Battery monomer, battery device and electric equipment

Abstract

The embodiment of the utility model discloses a battery monomer, a battery device and electric equipment. The battery cell includes: a housing having a first wall; an electrode assembly which is accommodated in the housing; the slow release structure is arranged on the first wall; the slow release structure is configured to expand towards the outside of the shell to form an expansion space under the condition that the slow release structure meets a design threshold value, and the expansion space communicates with the inner space of the shell and is isolated from the outside of the shell. According to the battery monomer, the battery device and the electric equipment provided by the embodiment of the invention, the reliability of the battery monomer can be improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more specifically, to a battery cell, a battery device and an electrical equipment. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] With the rapid development of battery technology, how to improve the safety performance of batteries is a technical problem that needs to be solved urgently. Utility Model Content

[0004] The embodiments of the present application provide a battery cell, a battery device and an electrical equipment, which can improve the reliability of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, comprising: a shell having a first wall; an electrode assembly, the electrode assembly being accommodated in the shell; a slow-release structure, the slow-release structure being arranged on the first wall; the slow-release structure being constructed to expand toward the outside of the shell to form an expansion space when the slow-release structure meets a design threshold, the expansion space being connected to the internal space of the shell and isolated from the outside of the shell.

[0006] In the technical solution of the embodiment of the present application, when an abnormality occurs in a battery cell, causing the slow-release structure to reach a design threshold, the slow-release structure expands outward, providing more internal space for the battery cell, reducing internal pressure, and reducing the risk of the battery cell being damaged and causing internal conductive liquids or gases and other emissions to flow out to the outside, thereby improving the insulation and safety performance of the system; in addition, under normal working conditions of the battery cell, the slow-release structure is arranged on the first wall and will not occupy additional space in the battery cell.

[0007] In some embodiments of the first aspect, the slow-release structure is constructed to expand toward the outside of the shell to form an expansion space when the slow-release structure meets a design threshold, including: the slow-release structure is constructed to expand toward the outside of the shell to form an expansion space when the internal air pressure of the slow-release structure meets a first threshold, and / or the slow-release structure is constructed to expand toward the outside of the shell to form an expansion space when the temperature of the slow-release structure meets a second threshold.

[0008] In an embodiment of the present application, the design threshold includes a first threshold and a second threshold, that is, when the slow-release structure meets any one of the thresholds, the slow-release structure expands toward the outside of the shell, thereby providing more internal space for the battery cell, reducing the internal pressure of the battery cell, and improving the safety performance of the battery cell.

[0009] In some embodiments of the first aspect, the sustained-release structure includes a retaining portion and an expansion portion, wherein the expansion portion is connected to the first wall, the retaining portion is configured to maintain the expansion portion in an initial state, and the retaining portion is further configured to release the expansion portion when the sustained-release structure meets the design threshold, so that the expansion portion changes from the initial state to the expansion state.

[0010] In the embodiment of the present application, by providing the retaining part and the expansion part, the slow-release structure can be in different states under different environmental conditions. When the battery cell is in normal working state, the retaining part keeps the expansion part in the initial state, ensuring that the slow-release structure does not occupy additional space of the battery cell; once an abnormality occurs and reaches the design threshold, the retaining part can quickly release the expansion part, thereby providing more internal space for the battery cell and reducing the internal pressure of the battery cell.

[0011] In some embodiments of the first aspect, the first wall has a through hole, and the slow-release structure is fixed in the through hole; the outer periphery of the retaining portion has a first protruding structure facing the inner side of the through hole; the inner side of the through hole has a second protruding structure facing the retaining portion; the side of the first protruding structure away from the interior of the shell and the side of the second protruding structure close to the interior of the shell abut against each other, so that the retaining portion applies pressure toward the interior of the shell to the expansion portion to maintain the expansion portion in the initial state.

[0012] In the embodiment of the present application, when no abnormality occurs in the battery cell or the air pressure inside the battery cell does not reach the first threshold, the retaining portion can keep the expansion portion in the initial state, thereby saving the internal space of the battery cell and reducing unnecessary space waste.

[0013] In some embodiments of the first aspect, the first protruding structure is bent toward a side away from the interior of the shell to form a first bending portion, and the second protruding structure is bent toward a side close to the interior of the shell to form a second bending portion, the first bending portion and the second bending portion are clamped together, and a weak area is provided on the second protruding structure away from the clamping point.

[0014] In the embodiment of the present application, by providing the first bending portion and the second bending portion, the slow-release structure can be kept in the initial state under normal conditions, thereby reducing unnecessary expansion; under abnormal conditions, the weak area of ​​the second protruding structure can make it easier for the retaining portion to detach from the first wall, thereby releasing the expansion portion.

[0015] In some embodiments of the first aspect, the length of the first wall along the first direction is greater than the length of the first wall along the second direction, the first direction is perpendicular to the second direction, and the first direction and the second direction are both perpendicular to the thickness direction of the first wall, wherein the second protrusion structure is arranged on the inner side surface of the through hole extending along the first direction.

[0016] In the embodiment of the present application, the first protruding structure and the second protruding structure are arranged in the direction of the longer side of the first wall. When an abnormality occurs in the battery cell and the expansion part needs to be released, the first protruding structure and the second protruding structure can be quickly separated to ensure effective expansion of the expansion part.

[0017] In some embodiments of the first aspect, the first wall has a through hole, and the slow-release structure is fixed in the through hole; the retaining portion includes a connecting structure, which is located between the retaining portion and the first wall, and is used to connect the retaining portion and the first wall, so that the retaining portion applies pressure toward the inside of the shell to the expansion portion to maintain the expansion portion in the initial state.

[0018] In an embodiment of the present application, when the battery cell is affected by thermal runaway, the temperature of the slow-release structure reaches a second threshold, the connecting structure is melted, the retaining portion and the first wall are no longer connected, the pressure of the retaining portion on the expansion portion toward the inside of the outer shell disappears, and the expansion portion expands toward the outside of the battery cell, thereby reducing the internal pressure of the battery cell.

[0019] In some embodiments of the first aspect, the melting point T1 of the connecting structure is less than the melting point T2 of the first wall.

[0020] In the embodiment of the present application, when the temperature of the sustained-release structure reaches the second threshold, the connecting structure melts, while the first wall maintains a certain heat resistance, thereby ensuring that the expansion part expands smoothly while the first wall also has a certain stability to ensure the performance of the battery cell.

[0021] In some embodiments of the first aspect, the melting point T1 of the connection structure is in the range of [60° C., 200° C.].

[0022] In the embodiment of the present application, the melting point of the connection structure is greater than or equal to 60°C, so as to prevent the connection structure from being melted at room temperature or when the battery cell is affected by thermal runaway but has not yet reached the second threshold, resulting in unnecessary expansion of the expansion part and occupying too much space of the battery cell. In addition, the melting point of the connection structure is less than or equal to 200°C, so that the expansion part can smoothly expand to the outside of the battery cell before the battery cell is irreversibly damaged, providing more internal space for the battery cell and delaying the time when the battery cell is damaged and fails.

[0023] In some embodiments of the first aspect, the connecting structure is close to an edge of the first wall.

[0024] In the embodiment of the present application, by setting the connecting structure at the edge position close to the first wall, when the adjacent battery cell of the battery cell experiences thermal runaway, its high temperature is transmitted to the connecting structure. Once the temperature reaches the melting point of the connecting structure, the connecting structure melts, and the expansion portion can quickly expand to the outside of the battery cell, thereby reducing the internal pressure of the battery cell, reducing the influence of other thermal runaway battery cells on the battery cell, effectively preventing the battery cell from being damaged and causing internal emissions to flow out, and reducing the risk of system insulation failure.

[0025] In some embodiments of the first aspect, the material of the connection structure includes one of polypropylene, polyethylene, polycarbonate, soluble polytetrafluoroethylene, polyphenylene sulfide, silicone rubber and fluororubber.

[0026] In the embodiment of the present application, the plastic or rubber material can be melted when the temperature reaches a certain threshold, thereby ensuring that the expansion part is released and expanded under certain conditions.

[0027] In some embodiments of the first aspect, the expansion portion includes a first connecting portion, a second connecting portion and an expansion portion, and the expansion portion is located between the first connecting portion and the second connecting portion; wherein the first connecting portion is connected to the retaining portion, and the second connecting portion is connected to the first wall.

[0028] In the embodiment of the present application, the expansion portion is connected to the retaining portion and the first wall, so that the slow-release structure can be fixed on the first wall and can expand when the design threshold is reached, thereby providing more internal space for the battery cell.

[0029] In some embodiments of the first aspect, the sustained-release structure also includes a compression component, which includes a first compression component and / or a second compression component, the first compression component is located between the first connecting part and the retaining part, and abuts against the first connecting part and the retaining part, and the second compression component is located between the second connecting part and the first wall, and abuts against the second connecting part and the first wall.

[0030] In the embodiment of the present application, by adding a compression component, a compression force can be provided to the expansion part, thereby enhancing the reliability of the connection between the expansion part, the retaining part and the first wall.

[0031] In some embodiments of the first aspect, the sustained-release structure further includes a first connecting ring and / or a second connecting ring, the first connecting ring is used to connect the expansion portion and the retaining portion, and the second connecting ring is used to connect the expansion portion and the first wall.

[0032] In the embodiment of the present application, by providing the first connecting ring or the second connecting ring, the clamping and fixing effect between the expansion part, the retaining part and the first wall can be strengthened, and the installation of the slow-release structure is more convenient.

[0033] In some embodiments of the first aspect, the first connecting ring is connected to the retaining portion by bonding or welding, or the second connecting ring is fixed to the first wall by bonding or welding, or the first connecting ring is connected to the expansion portion by snapping or bonding, or the second connecting ring is connected to the expansion portion by snapping or bonding.

[0034] In the embodiment of the present application, by connecting the first connecting ring to the retaining portion and connecting the first connecting ring to the first wall, the fixing effect on the expansion portion 2152 can be improved, ensuring that the slow-release structure 215 can expand effectively.

[0035] In some embodiments of the first aspect, the sustained-release structure also includes a compression component, which includes a first compression component and / or a second compression component. The first compression component is located between the expansion portion and the retaining portion and abuts against the expansion portion and the retaining portion. The second compression component is located between the expansion portion and the first wall and abuts against the expansion portion and the first wall.

[0036] In the embodiment of the present application, the compression component can provide compression force for the expansion part, thereby enhancing the reliability of the connection between the expansion part, the retaining part and the first wall.

[0037] In some embodiments of the first aspect, the material of the compression component includes one of rubber, latex, and polyurethane.

[0038] In the embodiment of the present application, by using a compressible material, better compression force can be provided for the expansion part, thereby improving the reliability of the connection between the expansion part, the retaining part and the first wall.

