Battery monomer, battery and electric device
By designing the expansion space between the bottom wall and the pressure relief mechanism in the battery cell, the problem of poor exhaust gas when the traditional battery cell is thermally out of control is solved, which significantly reduces safety risks and improves safety.
Patent Information
- Application Number
- CN202420317642.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-20
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-02-20
AI Technical Summary
Traditional battery cells have high safety risks, especially when the heat is out of control, poor exhaust may lead to explosion.
A battery cell is designed, including a housing, a pressure relief mechanism, an electrode assembly and an electrical isolation component. An expansion space is defined between the electrical isolation bottom wall and the pressure relief mechanism, so that the battery cell can discharge gas and other emissions through the space in a timely manner when it is thermally out of control.
Through the design of the expansion space, the battery cell can effectively reduce safety risks, improve safety, and improve the overall performance of the battery cell without affecting the energy density.
Smart Images
Figure CN222581214U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery technology, and in particular to battery cells, batteries and electrical devices. Background Art
[0002] With the development of new energy technologies, batteries are being used more and more widely. For example, lithium batteries are used in electric vehicles to provide power for them. However, traditional battery cells have high safety risks. Utility Model Content
[0003] Based on this, it is necessary to provide a battery cell, a battery and an electrical device to address the high potential safety hazards of traditional battery cells.
[0004] According to a first aspect of the present application, a battery cell is provided, comprising a shell, a pressure relief mechanism, an electrode assembly and an electrical isolation component. The shell comprises a shell bottom wall and has an inner cavity, and the pressure relief mechanism is arranged on the shell bottom wall. The electrode assembly and the electrical isolation component are arranged in the inner cavity, and the electrical isolation component is arranged between the electrode assembly and the shell. Among them, the electrical isolation component comprises an electrical isolation bottom wall, and an expansion space is defined between the electrical isolation bottom wall and the pressure relief mechanism.
[0005] In the technical solution of the present application, since an expansion space is defined between the electrically isolating bottom wall and the pressure relief mechanism, the battery cell can utilize the expansion space to provide expansion space for the electrode assembly during use. When the battery cell experiences thermal runaway, the gas and other emissions generated by the thermal runaway of the battery cell can be smoothly discharged toward the pressure relief mechanism through the expansion space. The gas generated by the thermal runaway of the battery cell can be released in time by utilizing the opened pressure relief mechanism, which can effectively reduce the potential safety hazards of the battery cell and improve the safety of the battery cell.
[0006] In one embodiment, a portion of the electrically isolating bottom wall is recessed along a first direction toward a side close to the electrode assembly to define an expansion space between the bottom wall and the pressure relief mechanism, wherein the first direction is parallel to the thickness direction of the bottom wall of the shell. In this way, on the one hand, the expansion space can be used to better provide expansion space for the electrode assembly and absorb the expansion force generated by the expansion of the battery cell. On the other hand, the expansion space can be used to allow the gas and other emissions generated by the thermal runaway of the battery cell to be discharged in time through the expansion space through the opened pressure relief mechanism, which can well reduce the safety hazards of the battery cell and improve the safety of the battery cell.
[0007] In one embodiment, the electrically isolating bottom wall includes a first portion that is recessed toward a side close to the electrode assembly along a first direction, and the first portion is disposed opposite to and spaced from the pressure relief mechanism along the first direction to define an expansion space. In this way, along the first direction, the expansion space can be located between the electrode assembly and the pressure relief mechanism above the electrically isolating bottom wall, and the first portion is disposed opposite to and spaced from the pressure relief mechanism along the first direction, which is conducive to shortening the flow path of the gas and other emissions generated by the battery cell due to thermal runaway toward the opened pressure relief mechanism, thereby reducing the emission time of this part of the emissions, and is more conducive to timely discharge of this part of the emissions through the expansion space and the opened pressure relief mechanism.
[0008] In one embodiment, the electrically isolating bottom wall further includes a second portion surrounding the first portion, and a third portion connected between the first portion and the second portion along the first direction, and the first portion, the third portion and the pressure relief mechanism enclose an expansion space. The electrically isolating bottom wall can be used to raise the electrode assembly, thereby allowing a certain distance between the electrode assembly and the pressure relief mechanism along the first direction, which is conducive to the timely discharge of gas and other emissions generated by the battery cell due to thermal runaway through the expansion space and the opened pressure relief mechanism.
[0009] In one embodiment, the first part and the third part define a avoidance groove, the notch of the avoidance groove is arranged along the first direction toward the pressure relief mechanism, and along the first direction, the depth of the avoidance groove is H, wherein 2mm≤H≤6mm. The depth of the avoidance groove is set within an appropriate range, such as 2mm≤H≤6mm, so that there is a sufficient interval between the electrode assembly and the pressure relief mechanism along the first direction, so that the gas and other emissions generated by the battery cell due to thermal runaway can be discharged in time through the expansion space and the opened pressure relief mechanism, and the influence of the avoidance groove on the volume of the electrode assembly can be reduced, and to a certain extent, both the safety and energy density of the battery cell can be taken into account.
