Battery module, battery pack, energy storage device and electric device

Abstract

The utility model discloses a battery module, a battery pack, an energy storage device and a power utilization device, and belongs to the technical field of batteries. The battery module comprises at least three battery monomers which are sequentially arranged in the first direction, each battery monomer comprises a shell and an electrode assembly arranged in the shell, the first direction is perpendicular to the large surface of the shell, the large surface is the outer surface, with the largest area, of the shell, and the electrode assembly is arranged between the first battery monomer and the last battery monomer in the first direction. The positive first set number of battery monomers and the last second set number of battery monomers are first battery monomers, the remaining battery monomers are second battery monomers, the large surface of the shell of each first battery monomer is made of a first material, and the large surface of the shell of each second battery monomer is made of a second material; the tensile strength of the first material is higher than that of the second material. The battery module, the battery pack, the energy storage device and the power utilization device provided by the utility model have high structural strength.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery modules, battery packs, energy storage devices and power-consuming devices. 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] The structural strength of the battery is related to the durability, reliability and safety of the battery. Therefore, how to improve the structural strength of the battery is one of the topics that the industry needs to study. Utility Model Content

[0004] In order to solve the above technical problems, the present application provides a battery module, a battery pack, an energy storage device and an electrical device with high structural strength.

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

[0006] A first aspect of the present application provides a battery module, comprising at least three battery cells arranged in sequence along a first direction, each of the battery cells comprising an outer shell and an electrode assembly disposed in the outer shell, the first direction being perpendicular to a large surface of the outer shell, the large surface being an outer surface of the outer shell with the largest area, and along the first direction, from the first battery cell to the last battery cell, a first set number of the battery cells and a second to last set number of the battery cells are both first battery cells, and the remaining battery cells are all second battery cells, the large surface of the outer shell of each of the first battery cells is made of a first material, the large surface of the outer shell of each of the second battery cells is made of a second material, and the tensile strength of the first material is higher than the tensile strength of the second material.

[0007] The second battery cell is located near the middle of the entire battery module, and the first battery cell is located at both ends of the entire battery module along the first direction. The tensile strength of the first material used for the large surface of the outer shell of the first battery cell is higher than the tensile strength of the second material used for the large surface of the outer shell of the second battery cell, so that the structural strength of the two ends of the entire battery module that were originally easily damaged is improved and becomes less likely to be damaged, thereby improving the structural strength of the entire battery module, and then being able to improve the durability, reliability and safety of the battery module.

[0008] In some embodiments, the outer shell includes a shell and a top cover, the shell has an opening, the top cover closes the opening of the shell to form a accommodating cavity for accommodating the electrode assembly, the shell includes the large surface, the shell and the top cover of the outer shell of each of the first battery cells are made of the first material, and the shell and the top cover of the outer shell of each of the second battery cells are made of the second material.

[0009] In this way, the structural strength of the outer shell of the first battery cell is further improved, and the outer shell of the first battery cell is less likely to deform than the outer shell of the second battery cell, so that the structural strength of the two ends of the entire battery module that are easily damaged is improved and becomes less likely to be damaged, thereby improving the structural strength of the entire battery module, and then being able to improve the durability, reliability and safety of the battery module.

[0010] In some embodiments, the shell wall of the shell opposite to the top cover is the shell bottom wall, the shell wall of the shell surrounding the shell bottom wall is the shell side wall, the thickness of the top cover of the outer shell of the first battery cell is in the range of 0.6mm to 1.0mm, the thickness of the shell side wall is in the range of 0.2mm to 0.5mm, and the thickness of the shell bottom wall is in the range of 0.2mm to 0.5mm; and / or, the thickness of the top cover of the outer shell of the second battery cell is in the range of 1.5mm to 2.5mm, the thickness of the shell side wall is in the range of 0.5mm to 0.8mm, and the thickness of the shell bottom wall is in the range of 1.0mm to 2.0mm.

[0011] By limiting the wall thickness of the outer shell of the first battery cell and the outer shell of the second battery cell respectively, the structural strength of the outer shell of the first battery cell is made higher than the structural strength of the outer shell of the second battery cell, so that the structural strength of the two ends of the entire battery module that are easily damaged is improved and becomes less likely to be damaged, thereby improving the structural strength of the entire battery module, and further improving the durability, reliability and safety of the battery module.

[0012] In some embodiments, the first material is steel, and the second material is aluminum.

[0013] The tensile strength of steel is higher than that of aluminum, and the density of aluminum is lower than that of steel. Thus, the outer shell made of aluminum is located near the middle of the entire battery module, and the outer shell made of steel is located at both ends of the entire battery module along the first direction. The tensile strength of steel is higher than that of aluminum, so that the structural strength of the easily damaged ends of the entire battery module is improved and becomes less likely to be damaged, and the weight of the less likely to be damaged middle part is reduced. Therefore, the structural strength of the battery module is improved and the weight is reduced.

[0014] In some embodiments, the first set number and the second set number are equal.

[0015] In this way, the number of first battery cells at both ends of the battery module along the first direction is the same, so that the structural strength of the battery module at both ends along the first direction is substantially consistent, improving the balance of the structural strength of the battery module, thereby further improving the structural strength of the battery module.

[0016] In some embodiments, the first set number includes one, two or three; the second set number includes one, two or three.