[0039] In some embodiments of the first aspect, the expansion portion includes a folding structure, and the expanded state is a state in which the expansion portion is unfolded from the folding structure; and / or, the expansion portion includes a contraction structure, and the expanded state is a state in which the expansion portion is stretched from the contraction structure.

[0040] In the embodiment of the present application, the folding structure and the contraction structure of the expansion portion do not occupy space in the initial state, and can provide more internal space for the battery cell in the expanded state.

[0041] In some embodiments of the first aspect, the slow-release structure is constructed to expand toward the outside of the shell to form an expansion space when the internal air pressure of the slow-release structure meets a first threshold value, and the battery cell also includes: a pressure relief mechanism, which is used to discharge the emissions of the battery cell when the pressure of the pressure relief mechanism reaches a third threshold value, wherein the first threshold value is less than the third threshold value.

[0042] In the embodiment of the present application, by setting the first threshold value to be smaller than the third threshold value, the slow-release structure can expand before the pressure relief mechanism is actuated, thereby quickly reducing the pressure inside the battery cell before the pressure relief mechanism is actuated.

[0043] In some embodiments of the first aspect, the absolute value of the difference between the first threshold and the third threshold is in the range of [0.1 MPa, 1 MPa].

[0044] In the embodiment of the present application, setting the absolute value of the difference between the first threshold and the third threshold to be greater than or equal to 0.1 MPa can ensure that the slow-release structure expands smoothly before the pressure relief mechanism is actuated, thereby avoiding the phenomenon of expansion failure. In addition, setting the absolute value of the difference between the first threshold and the third threshold to be less than or equal to 1 MPa can ensure that the slow-release structure can only expand under certain conditions, thereby avoiding the slow-release structure from expanding when the battery cell is in normal use, and reducing the phenomenon of unnecessary expansion of the slow-release structure leading to the occupation of additional space in the battery cell.

[0045] In some embodiments of the first aspect, the first threshold is in the range of [0.4 MPa, 3 MPa].

[0046] In the embodiment of the present application, setting the first threshold value to be greater than or equal to 0.4 MPa can reduce the probability of unnecessary expansion of the sustained-release structure and reduce the excessive space occupied by the battery cell; in addition, setting the first threshold value to be less than or equal to 3 MPa can enable the sustained-release structure to expand effectively when the battery cell is affected by thermal runaway, thereby providing more internal space for the battery cell, reducing the internal pressure of the battery cell, and improving the performance of the battery cell.

[0047] In some embodiments of the first aspect, the pressure relief mechanism is disposed on the first wall, the first wall has at least two electrode terminals, and the pressure relief mechanism is located between the at least two electrode terminals.

[0048] In the embodiment of the present application, the pressure relief mechanism, at least two electrode terminals and the slow-release structure are all arranged on the first wall, so as not to occupy too much space of the battery cell and improve the energy density of the battery cell.

[0049] In some embodiments of the first aspect, the slow-release structure is disposed on both sides of the pressure relief mechanism, and a projection of the slow-release structure in the thickness direction of the first wall does not overlap with a projection of the at least two electrode terminals in the thickness direction of the first wall.

[0050] In the embodiment of the present application, the slow-release structure is arranged on both sides of the pressure relief mechanism. After the slow-release structure expands, it does not affect the actuation of the pressure relief mechanism, thereby improving the safety performance of the battery cell.

[0051] In some embodiments of the first aspect, the pressure relief mechanism is disposed on the retaining portion of the slow-release structure.

[0052] In the embodiment of the present application, the pressure relief mechanism is arranged on the retaining portion, which can simplify the processing process and improve the processing efficiency.

[0053] In some embodiments of the first aspect, the housing includes: a shell body, which is a hollow structure with an opening; and a cover plate, which is used to cover the opening of the shell body; wherein the first wall is the cover plate.

[0054] In the embodiment of the present application, when the external space of the shell is limited, the slow-release structure is arranged on the cover plate, which not only ensures that the slow-release structure has sufficient expansion space, but also can provide sufficient installation thickness for the slow-release structure.

[0055] In some embodiments of the first aspect, the slow-release structure further includes a limiting portion, which is disposed at an end of the slow-release structure and is connected and fixed to the first wall, and the limiting portion is used to limit the expansion distance of the slow-release structure along the thickness direction of the retaining portion.

[0056] In the embodiment of the present application, by providing a limiting portion, the size of the expansion space formed after the expansion portion expands can be limited, thereby avoiding abnormal leakage of the expansion portion due to excessive expansion of the expansion portion, thereby improving the reliability of the sustained-release structure.

[0057] In a second aspect, a battery device is provided, including a battery cell in the first aspect or any one embodiment of the first aspect.

[0058] In a third aspect, an electrical device is provided, comprising: a battery device, the battery device comprising the battery cell of the first aspect or any one embodiment of the first aspect, the battery device being used to provide electrical energy to the electrical device.

[0059] In some embodiments of the third aspect, the electrical equipment is a vehicle, a ship, or a spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A schematic diagram of a vehicle according to an embodiment of the present application;

[0061] Figure 2 A schematic diagram of the structure of a battery device according to an embodiment of the present application;

[0062] Figure 3 A schematic diagram of the structure of a battery cell according to an embodiment of the present application;

[0063] Figure 4 A schematic diagram of a partial exploded structure of a battery cell according to an embodiment of the present application;

[0064] Figure 5 This is a schematic diagram of the structure of the sustained-release structure of an embodiment of the present application before expansion;

[0065] Figure 6 This is a schematic diagram of the structure of the sustained-release structure after expansion according to an embodiment of the present application;

[0066] Figure 7 Another structural schematic diagram of the sustained-release structure of an embodiment of the present application before expansion;

[0067] Figure 8 This is a schematic diagram of the cross-sectional structure of the sustained-release structure of an embodiment of the present application before expansion;

[0068] Fig. 9 This is a schematic diagram of the cross-sectional structure of the sustained-release structure of an embodiment of the present application after expansion;

[0069] Fig.10 This is a schematic diagram of a partial cross-sectional structure of the sustained-release structure of an embodiment of the present application before expansion;

[0070] Fig.11 This is a schematic diagram of a partial cross-sectional structure of the sustained-release structure after expansion according to an embodiment of the present application;

[0071] Fig.12 Another schematic diagram of a partial cross-sectional structure of the sustained-release structure of an embodiment of the present application before expansion;

[0072] Fig.13 This is another schematic cross-sectional structure diagram of the sustained-release structure of an embodiment of the present application before expansion;

[0073] Fig.14 It is another partial cross-sectional structural schematic diagram of the sustained-release structure of the embodiment of the present application before expansion;

[0074] Fig.15 It is another partial cross-sectional structural schematic diagram of the sustained-release structure of the embodiment of the present application before expansion;

[0075] Fig.16 This is another schematic cross-sectional structure diagram of the sustained-release structure of the embodiment of the present application before expansion;

[0076] Fig.17 This is another schematic diagram of a cross-sectional structure of the sustained-release structure after expansion according to an embodiment of the present application;

[0077] Fig.18 It is another partial cross-sectional structural schematic diagram of the sustained-release structure of the embodiment of the present application before expansion;

[0078] Fig.19 This is another schematic diagram of a partial cross-sectional structure of the sustained-release structure after expansion according to an embodiment of the present application;

[0079] Fig. 20 This is another schematic diagram of a partial cross-sectional structure of the sustained-release structure after expansion according to an embodiment of the present application;

[0080] Fig.21This is a schematic diagram of the decomposed structure of the sustained-release structure of an embodiment of the present application;

[0081] Fig. 22 Another schematic diagram of the decomposed structure of the sustained-release structure of an embodiment of the present application;

[0082] Fig.23 This is another schematic diagram of a partial cross-sectional structure of the sustained-release structure after expansion according to an embodiment of the present application;

[0083] Fig.24 This is another schematic diagram of a partial cross-sectional structure of the sustained-release structure after expansion according to an embodiment of the present application;

[0084] Fig.25 This is another structural schematic diagram of the sustained-release structure after expansion according to an embodiment of the present application;

[0085] Fig.26 This is another structural schematic diagram of the sustained-release structure after expansion according to an embodiment of the present application;

[0086] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0087] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0088] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0089] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0090] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0091] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0092] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0093] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0094] The term "multiple" as used in the present application refers to more than two (including two). Similarly, the term "multiple groups" refers to more than two groups (including two groups), and the term "multiple sheets" refers to more than two sheets (including two sheets).

[0095] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0096] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0097] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0098] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0099] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, which is arranged between the negative electrode and the positive electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and released back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0100] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0101] The electrode assembly may be a wound structure, a laminated structure, or a mixed structure of a wound structure and a laminated structure.

[0102] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0103] In some embodiments, the electrode assembly is a laminate structure.

[0104] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and multiple positive electrode sheets and multiple negative electrode sheets are alternately stacked. As an example, multiple positive electrode sheets can be provided, and the negative electrode sheet is folded to form multiple stacked folded sections, and a positive electrode sheet is sandwiched between adjacent folded sections.

[0105] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0106] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0107] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0108] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0109] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0110] In some embodiments, the battery cell may include a housing, which may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0111] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.

[0112] In some embodiments, at least one electrode terminal is disposed on the housing, and the electrode terminal is electrically connected to the electrode tab. The electrode terminal may be directly connected to the electrode tab, or may be indirectly connected to the electrode tab through a current collecting member. The electrode terminal may be disposed on an end cap, or may be disposed on the housing.

[0113] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, in parallel or in mixed connection through a busbar component.

[0114] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0115] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0116] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0117] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0118] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0119] As an example, the box may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0120] As an example, the box body 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 a closed space is formed inside the box body to accommodate the battery cell assembly.

[0121] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0122] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0123] The development of battery technology must consider many design factors at the same time, such as performance parameters such as energy density, cycle life, discharge capacity, charge and discharge rate, and also the reliability and safety of battery use. Battery cells will continue to produce gas inside during normal use. Especially when a battery cell experiences thermal runaway, battery cells that have not experienced thermal runaway are affected by the runaway battery cell, resulting in more serious internal gas production. Once the pressure or temperature inside the battery cell reaches a predetermined threshold, the pressure relief mechanism is activated, causing a large amount of conductive liquid to flow out of the battery cell, affecting the insulation of the system.