[0010] In one embodiment, 3 mm ≤ H ≤ 5 mm. In this way, the safety of the battery cell can be improved while better meeting the use requirements of the battery cell in terms of energy density.
[0011] In one embodiment, the first part, the second part and the third part are an integrated structure, which can improve the strength of the electrical isolation bottom wall and also help improve the production efficiency of the electrical isolation bottom wall.
[0012] In one embodiment, at least one of the first part, the second part and the third part is provided with a wetting hole communicating with the expansion space. In this way, the wetting hole can be used to allow the electrolyte to infiltrate the expansion space well, and the electrolyte in the expansion space can also be well connected with the electrolyte between the electrode assembly and the electrical isolation component, thereby improving the wetting effect of the electrolyte on the electrode assembly, thereby improving the service life of the battery cell.
[0013] In one embodiment, the electrical isolation component further includes an electrical isolation side wall connected to the top side of the electrical isolation bottom wall, and the electrical isolation side wall and the electrical isolation bottom wall define a storage space for accommodating the electrode assembly; the infiltration hole is connected to the storage space and the expansion space respectively. When the battery cell has thermal runaway, the discharge (gas, etc.) generated by the electrochemical reaction of the electrolyte in the storage space between the electrode assembly and the electrical isolation component can also flow to the expansion space better through the infiltration hole, so that this part of the discharge can be discharged in time through the opened pressure relief mechanism.
[0014] In one embodiment, the bottom surface of the shell bottom wall is configured as a plane, a plane parallel to the bottom surface of the shell bottom wall is defined as a target plane, and a first projection of the first part in the target plane covers a second projection of the pressure relief mechanism in the target plane. Since the first projection of the first part in the target plane covers the second projection of the pressure relief mechanism in the target plane, when thermal runaway occurs in the battery cell, the straight-line distance between the first part and the pressure relief mechanism along the first direction is short, so that the emissions in the expansion space can be discharged in time through the opened pressure relief mechanism, thereby improving the safety of the battery cell.
[0015] In one embodiment, the projection area of the first projection is larger than the projection area of the second projection. The expansion space can be better utilized to timely discharge the emissions generated when the battery cell undergoes thermal runaway through the opened pressure relief mechanism, thereby improving the safety of the battery cell.
[0016] In one embodiment, along the second direction, the size of the first part is L1, and the size of the pressure relief mechanism is L2, wherein L1-L2=L0, 1mm≤L0≤5mm; the second direction is parallel to the bottom surface of the bottom wall of the shell and intersects with the first direction. By setting L0 within a suitable range, such as 1mm≤L0≤5mm, the first part can protrude out of the pressure relief mechanism along the second direction, so that the gas and other emissions generated by the thermal runaway of the battery cell can be discharged in time through the expansion space and the opened pressure relief mechanism, and the influence of the size design of the first part on the overall volume of the battery cell can be reduced.
[0017] In one embodiment, 2mm≤L0≤4mm. In this way, while improving the safety of the battery cell, the influence of the size design of the first part on the overall volume of the battery cell can be reduced, and the contact area between the battery assembly and the electrical isolation bottom wall can be increased, so as to better support the battery assembly by using the electrical isolation bottom wall.
[0018] In one embodiment, along the third direction, the size of the first part is W1, and the size of the pressure relief mechanism is W2, wherein W1-W2=W0, 1mm≤W0≤5mm; the third direction is parallel to the bottom surface of the bottom wall of the shell and intersects with the first direction. By setting W0 within a suitable range, such as 1mm≤W0≤5mm, the first part can protrude out of the pressure relief mechanism along the third direction, so that the gas and other emissions generated by the thermal runaway of the battery cell can be discharged in time through the expansion space and the opened pressure relief mechanism, and the influence of the size design of the first part on the overall volume of the battery cell can be reduced.
[0019] In one embodiment, 2mm≤W0≤4mm. In this way, while improving the safety of the battery cell, the influence of the size design of the first part on the overall volume of the battery cell can be reduced, and the contact area between the battery assembly and the electrical isolation bottom wall can be increased, so as to better support the battery assembly by using the electrical isolation bottom wall.