[0017] In this way, the structural strength of the two ends of the entire battery module, which are originally easily damaged, is improved and becomes less likely to be damaged, thereby improving the structural strength of the entire battery module, and further improving the durability, reliability and safety of the battery module.

[0018] In some embodiments, the electrode assemblies of the battery cells are of the same shape and size.

[0019] In this way, the electrode assemblies have the same shape and size, and the same electrode assembly can be used during production, which is beneficial to reducing the production cost of battery cells.

[0020] In some embodiments, the outer shell of each of the battery cells has the same shape and size.

[0021] In this way, the shapes and dimensions of the battery cells are the same, that is, the sizes of the battery cells are the same, so that the edges of the large surfaces of adjacent battery cells in the battery module are relatively aligned, improving the utilization of space, thereby making the volume energy density of the assembled battery module high.

[0022] In some embodiments, each of the battery cells further includes a pressure relief mechanism, and the pressure relief mechanism is disposed on the top cover and / or the bottom wall of the shell.

[0023] The battery cells are arranged along the first direction, and the pressure relief mechanism is arranged on the top cover and / or the bottom wall of the shell, so that the pressure relief mechanism of each battery cell will not be blocked by the adjacent battery cells, so that the pressure relief mechanism can play a normal pressure relief function.

[0024] In some embodiments, the shell side wall includes two large surfaces opposite to each other along the first direction and two first walls opposite to each other along a second direction perpendicular to the first direction. Each battery cell also includes at least one pole, which is arranged on the top cover and / or the first wall and is connected to the pole ear of the electrode assembly.

[0025] In this way, the pole can output or input the electric energy of the battery cell, and the position of the pole is convenient for connecting the battery cells through the pole, and for connecting the pole to the adapter that inputs or outputs the entire battery module.

[0026] In some embodiments, the electrode column of each of the battery cells includes a positive electrode column and a negative electrode column. In the same battery cell, the positive electrode column and the negative electrode column are respectively connected to the positive electrode tab and the negative electrode tab of the electrode assembly. The positive electrode column is made of aluminum, and the negative electrode column includes an aluminum part and a copper part connected to the aluminum part. The copper part is arranged on the side of the aluminum part facing the accommodating cavity and is connected to the negative electrode tab.

[0027] The positive pole column is made of aluminum, which means that the entire positive pole column is made of aluminum. The cost of aluminum is low, which is conducive to reducing the material cost of the battery module. The negative pole column includes an aluminum part and a copper part connected to the aluminum part. The copper part is arranged on the side of the aluminum part facing the negative pole ear and connected to the negative pole ear. In this way, the copper part is blocked between the accommodating cavity of the shell and the aluminum part, reducing the probability of contact between the electrolyte and the aluminum part, thereby reducing the corrosion of the electrolyte to the aluminum part, thereby extending the service life of the battery module.

[0028] In some embodiments, the battery module also includes a first end plate and a second end plate. Along the first direction, the large surface of the first battery cell facing away from the second battery cell is connected to the first end plate, and the large surface of the last battery cell facing away from the second battery cell is connected to the second end plate.

[0029] The first end plate and the second end plate limit the two ends of all battery cells arranged along the first direction, further improving the structural strength of the easily damaged ends of the battery module and making it less susceptible to damage, thereby improving the structural strength of the entire battery module, and further improving the durability, reliability and safety of the battery module.

[0030] A second aspect of the present application provides a battery pack, comprising: a battery box; and at least one of the above-mentioned battery modules, disposed in the battery box.

[0031] Since the battery pack includes a battery module, the battery pack has all the beneficial effects of the battery module, and thus the structural strength of the battery pack is improved.

[0032] A third aspect of the present application provides an energy storage device, comprising the above-mentioned battery module or the above-mentioned battery pack.

[0033] Since the energy storage device includes a battery module or a battery pack, the energy storage device has all the beneficial effects of the battery module or the battery pack, and therefore, the structural strength of the energy storage device is improved.

[0034] A fourth aspect of the present application provides an electrical device, which includes the above-mentioned battery module or the above-mentioned battery pack for providing electrical energy.

[0035] Since the electric device includes a battery module or a battery pack, the electric device has all the beneficial effects of the battery module or the battery pack, and thus the structural strength of the electric device is improved.

[0036] Utility Model Effect

[0037] Through the present application, a battery module, a battery pack, an energy storage device and an electrical device with high structural strength can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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:

[0039] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application;

[0040] Figure 2 A three-dimensional exploded schematic diagram of a battery pack provided for some embodiments of the present application;

[0041] Figure 3 A three-dimensional exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0042] Figure 4 A schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0043] Figure 5 A schematic diagram of a three-dimensional structure of a battery module provided in some embodiments of the present application;

[0044] Figure 6 A front view of a battery module provided for some embodiments of the present application;

[0045] Figure 7 A schematic diagram of a three-dimensional structure of a first structure of a battery cell provided in some embodiments of the present application;

[0046] Figure 8 A schematic diagram of a three-dimensional structure of a second structure of a battery cell provided in some embodiments of the present application;

[0047] Fig. 9 A schematic diagram of a three-dimensional structure of a battery cell according to some embodiments of the present application;

[0048] Fig.10 A schematic three-dimensional structural diagram of a fourth structure of a battery cell provided in some embodiments of the present application.