[0124] Therefore, the embodiment of the present application provides a battery cell, a battery device and an electrical device, which can solve the above problems. The battery cell of the embodiment of the present application includes a shell and an electrode assembly. The shell has a first wall; the electrode assembly is contained in the shell. The battery cell also includes a slow release structure, which is arranged on the first wall; the slow release structure is configured to expand to the outside of the shell to form an expansion space when the slow release structure meets the design threshold, and the expansion space is connected to the internal space of the shell and isolated from the outside of the shell. On the one hand, the slow release structure expands outward when the design threshold condition is reached, which can provide more internal space for the battery cell and reduce the pressure inside the battery cell. Since a heat dissipation system is often provided in the battery, the heat dissipation system can help the battery cell cool down quickly. Therefore, as long as the battery cell supports for a period of time when the internal pressure or temperature threshold is reached, the time when the battery cell is damaged can be delayed, thereby reducing the risk of system insulation failure; on the other hand, the slow release structure does not occupy additional space in the battery cell when no expansion occurs.

[0125] The technical solutions described in the embodiments of the present application are applicable to various electrical equipment using battery devices.

[0126] Electrical equipment may be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, electric tools, and the like. Vehicles may be fuel vehicles, gas vehicles, or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles, or extended-range vehicles, and the like; spacecraft include airplanes, rockets, space shuttles, and spacecraft, and the like; electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0127] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0128] For example, Figure 1 As shown, it is a structural schematic diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A motor 40, a controller 30 and a battery device 10 may be provided inside the vehicle 1. The controller 30 is used to control the battery device 10 to power the motor 40. For example, a battery device 10 may be provided at the bottom, front or rear of the vehicle 1. The battery device 10 may be used to power the vehicle 1. For example, the battery device 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery device 10 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0129] Figure 2 FIG. 1 is a schematic diagram showing a partial structure of a battery device 10 according to an embodiment of the present application. Figure 2 As shown, the battery device 10 of the embodiment of the present application may include a plurality of battery cells 20 to meet different power requirements. The shape of the battery cell 20 of the embodiment of the present application may be set according to the actual application. For example, the battery cell 20 may be as follows: Figure 2 The cylindrical shape shown, or it can also be different from Figure 2 The rectangular parallelepiped or other shapes shown are not limited to the embodiments of the present application.

[0130] It should be understood that Figure 2As shown, the battery device 10 of the embodiment of the present application may further include a box body 11, which may be used to accommodate a plurality of battery cells 20. The interior of the box body 11 of the embodiment of the present application is a hollow structure, and a plurality of battery cells 20 are accommodated in the box body 11. The box body 11 may include two parts, which are respectively referred to as a first box body part 111 and a second box body part 112, and the first box body part 111 and the second box body part 112 are snapped together. The shapes of the first box body part 111 and the second box body part 112 may be determined according to the shapes of the components accommodated inside. For example, they may be determined according to the shape of the combination of the plurality of battery cells 20 accommodated inside. At least one of the first box body part 111 and the second box body part 112 may have an opening. For example, as Figure 2 As shown, the first box body 111 and the second box body 112 can both be hollow cuboids and each have an open face, the opening of the first box body 111 and the opening of the second box body 112 are arranged opposite to each other, and the first box body 111 and the second box body 112 are buckled together to form a box body 11 with a closed chamber, and the chamber can be used to accommodate multiple battery cells 20. Multiple battery cells 20 are connected in parallel, in series, or in mixed combination and placed in the box body 11 formed by the first box body 111 and the second box body 112 buckled together.

[0131] For example, unlike Figure 2 As shown, only one of the first box body 111 and the second box body 112 may be a hollow cuboid with an opening, while the other is in a plate shape to cover the opening. Taking the second box body 112 as a hollow cuboid with an opening and the first box body 111 as a plate, the first box body 111 covers the opening of the second box body 112 to form a box body 11 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0132] In some embodiments, the battery device 10 may further include other components. For example, the battery device 10 may further include a busbar component, which may be used to achieve electrical connection between multiple battery cells 20, such as parallel connection, series connection, or mixed connection. Specifically, the busbar component may achieve electrical connection between the battery cells 20 by connecting the electrode terminals 214 of the battery cells 20; or, the busbar component may also achieve electrical connection between the battery cells 20 by connecting other components of the battery cells 20. The busbar component may be fixed to the corresponding components of the battery cell 20 by welding, for example, it may be fixed to the electrode terminal 214, the sealing structure, or the housing, etc. by welding, and the embodiments of the present application are not limited thereto.

[0133] Next, the battery cell of the embodiment of the present application will be described in detail with reference to the accompanying drawings. Figure 3 A schematic diagram of the structure of a battery cell 20 according to an embodiment of the present application is shown; Figure 4The schematic diagram of the partial decomposition structure of the battery cell 20 of the embodiment of the present application is shown. Figure 4 Can be Figure 3 A schematic diagram of a partial exploded structure of a battery cell 20 is shown; Figure 5 The schematic diagram of the structure of the sustained-release structure of the embodiment of the present application before expansion is shown. For example, Figure 5 Can be Figure 4 The schematic diagram of the structure of the slow-release structure 215 on the first wall 201 of the battery cell 20 before expansion; Figure 6 The schematic diagram of the structure of the sustained-release structure after expansion of the embodiment of the present application is shown. For example, the Figure 6 Can be Figure 4 or Figure 5 The schematic diagram of the structure of the sustained-release structure 215 on the first wall 201 of the battery cell 20 after expansion is shown; Figure 7 Another schematic diagram of the structure of the sustained-release structure of the embodiment of the present application before expansion is shown. Figure 7 Can be Figure 4 or Figure 5 Another schematic diagram of the structure of the slow-release structure 215 on the first wall 201 of the battery cell 20 before expansion is shown.

[0134] like Figures 3 to 6 As shown, the battery cell 20 of the embodiment of the present application may include: a shell 21, the shell 21 having a first wall 201; an electrode assembly 22, the electrode assembly 22 being accommodated in the shell 21; a slow-release structure 215, the slow-release structure 215 being arranged on the first wall 201; the slow-release structure 215 being constructed to expand toward the outside of the shell 21 to form an expansion space 2156 when the slow-release structure 215 meets the design threshold, and the expansion space 2156 is connected to the internal space of the shell 21 and isolated from the outside of the shell 21.

[0135] It should be understood that the shape of the battery cell 20 in the embodiment of the present application can be flexibly set according to the actual application, that is, the shell 21 of the battery cell 20 can be any polyhedral structure, for example, it can be set to a rectangular parallelepiped or a cylinder. Figure 3 As shown, the shape of the exterior of the battery cell 20 may be the same as or different from the shape of the electrode assembly 22 inside it. For example, if the electrode assembly 22 is a cylindrical structure, the outer shell 21 of the battery cell 20 may also be a cylindrical structure, or may also be a rectangular parallelepiped structure; if the electrode assembly 22 is a rectangular parallelepiped structure, the outer shell 21 may also generally be a rectangular parallelepiped structure, but the embodiments of the present application are not limited thereto.

[0136] In addition, for the sake of convenience in description, the present embodiment defines three reference directions for the rectangular battery cell 20. The thickness direction of the battery cell 20 is direction X, the height direction of the battery cell 20 is direction Z, and the length direction of the battery cell 20 is direction Y, wherein the thickness direction X, the height direction Z, and the length direction Y of the battery cell 20 are perpendicular to each other, and the dimension of the thickness direction X of the battery cell 20 is smaller than the dimension of the length direction Y.

[0137] In some embodiments, Figure 3 and Figure 4 As shown, the housing 21 may include a shell 211 and a cover plate 212. The shell 211 may be a hollow structure with an opening 2101. The cover plate 212 may be used to cover the opening 2101 of the shell 211. The shell 211 may be provided with one or more openings 2101. One or more cover plates 212 may also be provided.

[0138] The material of the housing 211 in the embodiment of the present application may include one or more materials, for example, copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover plate 212 may also be one or more materials, for example, copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover plate 212 may be the same as or different from that of the housing 211; the materials of different walls of the housing 211 may also be the same or different.

[0139] The shapes of the shell 211 and the cover plate 212 of the embodiment of the present application match each other. For example, the shell 211 can be an approximately rectangular parallelepiped structure, and the cover plate 212 is an approximately rectangular plate-shaped structure that matches the shell 211. The cover plate 212 can be any wall of the shell 21. For example, the cover plate 212 can be the wall with the largest area among the multiple walls included in the shell 21, or the wall with the smallest area, or it can also be other walls. The embodiment of the present application is not limited to this. Alternatively, the cover plate 212 can also be other structures. For example, the cover plate 212 can also be a groove structure with an opening, so that the opening of the cover plate 212 covers the opening 2101 of the shell 211. The embodiment of the present application is not limited to this.

[0140] It should be understood that the first wall 201 may refer to any surface of the shell 211, or to the cover plate 212. The slow-release structure 215 is arranged on the first wall 201, that is, the slow-release structure 215 may be arranged on any surface of the shell 211, or on the cover plate 212. For example, the first wall 201 is the cover plate 212, that is, the slow-release structure 215 is arranged on the cover plate 212. In particular, when the external space of the shell 211 is limited, the slow-release structure 215 is arranged on the cover plate 212, which not only ensures that the slow-release structure 215 has sufficient expansion space, but also provides sufficient installation thickness for the slow-release structure.

[0141] It should be understood that when the slow-release structure 215 meets the design threshold, the slow-release structure 215 expands toward the outside of the housing 21 to form an expansion space 2156, that is, the slow-release structure 215 has two states. When the battery cell 20 works normally, the slow-release structure 215 is in the first state. When the battery cell 20 has an abnormality that reaches the design threshold, the slow-release structure 215 changes to the second state through expansion. In the first state, the slow-release structure 215 is arranged on the first wall 201, so it does not occupy additional space in the battery cell 20; Figure 6 As shown, the slow-release structure 215 expands toward the outside of the battery cell 20 in the second state to form a certain expansion space 2156, providing more internal space for the battery cell and reducing the pressure inside the battery cell.

[0142] In some embodiments, the slow-release structure 215 is constructed to expand toward the outside of the shell 21 when the slow-release structure 215 meets the design threshold, including: the slow-release structure 215 is constructed to expand toward the outside of the shell 21 to form an expansion space 2156 when the internal air pressure of the slow-release structure 215 meets a first threshold, and / or the slow-release structure 215 is constructed to expand toward the outside of the shell 21 to form an expansion space 2156 when the temperature of the slow-release structure 215 meets a second threshold.

[0143] It should be understood that the design threshold includes a first threshold and a second threshold, that is, when the slow-release structure 215 meets any one of the thresholds, the slow-release structure 215 expands toward the outside of the shell 21, thereby providing more internal space for the battery cell 20, reducing the internal pressure of the battery cell, and improving the safety performance of the battery cell.

[0144] The expansion space of the embodiment of the present application is connected to the internal space of the outer shell 21 and is isolated from the outside of the outer shell 21, that is, the slow-release structure 215 is sealed with the first wall. When the slow-release structure 215 expands, part of the gas inside the battery cell gradually moves to the expansion space 2156 formed by the slow-release structure 215, and will not leak to the outside of the battery cell, thereby reducing the risk of system insulation failure.

