Battery monomer, battery device, energy storage device, energy storage system and power utilization device

Abstract

The utility model discloses a battery monomer, a battery device, an energy storage device, an energy storage system, a power utilization device and a charging network. The battery cell includes: a housing including a first outer surface and a second outer surface, the first outer surface being an outer surface different from the second outer surface; an electrode assembly; the separator separates the electrode assembly from at least one first inner surface, and the first inner surface is an inner surface, opposite to the first outer surface, in the shell; wherein the first inner surface comprises a first sub-inner surface and a second sub-inner surface, a weak area is arranged on the second sub-inner surface, and the size of the separator for separating the electrode assembly from the second sub-inner surface in the direction perpendicular to the second sub-inner surface is smaller than that of the first sub-inner surface. A size of a separator separating the electrode assembly from the first sub-inner surface in a direction perpendicular to the first sub-inner surface is greater than a size of the separator in the direction perpendicular to the first sub-inner surface. According to the battery monomer, the connection stability and the sealing reliability between the first outer surface corresponding to the second sub-inner surface and the adjacent second outer surface can be ensured to a certain extent.

Description

Technical Field

[0001] This application relates to the field of batteries, specifically to a battery cell, battery device, energy storage device, energy storage system, power consumption device, and charging network. Background Technology

[0002] With the continuous development of battery technology, especially in the fields of electric vehicles and renewable energy storage, the energy density and charge / discharge efficiency of batteries have been significantly improved. However, battery safety remains a critical aspect, particularly in high-energy-density batteries, where factors such as overheating, short circuits, and overcharging can lead to battery failure, or even fires or explosions. Therefore, improving battery safety has become a key focus of battery technology research and development.

[0003] Currently, a common problem in existing battery technology is that the expansion of electrode components during charging and discharging often leads to battery casing cracking or deformation. This structural failure not only severely affects the normal use of the battery but can also cause electrolyte leakage, potentially leading to more serious safety hazards. Therefore, effectively solving the problem of battery casing cracking caused by electrode expansion has become an urgent technical challenge. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, battery device, energy storage device, energy storage system, power consumption device and charging network, which can increase the distance between the electrode assembly and the first inner surface of the housing, and to a certain extent increase the distance between the second outer surface under stress tension critical zone and the first outer surface, thereby improving the connection stability and sealing reliability between the first outer surface and the second outer surface.

[0005] In a first aspect, this application provides a battery cell, the battery cell comprising:

[0006] The housing includes a first outer surface and a second outer surface, wherein the second outer surface is the outer surface with the largest area, and the first outer surface is an outer surface different from the second outer surface.

[0007] The electrode assembly is located inside the housing;

[0008] An isolator is located inside the housing, the isolator separating the electrode assembly from at least one first inner surface, the first inner surface being an inner surface inside the housing opposite to the first outer surface;

[0009] The first inner surface includes a first sub-inner surface and a second sub-inner surface. A weak area is provided on the second sub-inner surface. The dimension of the separator separating the electrode assembly from the second sub-inner surface in the direction perpendicular to the second sub-inner surface is greater than the dimension of the separator separating the electrode assembly from the first sub-inner surface in the direction perpendicular to the first sub-inner surface.

[0010] In the technical solution of this application embodiment, the dimension of the separator separating the electrode assembly from the second sub-inner surface in the direction perpendicular to the second sub-inner surface is larger than the dimension of the separator separating the electrode assembly from the first sub-inner surface in the direction perpendicular to the first sub-inner surface. This allows for a larger distance between the electrode assembly and the second sub-inner surface, which to a certain extent ensures a larger distance between the first outer surface (small surface) corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface (large surface) under stress tension critical zone. This, in turn, ensures to a certain extent the connection stability and sealing reliability between the first outer surface corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface.

[0011] In some embodiments, the housing includes an end cap and a housing, the housing having an opening at at least one end along a first direction, the end cap closing the opening to form the internal environment of the battery cell, and the separator separating a first inner surface of the end cap from the electrode assembly, and / or separating a first inner surface of the housing from the electrode assembly.

[0012] In the above embodiments, the isolator separates the first inner surface of the end cap from the electrode assembly, and / or separates the first inner surface of the housing from the electrode assembly, thereby increasing the distance between the electrode assembly and the first inner surface of the end cap or housing, and to a certain extent increasing the distance between the second outer surface under stress tension critical zone and the first outer surface, thereby improving the connection stability and sealing reliability between the first outer surface and the second outer surface.

[0013] In some embodiments, the battery cell includes a pressure relief mechanism disposed on a first side plate of the housing along a second direction. The separator includes a first separator and a second separator. The first separator separates a first sub-inner surface of the housing along the second direction from the electrode assembly. The second separator separates another opposite second sub-inner surface of the housing along the second direction from the electrode assembly. The first direction is perpendicular to the second direction. The maximum thickness of the second separator is greater than the maximum thickness of the first separator.

[0014] In the above embodiments, it is beneficial to increase the connection stability and sealing reliability between the first outer surface corresponding to the second sub-inner surface of the battery cell with a weak area and the adjacent second outer surface.

[0015] In some embodiments, the battery cell includes a pressure relief mechanism, the end cap includes a first end cap and a second end cap, the first end cap and the second end cap are respectively disposed on both sides of the housing along the first direction, the pressure relief mechanism is disposed on the first end cap or the second end cap, the separator includes a first separator and a second separator, the first separator separates the first sub-inner surface of the end cap without the pressure relief mechanism from the electrode assembly, the second separator separates the second sub-inner surface of the end cap with the pressure relief mechanism from the electrode assembly, and the maximum thickness of the second separator is greater than the maximum thickness of the first separator.

[0016] In the above embodiments, it is beneficial to increase the connection stability and sealing reliability between the first outer surface corresponding to the second sub-inner surface of the battery cell with a weak area and the adjacent second outer surface.

[0017] In some embodiments, the insulating element is insulated.

[0018] In the above embodiments, the insulating separator can effectively isolate the electrical connection between the internal electrode assembly of the battery cell and other conductive components, thereby avoiding problems such as short circuits and overcurrents to a certain extent and improving the safety of the battery cell.

[0019] In some embodiments, the pressure relief mechanism includes an explosion-proof valve and / or grooves.

[0020] In the above embodiments, the pressure relief mechanism includes an explosion-proof valve and / or grooves, which can effectively improve the safety and reliability of the battery cell.

[0021] In some embodiments, the battery cell includes a venting channel, and the electrode assembly communicates with the pressure relief mechanism through the venting channel.

[0022] In the above embodiments, the gas generated by the battery cell can flow to the pressure relief mechanism through the exhaust channel, thereby expelling the battery cell from the outside, effectively improving the safety and reliability of the battery cell.

[0023] In some embodiments, the isolation element includes an exhaust channel through which the electrode assembly communicates with the pressure relief mechanism.

[0024] In the above embodiments, the gas generated by the battery cell can flow to the pressure relief mechanism through the exhaust channel on the separator, thereby expelling the battery cell from the outside and effectively improving the safety and reliability of the battery cell.

[0025] In some embodiments, the maximum thickness D1 of the first separator satisfies 0.3 mm ≤ D1, and the maximum thickness D2 of the second separator satisfies 0.3 mm. <D2。

[0026] In the above embodiments, the maximum thickness D1 of the first separator satisfies 0.3 mm ≤ D1, and the maximum thickness D2 of the second separator satisfies 0.3 mm < D2. The maximum thickness of the second separator can be made greater than that of the first separator, thereby enhancing the connection stability and sealing reliability between the first outer surface corresponding to the second inner surface with a weak area and the adjacent second outer surface.

[0027] In some embodiments, 1 mm ≤ D2 ≤ 2 mm.

[0028] In the above embodiments, the maximum thickness of the second separator can be made thicker, thereby more effectively enhancing the connection stability and sealing reliability between the first outer surface corresponding to the second inner surface with a weak area and the adjacent second outer surface.

[0029] In some embodiments, the second separator includes two separator layers, the two separator layers are stacked, and the maximum thicknesses of the two separator layers are d1 and d2 respectively, satisfying 1 mm ≤ (d1 + d2) ≤ 2 mm, and d1 ≥ 0.3 mm, d2 ≥ 0.3 mm.

[0030] In the above embodiments, the maximum thicknesses of the two separator layers are d1 and d2 respectively, satisfying 1 mm ≤ (d1 + d2) ≤ 2 mm, and d1 ≥ 0.3 mm, d2 ≥ 0.3 mm, which can enhance the connection stability and sealing reliability between the first outer surface corresponding to the second inner surface with a weak area of the battery cell and the adjacent second outer surface, and at the same time ensure that the maximum thickness of each separator layer is not less than the maximum thickness of the first separator to ensure that the maximum thickness of the second separator is greater than that of the first separator.

