devices are used to store or provide electrical energy.

24. A method for manufacturing a battery device, characterized in that: include: Make the base plate; Provide a frame, a top cover and multiple battery cells; Connecting the frame to the bottom plate to form a box having an opening on one side; Installing a plurality of the battery cells into the box through the opening; Seal the top cover on the opening of the box body; The bottom plate includes a first plate, a second plate and a third plate stacked in sequence, the second plate is arranged on the side of the first plate facing away from the top cover, a flow channel for heat exchange medium to flow is formed between the first plate and the second plate, the third plate is arranged on the side of the second plate facing away from the first plate, and a buffer gap is formed between a portion of the third plate and a portion of the second plate.

25. The method for manufacturing a battery device according to claim 24, characterized in that: The manufacturing of the base plate comprises: Forming the first plate, the second plate and the third plate respectively by stamping; The first plate, the second plate and the third plate are stacked in sequence and brazed as a whole.

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