[0145] On the one hand, when an abnormality occurs in the battery cell 20, causing the slow-release structure 215 to reach the design threshold, the slow-release structure 215 expands outward, providing more internal space for the battery cell 20, reducing the internal pressure, and reducing the risk of the battery cell 20 being damaged and causing internal conductive liquids or gases to flow out to the outside, thereby improving the insulation and safety performance of the system; on the other hand, under normal working conditions of the battery cell 20, the slow-release structure 215 is arranged on the first wall 201 and does not occupy additional space in the battery cell.

[0146] It should be understood that the housing 21 of the embodiment of the present application is used to accommodate the electrode assembly. The electrode assembly 22 is a component in the battery cell 20 where the electrochemical reaction occurs. According to actual use requirements, the electrode assembly 22 in the battery cell 20 can be set to one or more. For any electrode assembly 22, the electrode assembly 22 may include a pole ear 222 and a pole piece body 221. Specifically, as Figure 4 As shown, the electrode assembly 22 may include at least two pole tabs 222, and the at least two pole tabs 222 may include at least one positive pole tab and at least one negative pole tab. The positive pole tab may be formed by stacking a portion of the positive electrode sheet that is not coated with the positive electrode active material layer, and the portion of the positive electrode sheet that is coated with the positive electrode active material layer may form a pole sheet main body 221 by winding or stacking; the negative pole tab may be formed by stacking a portion of the negative electrode sheet that is not coated with the negative electrode active material layer, and the portion of the negative electrode sheet that is coated with the negative electrode active material layer may form a pole sheet main body 221 by winding or stacking.

[0147] In some embodiments, a pressure relief mechanism may be provided on the housing 21. Figure 4 As shown, the battery cell 20 may further include a pressure relief mechanism 213. The pressure relief mechanism 213 is used to discharge the internal gas of the battery cell.

[0148] As an example, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, it is actuated to release the internal pressure or temperature. When the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, the pressure relief mechanism 213 performs an action or a weak structure provided in the pressure relief mechanism 213 is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released. The threshold design varies according to different design requirements. The threshold may depend on one or more materials of the positive electrode sheet, negative electrode sheet, electrolyte and separator in the battery cell.

[0149] As an example, the pressure relief mechanism 213 may be integrally formed with the housing 21 .

[0150] As an example, the pressure relief mechanism 213 may also be separately provided and connected to the housing 21 .

[0151] The "actuation" mentioned in this application means that the pressure relief mechanism 213 is in action or activated to a certain state, so that the internal pressure and temperature of the battery cell 20 can be released. The action produced by the pressure relief mechanism 213 may include but is not limited to: the components in the pressure relief mechanism 213 move to form an exhaust channel, at least a part of the pressure relief mechanism 213 ruptures, breaks, is torn or opened, and so on. When the pressure relief mechanism 213 is actuated, the high-temperature and high-pressure substances inside the battery cell 20 will be discharged from the actuated part as emissions. In this way, the battery cell 20 can be depressurized and cooled under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0152] The emissions from the battery cells 20 mentioned in the present application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode sheets, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, and the like.

[0153] In some embodiments, the battery cell 20 further includes a pressure relief mechanism 213, which can be used to discharge the discharge of the battery cell 20 when the pressure of the pressure relief mechanism 213 reaches a third threshold, wherein the first threshold is less than the third threshold. By setting the first threshold to be less than the third threshold, the slow-release structure 215 can expand before the pressure relief mechanism 213 is actuated, thereby quickly reducing the pressure inside the battery cell 20 before the pressure relief mechanism 213 is actuated. In addition, when the battery cell 20 is affected by abnormal conditions such as thermal failure of other battery cells, the time for the pressure relief mechanism 213 to be actuated can also be delayed, and the battery cell 20 can be quickly cooled down under the action of other heat dissipation systems, thereby reducing the probability of the pressure relief mechanism being damaged and improving the performance of the battery cell 20.

[0154] It should be understood that the values ​​of the third threshold value at which the pressure relief mechanism 213 is actuated and the first threshold value at which the slow-release structure 215 expands in the embodiment of the present application can be flexibly set according to actual applications.

[0155] For example, the absolute value of the difference between the first threshold and the third threshold is in the range of [0.1MPa, 1MPa], or the absolute value of the difference between the first threshold and the third threshold is in the range of [0.2MPa, 0.5MPa]. On the one hand, setting the absolute value of the difference between the first threshold and the third threshold to be greater than or equal to 0.1MPa, or further, setting the absolute value of the difference between the first threshold and the third threshold to be greater than or equal to 0.2MPa can ensure that the slow-release structure 215 expands smoothly before the pressure relief mechanism 213 is actuated, thereby avoiding the phenomenon of expansion failure. On the other hand, setting the absolute value of the difference between the first threshold and the third threshold to be less than or equal to 1MPa, or further, setting the absolute value of the difference between the first threshold and the third threshold to be less than or equal to 0.5MPa can ensure that the slow-release structure 215 can expand only under certain conditions, thereby avoiding the slow-release structure 215 from expanding when the battery cell 20 is in normal use, and reducing the phenomenon of unnecessary expansion of the slow-release structure resulting in the occupation of additional space in the battery cell 20.

[0156] In some embodiments, the absolute value of the difference between the first threshold and the third threshold can be any of the following values ​​or between any two of the following values: 0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, 0.4MPa, 0.45MPa, 0.5MPa, 0.55MPa, 0.6MPa, 0.65MPa, 0.7MPa, 0.75MPa, 0.8MPa, 0.85MPa, 0.9MPa, 0.95MPa, 1MPa.

[0157] For example, the range of the first threshold value of the air pressure to which the slow-release structure is subjected is [0.4MPa, 3MPa], or the range of the first threshold value of the air pressure to which the slow-release structure is subjected is [0.7MPa, 1.1MPa]. On the one hand, setting the first threshold value to be greater than or equal to 0.4MPa, or further, setting the first threshold value to be greater than or equal to 0.7MPa, can reduce the probability of unnecessary expansion of the slow-release structure 215 and reduce the excessive space occupied by the battery cell 20; on the other hand, the first threshold value is less than or equal to 3MPa, or further, the first threshold value is less than or equal to 1.1MPa, so that when the battery cell 20 is affected by thermal runaway, the slow-release structure 215 can effectively expand, thereby providing more internal space for the battery cell 20, reducing the internal pressure of the battery cell 20, and improving the performance of the battery cell 20.

[0158] In some embodiments, the range of the first threshold can be any of the following values ​​or between any two of the following values: 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, 1.6MPa, 1.7MPa, 1.8MPa, 2MPa, 2.2MPa, 2.4MPa, 2.6MPa, 2.8MPa, 3MPa.

[0159] In some embodiments, the housing 21 of the battery cell 20 of the embodiment of the present application may also be provided with an electrode terminal 214, and the electrode terminal 214 is used to be electrically connected to the electrode assembly 22 to output the electrical energy of the battery cell 20. Figure 4 As shown, the battery cell 20 may include at least two electrode terminals 214, including at least one positive electrode terminal and at least one negative electrode terminal. Each electrode terminal 214 is used to be electrically connected to the corresponding pole ear 222. For example, each electrode terminal 214 can be electrically connected to the corresponding pole ear 222 through a connecting member. For example, the positive pole ear of the electrode assembly 22 can be connected to the positive electrode terminal through one connecting member, and the negative pole ear of the electrode assembly 22 can be connected to the negative electrode terminal through another connecting member.

[0160] At least two electrode terminals 214 of the battery cell 20 may be disposed on the same wall or different walls of the battery cell 20. For example, the positions of the electrode terminals 214 may be set according to the positions of the tabs 222 of the electrode assembly 22. Figure 5 and Figure 6 As shown, the embodiment of the present application mainly takes the example that the battery cell 20 includes two electrode terminals 214 , and the two electrode terminals 214 are arranged on the same wall of the housing 21 of the battery cell 20 .

[0161] In some embodiments, the pressure relief mechanism 213 is disposed on the first wall 201, the first wall 201 has at least two electrode terminals 214, and the pressure relief mechanism 213 is located between the at least two electrode terminals 214. It can be understood that the first wall 201 can also be a cover plate 212. That is, the pressure relief mechanism 213, at least two electrode terminals 214, and the slow-release structure 215 are all disposed on the first wall 201, so that too much space of the battery cell 20 is not occupied, and the energy density of the battery cell 20 is improved.

[0162] It should be understood that when the pressure relief mechanism 213, at least two electrode terminals 214 and the slow-release structure 215 are all disposed on the first wall 201, the positions of the slow-release structure 215 and the pressure relief mechanism 213 can be flexibly adjusted according to actual applications. Figure 5As shown, the pressure relief mechanism 213 can be disposed on the slow-release structure 215. For another example, Figure 7 As shown, the slow-release structure 215 can also be arranged on both sides of the pressure relief mechanism 213, and the projection of the slow-release structure 215 in the thickness direction of the first wall 201 does not overlap with the projection of the at least two electrode terminals 214 in the thickness direction of the first wall 201. The slow-release structure 215 can be arranged between the pressure relief mechanism 213 and any one of the at least two electrode terminals 214, and one or more slow-release structures 215 can be arranged. The slow-release structure 215 is arranged on both sides of the pressure relief mechanism 213, and does not affect the actuation of the pressure relief mechanism 213 after the slow-release structure 215 expands, thereby improving the safety performance of the battery cell 20.

[0163] The sustained-release structure 215 of the embodiment of the present application will be described below in conjunction with the accompanying drawings. Figure 8 The cross-sectional structure diagram of the sustained-release structure of the embodiment of the present application before expansion is shown. For example, Figure 8 Can be along Figure 5 A schematic diagram of the cross-sectional structure along the A-A' direction shown; Fig. 9 The cross-sectional structure schematic diagram of the sustained-release structure after expansion of the embodiment of the present application is shown. For example, Fig. 9 Can be along Figure 6 The cross-sectional structure schematic diagram along the BB' direction is shown.

[0164] In the embodiments of the present application, Figure 8 and Fig. 9 As shown, the slow-release structure 215 includes a retaining portion 2151 and an expansion portion 2152, wherein the expansion portion 2152 is connected to the first wall 201, and the retaining portion 2151 is configured to keep the expansion portion 2152 in an initial state. The retaining portion 2151 is also configured to release the expansion portion 2152 when the slow-release structure 215 meets a design threshold, so that the expansion portion 2152 changes from the initial state to the expansion state.