[0049] Description of Reference Numerals

[0050] 1000 vehicle; 100 battery pack; 200 controller; 300 motor; 10 battery box; 101 box cover; 102 box body; 20 battery module; 1 battery cell; 1a first battery cell; 1b second battery cell; 11 outer shell; 111 top cover; 112 shell; 1121 shell bottom wall; 1122 shell side wall; 1123 first wall; 1124 large surface; 12 electrode assembly; 121 positive electrode ear; 122 negative electrode ear; 13 pressure relief mechanism; 14 pole; 14a positive pole; 14b negative pole; 2 first end plate; 3 second end plate. DETAILED DESCRIPTION

[0051] The following embodiments of the technical solution of the present application will be 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] Below, this application is described in detail.

[0060] 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.

[0061] In the embodiment of the present application, the battery may include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid connection through a busbar component.

[0062] The battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged.

[0063] In the embodiments of the present application, a plurality refers to more than two.

[0064] In some embodiments of the present application, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0065] In some embodiments of the present application, the battery may be a battery pack, which includes a battery box and battery cells, wherein the battery cells or battery modules are accommodated in the battery box.

[0066] In some embodiments of the present application, 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.

[0067] The inventors of the present application noticed that multiple battery cells of a battery module are arranged along one direction. The battery cells closer to the head and tail ends of the arrangement direction are more likely to be deformed or even damaged, and are weak points in the entire battery module. Therefore, the overall structural strength of the battery module can be improved by increasing the structural strength of the battery cells close to the head and tail ends.

[0068] After research, the inventors of the present application discovered that by designing the structural strength of the outer shells of several battery cells near the head end and the tail end to be higher than the structural strength of the outer shells of the battery cells in other parts, the structural strength of the two ends of the battery module that were originally easily damaged is improved, thereby making the structural strength of the entire battery module along the arrangement direction more balanced, improving the structural strength of the entire battery module, and further improving the durability, reliability and safety of the battery module.

[0069] Based on such a design concept, the inventor of the present application designed a battery module, which includes at least three battery cells arranged in sequence along a first direction, each battery cell including an outer shell and an electrode assembly arranged in the outer shell, the first direction is perpendicular to the large surface of the outer shell, the large surface is the outer surface of the outer shell with the largest area, along the first direction, from the first battery cell to the last battery cell, the first set number of battery cells and the second to last set number of battery cells are both first battery cells, and the remaining battery cells are all second battery cells, the large surface of the outer shell of each first battery cell is made of a first material, the large surface of the outer shell of each second battery cell is made of a second material, and the tensile strength of the first material is higher than the tensile strength of the second material.

[0070] The large surface of the shell is the part that is most likely to deform, so improving the tensile strength of the large surface is beneficial to improving the structural strength of the entire shell. The second battery cell is located near the middle of the entire battery module, and the first battery cell is located at both ends of the entire battery module along the first direction. Since the structural strength of the shell of the first battery cell is improved, the structural strength of the two ends of the entire battery module that are easily damaged is improved and becomes less likely to be damaged, thereby improving the structural strength of the entire battery module, and further improving the durability, reliability and safety of the battery module.

[0071] The battery module provided in the embodiment of the present application can be used in, but not limited to, energy storage devices or power-consuming devices. The energy storage device can be, but not limited to, an energy storage container, an energy storage cabinet, etc. The power-consuming device can be, but not limited to, a vehicle, a ship, or an aircraft, for example, a mobile phone, a portable device, a laptop computer, a battery car, an electric toy, an electric tool, a vehicle, a ship, and a spacecraft, for example, a spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft.

[0072] The battery module provided in the embodiment of the present application can be accommodated in a battery box to form a battery pack. The battery pack can also be used in, but not limited to, an energy storage device or an electrical device. The energy storage device can be, but not limited to, an energy storage container, an energy storage cabinet, etc. The electrical device can be, but not limited to, a vehicle, a ship, or an aircraft, for example, a mobile phone, a portable device, a laptop computer, a battery car, an electric toy, an electric tool, a vehicle, a ship, and a spacecraft, for example, a spacecraft includes an airplane, a rocket, a space shuttle, and a spacecraft.

[0073] 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.

[0074] Figure 1 The schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. 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 pack 100 is disposed inside the vehicle 1000, and the battery pack 100 can be disposed at the bottom, head, or tail of the vehicle 1000. The battery pack 100 can be used to power the vehicle 1000, for example, the battery pack 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 pack 100 to power the motor 300, for example, for the starting, navigation, and working power requirements of the vehicle 1000 during driving.

[0075] In some embodiments of the present application, the battery pack 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0076] Figure 2 Schematic diagram of a three-dimensional exploded view of a battery pack 100 provided in some embodiments of the present application. Figure 2 As shown, the battery pack 100 includes a battery box 10 and at least one battery module 20. The battery box 10 is provided with a receiving space, and the at least one battery module 20 is received in the receiving space.

[0077] In some embodiments of the present application, the battery box 10 includes a box body 102 and a box cover 101 , and the box cover 101 covers the box body 102 , so that the accommodating space is formed between the box body 102 and the box cover 101 .