[0031] In some embodiments, the surface of the second separator facing the pressure relief mechanism is provided with a groove, and at least a part of the pressure relief mechanism is located in the groove.

[0032] In the above embodiments, the surface of the second separator facing the pressure relief mechanism is provided with a groove, and at least a part of the pressure relief mechanism is located in the groove, which can save costs and improve the space utilization rate inside the battery cell.

[0033] In some embodiments, the projection of the groove in the first direction is greater than the projection of the pressure relief mechanism in the first direction.

[0034] In the above embodiments, the projection of the groove in the first direction is greater than the projection of the pressure relief mechanism in the first direction, which can improve the selectivity of at least a part of the pressure relief mechanism being located in the groove.

[0035] In some embodiments, the second isolation member includes a plurality of isolation layers stacked together, and in a second direction, the isolation layer closest to the pressure relief mechanism includes two spaced-apart isolation segments, the two isolation segments and the adjacent isolation layer forming the groove.

[0036] In the above embodiments, the isolation layer closest to the pressure relief mechanism includes two spaced isolation sections. The two isolation sections and the adjacent isolation layer form a groove, which can further save costs and improve the space utilization rate inside the battery cell.

[0037] In some embodiments, the second isolation member includes at least one isolation layer, and in a second direction, the isolation layer closest to the pressure relief mechanism has the groove on its surface facing the pressure relief mechanism.

[0038] In the above embodiments, the surface of the isolation layer closest to the pressure relief mechanism facing the pressure relief mechanism is provided with a groove, which can save costs and improve the space utilization rate inside the battery cell.

[0039] In some embodiments, the electrode assembly includes stacked electrodes and a diaphragm. On the side of the second direction near the pressure relief mechanism, the diaphragm protrudes beyond the electrodes by a greater length than on the other side of the second direction away from the pressure relief mechanism.

[0040] In the above embodiment, on the side of the second direction closer to the pressure relief mechanism, the length of the portion of the diaphragm protruding from the electrode is greater than the length of the portion of the diaphragm protruding from the electrode on the other side of the second direction away from the pressure relief mechanism. This can increase the distance between the first outer surface corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface under stress tension critical zone, thereby increasing the connection stability and sealing reliability between the first outer surface corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface.

[0041] In some embodiments, on the side of the second direction near the pressure relief mechanism, the length X2 of the portion of the diaphragm protruding from the electrode satisfies 2mm < X2 ≤ 3mm, and / or, on the other side of the second direction away from the pressure relief mechanism, the length X1 of the portion of the diaphragm protruding from the electrode satisfies 1mm ≤ X1 < 2mm.

[0042] In the above embodiments, the length of the diaphragm protruding from the electrode on the side closer to the pressure relief mechanism in the second direction is greater than the length of the diaphragm protruding from the electrode on the other side away from the pressure relief mechanism. This helps to increase the connection stability and sealing reliability between the first outer surface corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface.

[0043] In some embodiments, on the side of the second direction near the pressure relief mechanism, the portion of the diaphragm protruding from the electrode has a length X2 that satisfies X2±0.5mm, and / or on the other side of the second direction away from the pressure relief mechanism, the portion of the diaphragm protruding from the electrode has a length X1 that satisfies X1±0.5mm.

[0044] In the above embodiments, the error tolerance can be improved to a certain extent to reduce the difficulty of production. At the same time, the length of the diaphragm protruding from the electrode on the side closer to the pressure relief mechanism in the second direction is greater than the length of the diaphragm protruding from the electrode on the other side away from the pressure relief mechanism. This helps to increase the connection stability and sealing reliability between the first outer surface corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface.

[0045] Secondly, this application provides a battery device comprising a plurality of battery cells according to any of the above embodiments.

[0046] Thirdly, this application provides an energy storage device that includes a plurality of battery devices as described in any of the above embodiments, the battery devices being used to store or provide electrical energy.

[0047] Fourthly, this application provides an energy storage system, which includes a power conversion device and an energy storage device as described in the above embodiments, wherein the power conversion device is used to electrically connect a power generation device and the energy storage device.

[0048] Fifthly, this application provides an electrical device that includes the battery device, energy storage device, or energy storage system described in the above embodiments, wherein the battery device is used to store or provide electrical energy.

[0049] Sixthly, this application provides a charging network including a charging pile and an energy storage device or energy storage system as described in the above embodiments, wherein the energy storage device is used to provide electrical energy to the charging pile.

[0050] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0051] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0052] Figure 1This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0053] Figure 2 This is an exploded view of the battery device according to some embodiments of this application;

[0054] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0055] Figures 4 to 10 This is a schematic cross-sectional view of a battery cell according to some embodiments of this application;

[0056] Figure 11 and Figure 12 This is a cross-sectional schematic diagram of an electrode assembly according to some embodiments of this application;

[0057] Figure 13 This is a schematic diagram of the energy storage system modules according to some embodiments of this application;

[0058] Figure 14 This is a schematic diagram of a charging network module according to some embodiments of this application.

[0059] The reference numerals in the detailed embodiments are as follows:

[0060] 1,000 vehicles, 2,000 energy storage systems, and 3,000 charging networks;

[0061] Energy storage device 1, power conversion device 2, power generation device 3, charging pile 4, connector 5;

[0062] Battery unit 100, controller 200, motor 300;

[0063] Box 10, Part 11, Part 2 12;

[0064] Battery cell 20, end cap 21, housing 22, electrode assembly 23, outer shell 24, pressure relief mechanism 25, separator 26;

[0065] Electrode terminal 21a, first end cap 211, second end cap 212, opening 221, electrode tab 23a, electrode plate 231, diaphragm 232, positive electrode plate 231a, negative electrode plate 231b, first outer surface 24a, second outer surface 24b, first inner surface 24c, first side plate 241, first separator 261, second separator 262, groove 262a, isolation layer 2621, isolation section 2621a. Detailed Implementation

[0066] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0068] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0069] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0070] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0071] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0072] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0073] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0074] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0075] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0076] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0077] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0078] During charge-discharge cycles, the insertion and extraction of ions from the positive and negative electrode active materials, along with the accumulation of side reactions in the electrode components and the peeling of graphite sheets, can lead to battery deformation or damage. Because the distance between the electrode components and the small faces of the casing is relatively small, the expansion of the electrode components during charge-discharge cycles generates significant internal stress on the casing. This stress concentration can cause deformation of the large faces of the casing, further causing the small faces to cave inwards. Small faces containing vulnerable areas such as explosion-proof valves are particularly prone to inward cave-in. If the deformation exceeds the elastic limit of the casing material, in extreme cases, it may lead to cracks or even rupture of the casing, affecting not only battery safety but also potentially causing battery failure.

[0079] To mitigate the deformation or even cracking of the outer casing caused by the expansion of the electrode assembly, a spacer can be provided between the electrode assembly and the small facet. This spacer isolates the electrode assembly and the small facet, creating an isolation zone. This increases the distance between the small facet and the critical stress zone of the large facet, thereby improving the connection stability and sealing reliability between the large and small facets. Furthermore, for small facets with weak areas that are more prone to inward indentation, the distance between the small facet with the weak area and the electrode assembly can be further increased by increasing the size of the spacer. This further increases the distance between the small facet with the weak area and the adjacent critical stress zone of the large facet, thus improving the connection stability and sealing reliability between the small facet with the weak area and the adjacent large facet.

[0080] The battery cell 20 disclosed in this application can be used in electrical devices that use batteries as a power source or in various energy storage systems that use batteries as energy storage elements. The battery device 100 can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0081] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0082] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0083] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0084] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for accommodating the battery cell 20, and the housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 jointly define the space; alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0085] In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel connections. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0086] Each battery cell 20 can be a secondary battery or a primary battery. A secondary battery refers to a battery cell 20 that can be recharged after discharge to activate the active materials and continue to be used. It can also be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., but this application embodiment is not limited in this regard. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0087] Please refer to Figure 3 , Figure 3 This is an exploded structural diagram of a battery cell 20 provided in some embodiments of this application. The battery cell 20 refers to the smallest unit that makes up a battery. Figure 3 The battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0088] End cap 21 refers to a component that covers the opening of housing 22 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 21 can be adapted to the shape of housing 22 to fit it. Optionally, end cap 21 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 21 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 21a can be provided on end cap 21. Electrode terminals 21a can be used for electrical connection with electrode assembly 23 to output or input electrical energy to battery cell 20. In some embodiments, end cap 21 can also be provided with a pressure relief mechanism 25 for releasing internal pressure when the internal pressure or temperature of battery cell 20 reaches a threshold. The material of end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0089] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and the housing 22 can be integrated. Specifically, the end cap 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the end cap 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0090] Electrode assembly 23 is the component in the battery cell 100 where electrochemical reactions occur. The casing 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or stacking positive electrode plates 231a and negative electrode plates 231b, and typically a separator is provided between the positive electrode plates 231a and negative electrode plates 231b. The portions of the positive electrode plates 231a and 231b containing active material constitute the main body of the electrode assembly 23, while the portions of the positive electrode plates 231a and 231b without active material each constitute a tab 23a. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs 23a connect to the electrode terminals 21a to form a current loop.