[0020] In one embodiment, the first part has a first symmetry axis parallel to the second direction, and the pressure relief mechanism is symmetrically arranged with the first symmetry axis as the object; and / or the first part has a second symmetry axis parallel to the third direction, and the pressure relief mechanism is symmetrically arranged with the second symmetry axis as the object; the second direction and the third direction are both parallel to the bottom surface of the bottom wall of the shell, and intersect with the first direction. In this way, the avoidance groove formed by the depression of the first part can be arranged toward the pressure relief mechanism, and the projection of the avoidance groove in the target plane can more comprehensively cover the second projection of the pressure relief mechanism in the target plane, thereby enabling the gas and other emissions generated by the battery cell due to thermal runaway to be discharged in time through the expansion space and the opened pressure relief mechanism, which is conducive to improving the safety of the battery cell.
[0021] According to a second aspect of the present application, a battery is provided, comprising the battery cell described in any one of the above embodiments.
[0022] According to a third aspect of the present application, there is provided an electrical device comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 A schematic structural diagram of a vehicle according to an embodiment of the present application is shown.
[0024] Figure 2 A schematic structural diagram of a battery cell according to an embodiment of the present application is shown.
[0025] Figure 3 An exploded schematic diagram of a battery cell according to an embodiment of the present application is shown (first viewing angle).
[0026] Figure 4 A schematic structural diagram of an electrical isolation component according to an embodiment of the present application is shown.
[0027] Figure 5 A top view of a battery cell according to an embodiment of the present application is shown.
[0028] Figure 6 Shows Figure 5 Schematic diagram of the BB cross section.
[0029] Figure 7 An exploded schematic diagram of a battery cell according to an embodiment of the present application is shown (second viewing angle).
[0030] Figure 8 Shows Figure 6 A partial enlarged schematic diagram of .
[0031] Reference numerals:
[0032] 1. Vehicles;
[0033] 10. Battery;
[0034] 100. Battery cell;
[0035] 110, outer shell; 111, bottom shell; 1111, bottom shell wall; 11111, bottom surface; 112, top cover;
[0036] 120. Pressure relief mechanism;
[0037] 130. Electrode assembly;
[0038] 140, electrically isolating component; 141, electrically isolating bottom wall; 1411, first portion; 1412, second portion; 1413, third portion; 142, electrically isolating side wall;
[0039] A, inner cavity; P, expansion space; C, accommodation space; k, infiltration hole;
[0040] 20. Motor;
[0041] 30. Controller. DETAILED DESCRIPTION
[0042] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0043] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0044] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0045] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0046] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0047] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.
[0048] In a traditional battery cell, the battery cell generally includes a shell, an electrode assembly disposed in the shell, and an insulating member disposed between the bottom of the electrode assembly and the bottom wall of the shell. The battery cell also includes an explosion-proof valve embedded in the bottom wall of the shell. However, along the thickness direction of the bottom wall of the shell, one side of the insulating member is attached to the bottom wall of the shell, and the other side of the insulating member is attached to the electrode assembly, which makes it easy for the battery cell to have poor exhaust when thermal runaway occurs, which in turn may cause the battery cell to explode, resulting in a high safety hazard of the battery cell.
[0049] In order to solve the problem of high safety hazards of battery cells, the present application designs a battery cell, which defines an expansion space between the electrically isolated bottom wall and the pressure relief mechanism of the battery cell, which can improve the poor exhaust of the battery cell during thermal failure, thereby reducing the safety hazards of the battery cell and improving the safety of the battery cell.
[0050] The battery cells and / or batteries disclosed in the embodiments of the present application may be used, but are not limited to, in electrical devices such as vehicles, ships or aircraft. Electrical devices may be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships and spacecraft, etc. Among them, electric toys may include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles and spacecraft, etc. A power supply system comprising the pole pieces, electrode assemblies, battery cells and / or batteries disclosed in this application may be used to form the electrical device, so that it is convenient to provide electric drive for the electrical device and the service life of the electrical device can be increased.
[0051] Figure 1 A schematic structural diagram of a vehicle 1 according to an embodiment of the present application is shown. 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 battery 10 is arranged inside the vehicle 1. For example, a battery 10 may be arranged at the bottom, front or rear of the vehicle 1. The battery 10 may be used to power the vehicle 1. For example, the battery 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, such as 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 10 may be used not only 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 force for the vehicle 1.
[0052] A motor 20 and a controller 30 may also be provided inside the vehicle 1 . The controller 30 is used to control the battery 10 to supply power to the motor 20 , for example, to meet the power requirements for starting, navigating, and driving the vehicle 1 .
[0053] The battery 10 may include one or more battery cells 100 , and the battery cells 100 may be connected in parallel and / or in series, which is not particularly limited herein.
[0054] Figure 2 1 shows a schematic structural diagram of a battery cell 100 in an embodiment of the present application. Figure 3 FIG. 1 shows an exploded schematic diagram of a battery cell 100 in an embodiment of the present application. Figure 4 A schematic structural diagram of the electrical isolation component 140 in an embodiment of the present application is shown.
