A battery cell, a battery device, and an electrical device

Abstract

An embodiment of the present application provides a battery cell, a battery device, and an electrical device. The battery cell includes an electrode assembly, a housing, and a pressure relief mechanism. The housing is provided with a receiving cavity, and a part of the first wall of the housing forms a protrusion. The electrode assembly is located in the receiving cavity and abuts against the protrusion along a first direction; the sum of the maximum dimensions of the contact area between the protrusion and the electrode assembly along a second direction is a first dimension, and the dimension of the electrode assembly along the second direction is a second dimension. The first dimension is smaller than the second dimension. The protrusion includes a first sub-protrusion, and the distance between the first bending portions of one first sub-protrusion and another first sub-protrusion gradually increases, and / or the distance between the second bending portions of one first sub-protrusion and another first sub-protrusion gradually increases. In the battery cell of the embodiment of the present application, it is beneficial to reduce the adverse effect that the volume of the discharge gap is reduced due to the deformation of the electrode assembly, and the risk of non-directional pressure relief of the housing is reduced.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of batteries, and more particularly to a battery cell, a battery device, and an electrical device. Background Art

[0002] In the related art, a battery cell includes an electrode assembly and a housing. A receiving cavity is provided inside the housing. The electrode assembly is located inside the receiving cavity. Protrusions are provided on the inner wall of the receiving cavity. The protrusions are used to abut against the electrode assembly so that a discharge gap is formed by spacing between the region of the inner wall of the receiving cavity without protrusions and the electrode assembly. In the state of thermal runaway of the battery cell, the generated emissions can enter the discharge gap and are finally discharged out of the battery cell through the discharge gap. The discharge gap can improve the discharge efficiency of the emissions.

[0003] Since the structural strength of the electrode assembly is lower than that of the housing, under the action of factors such as gravity and extrusion force, some regions of the electrode assembly can be deformed, thereby reducing the spacing between the region of the inner wall of the receiving cavity without protrusions and the electrode assembly, and thus reducing the cross-sectional area of the discharge gap. In the state of thermal runaway of the battery cell, it has an adverse effect on the discharge efficiency of the emissions. Summary of the Invention

[0004] In view of this, embodiments of the present application are expected to provide a battery cell, a battery device, and an electrical device that are conducive to improving the discharge efficiency of emissions.

[0005] To achieve the above object, the technical solution of the embodiments of the present application is realized as follows:

[0006] Embodiments of the present application provide a battery cell, including:

[0007] An electrode assembly;

[0008] A housing that encloses to form a receiving cavity. The housing includes a first wall. The first wall forms a part of the inner surface of the receiving cavity. A part of the surface of the first wall facing the receiving cavity protrudes in a first direction from other parts to form a protrusion. The electrode assembly is located inside the receiving cavity and abuts against the protrusion in the first direction, so that a discharge gap is formed by spacing between a part of the first wall and the electrode assembly;

[0009] The sum of the maximum dimensions of the contact area between the protrusion and the electrode assembly in a second direction perpendicular to the first direction is a first dimension, the dimension of the electrode assembly in the second direction is a second dimension, and the first dimension is less than the second dimension;

[0010] A pressure relief mechanism;

[0011] The plurality of the protrusions include first sub-protrusions, at least two of the first sub-protrusions are located on one side of the pressure relief mechanism along a third direction, the third direction is perpendicular to the first direction and intersects with the second direction, a first gap is formed between two of the first sub-protrusions, and an opening is formed on one side of the first gap along the third direction to be in fluid communication with the pressure relief mechanism;

[0012] The first sub-protrusion includes a first bending portion, the first bending portion is located on one side of the first sub-protrusion along the third direction close to the pressure relief mechanism, along the direction pointing to the pressure relief mechanism along the third direction, among the two first sub-protrusions forming the first gap, the distance between the first bending portion of one first sub-protrusion and the first bending portion of the other first sub-protrusion gradually increases; and / or, the first sub-protrusion includes a second bending portion, the second bending portion is located on one side of the first sub-protrusion along the third direction away from the pressure relief mechanism, along the direction pointing away from the pressure relief mechanism along the third direction, among the two first sub-protrusions forming the first gap, the distance between the second bending portion of one first sub-protrusion and the second bending portion of the other first sub-protrusion gradually increases.

[0013] In the battery cell of the embodiment of the present application, by limiting the first dimension and the second dimension within a reasonable range, it is beneficial to reduce the adverse effect of the deformation of the electrode assembly on the reduction of the volume of the discharge gap, and it is beneficial to reduce the blockage of the protrusion to the flow of the discharge during the thermal runaway of the battery cell, and it can allow a larger flow of the discharge to enter the discharge gap and be discharged from the battery cell through the discharge gap, which is beneficial to suppressing the increase of the pressure in the accommodation cavity or reducing the rate of increase, and reducing the risk of non-directional pressure relief of the outer shell; enabling the discharge entering the first gap to flow towards the pressure relief mechanism under the constraint of the first sub-protrusion, so as to improve the efficiency of discharging the discharge from the battery cell during the thermal runaway of the battery cell and reduce the risk of non-directional pressure relief; being beneficial to reducing the flow rate of the discharge in the first gap as it gradually approaches the pressure relief mechanism along the third direction and reducing the impact on the pressure relief mechanism; being beneficial to reducing the flow rate of the discharge in the first gap as it flows out of the first gap along the third direction and reducing the impact on the outer shell.