[0091] According to some embodiments of this application, refer to Figures 3 to 4 This application provides a battery cell 20. The battery cell 20 includes a housing 24, an electrode assembly 23, and a separator 26. The housing 24 includes a first outer surface 24a and a second outer surface 24b, where the second outer surface 24b is the outer surface with the largest area, and the first outer surface 24a is an outer surface different from the second outer surface 24b. The electrode assembly 23 is located inside the housing 24. The separator 26 is located inside the housing 24, separating the electrode assembly 23 from at least one first inner surface 24c, where the first inner surface 24c is an inner surface inside the housing 24 opposite to the first outer surface 24a. The first inner surface 24c includes a first sub-inner surface and a second sub-inner surface, with a weak region provided on the sub-inner surface. The dimension of the separator 26 separating the electrode assembly 23 from the second sub-inner surface in the direction perpendicular to the second sub-inner surface is larger than the dimension of the separator 26 separating the electrode assembly 23 from the first sub-inner surface in the direction perpendicular to the first sub-inner surface.

[0092] like Figures 11 to 12 As shown, the electrode assembly 23 is mainly formed by stacking positive electrode 231a and negative electrode 231b. During the expansion of the electrode assembly 23, side reactions will occur in the third direction, resulting in maximum thickness accumulation and graphite layer peeling. The third direction is the main expansion direction of the electrode assembly 23.

[0093] The first outer surface 24a is the outer surface of the shell 24 parallel to a third direction. The second outer surface 24b is the outer surface of the shell 24 perpendicular to a third direction. The inner surface corresponding to the first outer surface 24a is the first inner surface 24c, which includes a first sub-inner surface and a second sub-inner surface. The second sub-inner surface is the first inner surface 24c with a weak area.

[0094] It is understandable that, due to the thinness of the outer shell 24 and the small distance between the electrode assembly 23 and the first inner surface 24c of the outer shell 24, during the expansion of the electrode assembly 23, the second outer surface 24b perpendicular to the third direction will bulge outward due to the expansion, and the first outer surface 24a parallel to the third direction will be concave inward due to the stretching of the second outer surface 24b, ultimately causing the outer shell 24 to crack.

[0095] It should be noted that the second outer surface 24b is the outer surface with the largest area, which is the large surface of the battery cell 20. The first outer surface 24a is an outer surface different from the second outer surface 24b, which is the small surface of the battery cell 20.

[0096] To alleviate the problem of deformation or cracking of the outer casing 24 caused by the expansion of the electrode assembly 23, in this embodiment of the application, the battery cell 20 includes a separator 26, which is located inside the outer casing 24. The separator 26 separates the electrode assembly 23 from at least one first inner surface 24c, which is an inner surface inside the outer casing 24 opposite to the first outer surface 24a.

[0097] Understandably, the spacer 26 can create an isolation zone between the electrode assembly 23 and at least one first inner surface 24c, thereby increasing the distance between the electrode assembly 23 and at least one first inner surface 24c, and further increasing the distance between the second outer surface 24b under stress tensile critical zone and the first outer surface 24a. The second outer surface 24b under stress tensile critical zone refers to the area of ​​the second outer surface 24b where stress concentration or deformation is most severe.

[0098] It should be understood that by increasing the distance between the critical stress zone of the second outer surface 24b and the first outer surface 24a, the effect of the stretching of the second outer surface 24b on the first outer surface 24a is reduced.

[0099] It should be noted that the separator 26 separates the electrode assembly 23 from at least one first inner surface 24c. The first inner surface 24c is the inner surface of the outer shell 24 that is opposite to the first outer surface 24a, that is, the inner surface that is opposite to the small surface. This can increase the distance between the electrode assembly 23 and the first inner surface 24c of the outer shell 24, and to a certain extent increase the distance between the second outer surface 24b (large surface) under stress tension critical zone and the first outer surface 24a (small surface), thereby improving the connection stability and sealing reliability between the first outer surface 24a and the second outer surface 24b.

[0100] In this embodiment, the first inner surface 24c includes a first sub-inner surface and a second sub-inner surface, and the second sub-inner surface has a weak region. The weak region is a region within the battery cell 20 that is more susceptible to stress concentration and deformation compared to non-weak regions. In one embodiment, the battery cell 20 includes a pressure relief mechanism 25. The pressure relief mechanism 25 can be used to safely and orderly discharge the gas generated by the battery cell 20 to the outside of the battery cell 20. Since the pressure relief mechanism 25 needs to have a certain deformation capacity when the internal pressure of the battery cell 20 is too high in order to release the gas, when the battery cell 20 has a pressure relief mechanism 25, the region of the battery cell 20 containing the pressure relief mechanism 25 is more susceptible to stress concentration and deformation; that is, the region containing the pressure relief mechanism 25 is a weak region.

[0101] The dimension of the isolator 26 separating the electrode assembly 23 from the second sub-inner surface in the direction perpendicular to the second sub-inner surface is larger than the dimension of the isolator 26 separating the electrode assembly 23 from the first sub-inner surface in the direction perpendicular to the first sub-inner surface. In other words, the distance between the electrode assembly 23 and the second sub-inner surface is greater than the distance between the electrode assembly 23 and the first sub-inner surface. Similarly, the distance between the critical stress-tension zone of the first outer surface 24a corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b is greater than the distance between the critical stress-tension zone of the first outer surface 24a corresponding to the first sub-inner surface without the weak area and the adjacent second outer surface 24b. This ensures, to a certain extent, the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b. Optionally, the isolator 26 is made of an insulating material, which may include, but is not limited to, polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), and polytetrafluoroethylene (PTFE).

[0102] Optionally, a spacer 26 may include multiple spacer portions. The multiple spacer portions may be arranged along a third direction to form a spacer 26, and the multiple spacer portions may be connected by means of bonding or other methods. The third direction is perpendicular to the first and second directions.

[0103] In the technical solution of this application embodiment, the dimension of the isolator 26 separating the electrode assembly 23 from the second sub-inner surface in the direction perpendicular to the second sub-inner surface is larger than the dimension of the isolator 26 separating the electrode assembly 23 from the first sub-inner surface in the direction perpendicular to the first sub-inner surface. This allows for a larger distance between the electrode assembly 23 and the second sub-inner surface, which to a certain extent ensures a larger distance between the first outer surface 24a (small surface) corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b (large surface) under stress tension critical zone. This, in turn, ensures to a certain extent the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b.

[0104] According to some embodiments of this application, optionally, please refer to... Figure 3 and Figure 4 The housing 24 includes an end cap 21 and a housing 22. The housing 22 has an opening 221 at at least one end along a first direction. The end cap 21 closes the opening 221 to form the internal environment of the battery cell 20. A separator 26 separates the first inner surface 24c of the end cap 21 from the electrode assembly 23, and / or separates the first inner surface 24c of the housing 22 from the electrode assembly 23.

[0105] During the expansion of electrode assembly 23, side reactions and graphite layer peeling occur in the third direction. The third direction is the main expansion direction of electrode assembly 23.

[0106] An opening 221 may be provided on at least one side of the housing 22 along a first direction, the first direction being perpendicular to a third direction. In one embodiment, the housing 22 has an opening 221 on one side along the first direction, and the end cap 21 can cover the opening 221 to form the internal environment of the battery cell 20. The electrode assembly 23 may be placed in the internal environment of the battery cell 20 by winding or stacking positive electrode 231a and negative electrode 231b. A separator 26 is provided between the electrode assembly 23 and the end cap 21.

[0107] In one embodiment, the housing 22 has openings 221 on both sides along the first direction, and two end caps 21 can respectively cover the openings 221 on both sides to form the internal environment of the battery cell 20. The electrode assembly 23 can be wound or stacked in the internal environment of the battery cell 20 by a positive electrode 231a and a negative electrode 231b. Two spacers 26 are respectively disposed between the electrode assembly 23 and the two end caps 21.