[0055] See also Figure 2-Figure 4 According to the first aspect of the present application, a battery cell 100 provided in an embodiment of the present application includes a housing 110 , a pressure relief mechanism 120 , an electrode assembly 130 and an electrical isolation component 140 .
[0056] The shell 110 includes a shell bottom wall 1111 , and the shell 110 has an inner cavity A. The pressure relief mechanism 120 is disposed on the shell bottom wall 1111 , and the pressure relief mechanism 120 is configured to be in an open state when the pressure in the inner cavity A is greater than a preset value.
[0057] The pressure relief mechanism 120 refers to a structure that can be in an open state when the pressure in the inner cavity A is greater than a preset value. The pressure relief mechanism 120 may include a weak portion, a hot melt structure, or an electro-active switch. The weak portion refers to a structure that can be broken when the pressure in the inner cavity A is greater than a preset value to form an opening connected to the external environment. The hot melt structure refers to a structure that can be melted when the temperature in the inner cavity A is greater than a preset temperature value to form an opening connected to the external environment. The electro-active switch refers to a switch that can be triggered when the pressure in the inner cavity A is greater than a preset value.
[0058] Illustratively, the pressure relief mechanism 120 is an explosion-proof valve.
[0059] The electrode assembly 130 and the electrical isolation component 140 are disposed in the inner cavity A. The electrical isolation component 140 is disposed between the electrode assembly 130 and the outer shell 110 . The electrical isolation component 140 includes an electrical isolation bottom wall 141 . An expansion space P is defined between the electrical isolation bottom wall 141 and the pressure relief mechanism 120 .
[0060] The electrical isolation component 140 refers to a component that can electrically isolate the electrode assembly 130 from the housing 110. For example, the material of the electrical isolation component 140 may include an insulating material. In this way, the electrical isolation component 140 with an insulating material can be used to electrically isolate the electrode assembly 130 from the housing 110. For example, the material of the electrical isolation component 140 includes polypropylene or polyethylene. Polypropylene or polyethylene does not react with the electrolyte, and the corrosion resistance of the electrical isolation component 140 can be improved.
[0061] The expansion space P refers to a space formed between the electrical isolation bottom wall 141 and the pressure relief mechanism 120 and used for exhaust.
[0062] Since an expansion space P is defined between the electrical isolation bottom wall 141 and the pressure relief mechanism 120, the battery cell 100 can utilize the expansion space P to provide expansion space for the electrode assembly 130 during use, absorb the expansion force generated by the expansion of the battery cell 100, and thus well improve the safety of the battery cell 100. In addition, when the battery cell 100 has thermal runaway, the expansion space P can be utilized to allow the gas and other emissions generated by the thermal runaway of the battery cell 100 to be smoothly discharged toward the pressure relief mechanism 120 through the expansion space P, so that the gas and other emissions generated by the thermal runaway of the battery cell 100 can be released in time by utilizing the opened pressure relief mechanism 120, which can effectively reduce the safety hazards of the battery cell 100 and improve the safety of the battery cell 100.
[0063] In some embodiments, the housing 110 further includes a bottom housing 111 and a top cover 112, the top cover 112 is disposed at the top opening of the bottom housing 111, the top cover 112 and the bottom housing 111 define the inner cavity A, and the housing bottom wall 1111 is disposed at the bottom of the bottom housing 111. In this way, when assembling the battery cell 100, the electrode assembly 130 and the electrical isolation component 140 can be disposed in the inner cavity A first, and then the top cover 112 is disposed at the top opening of the bottom housing 111 to close the inner cavity A.
[0064] In some embodiments, a portion of the electrically isolated bottom wall 141 is disposed along the first direction F 1 The electrode assembly 130 is recessed toward one side thereof to define an expansion space P between the pressure relief mechanism 120 and the pressure relief mechanism 120. 1 Parallel to the thickness direction of the shell bottom wall 1111.
[0065] Since a portion of the electrically isolated bottom wall 141 is along the first direction F 1 The electrode assembly 130 is recessed toward one side thereof so that the electrode assembly 130 located above the electrical isolation bottom wall 141 and the pressure relief mechanism 120 on the shell bottom wall 1111 are spaced apart in the first direction F. 1 There is a certain interval on the first direction F, so that the expansion space P 1 The expansion space P has a certain size. In this way, on the one hand, the expansion space P can be used to better provide expansion space for the electrode assembly 130 and absorb the expansion force generated by the expansion of the battery cell 100. On the other hand, the expansion space P can be used to allow the gas and other emissions generated by the thermal runaway of the battery cell 100 to be discharged through the expansion space P in time through the opened pressure relief mechanism 120, which can well reduce the safety hazards of the battery cell 100 and improve the safety of the battery cell 100.