[0078] The box body 102 may be a hollow structure with one end open, and the box cover 101 may be a plate-like structure, and the box cover 101 covers the open side of the box body 102, so that the box cover 101 and the box body 102 jointly define a storage space; the box cover 101 and the box body 102 may also be hollow structures with one side open, and the open side of the box cover 101 covers the open side of the box body 102. Of course, the battery box 10 formed by the box cover 101 and the box body 102 may be in various shapes, such as a cylinder, a cuboid, etc.

[0079] The battery module 20 is composed of multiple battery cells 1 connected in series, in parallel or in mixed connection. In the battery pack 100, there can be multiple battery modules 20, and the multiple battery modules 20 can be connected in series, in parallel or in mixed connection. Mixed connection means that the multiple battery modules 20 are both connected in series and in parallel. The multiple battery modules 20 can be directly connected in series, in parallel or in mixed connection, and then the whole composed of the multiple battery modules 20 is placed in the accommodation space formed by the box body 102 and the box cover 101. The battery pack 100 may also include other structures. For example, the battery pack 100 may also include a busbar component for realizing electrical connection between multiple battery cells 1 or multiple battery modules 20.

[0080] In the embodiment of the present application, 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., and the embodiment of the present application is not limited to this.

[0081] As an example, the battery cell 1 may be a prismatic battery, which includes a square-shell battery, a blade-shaped battery, a polygonal battery, and a polygonal battery, such as a hexagonal battery, etc., and there is no particular limitation in the present application.

[0082] Below, refer to Figures 3 to 10Some embodiments of the present application are described in detail.

[0083] Figure 3 A three-dimensional exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 4 A schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application; Figure 5 A schematic diagram of a three-dimensional structure of a battery module provided in some embodiments of the present application; Figure 6 A front view of a battery module provided for some embodiments of the present application; Figure 7 A schematic diagram of a three-dimensional structure of a first structure of a battery cell provided in some embodiments of the present application; Figure 8 A schematic diagram of a three-dimensional structure of a second structure of a battery cell provided in some embodiments of the present application; Fig. 9 A schematic diagram of a three-dimensional structure of a battery cell according to some embodiments of the present application; Fig.10 A schematic three-dimensional structural diagram of a fourth structure of a battery cell provided in some embodiments of the present application.

[0084] For ease of explanation, Figures 4 to 10 As shown by the arrows in , the direction of arrow X is the first direction, the direction of arrow Y is the second direction, and the direction of arrow Z is the third direction. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0085] A first aspect of the present application provides a battery module 20, such as Figures 3 to 6 As shown, the battery module 20 includes at least three battery cells 1 arranged in sequence along a first direction X, each battery cell 1 includes a shell 11 and an electrode assembly 12 arranged in the shell 11, the first direction X is perpendicular to the large surface 1124 of the shell 11, the large surface 1124 is the outer surface of the shell 11 with the largest area, along the first direction X, from the first battery cell 1 to the last battery cell 1, the first set number of battery cells 1 and the second to last set number of battery cells 1 are all first battery cells 1a, and the remaining battery cells 1 are all second battery cells 1b, the large surface 1124 of the shell 11 of each first battery cell 1a is made of a first material, and the large surface 1124 of the shell 11 of each second battery cell 1b is made of a second material, and the tensile strength of the first material is higher than the tensile strength of the second material.

[0086] The housing 11 is a component having a housing cavity isolated from the external environment. The housing cavity is used to accommodate the electrode assembly, electrolyte and other components. The housing 11 can be in various shapes and sizes, such as a rectangular parallelepiped, a hexagonal prism, etc. Specifically, the shape of the housing 11 can be determined according to the specific shape and size of the electrode assembly. The material of the housing 11 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.

[0087] The electrode assembly 12 is a component in the battery cell 1 where electrochemical reactions occur. The housing 11 may contain one, two or more electrode assemblies. When there are more than two electrode assemblies, the electrode assemblies are connected in parallel or in series. The electrode assembly is mainly formed by winding or stacking positive and negative electrode sheets, and an isolator 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 constitute the positive electrode tabs and the negative electrode tabs, respectively. During the charge and discharge process of the battery cell 1, the positive electrode active material and the negative electrode active material react with the electrolyte, and the electrons pass through the closed electrical circuit to form a current circuit.

[0088] Tensile strength is the critical value of the material's transition from uniform plastic deformation to local concentrated plastic deformation, and is also the material's maximum load-bearing capacity under static tension. Tensile strength is the resistance to the maximum uniform plastic deformation of the material, and also refers to the maximum stress value that the material can withstand before being damaged. The first material has a high tensile strength, which is beneficial to improving the structural strength of the housing 11 of the first battery cell 1a. The first material and the second material can be, but are not limited to, copper, iron, aluminum, stainless steel, aluminum alloy or plastic, as long as the tensile strength of the first material is higher than the tensile strength of the second material.