[0108] The outer surface of the housing 22 parallel to a third direction is the first outer surface 24a, and the outer surface of the housing 22 perpendicular to a third direction is the second outer surface 24b. Figure 3 and Figure 4In one embodiment, the housing 22 includes two first outer surfaces 24a along a second direction and two second outer surfaces 24b along a third direction, with the two first outer surfaces 24a corresponding to the two first inner surfaces 24c respectively.

[0109] A spacer 26 is provided between at least one first inner surface 24c of the housing 22 and the electrode assembly 23 along a second direction perpendicular to a third direction. In one embodiment, a spacer 26 is provided between the first inner surface 24c of the housing 22 on one side along the second direction and the electrode assembly 23. In another embodiment, spacers 26 are provided between the first inner surfaces 24c of the housing 22 on both sides along the second direction and the electrode assembly 23.

[0110] In the above embodiments, the isolator 26 separates the first inner surface 24c of the end cap 21 from the electrode assembly 23, and / or separates the first inner surface 24c of the housing 22 from the electrode assembly 23, thereby increasing the distance between the electrode assembly 23 and the first inner surface 24c of the end cap 21 or the housing 22, and to a certain extent increasing the distance between the second outer surface 24b under stress tension critical zone and the first outer surface 24a, thereby improving the connection stability and sealing reliability between the first outer surface 24a and the second outer surface 24b.

[0111] According to some embodiments of this application, optionally, please refer to... Figure 3 The end cap 21 is located on at least one side of the housing 22 along the first direction, and the end cap 21 is provided with an electrode terminal 21a, which is connected to the electrode assembly 23.

[0112] Electrode terminal 21a can be used to electrically connect to electrode assembly 23 for outputting or inputting electrical energy into battery cell 20.

[0113] In one embodiment, an end cap 21 is disposed on one side of the housing 22 along the first direction, and the end cap 21 is provided with two electrode terminals 21a. The two electrode terminals 21a are electrically connected to the electrode assembly 23 to output or input electrical energy of the battery cell 20. In another embodiment, two end caps 21 are respectively disposed on both sides of the housing 22 along the first direction, and each end cap 21 is provided with one electrode terminal 21a. The electrode terminals 21a on the two end caps 21 are electrically connected to the electrode assembly 23 to output or input electrical energy of the battery cell 20.

[0114] In the above embodiments, the electrode terminal 21a enables the battery cell 20 to communicate with an external circuit, thereby realizing the charging and discharging function of the battery cell 20.

[0115] According to some embodiments of this application, optionally, please refer to... Figure 4 and Figure 5The battery cell 20 includes a pressure relief mechanism 25, which is disposed on a first side plate 241 of the housing 22 along a second direction. The separator 26 includes a first separator 261 and a second separator 262. The first separator 261 separates a first sub-inner surface of the housing 22 along the second direction from the electrode assembly 23. The second separator 262 separates a second sub-inner surface of the first side plate 241 from the electrode assembly 23. The first direction is perpendicular to the second direction, and the maximum thickness of the second separator 262 is greater than the maximum thickness of the first separator 261.

[0116] The first isolator 261 can form a first isolation area between the first sub-inner surface of the housing 22 along the second direction and the electrode assembly 23, and the second isolator 262 can form a second isolation area between the second sub-inner surface of the first side plate 241 and the electrode assembly 23.

[0117] The first isolation zone and the second isolation zone can increase the distance between the first inner surface 24c and the electrode assembly 23, thereby increasing the distance between the first outer surface 24a and the second outer surface 24b under stress tension critical zone.

[0118] The pressure relief mechanism 25 is an installation device used to release excessive pressure inside the battery cell 20. When an abnormality occurs in the battery cell 20, the pressure relief mechanism 25 can take various forms, such as valves, diaphragms, or other forms, to automatically release pressure when the internal pressure of the battery cell 20 reaches a certain threshold, thereby preventing excessive internal pressure of the battery cell 20 from causing the casing 24 to rupture, leak, or explode.

[0119] In order to automatically release pressure when the internal pressure of the battery cell 20 reaches a certain threshold, the pressure relief mechanism 25 has low structural strength. Therefore, the inner surface of the first side plate 241 with the pressure relief mechanism 25 is a second sub-inner surface with a weak area.

[0120] The second separator 262 is disposed between the second sub-inner surface of the first side plate 241 and the electrode assembly 23. The maximum thickness of the second separator 262 is greater than the maximum thickness of the first partition, that is, the distance between the second sub-inner surface of the first side plate 241 and the electrode assembly 23 is greater, which can increase the distance between the stress tensile critical zone of the second outer surface 24b and the first outer surface 24a corresponding to the second sub-inner surface of the battery cell 20 where the weak area is located.

[0121] It should be understood that the greater the maximum thickness of the separator 26, the greater the distance between the corresponding first inner surface 24c and the electrode assembly 23, which means that the distance between the corresponding first outer surface 24a and the second outer surface 24b under stress tension critical zone increases, and the better the connection stability and sealing reliability between the corresponding first outer surface 24a and the adjacent second outer surface 24b.

[0122] In the above embodiments, it is beneficial to increase the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface of the battery cell 20 where the weak area is located and the adjacent second outer surface 24b.

[0123] According to some embodiments of this application, optionally, please refer to... Figure 4 The battery cell 20 includes a pressure relief mechanism 25. The end cap 21 includes a first end cap 211 and a second end cap 212. The first end cap 211 and the second end cap 212 are respectively disposed on both sides of the housing 22 along the first direction. The pressure relief mechanism 25 is disposed on the first end cap 211 or the second end cap 212. The separator 26 includes a first separator 261 and a second separator 262. The first separator 261 separates the first sub-inner surface of the end cap without the pressure relief mechanism 25 from the electrode assembly 23. The second separator 262 separates the second sub-inner surface of the end cap with the pressure relief mechanism 25 from the electrode assembly 23. The maximum thickness of the second separator 262 is greater than the maximum thickness of the first separator 261.

[0124] The first isolator 261 can form a first isolation area between the first sub-inner surface of the end cap without the pressure relief mechanism 25 and the electrode assembly 23, and the second isolator 262 can form a second isolation area between the second sub-inner surface 2 of the end cap with the pressure relief mechanism 25 and the electrode assembly 23.

[0125] The first isolation zone and the second isolation zone can increase the distance between the first inner surface 24c and the electrode assembly 23, thereby increasing the distance between the first outer surface 24a and the second outer surface 24b under stress tension critical zone.

[0126] According to some embodiments of this application, optionally, please refer to... Figure 4 The battery cell 20 includes a pressure relief mechanism 25, which is disposed on the first end cover 211 or the second end cover 212. The second isolation member 262 is located between the first inner surface 24c of the end cover 21 with the pressure relief mechanism 25 and the electrode assembly 23. The maximum thickness of the second isolation member 262 is greater than the maximum thickness of the first isolation member 261.

[0127] The pressure relief mechanism 25 is an installation device used to release excessive pressure inside the battery cell 20. When an abnormality occurs in the battery cell 20, the pressure relief mechanism 25 can take various forms, such as valves, diaphragms, or other forms, to automatically release pressure when the internal pressure of the battery cell 20 reaches a certain threshold, thereby preventing excessive internal pressure of the battery cell 20 from causing the casing 24 to rupture, leak, or explode.

[0128] In order to automatically release pressure when the internal pressure of the battery cell 20 reaches a certain threshold, the pressure relief mechanism 25 has low structural strength. Therefore, the inner surface of the end cap with the pressure relief mechanism 25 is a second sub-inner surface with a weak area.

[0129] The second separator 262 is disposed between the second sub-inner surface and the electrode assembly 23. The maximum thickness of the second separator 262 is greater than the maximum thickness of the first separator 261. That is, the distance between the second sub-inner surface of the end cap with the pressure relief mechanism 25 and the electrode assembly 23 is greater. This can increase the distance between the stress-tensile critical zone of the second outer surface 24b and the first outer surface 24a corresponding to the second sub-inner surface of the battery cell 20 with the weak area.

[0130] It should be understood that the greater the maximum thickness of the separator 26, the greater the distance between the corresponding first inner surface 24c and the electrode assembly 23, which means that the distance between the corresponding first outer surface 24a and the second outer surface 24b under stress tension critical zone increases, and the better the connection stability and sealing reliability between the corresponding first outer surface 24a and the adjacent second outer surface 24b.

[0131] In the above embodiments, it is beneficial to increase the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface of the battery cell 20 where the weak area is located and the adjacent second outer surface 24b.