[0066] In some embodiments, see Figure 4 , and refer to Figure 5 and Figure 6 The electrically isolating bottom wall 141 includes a first direction F 1 The first portion 1411 is recessed toward the side close to the electrode assembly 130, and the first portion 1411 is along the first direction F 1 The expansion space P is defined opposite to the pressure relief mechanism 120 and spaced apart therefrom.
[0067] Thus, along the first direction F 1 , the expansion space P can be located between the electrode assembly 130 and the pressure relief mechanism 120 above the electrical isolation bottom wall 141, and the first portion 1411 is along the first direction F 1Being arranged opposite to and at a distance from the pressure relief mechanism 120 is beneficial to shortening the flow path of emissions such as gas generated by thermal runaway of the battery cell 100 flowing toward the opened pressure relief mechanism 120, thereby reducing the discharge time of such emissions and being more conducive to timely discharge of such emissions through the expansion space P and the opened pressure relief mechanism 120.
[0068] In some embodiments, the electrically isolating bottom wall 141 further includes a second portion 1412 surrounding the first portion 1411 and a second portion 1413 extending along the first direction F 1 The third portion 1413 is connected between the first portion 1411 and the second portion 1412 . The first portion 1411 , the third portion 1413 , and the pressure relief mechanism 120 enclose an expansion space P.
[0069] Optionally, the second portion 1412 is arranged around the first portion 1411, and the third portion 1413 is an annular structure, which can improve the structural stability of the electrical isolation bottom wall 141 and is also conducive to better utilizing the electrical isolation component 140 to separate the electrode assembly 130 from the pressure relief mechanism 120.
[0070] The electrical isolation bottom wall 141 can be used to raise the electrode assembly 130, thereby making the distance between the electrode assembly 130 and the pressure relief mechanism 120 along the first direction F 1 Having a certain interval is conducive to timely discharge of emissions such as gas generated by thermal runaway of the battery cell 100 through the expansion space P and the opened pressure relief mechanism 120 .
[0071] In some embodiments, the first portion 1411 and the third portion 1413 define a avoiding groove, and the notch of the avoiding groove is along the first direction F 1 The pressure relief mechanism 120 is arranged along the first direction F 1 , the depth of the avoidance groove is H, wherein 2mm≤H≤6mm. For example, H may be 2mm, 3mm, 4mm, 5mm or 6mm.
[0072] The depth of the avoidance groove is set within a suitable range, such as 2 mm ≤ H ≤ 6 mm, so that the electrode assembly 130 and the pressure relief mechanism 120 can be spaced along the first direction F 1 There is sufficient spacing to facilitate the timely discharge of emissions such as gas generated by thermal runaway of the battery cell 100 through the expansion space P and the opened pressure relief mechanism 120, and can also reduce the impact of the avoidance groove on the volume of the electrode assembly 130, which can take into account both the safety and energy density of the battery cell 100 to a certain extent.
[0073] In some embodiments, 3 mm ≤ H ≤ 5 mm. For example, H may be 3 mm, 4 mm or 5 mm.
[0074] In this way, the safety of the battery cell 100 can be improved and the energy density requirements of the battery cell 100 can be better met.
[0075] In some embodiments, the first portion 1411 , the second portion 1412 , and the third portion 1413 are an integral structure.
[0076] The strength of the electrical isolation bottom wall 141 can be improved, and the production efficiency of the electrical isolation bottom wall 141 can also be improved.
[0077] In some embodiments, at least one of the first portion 1411 , the second portion 1412 , and the third portion 1413 is provided with a wetting hole k communicating with the expansion space P.
[0078] In this way, the infiltration hole k can be used to allow the electrolyte to infiltrate the expansion space P well, and the electrolyte in the expansion space P can also be well connected with the electrolyte between the electrode assembly 130 and the electrical isolation component 140, thereby improving the infiltration effect of the electrolyte on the electrode assembly 130, thereby improving the service life of the battery cell 100. In addition, when the battery cell 100 has thermal runaway, the discharge (gas, etc.) generated by the electrochemical reaction of the electrolyte in the accommodating space C between the electrode assembly 130 and the electrical isolation component 140 can also flow to the expansion space P through the infiltration hole k better, so that this part of the discharge is discharged in time through the opened pressure relief mechanism 120.
[0079] In some embodiments, see Figure 4 , and refer to Figure 7 The electrical isolation component 140 also includes an electrical isolation side wall 142 connected to the top side of the electrical isolation bottom wall 141. The electrical isolation side wall 142 and the electrical isolation bottom wall 141 define a receiving space C for receiving the electrode assembly 130. The wetting hole k is connected to the receiving space C and the expansion space P respectively.