[0089] It is understandable that the first set number is an integer not less than 1, which may be 1, 2, 3 or 4, etc.; the second set number is an integer not less than 1, which may be 1, 2, 3 or 4, etc. The first set number may be equal to the second set number, or may not be equal. Exemplarily, the first set number is N1, the second set number is N2, the number of battery cells 1 from the beginning to the end along the first direction X is N in total, the number of first battery cells 1a is N1+N2, and the number of second battery cells 1b is N-N1-N2. Along the first direction X, from the first battery cell 1 to the last battery cell 1, the positive number N1 battery cells 1 refer to the first battery cell 1, the second battery cell 1, ... and the N1th battery cell 1 along the first direction X; the reciprocal N2 battery cells 1 refer to the first-to-last battery cell 1, the second-to-last battery cell 1, ... and the N2th-to-last battery cell 1; the remaining battery cells 1 refer to all the battery cells 1 arranged along the first direction X except the positive number N1 battery cell 1 and the reciprocal N2 battery cell 1.

[0090] The second battery cell 1b is located near the middle of the entire battery module 20, and the first battery cell 1a is located at both ends of the entire battery module 20 along the first direction X. The tensile strength of the first material used for the large surface 1124 of the outer shell 11 of the first battery cell 1a is higher than the tensile strength of the second material used for the large surface 1124 of the outer shell 11 of the second battery cell 1b, which is beneficial to improving the structural strength of the outer shell 11 of the first battery cell 1a, so that the structural strength of the two ends of the entire battery module 20 that were originally easily damaged is improved and becomes less likely to be damaged, thereby improving the structural strength of the entire battery module 20, and then being able to improve the durability, reliability and safety of the battery module 20.

[0091] In some embodiments of the present application, the housing 11 includes a top cover 111 and a shell 112 . The shell 112 has an opening. The top cover 111 closes the opening of the shell 112 to form a receiving cavity. The electrode assembly 12 is disposed in the receiving cavity.

[0092] The top cover 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 top cover 111 can be adapted to the shape of the shell 112 to match the shell 112. Optionally, the top cover 111 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the top cover 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.

[0093] In some embodiments of the present application, a pressure relief mechanism 13 for releasing the internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold value may also be provided on the top cover 111. The material of the top cover 111 may also be a variety of materials, 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.

[0094] In some embodiments of the present application, an insulating member may be provided inside the top cover 111, and the insulating member may be used to isolate the electrical connection components in the housing 112 from the top cover 111 to reduce the risk of short circuit. For example, the insulating member may be plastic, rubber, etc.

[0095] The shell 112 is a component used to cooperate with the top cover 111 to form the internal environment of the battery cell 1, wherein the formed internal environment can be used to accommodate the electrode assembly, electrolyte and other components. The shell 112 and the top cover 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 top cover 111 at the opening. Without limitation, the top cover 111 and the shell 112 can also be integrated. Specifically, the top cover 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 top cover 111 is covered with the shell 112. The shell 112 can be of various shapes and sizes, such as a rectangular parallelepiped, 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. 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.

[0096] In some embodiments of the present application, Figure 3 and Figure 4 As shown, the outer shell 11 includes a shell 112 and a top cover 111, the shell 112 has an opening, and the top cover 111 closes the opening of the shell 112 to form an accommodating cavity for accommodating the electrode assembly 12, the shell 112 includes a large surface 1124, the shell 112 and the top cover 111 of each first battery cell 1a are made of a first material, and the shell 112 and the top cover 111 of each second battery cell 1b are made of a second material.

[0097] In this way, the structural strength of the outer shell 11 of the first battery cell 1a is further improved, making the outer shell 11 of the first battery cell 1a less susceptible to damage than the outer shell 11 of the second battery cell 1b, and the structural strength of the two ends of the entire battery module 20 that were originally easily damaged is improved and becomes less susceptible to damage, thereby improving the structural strength of the entire battery module 20, and further improving the durability, reliability and safety of the battery module 20.

[0098] In some embodiments of the present application, the shell wall of the shell 112 opposite to the top cover 111 is the shell bottom wall 1121, the shell wall of the shell 112 surrounding the shell bottom wall 1121 is the shell side wall 1122, the thickness of the top cover 111 of the outer shell 11 of the first battery cell 1a is in the range of 0.6mm to 1.0mm, the thickness of the shell side wall 1122 of the outer shell 11 of the first battery cell 1a is in the range of 0.2mm to 0.5mm, and the thickness of the shell bottom wall 1121 of the outer shell 11 of the first battery cell 1a is in the range of 0.2mm to 0.5mm; and / or, the thickness of the top cover 111 of the outer shell 11 of the second battery cell 1b is in the range of 1.5mm to 2.5mm, the thickness of the shell side wall 1122 of the outer shell 11 of the second battery cell 1b is in the range of 0.5mm to 0.8mm, and the thickness of the shell bottom wall 1121 of the outer shell 11 of the second battery cell 1b is in the range of 1.0mm to 2.0mm.

[0099] Exemplarily, the thickness of the top cover 111 of the outer shell 11 of the first battery cell 1a may be, but is not limited to, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, and 1.0 mm. The thickness of the shell side wall 1122 of the outer shell 11 of the first battery cell 1a may be, but is not limited to, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, and 0.5 mm; the thickness of the shell bottom wall 1121 of the outer shell 11 of the first battery cell 1a may be, but is not limited to, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, and 0.5 mm.