[0132] According to some embodiments of this application, the spacer 26 may optionally be insulating.

[0133] The insulating separator 26 can, to some extent, prevent the electrode assembly 23 inside the battery cell 20 from being electrically connected to other conductive components through the separator 26, which could lead to problems such as short circuits, overcurrent, or battery performance degradation.

[0134] In one embodiment, the isolator 26 is made of an insulating material. The insulating material has high resistance, which can effectively block the flow of current, thereby preventing electrical interference to a certain extent.

[0135] In one embodiment, the surface of the separator 26 is coated with an insulating coating. The insulating coating can, to a certain extent, ensure electrical isolation between the electrode assembly 23 inside the battery cell 20 and other conductive components, thereby preventing electrical interference to some extent.

[0136] In the above embodiments, the insulating separator 26 can effectively isolate the electrical connection between the internal electrode assembly 23 of the battery cell 20 and other conductive components, thereby avoiding short circuits, overcurrent and other problems to a certain extent and improving the safety of the battery cell 20.

[0137] According to some embodiments of this application, optionally, please refer to... Figure 5 The pressure relief mechanism 25 includes an explosion-proof valve and / or grooves.

[0138] In one embodiment, the pressure relief mechanism 25 includes an explosion-proof valve. An explosion-proof valve is a device that automatically opens to relieve pressure when the internal pressure of the battery exceeds a safe threshold.

[0139] In one embodiment, the pressure relief mechanism 25 includes grooves. The grooves may be small notches or lines on the housing 24. When the internal pressure of the battery cell 20 reaches a certain level, it will first crack or break along the grooves, allowing the battery cell 20 to release gas orderly from the grooves when overpressured, rather than experiencing a sudden and violent explosion.

[0140] In one embodiment, the pressure relief mechanism 25 includes an explosion-proof valve and a groove. The explosion-proof valve can serve as a first pressure relief point, preventing the battery cell 20 from exploding due to excessive internal pressure to a certain extent; if the explosion-proof valve fails to trigger in time or fails to fully release the pressure, the groove can provide a second safety barrier, ensuring that the pressure can be safely released along the groove.

[0141] In the above embodiments, the pressure relief mechanism 25 includes an explosion-proof valve and / or grooves, which can effectively improve the safety and reliability of the battery cell 20.

[0142] According to some embodiments of this application, optionally, the battery cell 20 includes an exhaust channel, and the electrode assembly 232 is connected to the pressure relief mechanism 25 through the exhaust channel.

[0143] During the charging and discharging process of the battery cell 20, the electrode assembly 23 inside the battery cell 20 will generate gas. If this gas cannot be discharged in time, it may cause excessive pressure inside the battery cell 20, which may cause the outer casing 24 of the battery cell 20 to deform or crack, thereby affecting the safety and performance of the battery cell 20.

[0144] The pressure relief mechanism 25 is a safety device used to release excess gas to the outside of the battery cell 20 when there is too much gas inside the battery cell 20.

[0145] The battery cell 20 includes an exhaust channel that connects the electrode assembly 23 and the pressure relief mechanism 25. Gas generated by the electrode assembly 23 can flow along the exhaust channel to the pressure relief mechanism 25, so that the pressure relief mechanism 25 can effectively discharge excess gas inside the battery cell 20 to the outside of the battery cell 20.

[0146] In one embodiment, a gap is provided between the separator 26, the electrode assembly 23, and the housing 24 of the battery cell 20. The gap can be used for the flow of gas generated by the electrode assembly 23.

[0147] In the above embodiments, the gas generated by the battery cell 20 can flow to the pressure relief mechanism 25 through the exhaust channel, thereby expelling the battery cell 20 to the outside, effectively improving the safety and reliability of the battery cell 20.

[0148] According to some embodiments of this application, optionally, the isolation member 26 includes an exhaust channel, through which the electrode assembly 23 is connected to the pressure relief mechanism 25.

[0149] During the charging and discharging process of the battery cell 20, the electrode assembly 23 inside the battery cell 20 will generate gas. If this gas cannot be discharged in time, it may cause excessive pressure inside the battery cell 20, which may cause the outer casing 24 of the battery cell 20 to deform or crack, thereby affecting the safety and performance of the battery cell 20.

[0150] The pressure relief mechanism 25 is a safety device used to release excess gas to the outside of the battery cell 20 when there is too much gas inside the battery cell 20.

[0151] The separator 20 includes an exhaust channel that connects the electrode assembly 23 and the pressure relief mechanism 25. Gas generated by the electrode assembly 23 can flow along the exhaust channel to the pressure relief mechanism 25, so that the pressure relief mechanism 25 can effectively discharge excess gas inside the battery cell 20 to the outside of the battery cell 20.

[0152] In one embodiment, the isolation member 26 includes a plurality of vent holes communicating along a second direction, each vent hole communicating with the side of the electrode assembly 23 and the housing 24 where the pressure relief mechanism 25 is provided, and the plurality of vent holes constitute an exhaust channel.

[0153] In the above embodiments, the gas generated by the battery cell 20 can flow to the pressure relief mechanism 25 through the exhaust channel on the separator 26, thereby expelling the battery cell 20 to the outside, effectively improving the safety and reliability of the battery cell 20.

[0154] According to some embodiments of this application, optionally, please refer to... Figure 5 The maximum thickness D1 of the first spacer 261 satisfies 0.3mm ≤ D1, and the maximum thickness D2 of the second spacer 262 satisfies 0.3mm. <D2。

[0155] When the maximum thickness of the second isolation member 262 is greater than the maximum thickness of the first isolation member 261, the maximum thickness D1 of the first isolation member 261 satisfies 0.3mm ≤ D1, and the maximum thickness D2 of the second isolation member 262 satisfies 0.3mm. <D2。

[0156] In one example, the maximum thickness D1 of the first separator 261 is 0.3 mm, and the maximum thickness D2 of the second separator 262 satisfies 0.3 mm < D2 < 1 mm. In one example, the maximum thickness D1 of the first separator 261 is 0.3 mm, and the maximum thickness D2 of the second separator 262 satisfies 1 mm ≤ D2 ≤ 2 mm.

[0157] The specific maximum thicknesses of the first separator 261 and the second separator 262 can be determined comprehensively according to factors such as the application scenario, manufacturing process, material properties, and cost and volume limitations.

[0158] It should be noted that in the embodiments of the present application, the first separator 261 may include one or more separator layers, and the second separator 262 may include one or more separator layers 2621. In one embodiment, the second separator 262 includes a single separator layer 2621, and the maximum thickness D2 of the single separator layer 2621 satisfies 0.3 mm < D2. In one embodiment, the second separator 262 includes multiple separator layers 2621, and the sum D2 of the maximum thicknesses of all the separator layers 2621 satisfies 0.3 mm < D2. Among them, the maximum thicknesses of different separator layers 2621 may be equal or unequal.

[0159] In one embodiment, the first separator 261 includes a single separator layer 2621, and the maximum thickness D1 of the single separator layer 2621 satisfies 0.3 mm ≤ D1. In one embodiment, the first separator 261 includes multiple separator layers 2621, and the sum D1 of the maximum thicknesses of all the separator layers 2621 satisfies 0.3 mm ≤ D1. Among them, the maximum thicknesses of different separator layers 2621 may be equal or unequal.

[0160] In some examples, the maximum thickness D1 of the first separator 261 is 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm or other values that satisfy 0.3 mm ≤ D1. The upper limit of D1 can be determined according to factors such as the spatial configuration and cost of the battery cell 20, and the present application does not make specific limitations thereto.

[0161] In some examples, the maximum thickness D2 of the second separator 262 is 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.3 mm or other values that satisfy 0.3 mm < D2. The upper limit of D2 can be determined according to factors such as the spatial configuration and cost of the battery cell 20, and the present application does not make specific limitations thereto.

[0162] Optionally, an isolation layer may include a plurality of isolation portions. The plurality of isolation portions may be arranged along a third direction to form an isolation layer, and the plurality of isolation portions may be connected by means of bonding or the like. The third direction is perpendicular to the first direction and the second direction.

[0163] In the above embodiment, the maximum thickness D1 of the first isolation member 261 satisfies 0.3 mm ≤ D1, and the maximum thickness D2 of the second isolation member 262 satisfies 0.3 mm < D2, which can increase the distance between more of the first inner surface 24c and the electrode assembly 23 to further improve the connection stability and sealing reliability between the first outer surface 24a and the second outer surface 24b. At the same time, the maximum thickness of the second isolation member 262 being greater than the maximum thickness of the first isolation member 261 can enhance the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface provided with a weak area and the adjacent second outer surface 24b.