[0165] It should be understood that the retaining portion 2151 can keep the expansion portion 2152 in the initial state, that is, the retaining portion 2151 has a force on the expansion portion 2152 along the thickness direction of the retaining portion 2151, and the force is directed toward the inside of the shell 21, so that the expansion portion 2152 cannot expand to the outside of the shell 21. When the slow-release structure 215 meets the design threshold, the force disappears, so that the expansion portion 2152 expands to the outside of the shell 21, and the expansion portion 2152 changes from the initial state to the expansion state. By setting the retaining portion 2151 and the expansion portion 2152, the slow-release structure 215 can be in different states under different environmental conditions. Under the normal working state of the battery cell 20, the retaining portion 2151 allows the expansion portion 2152 to maintain the initial state, ensuring that the slow-release structure 215 does not occupy additional space of the battery cell 20; once an abnormality occurs and reaches the design threshold, the retaining portion 2151 can quickly release the expansion portion 2152, thereby providing more internal space for the battery cell 20 and reducing the internal pressure of the battery cell 20.

[0166] In some embodiments, the pressure relief mechanism 213 can be disposed on the retaining portion 2151 of the slow-release structure 215. When the slow-release structure 215 expands, the retaining portion 2151 drives the pressure relief mechanism 213 to move toward the outside of the battery cell 20 along the thickness direction of the first wall 201. It should be understood that the expansion of the slow-release structure 215 occurs before the actuation of the pressure relief mechanism 213, so the expansion space 2156 formed after the expansion of the slow-release structure 215 is isolated from the external space of the shell 21 and communicates with the internal space of the shell 21. The expansion space 2156 will only communicate with the external space of the shell 21 after the pressure relief mechanism 213 is actuated and destroyed. Providing the pressure relief mechanism 213 on the retaining portion 2151 of the slow-release structure 215 can simplify the processing process and improve processing efficiency.

[0167] The retaining portion 2151 in the slow-release structure 215 will be described below with reference to the accompanying drawings. Fig.10 FIG. 4 shows a schematic diagram of a partial cross-sectional structure of a sustained-release structure of an embodiment of the present application before expansion. For example, Fig.10 Can be Figure 8 A schematic cross-sectional structure diagram of the local C shown; Fig.11 The schematic diagram of the partial cross-sectional structure of the sustained-release structure after expansion of the embodiment of the present application is shown. Fig.11 Can be Fig. 9 A schematic cross-sectional structure diagram of a local D shown; Fig.12 Another partial cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application before expansion is shown. For example, Fig.12 Can be Figure 8 Another schematic diagram of the cross-sectional structure of the local C shown.

[0168] like Fig.10 and Fig.11As shown, the first wall 201 has a through hole 2011, the slow-release structure 215 is fixed in the through hole 2011, the outer periphery of the holding portion 2151 has a first protruding structure 2110 facing the inner side of the through hole 2011, and the inner side of the through hole 2011 has a second protruding structure 2120 facing the holding portion 2151. The side of the first protruding structure 2110 away from the inside of the shell 21 and the side of the second protruding structure 2120 close to the inside of the shell 21 abut against each other, so that the holding portion 2151 applies pressure toward the inside of the shell 21 to the expansion portion 2152, so as to keep the expansion portion 2152 in the initial state.

[0169] It should be understood that there only needs to be a portion of the mutually abutting area between the first protruding structure 2110 and the second protruding structure 2120, so that the expansion portion 2152 can be maintained in the initial state. When the internal air pressure of the battery cell 20 reaches the first threshold, the first wall 201 is deformed, so that the mutually abutting portion of the first protruding structure 2110 and the second protruding structure 2120 is dislocated and separated, and the retaining portion 2151 loses the pressure on the expansion portion 2152 toward the inside of the housing 21, and the expansion portion 2152 expands and changes from the initial state to the expansion state. When there is no abnormality in the battery cell 20, or when the air pressure inside the battery cell 20 does not reach the first threshold, the retaining portion 2151 can keep the expansion portion 2152 in the initial state, thereby saving the internal space of the battery cell 20 and reducing unnecessary space waste.

[0170] It should be understood that the shape of the through hole 2011 can be similar to that of the first wall 201, or can be other shapes. For ease of description, the embodiment of the present application mainly takes the shape of the through hole 2011 being similar to that of the first wall as an example. In addition, the projection of the through hole 2011 in the thickness direction of the first wall 201 is in the shape of a rectangle, and the direction of its long side can be parallel to the direction of the long side of the first wall 201, or can be parallel to the direction of the short side of the first wall 201, and the present application does not limit it.

[0171] The specific shapes of the first protruding structure 2110 and the second protruding structure 2120 of the through hole 2011 can be flexibly adjusted to achieve the design purpose, that is, the two can abut against each other, so that the retaining part 2151 can exert a certain force on the expansion part 2152, so that the expansion part 2152 remains in the initial state, and releases the expansion part 2152 under certain conditions.

[0172] For example, Fig.12As shown, in some embodiments, the first protruding structure 2110 is bent toward a side away from the interior of the shell 21 to form a first bending portion 2111, and the second protruding structure 2120 is bent toward a side close to the interior of the shell 21 to form a second bending portion 2121, and the first bending portion 2111 and the second bending portion 2121 are clamped together, wherein a weak area 2122 is provided on the second protruding structure 2120 away from the clamping point.

[0173] It should be understood that the weak area 2122 can be a groove arranged on the second protruding structure 2120 along the thickness direction of the first wall 201, or can be some notches on the second protruding structure 2120, so that the position with the notches is easy to break. In some battery cells 20 with relatively narrow first walls 201, when the battery cell 20 is abnormal and the pressure on the slow-release structure 215 reaches the first threshold, the first wall 201 is deformed less, so that the first protruding structure 2110 and the second protruding structure 2120 are not enough to be misaligned. The weak area 2122 is arranged on the second protruding structure 2120 so that the strength of the second protruding structure 2120 is weakened, and the stress at the weak area 2122 is concentrated, so that the second protruding structure 2120 breaks and releases the expansion part 2152. By setting in this way, the slow-release structure 215 can be ensured to be in the initial state under normal conditions, reducing unnecessary expansion. In abnormal conditions, it can also make it easier for the retaining part 2151 to detach from the first wall 201, thereby releasing the expansion part 2152.

[0174] It should be understood that the first protruding structure 2110 can be arranged on two opposite sides of the outer periphery of the holding portion 2151, or the first protruding structure 2110 can be arranged on all four sides of the outer periphery. The second protruding structure 2120 is arranged on the inner side of the through hole 2011 corresponding to the first protruding structure. The number of the first protruding structure 2110 and the second protruding structure 2120 is not limited. For example, Figure 6 As shown, the number of the first protruding structure 2110 can be one, and the length of the first protruding structure 2110 along the first direction is equal to the length of the holding portion 2151 along the first direction, or the length of the first protruding structure 2110 along the first direction is slightly less than the length of the holding portion 2151 along the first direction. Figure 6 For another example, the number of the first protruding structures 2110 may be multiple, and the multiple first protruding structures 2110 are arranged along the first direction.

[0175] In some embodiments, the length of the first wall 201 along the first direction is greater than the length of the first wall 201 along the second direction, the first direction is perpendicular to the second direction, and the first direction and the second direction are both perpendicular to the thickness direction of the first wall 201, wherein the second protruding structure 2120 is disposed on the inner side surface of the through hole 2011 extending along the first direction. The first direction may be Figure 6The Y direction in the second direction can be Figure 6 The second protruding structure 2120 is arranged on the inner side surface of the first wall 201 where the longer side is located, and the first protruding structure 2110 and the second protruding structure 2120 are arranged correspondingly, that is, the first protruding structure is arranged on the side surface of the outer periphery where the side parallel to the longer side of the first wall 201 is located in the retaining portion 2151. The first protruding structure 2110 and the second protruding structure 2120 are arranged in the direction where the longer side of the first wall 201 is located. When an abnormality occurs in the battery cell 20 and the expansion portion 2152 needs to be released, the first protruding structure 2110 and the second protruding structure 2120 can be quickly separated to ensure that the expansion portion 2152 expands effectively.

[0176] In some embodiments, the retaining portion 2151 may include a connecting structure 2130, which is located between the retaining portion 2151 and the first wall 201, and is used to connect the retaining portion 2151 and the first wall 201, so that the retaining portion 2151 applies pressure toward the inside of the shell 21 on the expansion portion 2152 to maintain the expansion portion 2152 in an initial state.

[0177] It should be understood that the connection structure 2130 maintains the expansion portion 2152 in the initial state by connecting the retaining portion 2151 and the first wall 201. When the slow-release structure 215 reaches the design threshold, the connection structure 2130 is destroyed, thereby releasing the expansion portion. Among them, the connection structure 2130 is destroyed in a variety of ways including but not limited to softening, melting, decomposition, etc. For example, the melting point T1 of the connection structure 2130 is the second threshold. When the battery cell 20 is affected by thermal runaway and the temperature of the slow-release structure 215 reaches the second threshold, the connection structure 2130 is melted, the retaining portion 2151 is no longer connected to the first wall 201, the pressure of the retaining portion 2151 on the expansion portion 2152 toward the inside of the shell 21 disappears, and the expansion portion 2152 expands toward the outside of the battery cell 20, thereby reducing the internal pressure of the battery cell 20.

[0178] The structure of the connecting structure 2130 and the connection between the connecting structure 2130, the retaining portion 2151 and the first wall 201 can be in different forms. For example, Figures 13 to 15 The positions and different structural forms of the connection structure 2130 are shown respectively. Fig.13 Another possible cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application before expansion is shown. For example, Fig.13 Can be along Figure 5 Another schematic diagram of the cross-sectional structure in the AA' direction shown; Fig.14 FIG. 4 shows another partial cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application before expansion. For example, Fig.14 Can be Fig.13A schematic cross-sectional structure diagram of the local E shown; Fig.15 FIG. 4 shows another partial cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application before expansion. For example, Fig.15 Can be Fig.13 Another schematic diagram of the cross-sectional structure of the local E shown.

[0179] For example, the connection structure 2130 can be connected and fixed to the holding portion 2151 and the first wall 201 by means of clamping, bonding, injection molding, hot melting, etc. Fig.14 A schematic diagram of a partial cross-sectional structure of the sustained-release structure of the embodiment of the present application before expansion is shown, in which the retaining portion 2151 and the first wall 201 both have portions protruding toward each other. In the thickness direction of the first wall 201, the thickness of the protruding portion of the retaining portion 2151 is less than the thickness of the retaining portion 2151, and the protruding portions are all located near the middle position of the retaining portion 2151 along the thickness direction, so that a step is formed between the protruding portion of the retaining portion 2151 and the upper and lower surfaces of the retaining portion 2151; similarly, in the thickness direction of the first wall 201, the thickness of the protruding portion of the first wall 201 is less than the thickness of the first wall 201, and the protruding portions are all located near the middle position of the first wall 201 along the thickness direction, so that a step is formed between the protruding portion of the first wall 201 and the upper and lower surfaces of the first wall 201. The connection structure 2130 is respectively connected to the protruding portion of the holding portion 2151 and the protruding portion of the first wall 201, so that the holding portion 2151 applies pressure toward the inside of the housing 21 to the expansion portion 2152 to maintain the expansion portion 2152 in the initial state. That is, the connection structure 2130 is an "I"-shaped structure to achieve a snap connection between the holding portion 2151 and the first wall 201.