[0100] Exemplarily, the thickness of the top cover 111 of the housing 11 of the second battery cell 1b may be, but is not limited to, 1.5 mm, 1.55 mm, 1.6 mm, 1.65 mm, 1.7 mm, 1.75 mm, 1.8 mm, 1.85 mm, 1.9 mm, 1.95 mm, 2.0 mm, 2.05 mm, 2.1 mm, 2.15 mm, 2.2 mm, 2.25 mm, 2.3 mm, 2.35 mm, 2.4 mm, 2.45 mm, and 2.5 mm. The thickness of the shell side wall 1122 of the shell 11 of the second battery cell 1b can be but not limited to 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm and 0.8mm; the thickness of the shell bottom wall 1121 of the shell 11 of the second battery cell 1b can be but not limited to 1.0mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, 1.9mm, 1.95mm and 2.0mm.

[0101] By respectively limiting the wall thicknesses of the outer shell 11 of the first battery cell 1a and the outer shell 11 of the second battery cell 1b, the structural strength of the outer shell 11 of the first battery cell 1a can be ensured to be higher than the structural strength of the outer shell 11 of the second battery cell 1b, thereby improving the structural strength of the two ends of the entire battery module 20 that are originally easily damaged, thereby improving the structural strength of the entire battery module 20, and further improving the durability, reliability and safety of the battery module 20.

[0102] In some embodiments of the present application, the density of the second material is less than the density of the first material.

[0103] In this way, when the volume of the shell 11 is the same, the weight of the shell 11 made of the second material is less than the weight of the shell 11 made of the first material, thereby reducing the weight of the battery module 20 while improving the structural strength.

[0104] In some embodiments of the present application, the first material includes steel, and the second material includes aluminum.

[0105] The tensile strength of steel is higher than that of aluminum, and the density of aluminum is lower than that of steel. Thus, the outer shell 11 made of aluminum is located near the middle of the entire battery module 20, and the outer shell 11 made of steel is located at both ends of the entire battery module 20 along the first direction X. The tensile strength of steel is higher than that of aluminum, so that the structural strength of the two ends of the entire battery module 20 that were originally easily damaged is improved and becomes less likely to be damaged, and the weight of the middle part that is less likely to be damaged is reduced. Therefore, the structural strength of the battery module 20 is improved and the weight is reduced.

[0106] In some embodiments of the present application, the first set number and the second set number are equal.

[0107] In this way, the number of first battery cells 1a at both ends of the battery module 20 along the first direction X is the same, so that the structural strength of the battery module 20 at both ends along the first direction X is substantially consistent, thereby improving the balance of the structural strength of the battery module 20 and further improving the structural strength of the battery module 20.

[0108] In some embodiments of the present application, the first set number includes one, two or three; the second set number includes one, two or three.

[0109] The first set number and the second set number may be equal or unequal.

[0110] In this way, the structural strength of the two ends of the entire battery module 20 that are easily damaged is improved and becomes less likely to be damaged, thereby improving the structural strength of the entire battery module 20, and further improving the durability, reliability and safety of the battery module 20.

[0111] Exemplarily, the first set number and the second set number are both one, that is, Figure 5 As shown, along the first direction X, the first battery cell 1 from the positive end and the last battery cell 1 from the negative end are both first battery cells 1 a , and the remaining battery cells 1 are all second battery cells 1 b .

[0112] Exemplarily, the first set number and the second set number are both two, that is, Figure 6 As shown, along the first direction X, the two battery cells 1 in the positive direction and the two battery cells 1 in the negative direction are all first battery cells 1 a , and the remaining battery cells 1 are all second battery cells 1 b .

[0113] In some embodiments of the present application, the electrode assemblies 12 of the battery cells 1 are of the same shape and size.

[0114] Exemplarily, the battery cells 1 are all the same, which means that the shape and size of the electrode assemblies 12 are the same, and the electrochemical properties of the electrode assemblies 12 are also the same.

[0115] In this way, the electrode assemblies 12 have the same shape and size, and the same electrode assemblies 12 can be used during production, which is beneficial to reducing the production cost of the battery cell 1.

[0116] In some embodiments of the present application, the outer shell 11 of each battery cell 1 has the same shape and size.

[0117] The outer shape of the shell 11 refers to the shape of the outer contour of the shell 11 . For example, when the battery cell 1 is a square-shell battery, the outer contour of the shell 11 of each battery cell 1 is a cube, and the length, width and height of the outer contour of each shell 11 are the same.

[0118] In this way, the shapes and dimensions of the battery cells 1 are the same, that is, the sizes of the battery cells 1 are the same, so that the edges of the large surfaces 1124 of adjacent battery cells 1 in the battery module 20 are relatively aligned, thereby improving the utilization of space and making the volume energy density of the composed battery module 20 high.

[0119] In some embodiments of the present application, each battery cell 1 further includes a pressure relief mechanism 13 , and the pressure relief mechanism 13 is disposed on the top cover 111 and / or the shell bottom wall 1121 .

[0120] For example, Figure 3 and Figure 7 As shown, the pressure relief mechanism 13 is disposed on the top cover 111. Figure 8 and Fig.10 As shown, the pressure relief mechanism 13 is disposed on the shell bottom wall 1121 .

[0121] The battery cells 1 are arranged along the first direction X, and the pressure relief mechanism 13 is disposed on the top cover 111 and / or the shell bottom wall 1121, so that the pressure relief mechanism 13 of each battery cell 1 will not be blocked by adjacent battery cells 1, thereby enabling the pressure relief mechanism 13 to perform normal pressure relief function.