[0164] According to some embodiments of the present application, optionally, please combine Figure 5 , 1 mm ≤ D2 ≤ 2 mm.

[0165] In some examples, the maximum thickness D2 of the second isolation member 262 = 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm or other values satisfying 1 mm ≤ D2 ≤ 2 mm.

[0166] In the above embodiment, the maximum maximum thickness of the second isolation member 262 can be made thicker, so as to more effectively enhance the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface provided with a weak area and the adjacent second outer surface 24b.

[0167] According to some embodiments of the present application, optionally, please combine Figure 6 , the second isolation member 262 includes two isolation layers 2621, the two isolation layers 2621 are stacked, and the maximum thicknesses of the two isolation layers 2621 are d1 and d2 respectively, satisfying 1 mm ≤ (d1 + d2) ≤ 2 mm, and d1 ≥ 0.3 mm, d2 ≥ 0.3 mm.

[0168] The maximum thicknesses of the two isolation layers 2621 may be equal or unequal. In one example, the maximum thickness of one isolation layer 2621 is 0.3 mm, and the maximum thickness of the other isolation layer 2621 is 0.7 mm. In one example, the maximum thickness of one isolation layer 2621 is 0.5 mm, and the maximum thickness of the other isolation layer 2621 is 1 mm. In one example, the maximum thickness of one isolation layer 2621 is 1 mm, and the maximum thickness of the other isolation layer 2621 is 1 mm.

[0169] The maximum thickness D1 of the first isolation member 261 satisfies 0.3mm≤D1, and the two isolation layers 2621 of the second isolation member 262 satisfy 1mm≤(d1+d2)≤2mm, and d1≥0.3mm, d2≥0.3mm. That is, the sum of the maximum thicknesses of the two isolation layers 2621 of the second isolation member 262 is greater than the maximum thickness of the first isolation member 261.

[0170] In some examples, d1+d2 = 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm or other values ​​that satisfy 1mm≤(d1+d2)≤2mm.

[0171] In some examples, d1 = 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm or other values ​​that satisfy 1mm≤(d1+d2)≤2mm and d1≥0.3mm.

[0172] In some examples, d2 = 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm or other values ​​that satisfy 1mm≤(d1+d2)≤2mm and d2≥0.3mm.

[0173] In the above embodiment, the maximum thicknesses of the two isolation layers 2621 are d1 and d2, respectively, satisfying 1mm≤(d1+d2)≤2mm, and d1≥0.3mm, d2≥0.3mm. This can enhance the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface of the battery cell 20 with a weak area and the adjacent second outer surface 24b. At the same time, it ensures that the maximum thickness of each isolation layer 2621 is not less than the maximum thickness of the first isolation member 261, and ensures that the maximum thickness of the second isolation member 262 is greater than the maximum thickness of the first isolation member 261.

[0174] According to some embodiments of this application, optionally, please refer to... Figure 7 and Figure 8 The second isolation member 262 has a groove 262a on its surface facing the pressure relief mechanism 25, and at least a portion of the pressure relief mechanism 25 is located in the groove 262a.

[0175] Optionally, the location of the pressure relief mechanism 25 in the groove 262a can be determined based on factors such as structural strength and safety, the shape and size limitations of the battery cell 20, manufacturing and assembly processes, and cost control.

[0176] In one embodiment, the projection W1 of the groove 262a in the first direction is greater than the projection W2 of the pressure relief mechanism 25 in the first direction. The pressure relief mechanism 25 can be circular or elliptical, and the pressure relief mechanism 25 is partially located within the groove 262a.

[0177] In one embodiment, the projection W1 of the groove 262a in the first direction is smaller than the projection W2 of the pressure relief mechanism 25 in the first direction, and the pressure relief mechanism 25 may be partially or entirely located within the groove 262a.

[0178] In one embodiment, the second isolator 262 includes an isolation layer 2621, the surface of which facing the pressure relief mechanism 25 is provided with a groove 262a, at least a portion of the pressure relief mechanism 25 being located in the groove 262a. It should be understood that the dimension W3 of the groove 262a along the second direction is smaller than the dimension of the isolation layer 2621 along the second direction.

[0179] In one embodiment, the second isolation member 262 includes a plurality of isolation layers 2621. In the second direction, the surface of the isolation layer 2621 closest to the pressure relief mechanism 25 has a groove 262a facing the pressure relief mechanism 25, and at least a portion of the pressure relief mechanism 25 is located in the groove 262a. It should be understood that the dimension W3 of the groove 262a in the second direction is smaller than the dimension of the isolation layer 2621 closest to the pressure relief mechanism 25 in the second direction.

[0180] In the above embodiment, the surface of the second isolation member 262 facing the pressure relief mechanism 25 is provided with a groove 262a, and at least a part of the pressure relief mechanism 25 is located in the groove 262a, which can save costs and improve the space utilization rate inside the battery cell 20.

[0181] According to some embodiments of this application, optionally, please refer to... Figures 7 to 9 The projection W1 of the groove 262a in the first direction is greater than the projection W2 of the pressure relief mechanism 25 in the first direction.

[0182] The projection W1 of the groove 262a in the first direction is greater than the projection W2 of the pressure relief mechanism 25 in the first direction. That is, the size of the groove 262a in one direction is greater than the size of the pressure relief mechanism 25 in the first direction. This is beneficial to realize that the pressure relief mechanism 25 is entirely located in the groove 262a to improve the space utilization rate inside the battery cell 20.

[0183] In the above embodiments, the projection W1 of the groove 262a in the first direction is greater than the projection W2 of the pressure relief mechanism 25 in the first direction, which can improve the selectivity of at least a portion of the pressure relief mechanism 25 being located in the groove 262a.

[0184] According to some embodiments of this application, optionally, please refer to... Figure 9 The second isolation member 262 includes a plurality of isolation layers 2621 stacked together. In the second direction, the isolation layer 2621 closest to the pressure relief mechanism 25 includes two spaced isolation segments 2621a, which together with the adjacent isolation layer 2621 form a groove 262a.

[0185] At least a portion of the pressure relief mechanism 25 is located in the groove 262a formed by the two isolation sections 2621a and the adjacent isolation layer 2621.

[0186] Optionally, the dimensions of the two isolation segments 2621a along the first direction may be equal or unequal.

[0187] Optionally, each of the multiple isolation layers 2621 near the pressure relief mechanism 25 includes two isolation segments 2621a, and all isolation segments 2621a and adjacent isolation layers 2621 form a groove 262a. For example, the second isolation member 262 includes a first isolation layer, a second isolation layer, and a third isolation layer stacked in one step, with the first isolation layer being closest to the electrode assembly 23. The second isolation layer includes two isolation segments 2621a, and the third isolation layer includes two isolation segments 2621a. The four isolation segments 2621a and the first isolation layer form a groove 262a.

[0188] In the above embodiment, the isolation layer 2621 closest to the pressure relief mechanism 25 includes two spaced isolation sections 2621a. The two isolation sections 2621a and the adjacent isolation layer 2621 form a groove 262a, which can further save costs and improve the space utilization rate inside the battery cell 20.

[0189] According to some embodiments of this application, optionally, please refer to... Figure 7 and Figure 8 The second isolation member 262 includes at least one isolation layer 2621, and in the second direction, the surface of the isolation layer 2621 closest to the pressure relief mechanism 25 is provided with a groove 262a facing the pressure relief mechanism 25.

[0190] exist Figure 8 In this embodiment, the second isolation member 262 includes an isolation layer 2621, and the surface of the isolation layer 2621 facing the pressure relief mechanism 25 has a groove 262a. Figure 7In one embodiment, the second isolation member 262 includes two isolation layers 2621, and the surface of the isolation layer 2621 closest to the pressure relief mechanism 25 facing the pressure relief mechanism 25 has a groove 262a. In other embodiments, the second isolation member 262 includes multiple isolation layers 2621, and the surface of the isolation layer 2621 closest to the pressure relief mechanism 25 facing the pressure relief mechanism 25 has a groove 262a.

[0191] In the above embodiment, the surface of the isolation layer 2621 closest to the pressure relief mechanism 25 facing the pressure relief mechanism 25 is provided with a groove 262a, which can save costs and improve the space utilization rate inside the battery cell 20.

[0192] According to some embodiments of this application, optionally, please refer to... Figures 10 to 12 The electrode assembly 23 includes a stacked electrode 231 and a diaphragm 232. On the side closer to the pressure relief mechanism 25 in the second direction, the diaphragm 232 protrudes beyond the electrode 231 by a greater length than on the other side away from the pressure relief mechanism 25.