[0180] In some embodiments, Fig.15As shown, the retaining portion 2151 and the first wall 201 both have portions protruding toward each other, and in the thickness direction of the first wall 201, the thickness of the protruding portion of the retaining portion 2151 is less than the thickness of the retaining portion 2151, and the protruding portions are all located near the middle position of the retaining portion 2151 along the thickness direction, so that a step is formed between the protruding portion of the retaining portion 2151 and the upper and lower surfaces of the retaining portion 2151; similarly, in the thickness direction of the first wall 201, the thickness of the protruding portion of the first wall 201 is less than the thickness of the first wall 201, and the protruding portions are all located near the middle position of the first wall 201 along the thickness direction, so that a step is formed between the protruding portion of the first wall 201 and the upper and lower surfaces of the first wall 201, and the protruding portions of the retaining portion 2151 and the first wall 201 are both provided with through holes along the thickness direction of the first wall 201. The connection structure 2130 is formed by injection molding from the through hole, so that the retaining portion 2151 applies pressure toward the inside of the housing 21 to the expansion portion 2152 to maintain the expansion portion 2152 in the initial state. When the temperature of the slow-release structure 215 reaches the melting point of the connection structure 2130, the connection structure 2130 is melted and destroyed, and the retaining portion 2151 no longer applies pressure toward the inside of the housing 21 to the expansion portion 2152, and the expansion portion 2152 expands toward the outside of the battery cell 20.

[0181] In some embodiments, the melting point T1 of the connection structure 2130 is lower than the melting point T2 of the first wall 201. When the temperature of the sustained-release structure 215 reaches the second threshold, the connection structure 2130 melts, while the first wall 201 maintains a certain heat resistance, thereby ensuring that the expansion portion 2152 expands smoothly, and the first wall 201 also has a certain stability, ensuring the performance of the battery cell.

[0182] In some embodiments, the melting point T1 of the connection structure 2130 is in the range of [60°C, 400°C], or the melting point T1 of the connection structure 2130 is in the range of [60°C, 200°C]. On the one hand, the melting point T1 of the connection structure 2130 is greater than or equal to 60°C, which prevents the connection structure 2130 from being melted at room temperature or when the battery cell 20 is affected by thermal runaway and has not yet reached the second threshold, resulting in unnecessary expansion of the expansion portion 2152 and occupying too much space of the battery cell. On the other hand, the melting point T1 of the connection structure 2130 is less than or equal to 400°C, or further, the melting point T1 of the connection structure 2130 is less than or equal to 200°C, which can make the expansion portion 2152 expand smoothly to the outside of the battery cell 20 before the battery cell 20 is irreversibly damaged, provide more internal space for the battery cell 20, and delay the time when the battery cell 20 is damaged and fails.

[0183] In some embodiments, the melting point T1 of the connecting structure 2130 can be any of the following values ​​or between any two of the following values: 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, 340°C, 360°C, 380°C, 400°C.

[0184] In some embodiments, the material of the connection structure 2130 can be plastic or rubber, including one of polypropylene, polyethylene, polycarbonate, soluble polytetrafluoroethylene, polyphenylene sulfide, silicone rubber and fluororubber. The plastic or rubber material can be melted when the temperature reaches a certain threshold, thereby ensuring that the expansion portion 2152 is released and expanded under certain conditions.

[0185] In some embodiments, the connection structure 2130 is close to the edge of the first wall 201. For example, Fig.13 As shown, the relationship between the minimum distance L1 between the connecting structure 2130 and the side surface of the first wall 201 along the second direction and the length L2 of the first wall 201 along the second direction satisfies L1≤L2 / 2, or L1≤L2 / 3. Fig.13 The X direction in the figure is the thickness direction of the battery cell. By arranging the connection structure 2130 at the edge position close to the first wall 201, when the adjacent battery cell of the battery cell 20 has thermal runaway, its high temperature is transferred to the connection structure 2130. Once the temperature reaches the melting point T1 of the connection structure 2130, the connection structure 2130 melts, and the expansion portion 2152 can quickly expand to the outside of the battery cell 20, reducing the internal pressure of the battery cell 20, reducing the influence of other thermal runaway battery cells on the battery cell 20, effectively preventing the battery cell 20 from being damaged and causing the internal emissions to flow out, and reducing the risk of system insulation failure.

[0186] Next, the expansion portion 2152 of the sustained-release structure 215 will be mainly described. Figures 16 to 19 As shown, Fig.16 A possible cross-sectional structure schematic diagram of the sustained-release structure of an embodiment of the present application before expansion is shown. For example, Fig.16 Can be along Figure 5 Another schematic cross-sectional structure diagram along the AA' direction shown; Fig.17 A possible cross-sectional structure schematic diagram of the sustained-release structure of an embodiment of the present application after expansion is shown. For example, Fig.17 Can be along Figure 6 Another schematic cross-sectional structure diagram in the BB' direction shown; Fig.18A possible partial cross-sectional structure schematic diagram of the sustained-release structure of an embodiment of the present application before expansion is shown. For example, Fig.17 Can be Fig.16 A schematic cross-sectional structure diagram of a local F shown; Fig.19 A possible partial cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application after expansion is shown. For example, Fig.19 Can be Fig.17 A schematic cross-sectional structure diagram of the local G shown.

[0187] In the embodiment of the present application, the expansion portion 2152 includes a folding structure, and the expansion state is a state in which the expansion portion 2152 is unfolded from the folding structure, and / or the expansion portion includes a contraction structure, and the expansion state is a state in which the expansion portion 2152 is stretched from the contraction structure. The folding structure and the contraction structure of the expansion portion 2152 do not occupy space in the initial state, and can provide more internal space for the battery cell 20 in the expanded state.

[0188] For example, Figure 8 and Fig.10 The compressed structure of the expansion portion 2152 of the sustained-release structure 215 before expansion is shown. Fig. 9 and Fig.11 The expansion part 2152 of the expansion part 2152 is shown after the slow-release structure 215 expands. During the normal operation of the battery cell 20, the expansion part 2152 maintains a compressed structure; when the slow-release structure 215 reaches the design threshold, the compressed structure of the expansion part 2152 expands toward the outside of the housing 21 to form an expansion space 2156 through deformation and stretching.

[0189] For example, Fig.16 and Fig.18 The folded structure of the expansion portion 2152 of the sustained-release structure 215 before expansion is shown. Fig.17 and Fig.19 The expanded structure of the expansion part 2152 after the slow-release structure 215 expands is shown. During normal operation of the battery cell 20, the expansion part 2152 maintains a folded structure; when the slow-release structure 215 reaches the design threshold, the folded structure of the expansion part 2152 expands toward the outside of the housing 21 to form an expansion space 2156 by expanding and stretching.

[0190] In some embodiments, the compression structure and the folding structure of the expansion portion 2152 may use the same material or different materials. For example, both the compression structure and the folding structure of the expansion portion 2152 may use some stretchable materials, such as latex or rubber, including silicone rubber and fluororubber. The folding structure of the expansion portion 2152 may also use a material different from the compression structure. For example, the folding structure of the expansion portion 2152 may also use some materials that are resistant to stretching, such as organic film materials or heat-resistant fiber polymer films. The materials of the folding structure of the expansion portion 2152 include polypropylene, polyethylene terephthalate, polyimide, ceramic fiber, or glass fiber.

[0191] In the present application embodiment, Fig.10 and Fig.18 As shown, the expansion portion 2152 may include a first connection portion 2152a, a second connection portion 2152b and an expansion portion 2152c, wherein the expansion portion 2152c is located between the first connection portion 2152a and the second connection portion 2152b. The first connection portion 2152a is connected to the retaining portion 2151, and the second connection portion 2152b is connected to the first wall 201. By connecting the expansion portion 2152 to the retaining portion 2151 and the first wall 201, the slow-release structure 215 can be fixed on the first wall 201, and can expand when the design threshold is reached, thereby providing more internal space for the battery cell 20.

[0192] In some embodiments, the first connection part 2152a is connected to the holding part 2151 by snapping or bonding, and the second connection part 2152b is fixed to the first wall 201 by snapping or bonding. It should be understood that the first connection part 2152a and the holding part 2151 can be connected by a layer of adhesive material, or by designing the structures of the first connection part 2152a and the holding part 2151 accordingly, or by adding some connecting parts, so that the two can be snap-connected and fixed; the second connection part 2152b and the first wall 201 can also be connected by a layer of adhesive material, or by designing the structures of the second connection part 2152b and the first wall 201 accordingly, or by adding some connecting parts, so that the two can be snap-connected and fixed.

[0193] Fig. 20 FIG. 4 shows another partial cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application after expansion. For example, Fig. 20 Can be Fig. 9 Another cross-sectional structural schematic diagram of the local D shown in FIG. Fig. 20As shown, the first connection part 2152a can be designed such that the length of the first connection part 2152a on the side close to the retaining part 2151 in the thickness direction of the first wall 201 is greater than the length of the side close to the first wall 201; the second connection part 2152b can be designed such that the length of the second connection part 2152b on the side close to the first wall 201 in the thickness direction of the first wall 201 is greater than the length of the side close to the retaining part 2151. The side surface of the retaining part 2151 has a groove that is engaged with the first connection part 2152a, and the inner side surface of the first wall 201 has a groove that is engaged with the second connection part 2152b. By engaging the first connection part 2152a and the second connection part 2152b with the retaining part 2151 and the first wall 201 respectively, the expansion part can be prevented from falling off during expansion, which affects the expansion effect.

[0194] It should be understood that when assembling the slow-release structure 215, the retaining portion 2151 can be first installed from the side of the first wall 201 close to the interior of the battery cell 20, so that there is a mutually abutting portion between the retaining portion 2151 and the first wall 201, and then the expansion portion is clamped between the retaining portion 2151 and the first wall 201 by injection molding or the like, thereby achieving clamping between the expansion portion, the retaining portion 2151 and the first wall 201.

[0195] In some embodiments, Fig.10 and Fig.19 As shown, the slow-release structure 215 may further include a first connecting ring 2153 and / or a second connecting ring 2154 , wherein the first connecting ring 2153 is used to connect the expansion portion 2152 and the retaining portion 2151 , and the second connecting ring 2154 is used to connect the expansion portion 2152 and the first wall 201 .