[0080] Optionally, an opening communicating with the accommodation space C is provided at the top of the electrical isolation side wall 142 , so that the electrode assembly 130 can be conveniently received in the accommodation space C through the opening.
[0081] The electrical isolation component 140 can be used to better electrically isolate the electrode assembly 130 and the outer shell 110, which is beneficial to improving the safety of the battery cell 100. In addition, when the battery cell 100 undergoes thermal runaway, the emissions (gas, etc.) generated by the electrochemical reaction of the electrolyte in the accommodating space C can also flow to the expansion space P through the infiltration hole k, so that this part of the emissions can be discharged in time through the opened pressure relief mechanism 120.
[0082] In some embodiments, the first portion 1411 is provided with a plurality of infiltration holes k arranged in an array. For example, the plurality of infiltration holes k are arranged to form a plurality of infiltration holes k along the third direction F. 3 Two groups of infiltration holes are arranged at intervals, each of which includes a plurality of infiltration holes along the second direction F 2 Multiple infiltration holes k are arranged at intervals. In this way, when the battery cell 100 has thermal runaway, the discharge (gas, etc.) generated by the electrochemical reaction of the electrolyte in the accommodating space C can flow to the expansion space P through the multiple infiltration holes k more quickly and evenly, so that this part of the discharge is discharged in time through the opened pressure relief mechanism 120, which can effectively improve the safety of the battery cell 100. Among them, the second direction F 2 With third parties to F 3 intersect each other and are parallel to the bottom surface 11111 of the shell bottom wall 1111. For example, the second direction F 2 With third parties to F 3 perpendicular to each other and parallel to the bottom surface 11111 of the shell bottom wall 1111, the second direction F 2 The third direction F is parallel to the length direction of the battery cell 100. 3 Parallel to the width direction of the battery cell 100; of course, it can also be the second direction F 2 The third direction F is parallel to the width direction of the battery cell 100. 3 Parallel to the length direction of the battery cell 100 .
[0083] In some embodiments, the bottom surface 11111 of the shell bottom wall 1111 is constructed as a plane, and a plane parallel to the bottom surface 11111 of the shell bottom wall 1111 is defined as a target plane, and the first projection of the first part 1411 in the target plane covers the second projection of the pressure relief mechanism 120 in the target plane.
[0084] Since the first projection of the first portion 1411 in the target plane covers the second projection of the pressure relief mechanism 120 in the target plane, when the battery cell 100 has thermal runaway, the first portion 1411 and the pressure relief mechanism 120 are spaced apart along the first direction F. 1 The straight-line distance is short, so that the emissions in the expansion space P can be discharged in time through the opened pressure relief mechanism 120, which can improve the safety of the battery cell 100.
[0085] In some embodiments, a projection area of the first projection is larger than a projection area of the second projection.
[0086] In this way, the avoidance groove formed by the depression of the first part 1411 can be set toward the pressure relief mechanism 120, and the projection of the avoidance groove in the target plane can more comprehensively cover the second projection of the pressure relief mechanism 120 in the target plane, so as to better utilize the expansion space P to timely discharge the emissions formed when the battery cell 100 has thermal runaway through the opened pressure relief mechanism 120, thereby improving the safety of the battery cell 100.
[0087] In some embodiments, along the second direction F 2 The size of the first part 1411 is L1, and the size of the pressure relief mechanism 120 is L2, wherein L1-L2=L0, 1mm≤L0≤5mm, and the second direction F 2 Parallel to the bottom surface 11111 of the bottom wall 1111 of the housing and intersecting in the first direction F 1 .
[0088] It should be noted that L1 and L2 are not shown in the figure, but can be combined Figure 4 and Figure 8 Provide corresponding understanding.
[0089] For example, the second direction F 2 The first direction F may be parallel to the length direction or the width direction of the battery cell 100. 1 The direction may be parallel to the height direction of the battery cell 100 .
[0090] Illustratively, L0 may be 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm.
[0091] By setting L0 within a suitable range, such as 1 mm ≤ L0 ≤ 5 mm, the first portion 1411 can be arranged along the second direction F 2 The protrusion out of the pressure relief mechanism 120 facilitates the timely discharge of emissions such as gas generated by thermal runaway of the battery cell 100 through the expansion space P and the opened pressure relief mechanism 120 , and also reduces the impact of the size design of the first part 1411 on the overall volume of the battery cell 100 .
[0092] In some embodiments, 2 mm ≤ L0 ≤ 4 mm. For example, L0 may be 2 mm, 3 mm, or 4 mm.
[0093] In this way, while improving the safety of the battery cell 100, the impact of the size design of the first part 1411 on the overall volume of the battery cell 100 can be reduced, and it is also beneficial to increase the contact area between the electrode assembly 130 and the electrically isolated bottom wall 141, so as to utilize the electrically isolated bottom wall 141 to better support the electrode assembly 130.