[0193] The electrode 231 may include a positive electrode 231a and a negative electrode 231b, which are alternately stacked to form an electrode assembly 23. A separator 232 is provided between the positive electrode 231a and the negative electrode 231b to isolate the positive electrode 231a and the negative electrode 231b, preventing short circuits inside the battery cell 20, while allowing electrons or ions to flow.

[0194] Please combine Figures 10 to 12 On the side of the second direction closer to the pressure relief mechanism 25, the length of the diaphragm 232 protruding from the electrode 231 is greater than the length of the diaphragm 232 protruding from the electrode 231 on the other side away from the pressure relief mechanism 25.

[0195] It is understandable that the side with the pressure relief mechanism 25 is the weak side of the battery cell 20. On the weak side of the battery cell 20, the portion of the separator 232 protruding from the electrode 231 is longer, which can make the distance between the first inner surface 24c of the weak side and the electrode assembly 23 larger. This can make the distance between the first outer surface 24a corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b under stress tension critical zone larger.

[0196] Optionally, in one embodiment, the length of the portion of the diaphragm 232 protruding from the electrode 231 on the side closer to the pressure relief mechanism 25 in the second direction can be increased to be greater than the length of the portion of the diaphragm 232 protruding from the electrode 231 on the side farther from the pressure relief mechanism 25. In another embodiment, the length of the portion of the diaphragm 232 protruding from the electrode 231 on the side farther from the pressure relief mechanism 25 in the second direction can be decreased to be greater than the length of the portion of the diaphragm 232 protruding from the electrode 231 on the side closer to the pressure relief mechanism 25. In one embodiment, the length of the portion of the diaphragm 232 protruding from the electrode 231 on the side closer to the pressure relief mechanism 25 in the second direction can be increased, and the length of the portion of the diaphragm 232 protruding from the electrode 231 on the other side away from the pressure relief mechanism 25 in the second direction can be decreased, so that the length of the portion of the diaphragm 232 protruding from the electrode 231 on the side closer to the pressure relief mechanism 25 in the second direction is greater than the length of the portion of the diaphragm 232 protruding from the electrode 231 on the other side away from the pressure relief mechanism 25.

[0197] It should be noted that, in one embodiment, the portion of the diaphragm 232 that protrudes from the electrode 231 refers to the portion of the diaphragm 232 that protrudes from the negative electrode 231b, which is SAOH (Separator-Anode Overhang).

[0198] In the above embodiment, on the side of the second direction near the pressure relief mechanism 25, the length of the diaphragm 232 protruding from the electrode 231 is greater than that on the other side away from the pressure relief mechanism 25. The length of the diaphragm 232 protruding from the electrode 231 can increase the distance between the critical stress tension zones of the first outer surface 24a and the second outer surface 24b corresponding to the second sub-inner surface with the weak area, thereby increasing the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b.

[0199] According to some embodiments of this application, optionally, please refer to... Figure 10 On the side of the second direction closer to the pressure relief mechanism 25, the distance X2 between the diaphragm 232 and the electrode 231 satisfies 2mm < X2 ≤ 3mm, and / or on the other side of the second direction away from the pressure relief mechanism 25, the distance X1 between the diaphragm 232 and the electrode 231 satisfies 1mm ≤ X1 < 2mm.

[0200] In some examples, X2 = 2.1m, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.7mm, 2.8mm, 2.9mm, 3mm or other values ​​that satisfy 2mm < X2 ≤ 3mm.

[0201] In some examples, X1 = 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.7mm, 1.8mm, 1.9mm or other values ​​that satisfy 1mm≤X1<2mm.

[0202] In the above embodiments, the length of the diaphragm 232 protruding from the electrode 231 on the side closer to the pressure relief mechanism 25 in the second direction is greater than the length of the diaphragm 232 protruding from the electrode 231 on the other side away from the pressure relief mechanism 25. This helps to increase the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b.

[0203] According to some embodiments of this application, optionally, please refer to... Figure 10 On the side of the second direction closer to the pressure relief mechanism 25, the portion of the diaphragm 232 protruding from the electrode 231 has a length X2 that satisfies X2±0.5mm, and / or on the other side of the second direction away from the pressure relief mechanism 25, the portion of the diaphragm 232 protruding from the electrode 231 has a length X1 that satisfies X1±0.5mm.

[0204] The length X2 of the portion of the diaphragm 232 protruding from the electrode 231 satisfies X2 ± 0.5 mm. Optionally, in one embodiment, 2 mm < X2 ≤ 3 mm, that is, X2 satisfies 1.5 mm < X2 ≤ 3.5 mm. Optionally, in one embodiment, 1 mm ≤ X1 < 2 mm, and the length X1 of the portion of the diaphragm 232 protruding from the electrode 231 satisfies X1 ± 0.5 mm, that is, X1 satisfies 0.5 mm ≤ X1 < 2.5 mm.

[0205] It should be understood that, on the side of the pressure relief mechanism 25 in the second direction, the portion of the diaphragm 232 protruding from the electrode 231 is longer than the portion of the diaphragm 232 protruding from the electrode 231 on the side of the diaphragm 232 away from the pressure relief mechanism 25. In one embodiment, X1 satisfies 0.5mm ≤ X1 < 2.5mm, X2 satisfies 1.5mm < X2 ≤ 3.5mm, and X1 < X2. In another embodiment, X1 ≤ 1.5mm, and X2 satisfies 1.5mm < X2 ≤ 3.5mm. In yet another embodiment, X1 > 1.5mm, and X2 satisfies X1 < X2 ≤ 3.5mm. Conversely, in one embodiment, X2 ≥ 2.5mm, and X1 satisfies 0.5mm ≤ X1 < 2.5mm. In yet another embodiment, X2 < 2.5mm, and X1 satisfies 0.5mm ≤ X1 < X2.

[0206] In the above embodiments, the error tolerance can be improved to a certain extent to reduce the difficulty of production. At the same time, on the side of the second direction near the pressure relief mechanism 25, the length of the diaphragm 232 protruding from the electrode 231 is greater than the length of the diaphragm 232 protruding from the electrode 231 on the other side away from the pressure relief mechanism 25. This helps to increase the connection stability and sealing reliability between the first outer surface 24a corresponding to the second sub-inner surface with the weak area and the adjacent second outer surface 24b.

[0207] According to some embodiments of this application, this application also provides a battery device 100, which includes a battery cell 20 as described in any of the above embodiments.

[0208] The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells 20, which are connected in series, parallel, or mixed connections via busbars.

[0209] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0210] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells 20 together. As an example, a battery module can also be formed by bundling multiple battery cells 20 together with cable ties.

[0211] In some embodiments, the battery device 100 may be a battery pack, which includes a housing 10 and one or more battery cell assemblies housed within the housing 10.

[0212] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing 10 by fixing the battery module in the housing 10.

[0213] As an example, the battery cell assembly can also be housed in the housing 10 by directly fixing multiple battery cells 20 to the housing 10.

[0214] As an example, the housing 10 may include a first part 11 and a second part 12. The first part 11 and the second part 12 are fastened together to form a closed space inside the housing 10 for housing the battery cell assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first part 11 may be a top cover or a bottom plate.

[0215] As an example, the housing 10 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 10 forms an enclosed space to accommodate the battery cell assembly.

[0216] In some embodiments, the housing 10 may be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 may be at least a portion of the floor of the vehicle 1000, or a portion of the housing 10 may be at least a portion of the crossbeams and longitudinal beams of the vehicle 1000.

[0217] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells 20, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0218] According to some embodiments of this application, this application also provides an energy storage device 1, which includes a battery device 100 as described in any of the above embodiments, and the battery device 100 is used to store or provide electrical energy.

[0219] Energy storage device 1 includes one or more battery clusters to increase the voltage and capacity of energy storage device 1. A battery cluster may include multiple battery devices 100, which are connected in series via a busbar to increase the voltage of energy storage device 1. When energy storage device 1 includes multiple battery clusters, the battery clusters are connected in parallel to increase the capacity of energy storage device 1. The definition of battery device 100 is given above and will not be repeated here.

[0220] The energy storage device 1 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems, etc. The energy storage device 1 can store electrical energy as needed and output it at appropriate times. For example, the energy storage device 1 can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage system 2000 provided in this application embodiment can be any power system that requires the use of the energy storage device 1.

[0221] In some embodiments, the energy storage device 1 is an energy storage container or an energy storage cabinet.

[0222] In some embodiments, the energy storage device 1 may include a cabinet and one or more battery clusters, with the battery clusters housed in the cabinet.