[0122] In some embodiments of the present application, Figure 4 , Figures 7 to 10 As shown, the shell side wall 1122 includes two large surfaces 1124 opposite to each other along a first direction X and two first walls 1123 opposite to each other along a second direction Y perpendicular to the first direction X. Each battery cell 1 also includes at least one pole 14, which is arranged on the top cover 111 and / or the first wall 1123 and is connected to the pole ear of the electrode assembly 12.

[0123] For example, Figure 7 and Figure 8 As shown, the pole 14 is arranged on the first wall 1123. Fig. 9 and Fig.10 As shown, the pole 14 is disposed on the top cover 111 .

[0124] Exemplarily, each battery cell 1 is provided with a pole 14 , one of the positive pole tab and the negative pole tab of the electrode assembly 12 is connected to the pole 14 , and the other is connected to the housing 11 , and at this time, the housing 11 is charged.

[0125] Exemplarily, each battery cell 1 is provided with two poles 14 , one pole 14 is connected to the positive electrode tab 121 of the electrode assembly 12 , and the other pole 14 is connected to the negative electrode tab 122 of the electrode assembly 12 .

[0126] In this way, the pole 14 can output or input the electric energy of the battery cell 1, and the position of the pole 14 is convenient for connecting the battery cells 1 through the pole 14, and for connecting the pole 14 to the adapter that inputs or outputs the entire battery module 20.

[0127] In some embodiments of the present application, the shell bottom wall 1121 and the top cover 111 are opposite to each other along the third direction Z, and the third direction Z, the first direction X, and the second direction Y are perpendicular to each other.

[0128] In this way, the battery cell 1 forms a square-cased battery.

[0129] In some embodiments of the present application, Figure 3 As shown, the pole 14 of each battery cell 1 includes a positive pole 14a and a negative pole 14b. In the same battery cell 1, the positive pole 14a and the negative pole 14b are respectively connected to the positive pole ear 121 and the negative pole ear 122 of the electrode assembly 12. The positive pole 14a is made of aluminum, and the negative pole 14b includes an aluminum part and a copper part connected to the aluminum part. The copper part is arranged on the side of the aluminum part facing the accommodating cavity and is connected to the negative pole ear 122.

[0130] The positive electrode column 14a is made of aluminum, which means that the entire positive electrode column 14a is made of aluminum. The cost of aluminum is low, which is conducive to reducing the material cost of the battery module 20. The negative electrode column 14b includes an aluminum part and a copper part connected to the aluminum part. The copper part is arranged on the side of the aluminum part facing the accommodating cavity and is connected to the negative electrode tab 122. In this way, the copper part is blocked between the accommodating cavity of the housing 11 and the aluminum part, reducing the probability of contact between the electrolyte and the aluminum part, thereby reducing the corrosion of the electrolyte to the aluminum part, thereby extending the service life of the battery module 20.

[0131] In some embodiments of the present application, the battery module 20 also includes a first end plate 2 and a second end plate 3. Along the first direction X, the large surface 1124 of the first positive battery cell 1 facing away from the second positive battery cell 1 is connected to the first end plate 2, and the large surface 1124 of the last battery cell 1 facing away from the second last battery cell 1 is connected to the second end plate 3.

[0132] The first end plate 2 and the second end plate 3 limit the two ends of all battery cells 1 arranged along the first direction X, further improving the structural strength of the two ends of the battery module 20 that are easily damaged and making them less likely to be damaged, thereby improving the structural strength of the entire battery module 20, and further improving the durability, reliability and safety of the battery module 20.

[0133] A second aspect of the present application provides a battery pack 100 , which includes a battery box 10 and at least one battery module 20 provided in the first aspect, which is disposed in the battery box 10 .

[0134] Since the battery pack 100 includes the battery module 20 , the battery pack 100 has all the beneficial effects of the battery module 20 , and thus the structural strength of the battery pack 100 is improved.

[0135] A third aspect of the present application provides an energy storage device, which includes the battery module 20 provided in the first aspect or the battery pack 100 provided in the second aspect.

[0136] Since the energy storage device includes the battery module 20 or the battery pack 100 , the energy storage device has all the beneficial effects of the battery module 20 or the battery pack 100 , and therefore, the structural strength of the energy storage device is improved.

[0137] A fourth aspect of the present application provides an electrical device, which includes the battery module 20 provided by the first aspect or the battery pack 100 provided by the second aspect for providing electrical energy.

[0138] Since the electric device includes the battery module 20 or the battery pack 100 , the electric device has all the beneficial effects of the battery module 20 or the battery pack 100 , and thus the structural strength of the electric device is improved.

[0139] Specific examples of some embodiments of the present application are described below with reference to the accompanying drawings.