[0094] In some embodiments, see Figure 8 , along the third direction F 3The size of the first part 1411 is W1, and the size of the pressure relief mechanism 120 is W2, wherein W1-W2=W0, 1mm≤W0≤5mm, and the third direction F 3 Parallel to the bottom surface 11111 of the bottom wall 1111 of the housing and intersecting in the first direction F 1 .
[0095] For example, the second direction F 2 and third parties to F 3 One of the two directions F is parallel to the length direction of the battery cell 100, and the second direction F 2 and third parties to F 3 The other of them is parallel to the width direction of the battery cell 100, the first direction F 1 The direction may be parallel to the height direction of the battery cell 100 .
[0096] Illustratively, W0 may be 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm.
[0097] By setting W0 within a suitable range, such as 1 mm ≤ W0 ≤ 5 mm, the first portion 1411 can be made to be within a range of 1 mm ≤ W0 ≤ 5 mm. 3 The protrusion out of the pressure relief mechanism 120 facilitates the timely discharge of emissions such as gas generated by thermal runaway of the battery cell 100 through the expansion space P and the opened pressure relief mechanism 120 , and can also reduce the impact of the size design of the first part 1411 on the overall volume of the battery cell 100 .
[0098] In some embodiments, 2mm≤W0≤4mm.
[0099] Illustratively, W0 may be 2 mm, 3 mm or 4 mm.
[0100] In this way, while improving the safety of the battery cell 100, the impact of the size design of the first part 1411 on the overall volume of the battery cell 100 can be reduced, and it is also beneficial to increase the contact area between the electrode assembly 130 and the electrically isolated bottom wall 141, so as to utilize the electrically isolated bottom wall 141 to better support the electrode assembly 130.
[0101] In some other embodiments, 1 mm ≤ L0 ≤ 5 mm, and 1 mm ≤ W0 ≤ 5 mm. Furthermore, 2 mm ≤ L0 ≤ 4 mm, and 2 mm ≤ W0 ≤ 4 mm.
[0102] In this way, while improving the safety of the battery cell 100, the impact of the size design of the first part 1411 on the overall volume of the battery cell 100 can be reduced, and it is also beneficial to increase the contact area between the electrode assembly 130 and the electrically isolated bottom wall 141, so as to utilize the electrically isolated bottom wall 141 to better support the electrode assembly 130.
[0103] In some embodiments, the first portion 1411 may have a direction parallel to the second direction F 2 The pressure relief mechanism 120 is symmetrically arranged around the first symmetry axis; alternatively, the first portion 1411 has a first symmetry axis parallel to the third direction F. 3 The second symmetry axis of the pressure relief mechanism 120 is symmetrically arranged with the second symmetry axis as the object; of course, it can also be that the pressure relief mechanism 120 is symmetrically arranged with the first symmetry axis as the object, and the pressure relief mechanism 120 is symmetrically arranged with the second symmetry axis as the object. 2 and third parties to F 3 are parallel to the bottom surface 11111 of the shell bottom wall 1111 and intersect in the first direction F 1 .
[0104] In this way, the avoidance groove formed by the depression of the first part 1411 can be set toward the pressure relief mechanism 120, and the projection of the avoidance groove in the target plane can more comprehensively cover the second projection of the pressure relief mechanism 120 in the target plane, so that the gas and other emissions generated by the thermal runaway of the battery cell 100 can be discharged in time through the expansion space P and the opened pressure relief mechanism 120, which is beneficial to improving the safety of the battery cell 100.
[0105] In some embodiments, a wetting hole k is disposed on the first portion 1411 , and a first projection of the first portion 1411 in the target plane covers a second projection of the pressure relief mechanism 120 in the target plane.
[0106] In this way, when the battery cell 100 has thermal runaway, the discharge (gas, etc.) generated by the electrochemical reaction of the electrolyte in the accommodation space C between the electrode assembly 130 and the electrical isolation component 140 can better flow to the expansion space P through the infiltration hole k, and the projection of the avoidance groove formed by the depression of the first part 1411 in the target plane can cover the second projection of the pressure relief mechanism 120 in the target plane, so that the discharge flowing to the expansion space P can be roughly along the first direction F 1 And the exhaust gas flows roughly in a straight line toward the pressure relief mechanism 120 , which is helpful to shorten the flow path of this part of the exhaust gas and discharge this part of the exhaust gas through the opened pressure relief mechanism 120 in time, which can better improve the safety of the battery cell 100 .
[0107] According to a second aspect of the present application, a battery 10 is provided, comprising the above-mentioned battery cell 100 .
[0108] According to a third aspect of the present application, there is provided an electrical device comprising the above-mentioned battery 10.