[0196] In some embodiments, the first connecting ring 2153 and the retaining portion 2151 may be connected by bonding or welding, or the second connecting ring 2154 and the first wall 201 may be fixed by bonding or welding, or the first connecting ring 2153 and the expansion portion 2152 may be connected by snapping or bonding, or the second connecting ring 2154 and the expansion portion 2152 may also be connected by snapping or bonding.

[0197] In order to better reflect the specific structural form of the sustained-release structure 215 in the embodiment of the present application, the following is provided: Fig.21 and Fig. 22 The schematic diagram of the decomposed structure of the sustained-release structure of the embodiment of the present application is shown. Fig.21 The schematic diagram of the decomposition structure of the sustained-release structure of the embodiment of the present application is shown, for example Fig.21 Can be Figure 4 The schematic diagram of the exploded structure of the slow-release structure 215 on the first wall 201 of the battery cell 20 is shown; Fig. 22Another schematic diagram of the decomposed structure of the sustained-release structure of the embodiment of the present application is shown. Fig. 22 Can be Figure 4 Another exploded schematic diagram of the slow-release structure 215 on the first wall 201 of the battery cell 20 is shown.

[0198] like Fig.10 and Fig.21 As shown, in the process of assembling the slow-release structure 215, the retaining portion 2151 can be first installed from the side of the first wall 201 close to the inside of the battery cell 20, so that there is a mutually abutting portion between the retaining portion 2151 and the first wall 201, and then the expansion portion 2152 is installed between the retaining portion 2151 and the first wall 201 from the side of the first wall 201 close to the inside of the battery cell 20 in the same orientation, and finally the first connecting ring 2153 and the second connecting ring 2154 are installed on one side of the retaining portion 2151 and one side of the first wall 201 respectively, and the first connecting ring 2153 is connected to the retaining portion 2151, and the second connecting ring 2154 is connected to the first wall 201 by welding or bonding. By connecting the first connecting ring 2153 to the retaining portion 2151 and the first connecting ring 2154 to the first wall 201, the fixing effect of the expansion portion 2152 can be improved, and it is ensured that the slow-release structure 215 can be effectively expanded.

[0199] The slow-release structure 215 may include only the first connecting ring 2153 or only the second connecting ring 2154. For example, Fig.23 and Fig.24 The partial cross-sectional structural schematic diagrams of the slow-release structure 215 are respectively shown in two cases where the slow-release structure 215 only includes the first connecting ring 2153 and only includes the second connecting ring 2154. Fig.23 FIG. 4 shows another partial cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application after expansion. For example, Fig.23 Can be Fig. 9 Another cross-sectional structural schematic diagram of the local D shown; Fig.24 FIG. 4 shows another partial cross-sectional structure schematic diagram of the sustained-release structure of the embodiment of the present application after expansion. For example, Fig.24 Can be Fig. 9 Another cross-sectional structural schematic diagram of the local D is shown.

[0200] In some embodiments, Fig.11 As shown, the slow-release structure 215 may also include both a first connecting ring 2153 and a second connecting ring 2154. By providing the first connecting ring 2153 and the second connecting ring 2154, the clamping and fixing effect between the expansion part 2152 and the retaining part 2151 and the first wall 201 can be strengthened, and the installation of the slow-release structure is more convenient.

[0201] In some embodiments, Fig.18 As shown, the slow-release structure 215 may further include a compression component 2155, and the compression component 2155 includes a first compression component 2155a and / or a second compression component 2155b. The first compression component 2155a is located between the first connecting portion 2152a and the retaining portion 2151, and abuts against the first connecting portion 2152a and the retaining portion 2151, and the second compression component 2155b is located between the second connecting portion 2152b and the first wall 201, and abuts against the second connecting portion 2152b and the first wall 201.

[0202] In some embodiments, the first compression component 2155a is located between the expansion portion 2152 and the retaining portion 2151 and abuts against the expansion portion 2152 and the retaining portion 2151, and the second compression component 2155b is located between the expansion portion 2152 and the first wall 201 and abuts against the expansion portion 2152 and the first wall 201.

[0203] It should be understood that the slow-release structure 215 may include only the first compression component 2155a, or only the second compression component 2155b, or both the first compression component 2155a and the second compression component 2155b, and the actual use of the compression component 2155 can be flexibly adjusted. And the number of the first compression component 2155a and the second compression component 2155b can be one or more. By adding the compression component, a compression force can be provided for the expansion part 2152, and the reliability of the connection between the expansion part 2152 and the retaining part 2151 and the first wall 201 is enhanced.

[0204] Fig.18 and Fig. 22 The schematic diagram of a possible partial cross-sectional structure and the schematic diagram of a possible exploded structure of the sustained-release structure of the embodiment of the present application are respectively shown, including a first connecting ring 2153, a second connecting ring 2154 and a compression component 2155. Fig.18 and Fig. 22 As shown, during the process of assembling the slow-release structure 215, the retaining portion 2151, the expansion portion 2152, the compression component 2155, the first connecting ring 2153 and the second connecting ring can be installed in sequence from the side of the first wall 201 close to the interior of the battery cell 20, or the retaining portion 2151, the compression component 2155, the expansion portion 2152, the first connecting ring 2153 and the second connecting ring can be installed in sequence from the side of the first wall 201 close to the interior of the battery cell 20.

[0205] In some embodiments, the compression component 2155 may be some elastic and compressible material, such as compressed foam, etc. The material of the compression component may include one of rubber, latex, and polyurethane.

[0206] In some embodiments, the slow-release structure 215 may further include a limiting portion 2157 , which is disposed at the end of the slow-release structure 215 and fixedly connected to the first wall 201 , and is used to limit the expansion distance of the slow-release structure 215 along the thickness direction of the retaining portion 2151 .

[0207] It should be understood that the limiting portion 2157 and the first wall 201 may be connected in various ways, including welding, bonding, etc. The expansion distance may be the minimum distance between the surface of the limiting portion 2157 perpendicular to the thickness direction of the first wall 201 and the first wall 201 .

[0208] The actual arrangement form and quantity of the limiter 2157 can be flexibly adjusted. For example, the limiter 2157 can be as follows: Fig.25 and Fig.26 There are two forms shown. Fig.25 FIG. 4 shows another structural schematic diagram of the sustained-release structure of an embodiment of the present application after expansion. For example, the Fig.25 Can be Figures 3 to 5 Another structural schematic diagram of the sustained-release structure 215 on the first wall 201 of the battery cell 20 after expansion is shown; Fig.26 FIG. 4 shows another structural schematic diagram of the sustained-release structure of an embodiment of the present application after expansion. For example, the Fig.26 Can be Figures 3 to 5 Another structural schematic diagram of the sustained-release structure 215 on the first wall 201 of the battery cell 20 after expansion is shown.

[0209] For example, Fig.25 As shown, the number of the limiting parts 2157 can be two, and the limiting parts 2157 are arranged on the retaining parts 2151 on both sides of the pressure relief mechanism and connected to the first wall 201. Fig.26 As shown, the number of the limiting parts 2157 can be four, and the limiting parts 2157 are arranged at the edge of the retaining part 2151 and connected to the first wall 201. By setting the limiting parts 2157, the size of the expansion space formed after the expansion part 2152 is expanded can be limited, so as to avoid the excessive expansion of the expansion part 2152 causing abnormal leakage of the expansion part 2152, and improve the reliability of the slow-release structure 215.

[0210] According to some embodiments of the present application, the present application further provides a battery device 10, comprising a plurality of battery cells 20 of any of the above schemes. For example, the battery cell 20 may include: a housing 21, an electrode assembly 22, a pressure relief mechanism 213, an electrode terminal 214, and a slow release structure 215. The battery device 10 may be used to provide voltage and capacity.

[0211] According to some embodiments of the present application, the present application further provides an electrical device, comprising the battery device 10 described in any of the above schemes, and the battery device 10 is used to provide electrical energy to the electrical device.

[0212] The power-consuming device may be any of the aforementioned devices or systems using a battery device.

[0213] According to some embodiments of the present application, the present application provides a battery cell 20, including: an outer shell 21, the outer shell 21 having a first wall 201; an electrode assembly 22, the electrode assembly 22 being accommodated in the outer shell 21; a slow-release structure 215, the slow-release structure 215 being arranged on the first wall 201; the slow-release structure 215 being constructed to expand toward the outside of the outer shell 21 to form an expansion space 2156 when the slow-release structure 215 meets a design threshold, and the expansion space 2156 is connected to the internal space of the outer shell 21 and isolated from the outside of the outer shell 21.

[0214] The slow-release structure 215 is constructed to expand toward the outside of the shell 21 to form an expansion space 2156 when the slow-release structure 215 meets a design threshold, including: the slow-release structure 215 is constructed to expand toward the outside of the shell 21 to form an expansion space 2156 when the internal air pressure of the slow-release structure 215 meets a first threshold, and / or the slow-release structure 215 is constructed to expand toward the outside of the shell 21 to form an expansion space 2156 when the temperature of the slow-release structure 215 meets a second threshold.

[0215] The battery cell 20 further includes a pressure relief mechanism 213 , which is used to discharge the exhaust of the battery cell 20 when the pressure of the pressure relief mechanism 213 reaches a third threshold, wherein the first threshold is smaller than the third threshold.

[0216] The pressure relief mechanism 213 is disposed on the first wall 201 . The first wall 201 has at least two electrode terminals 214 . The pressure relief mechanism 213 is located between the at least two electrode terminals 214 .

[0217] The slow-release structure 215 may be disposed on both sides of the pressure relief mechanism 213 , and a projection of the slow-release structure 215 in the thickness direction of the first wall 201 does not overlap with a projection of the at least two electrode terminals 214 in the thickness direction of the first wall 201 .

[0218] The slow-release structure 215 includes a retaining portion 2151 and an expansion portion 2152, wherein the expansion portion 2152 is connected to the first wall 201, and the retaining portion 2151 is configured to maintain the expansion portion 2152 in an initial state. The retaining portion is also configured to release the expansion portion 2152 when the slow-release structure 215 meets the design threshold, so that the expansion portion 2152 changes from the initial state to the expansion state.

[0219] The pressure relief mechanism 213 may be disposed on the retaining portion 2151 of the slow-release structure 215 .

[0220] The housing 21 may include a shell 211 and a cover plate 212 . The shell 211 may be a hollow structure having an opening 2101 . The cover plate 212 may be used to cover the opening 2101 of the shell 211 . The first wall 201 is the cover plate 212 .

[0221] The first wall 201 has a through hole 2011, and the slow-release structure 215 is fixed in the through hole 2011. The retaining portion 2151 may include a connecting structure 2130, and the connecting structure 2130 is located between the retaining portion 2151 and the first wall 201, and is used to connect the retaining portion 2151 and the first wall 201, so that the retaining portion 2151 applies pressure to the expansion portion 2152 toward the inside of the shell 21 to keep the expansion portion 2152 in an initial state.