[0140] As a specific example, the battery cells (battery cells 1) in the battery module (battery module 20) are divided into two categories. The first type of battery cells (first battery cells 1a) are the two battery cells near the ends of the module, and the second type of battery cells (second battery cells 1b) are the other battery cells except the two end battery cells. This application mainly improves the reliability of the battery module by improving the structural strength of the first type of battery cells. The shell (shell 112) and top cover (top cover 111) of the first type of battery cell (first battery cell 1a) are both made of steel; the shell (shell 112) and top cover (top cover 111) of the second type of battery cell (second battery cell 1b) are both made of aluminum. The electrode assemblies (electrode assemblies 12) inside the first type of battery cell and the second type of battery cell are designed exactly the same to ensure that the electrochemical properties such as capacity and life of each battery cell are the same. The thickness of the top cover (top cover 111) of the aluminum shell battery is generally 1.5mm to 2.5mm, the thickness of the aluminum shell wall (shell side wall 1122) is generally 0.5mm to 0.8mm, and the thickness of the bottom of the aluminum shell (shell bottom wall 1121) is generally 1.0mm to 2.0mm; the aluminum shell is generally formed by stretching or stamping; the thickness of the top cover of the steel shell battery is generally 0.6mm to 1.0mm, the thickness of the steel shell wall is generally 0.2mm to 0.5mm, and the thickness of the bottom of the steel shell is generally 0.2mm to 0.5mm; the steel shell is generally formed by splicing welding. For steel shell batteries, the positive pole is made of aluminum, and the negative pole is made of copper-aluminum composite pole or copper; the pole and the steel top cover are insulated. The first type of battery and the second type of battery have exactly the same dimensions.

[0141] 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 module, characterized in that: The invention comprises at least three battery cells arranged in sequence along a first direction, each of the battery cells comprises a shell and an electrode assembly arranged in the shell, the first direction is perpendicular to a large surface of the shell, and the large surface is an outer surface of the shell with the largest area, Along the first direction, from the first battery cell to the last battery cell, the first set number of the battery cells and the second to last set number of the battery cells are all first battery cells, and the remaining battery cells are all second battery cells. The large surface of the outer shell of each of the first battery cells is made of a first material, and the large surface of the outer shell of each of the second battery cells is made of a second material, and the tensile strength of the first material is higher than the tensile strength of the second material.

2. The battery module according to claim 1, characterized in that: The housing comprises a shell and a top cover, the shell has an opening, the top cover closes the opening of the shell to form a housing cavity for accommodating the electrode assembly, the shell comprises the large surface, The shell and the top cover of the outer shell of each of the first battery cells are both made of the first material, and the shell and the top cover of the outer shell of each of the second battery cells are both made of the second material.

3. The battery module according to claim 2, characterized in that: The shell wall of the shell opposite to the top cover is the shell bottom wall, and the shell wall of the shell surrounding the shell bottom wall is the shell side wall. The thickness of the top cover of the outer shell of the first battery cell is in the range of 0.6 mm to 1.0 mm, the thickness of the shell side wall is in the range of 0.2 mm to 0.5 mm, and the thickness of the shell bottom wall is in the range of 0.2 mm to 0.5 mm; and / or The thickness of the top cover of the outer shell of the second battery cell is in the range of 1.5 mm to 2.5 mm, the thickness of the shell side wall is in the range of 0.5 mm to 0.8 mm, and the thickness of the shell bottom wall is in the range of 1.0 mm to 2.0 mm.

4. The battery module according to any one of claims 1 to 3, characterized in that: The first material is steel, and the second material is aluminum.

5. The battery module according to any one of claims 1 to 4, characterized in that: The first set number and the second set number are equal.

6. The battery module according to any one of claims 1 to 5, characterized in that: The first set number includes one, two or three; The second set number includes one, two or three.

7. The battery module according to any one of claims 1 to 6, characterized in that: The electrode assemblies of the battery cells are of the same shape and size.

8. The battery module according to any one of claims 1 to 7, characterized in that: The outer shells of the battery cells have the same shape and size.

9. The battery module according to claim 3, characterized in that: Each of the battery cells further comprises a pressure relief mechanism, and the pressure relief mechanism is arranged on the top cover and / or the bottom wall of the shell.

10. The battery module according to claim 3, characterized in that: The shell side wall includes two large faces opposite to each other along the first direction and two first walls opposite to each other along a second direction perpendicular to the first direction. Each of the battery cells further includes at least one pole, which is disposed on the top cover and / or the first wall and connected to a pole lug of the electrode assembly.

11. The battery module according to claim 10, characterized in that: The poles of each battery cell include a positive pole and a negative pole. In the same battery cell, the positive pole and the negative pole are connected to the positive pole tab and the negative pole tab of the electrode assembly, respectively. The positive electrode pole is made of aluminum, and the negative electrode pole includes an aluminum part and a copper part connected to the aluminum part. The copper part is arranged on a side of the aluminum part facing the accommodating cavity and is connected to the negative electrode tab.

12. The battery module according to any one of claims 1 to 11, characterized in that: The battery module further includes a first end plate and a second end plate. Along the first direction, the large surface of the first positive battery cell facing away from the second positive battery cell is connected to the first end plate, and the large surface of the last positive battery cell facing away from the second last battery cell is connected to the second end plate.

13. A battery pack, characterized in that: include: Battery box; and At least one battery module according to any one of claims 1 to 12 is arranged in the battery box.

14. An energy storage device, characterized in that: A battery module comprising any one of claims 1 to 12 or a battery pack according to claim 13.

15. An electrical device, characterized in that: The electrical device comprises the battery module according to any one of claims 1 to 12 or the battery pack according to claim 13 for providing electrical energy.

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