[0109] The battery cell 100 of any of the above embodiments can be used to improve the safety of the battery 10 and the safety of electrical devices.
[0110] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0111] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A battery cell, characterized in that: include: The housing (110) includes a housing bottom wall (1111) and has an inner cavity (A); A pressure relief mechanism (120) is arranged on the shell bottom wall (1111); as well as An electrode assembly (130) and an electrical isolation component (140) are disposed in the inner cavity (A), and the electrical isolation component (140) is disposed between the electrode assembly (130) and the outer shell (110); The electrical isolation component (140) comprises an electrical isolation bottom wall (141), and an expansion space (P) is defined between the electrical isolation bottom wall (141) and the pressure relief mechanism (120).
2. The battery cell according to claim 1, characterized in that: A portion of the electrical isolation bottom wall (141) is recessed along a first direction toward a side close to the electrode assembly (130) so as to define the expansion space (P) between the bottom wall and the pressure relief mechanism (120); Wherein, the first direction is parallel to the thickness direction of the shell bottom wall (1111).
3. The battery cell according to claim 2, characterized in that: The electrically isolating bottom wall (141) comprises a first portion (1411) which is recessed along the first direction toward a side close to the electrode assembly (130), and the first portion (1411) is disposed opposite to and spaced from the pressure relief mechanism (120) along the first direction to define the expansion space (P).
4. The battery cell according to claim 3, characterized in that: The electrically isolating bottom wall (141) further includes a second portion (1412) surrounding the first portion (1411), and a third portion (1413) connected between the first portion (1411) and the second portion (1412) along the first direction; The first part (1411), the third part (1413) and the pressure relief mechanism (120) enclose the expansion space (P).
5. The battery cell according to claim 4, characterized in that: The first portion (1411) and the third portion (1413) define an avoidance groove, and the notch of the avoidance groove is arranged along the first direction toward the pressure relief mechanism (120); Along the first direction, the depth of the avoidance groove is H, wherein 2mm≤H≤6mm.
6. The battery cell according to claim 5, characterized in that: 3mm≤H≤5mm.
7. The battery cell according to claim 4, characterized in that: The first part (1411), the second part (1412) and the third part (1413) are an integrated structure.
8. The battery cell according to claim 4, characterized in that: At least one of the first part (1411), the second part (1412) and the third part (1413) is provided with an infiltration hole (k) communicating with the expansion space (P).
9. The battery cell according to claim 8, characterized in that: The electrical isolation component (140) further comprises an electrical isolation side wall (142) connected to the top side of the electrical isolation bottom wall (141), wherein the electrical isolation side wall (142) and the electrical isolation bottom wall (141) define a receiving space (C) for receiving the electrode assembly (130); The infiltration holes (k) are respectively connected to the accommodation space (C) and the expansion space (P).
10. The battery cell according to any one of claims 3 to 9, characterized in that: The bottom surface (11111) of the shell bottom wall (1111) is constructed as a plane, and a plane parallel to the bottom surface (11111) of the shell bottom wall (1111) is defined as a target plane, and a first projection of the first part (1411) in the target plane covers a second projection of the pressure relief mechanism (120) in the target plane.
11. The battery cell according to claim 10, characterized in that: A projection area of the first projection is greater than a projection area of the second projection.
12. The battery cell according to claim 11, characterized in that: Along the second direction, the size of the first portion (1411) is L1, and the size of the pressure relief mechanism (120) is L2, wherein L1-L2=L0, 1mm≤L0≤5mm; The second direction is parallel to the bottom surface of the shell bottom wall (1111) and intersects with the first direction.
13. The battery cell according to claim 12, characterized in that: 2mm≤L0≤4mm.
14. The battery cell according to claim 11, characterized in that: Along the third direction, the size of the first part (1411) is W1, and the size of the pressure relief mechanism (120) is W2, wherein W1-W2=W0, 1mm≤W0≤5mm; The third direction is parallel to the bottom surface of the shell bottom wall (1111) and intersects with the first direction.
15. The battery cell according to claim 14, characterized in that: 2mm≤W0≤4mm.
16. The battery cell according to claim 11, characterized in that: The first part (1411) has a first symmetry axis parallel to the second direction, and the pressure relief mechanism (120) is symmetrically arranged around the first symmetry axis; and / or The first part (1411) has a second symmetry axis parallel to the third direction, and the pressure relief mechanism (120) is symmetrically arranged around the second symmetry axis; The second direction and the third direction are both parallel to the bottom surface of the shell bottom wall (1111) and intersect with the first direction.
17. A battery, characterized in that: Comprising a battery cell as claimed in any one of claims 1 to 16.
18. An electrical device, characterized in that: Comprising the battery of claim 17.