[0223] In some embodiments, the energy storage device 1 may include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0224] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery device 100 via piping to regulate the temperature of the individual battery cells 20.

[0225] As an example, the main control module can serve as the battery management unit for the battery cluster, used to monitor and manage the battery cluster. The main control module can monitor information such as the current, voltage, power, or temperature of the battery cluster. For instance, it can control the charging and discharging current and voltage of the battery cluster. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0226] As an example, the central control module can serve as the battery management unit for energy storage device 1, used to monitor and manage it. The central control module can monitor information such as current, voltage, power, state of charge, and temperature of energy storage device 1. For example, it can control the charging and discharging current and voltage of energy storage device 1. As an example, the central control module includes modules such as an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH) module, and a fiber optic conversion module.

[0227] As an example, the fire protection module includes a control panel, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in the energy storage system 2000.

[0228] As an example, the power distribution module can be used to distribute power to the power supply module of the energy storage device 1.

[0229] Based on some embodiments of this application, please refer to... Figure 13 This application also provides an energy storage system 2000, which includes a power conversion device 2 and an energy storage device 1 as described in any of the above schemes, and a battery device 100 for storing or providing electrical energy.

[0230] The energy storage system 2000 may include one or more energy storage devices 1 and a power conversion device 2 (PCS), wherein the power conversion device 2 is used to connect the power generation device 3 and the energy storage device 1. The power generation device 3 is used to generate electrical energy, and the electrical energy generated by the power generation device 3 can be stored in the energy storage device 1 through the power conversion device 2. As an example, the power generation device 3 may specifically be a solar panel, a hydroelectric power generation device, a thermal power generation device, a wind power generation device, etc. The specific type of the power generation device 3 is not limited in this application.

[0231] According to some embodiments of this application, this application also provides an electrical device, which includes a battery device 100, an energy storage device 1, or an energy storage system 2000 as described in any of the above solutions, wherein the battery device 100 is used to store or provide electrical energy.

[0232] Based on some embodiments of this application, please refer to... Figure 14 This application also provides a charging network 3000, which includes a connector 5 and an energy storage device 1 or an energy storage system 2000 as described in any of the above schemes. The energy storage device 1 is used to provide electrical energy to the charging pile 4.

[0233] The charging network 3000 may include a charging pile 4 and an energy storage device 1. The charging pile 4 is electrically connected to the energy storage device 1, which provides power to the charging pile 4. The charging pile 4 is electrically connected to a battery device 100 in the energy storage device 1 via a cable. The battery device 100 can provide its stored electrical energy to the charging pile 4. The charging pile 4 has one or more connectors 5 for connecting to electrical devices (such as a vehicle 1000) to replenish power to them. The definition of the battery device 100 is given above and will not be repeated here.

[0234] The energy storage device 1 can be located inside the charging pile 4 (e.g., an integrated energy storage and charging unit) or outside the charging pile 4.

[0235] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery cell comprises: a housing comprising a first outer surface and a second outer surface, the second outer surface being an outer surface with the largest area, and the first outer surface being an outer surface different from the second outer surface; an electrode assembly located in the housing; a separator located in the housing, the separator separating the electrode assembly from at least one first inner surface, the first inner surface being an inner surface of the housing opposite to the first outer surface; wherein the first inner surface comprises a first sub-inner surface and a second sub-inner surface, the second sub-inner surface being provided with a weak area, and a dimension of the separator separating the electrode assembly and the second sub-inner surface in a direction perpendicular to the second sub-inner surface is greater than a dimension of the separator separating the electrode assembly and the first sub-inner surface in a direction perpendicular to the first sub-inner surface.

2. The battery cell of claim 1, wherein, The housing comprises an end cover and a shell, the shell is provided with an opening at least at one end in a first direction, the end cover covers the opening to form an internal environment of the battery cell, the separator separates a first inner surface of the end cover and the electrode assembly, and / or separates a first inner surface of the shell and the electrode assembly.

3. The battery cell of claim 2, wherein, The battery cell comprises a pressure relief mechanism, the pressure relief mechanism is arranged on a first side plate of the shell in a second direction, the separator comprises a first separator and a second separator, the first separator separates the first sub-inner surface of the shell in the second direction and the electrode assembly, and the second separator separates the second sub-inner surface of the first side plate and the electrode assembly, the first direction is perpendicular to the second direction, and a maximum thickness of the second separator is greater than a maximum thickness of the first separator.

4. The battery cell of claim 2, wherein, The battery cell comprises a pressure relief mechanism, the end cover comprises a first end cover and a second end cover, the first end cover and the second end cover are respectively arranged on both sides of the shell in the first direction, the pressure relief mechanism is arranged on the first end cover or the second end cover, the separator comprises a first separator and a second separator, the first separator separates a first sub-inner surface of the end cover without the pressure relief mechanism and the electrode assembly, and the second separator separates a second sub-inner surface of the end cover with the pressure relief mechanism and the electrode assembly, and a maximum thickness of the second separator is greater than a maximum thickness of the first separator.

5. The battery cell according to any one of claims 1 to 4, characterized in that, The separator is insulating.

6. The battery cell according to claim 3 or 4, characterized in that, The pressure relief mechanism comprises an explosion-proof valve and / or a notch.

7. The battery cell according to claim 3 or 4, characterized in that, The battery cell comprises an exhaust passage, and the electrode assembly communicates with the pressure relief mechanism through the exhaust passage.

8. The battery cell according to claim 3 or 4, characterized in that, The separator comprises an exhaust passage, and the electrode assembly communicates with the pressure relief mechanism through the exhaust passage.

9. The battery cell according to claim 3 or 4, characterized in that, A maximum thickness D1 of the first separator satisfies 0.3mm≤D1, and a maximum thickness D2 of the second separator satisfies 0.3mm<D2.

10. The battery cell of claim 9, wherein, 1mm≤D2≤2mm.

11. The battery cell of claim 10, wherein, The second separator comprises two separator layers, the two separator layers are stacked, maximum thicknesses of the two separator layers are d1 and d2 respectively, 1mm≤(d1+d2)≤2mm is satisfied, d1≥0.3mm, and d2≥0.3mm.

12. The battery cell according to claim 3 or 4, characterized in that, The surface of the second separator facing the pressure relief mechanism is provided with a groove, and at least a portion of the pressure relief mechanism is located in the groove.

13. The battery cell of claim 12, wherein, A projection of the groove in the first direction is greater than a projection of the pressure relief mechanism in the first direction.

14. The battery cell of claim 13, wherein, The second separator comprises a plurality of stacked isolation layers, and in the second direction, the isolation layer closest to the pressure relief mechanism comprises two spaced isolation segments, and the two isolation segments and the adjacent isolation layers form the groove.

15. The battery cell of claim 13, wherein, The second separator comprises at least one isolation layer, and in the second direction, the isolation layer closest to the pressure relief mechanism is provided with the groove on the surface facing the pressure relief mechanism.

16. The battery cell of claim 3, wherein, The electrode assembly comprises a plurality of stacked electrode plates and separators, and in the second direction, on the side close to the pressure relief mechanism, the separator protrudes from the electrode plate by a length X2, and on the side away from the pressure relief mechanism, the separator protrudes from the electrode plate by a length X1.

17. The battery cell of claim 16, wherein, In the second direction, on the side close to the pressure relief mechanism, the length X2 by which the separator protrudes from the electrode plate satisfies 2mm < X2 ≤ 3mm, and / or, on the side away from the pressure relief mechanism, the length X1 by which the separator protrudes from the electrode plate satisfies 1mm ≤ X1 < 2mm.

18. The battery cell of claim 17, wherein, In the second direction, on the side close to the pressure relief mechanism, the length X2 by which the separator protrudes from the electrode plate satisfies X2 ± 0.5mm, and / or, on the side away from the pressure relief mechanism, the length X1 by which the separator protrudes from the electrode plate satisfies X1 ± 0.5mm.

19. A battery device characterized by comprising: A plurality of battery cells according to any one of claims 1-18 are included.

20. An energy storage device, comprising: A battery device according to claim 19 is included, and the battery device is used for storing or providing electric energy.

21. An energy storage system characterized by, A power conversion device and an energy storage device according to claim 20 are included, and the power conversion device is used for electrically connecting a power generation device and the energy storage device.

22. An electrical device, comprising: A battery device according to claim 19, an energy storage device according to claim 20, or an energy storage system according to claim 21 is included, and the battery device is used for storing or providing electric energy.

23. A charging network characterized by, A charging pile and an energy storage device according to claim 20 or an energy storage system according to claim 21 are included, and the energy storage device is used for providing electric energy for the charging pile.

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