[0222] The melting point T1 of the connection structure 2130 is lower than the melting point T2 of the first wall.

[0223] The melting point T1 of the connection structure 2130 is in the range of [60° C., 200° C.].

[0224] The connection structure 2130 is close to the edge of the first wall 201 .

[0225] The material of the connection structure 2130 includes one of polypropylene, polyethylene, polycarbonate, soluble polytetrafluoroethylene, polyphenylene sulfide, silicone rubber and fluororubber.

[0226] The expansion portion 2152 includes a folding structure, and the expansion state is a state in which the expansion portion 2152 is unfolded from the folding structure, and / or the expansion portion 2152 includes a contraction structure, and the expansion state is a state in which the expansion portion 2152 is stretched from the contraction structure.

[0227] The expansion portion 2152 may include a first connection portion 2152a, a second connection portion 2152b, and an expansion portion 2152c, wherein the expansion portion 2152c is located between the first connection portion 2152a and the second connection portion 2152b. The first connection portion 2152a is connected to the retaining portion 2151, and the second connection portion 2152b is connected to the first wall 201.

[0228] The slow-release structure 215 may further include a first connecting ring 2153 and / or a second connecting ring 2154 , wherein the first connecting ring 2153 is used to connect the expansion portion 2152 and the retaining portion 2151 , and the second connecting ring 2154 is used to connect the expansion portion 2152 and the first wall 201 .

[0229] The slow-release structure 215 may further include a compression component 2155, which includes a first compression component 2155a and / or a second compression component 2155b. The first compression component 2155a is located between the first connecting portion 2152a and the retaining portion 2151, and abuts against the first connecting portion 2152a and the retaining portion 2151, and the second compression component 2155b is located between the second connecting portion 2152b and the first wall 201, and abuts against the second connecting portion 2152b and the first wall 201.

[0230] The material of the compression component 2155 may include one of rubber, latex, and polyurethane.

[0231] The slow-release structure 215 may further include a limiting portion 2157 , which is disposed at the end of the slow-release structure 215 and is fixedly connected to the first wall 201 . The limiting portion 2157 is used to limit the expansion distance of the slow-release structure 215 along the thickness direction of the retaining portion 2151 .

[0232] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: A housing (21), wherein the housing (21) has a first wall (201); an electrode assembly (22), the electrode assembly (22) being accommodated in the housing (21); a slow-release structure (215), wherein the slow-release structure (215) is arranged on the first wall (201); The slow-release structure (215) is configured to expand toward the outside of the housing (21) to form an expansion space (2156) when the slow-release structure (215) meets a design threshold, wherein the expansion space (2156) is connected to the internal space of the housing (21) and isolated from the outside of the housing (21).

2. The battery cell according to claim 1, characterized in that: The sustained-release structure (215) comprises a retaining portion (2151) and an expansion portion (2152), wherein the expansion portion (2152) is connected to the first wall (201), and the retaining portion (2151) is configured to retain the expansion portion (2152) in an initial state. The retaining portion is also configured to release the expansion portion (2152) when the sustained-release structure (215) meets a design threshold, so that the expansion portion (2152) changes from the initial state to an expanded state.

3. The battery cell according to claim 2, characterized in that: The first wall (201) has a through hole (2011), and the slow-release structure (215) is fixed in the through hole (2011); The outer periphery of the retaining portion (2151) has a first protruding structure (2110) facing the inner side of the through hole (2011); The inner side surface of the through hole (2011) has a second protruding structure (2120) facing the retaining portion (2151); The side of the first protruding structure (2110) away from the interior of the shell (21) and the side of the second protruding structure (2120) close to the interior of the shell (21) abut against each other, so that the retaining portion (2151) applies pressure toward the interior of the shell (21) to the expansion portion (2152) to maintain the expansion portion (2152) in the initial state.

4. The battery cell according to claim 3, characterized in that: The first protruding structure (2110) is bent toward a side away from the interior of the shell (21) to form a first bent portion (2111), and the second protruding structure (2120) is bent toward a side close to the interior of the shell (21) to form a second bent portion (2121). The first bent portion (2111) and the second bent portion (2121) are mutually clamped, and a weak area (2122) is provided on the second protruding structure (2120) away from the clamping point.

5. The battery cell according to claim 3, characterized in that: The length of the first wall (201) along the first direction is greater than the length of the first wall (201) along the second direction, the first direction is perpendicular to the second direction, and the first direction and the second direction are both perpendicular to the thickness direction of the first wall (201), wherein the second protruding structure (2120) is arranged on the inner side surface of the through hole (2011) extending along the first direction.

6. The battery cell according to claim 2, characterized in that: The first wall (201) has a through hole (2011), and the slow-release structure (215) is fixed in the through hole (2011); The retaining portion (2151) includes a connecting structure (2130), which is located between the retaining portion (2151) and the first wall (201) and is used to connect the retaining portion (2151) and the first wall (201) so that the retaining portion (2151) applies pressure toward the inside of the shell (21) to the expansion portion (2152) to maintain the expansion portion (2152) in the initial state.

7. The battery cell according to claim 6, characterized in that: The melting point T1 of the connection structure (2130) is lower than the melting point T2 of the first wall (201).

8. The battery cell according to claim 6, characterized in that: The melting point T1 of the connection structure (2130) is in the range of [60°C, 200°C].

9. The battery cell according to claim 6, characterized in that: The connection structure (2130) is close to the edge of the first wall (201).

10. The battery cell according to claim 6, characterized in that: The material of the connection structure (2130) includes one of polypropylene, polyethylene, polycarbonate, soluble polytetrafluoroethylene, polyphenylene sulfide, silicone rubber and fluororubber.

11. The battery cell according to any one of claims 2 to 10, characterized in that: The expansion portion (2152) comprises a first connection portion (2152a), a second connection portion (2152b) and an expansion portion (2152c), wherein the expansion portion (2152c) is located between the first connection portion (2152a) and the second connection portion (2152b); Wherein, the first connecting portion (2152a) is connected to the retaining portion (2151), and the second connecting portion (2152b) is connected to the first wall (201).

12. The battery cell according to claim 11, characterized in that: The sustained-release structure (215) further includes a compression component (2155), wherein the compression component (2155) includes a first compression component (2155a) and / or a second compression component (2155b), wherein the first compression component (2155a) is located between the first connecting portion (2152a) and the retaining portion (2151), and abuts against the first connecting portion (2152a) and the retaining portion (2151), and the second compression component (2155b) is located between the second connecting portion (2152b) and the first wall (201), and abuts against the second connecting portion (2152b) and the first wall (201).

13. The battery cell according to any one of claims 2 to 10, characterized in that: The sustained-release structure (215) further comprises a first connecting ring (2153) and / or a second connecting ring (2154), wherein the first connecting ring (2153) is used to connect the expansion portion (2152) and the retaining portion (2151), and the second connecting ring (2154) is used to connect the expansion portion (2152) and the first wall (201).

14. The battery cell according to claim 13, characterized in that: The first connecting ring (2153) is connected to the retaining portion (2151) by bonding or welding; or The second connecting ring (2154) is fixed to the first wall (201) by bonding or welding; or The first connecting ring (2153) is connected to the expansion portion (2152) by means of snap connection or bonding; or The second connecting ring (2154) is connected to the expansion portion (2152) by means of snap-fitting or bonding.

15. The battery cell according to claim 13, characterized in that: The sustained-release structure (215) further includes a compression component (2155), wherein the compression component (2155) includes a first compression component (2155a) and / or a second compression component (2155b), wherein the first compression component (2155a) is located between the expansion portion (2152) and the retaining portion (2151), and abuts against the expansion portion (2152) and the retaining portion (2151), and the second compression component (2155b) is located between the expansion portion (2152) and the first wall (201), and abuts against the expansion portion (2152) and the first wall (201).

16. The battery cell according to claim 12 or 15, characterized in that: The material of the compression component (2155) includes one of rubber, latex and polyurethane.

17. The battery cell according to any one of claims 2 to 10, characterized in that: The expansion portion (2152) includes a folding structure, and the expansion state is a state in which the expansion portion (2152) is unfolded from the folding structure; and / or, The expansion portion (2152) includes a contraction structure, and the expansion state is a state in which the expansion portion (2152) is stretched from the contraction structure.

18. The battery cell according to any one of claims 2 to 10, characterized in that: The slow-release structure (215) is configured to expand toward the outside of the housing (21) to form an expansion space (2156) when the internal air pressure of the slow-release structure (215) meets a first threshold value. The battery cell further includes: A pressure relief mechanism (213), the pressure relief mechanism (213) being used to discharge emissions from the battery cell when the pressure of the pressure relief mechanism (213) reaches a third threshold, wherein the first threshold is less than the third threshold.

19. The battery cell according to claim 18, characterized in that: The absolute value of the difference between the first threshold and the third threshold is in the range of [0.1 MPa, 1 MPa].

20. The battery cell according to claim 18, characterized in that: The range of the first threshold is [0.4MPa, 3MPa].

21. The battery cell according to claim 18, characterized in that: The pressure relief mechanism (213) is arranged on the first wall (201); the first wall (201) has at least two electrode terminals (214); and the pressure relief mechanism (213) is located between the at least two electrode terminals (214).

22. The battery cell according to claim 21, characterized in that: The slow-release structure (215) is arranged on both sides of the pressure relief mechanism (213), and the projection of the slow-release structure (215) in the thickness direction of the first wall (201) does not overlap with the projection of the at least two electrode terminals (214) in the thickness direction of the first wall (201).

23. The battery cell according to claim 21, characterized in that: The pressure relief mechanism (213) is arranged on the retaining portion (2151) of the slow-release structure (215).

24. The battery cell according to any one of claims 21 to 23, characterized in that: The housing (21) comprises: A shell (211), wherein the shell (211) is a hollow structure having an opening (2101); A cover plate (212), used for covering the opening (2101) of the housing (211); Wherein, the first wall (201) is the cover plate (212).

25. The battery cell according to any one of claims 2 to 10, characterized in that: The slow-release structure (215) further comprises a limiting portion (2157), wherein the limiting portion (2157) is arranged at an end of the slow-release structure (215) and is connected and fixed to the first wall (201), and the limiting portion (2157) is used to limit the expansion distance of the slow-release structure (215) along the thickness direction of the first wall (201).

26. A battery device, characterized in that: include: A plurality of battery cells, wherein the battery cells are the battery cells according to any one of claims 1 to 25.

27. An electrical equipment, characterized in that: include: A battery device, comprising a battery cell as claimed in any one of claims 1 to 25, and used for providing electrical energy to the electrical device.

Images