[0014] In some embodiments, the ratio range of the first dimension to the second dimension is 0.4 to 0.8. In this way, it is beneficial to both reduce the occupation of the space of the discharge gap by the protrusion itself and reduce the adverse effect of the deformation of the electrode assembly on the reduction of the volume of the discharge gap, and it is beneficial to allowing a larger flow of the discharge to enter the discharge gap and be discharged from the battery cell through the discharge gap during the thermal runaway of the battery cell, and it is beneficial to suppressing the increase of the pressure in the accommodation cavity or reducing the rate of increase, and reducing the risk of non-directional pressure relief of the outer shell.

[0015] In some embodiments, the ratio of the first dimension to the second dimension ranges from 0.5 to 0.7. In this way, it is further beneficial to reduce the occupation of the space of the discharge gap by the protrusion itself, further beneficial to reducing the adverse effect of the deformation of the electrode assembly on the reduction of the volume of the discharge gap, and further reducing the risk of non-directional pressure relief of the housing.

[0016] In some embodiments, the number of the electrode assemblies is two, the two electrode assemblies are arranged along the second direction, the protrusion includes a first protrusion and a second protrusion, the first protrusion abuts against one of the electrode assemblies along the first direction, and the maximum dimension of the contact area between the two along the second direction is a third dimension, and the ratio of the third dimension to the second dimension ranges from 0.4 to 0.8;

[0017] The second protrusion abuts against the other electrode assembly along the first direction, and the maximum dimension of the contact area between the two along the second direction is a fourth dimension, and the ratio of the fourth dimension to the second dimension ranges from 0.4 to 0.8.

[0018] In this way, the two electrode assemblies can be respectively supported by the first protrusion and the second protrusion. At the same time, it is beneficial to reduce the adverse effect of the deformation of each of the two electrode assemblies on the discharge of the discharge material, and reduces the risk of non-directional pressure relief of the housing.

[0019] In some embodiments, the battery cell is a square shell battery cell, and the width direction of the battery cell is the second direction. In this way, it is beneficial to enable the protrusion on the first wall to better support and restrain the electrode assembly, and beneficial to reducing the deformation of the part of the electrode assembly that is not abutted by the protrusion towards the first wall.

[0020] In some embodiments, the pressure relief mechanism is arranged in the area where the first wall does not form the protrusion. In this way, under the limiting action of the protrusion, it is beneficial to form a gap between the pressure relief mechanism and the electrode assembly, so that the discharge material in the cavity can enter the pressure relief mechanism through the gap, and is beneficial to reducing the adverse effect of the shielding of the electrode assembly itself on the discharge efficiency of the discharge material.

[0021] In some embodiments, two of the first sub-protrusions forming the first gap are in a group, and multiple groups of the first sub-protrusions are arranged at intervals along the third direction, and the first gaps in each group communicate with each other. In this way, it is beneficial for the discharge material in other parts of the accommodation space to enter the first gap through the gap between adjacent two groups, and flow towards the pressure relief mechanism under the guiding action of the first sub-protrusion, which is beneficial to improving the discharge efficiency of the discharge material.

[0022] In some embodiments, the multiple first sub - protrusions are divided into at least two groups. The two groups of first sub - protrusions are respectively located on one side of the pressure - relief mechanism along the third direction. The number of the first sub - protrusions in each group is multiple and forms at least one first gap. The two groups of first sub - protrusions are both in contact with the same electrode assembly. In this way, it is beneficial for the emissions on both sides of the pressure - relief mechanism along the third direction to enter the pressure - relief mechanism through the first gap, which is conducive to improving the discharge efficiency of the emissions; it is beneficial for the emissions generated by the electrode assembly to directly enter the pressure - relief mechanism along the first direction, which is conducive to improving the discharge efficiency of the emissions.

[0023] In some embodiments, the multiple protrusions include second sub - protrusions. The second sub - protrusions are located in the first gap and at the open position of the first gap. The second sub - protrusions are spaced from both of the first sub - protrusions that form the first gap. In this way, the second sub - protrusions can play a better constraining effect on the electrode assembly, reducing the part of the electrode assembly that enters the first gap due to deformation, which is conducive to increasing the space of the discharge gap and improving the discharge efficiency of the emissions.

[0024] In some embodiments, the multiple protrusions include third sub - protrusions. The multiple third sub - protrusions are located on one side of the pressure - relief mechanism along the third direction and are spaced from each other along the third direction. In the projection plane perpendicular to the third direction, the projections of the third sub - protrusions along the third direction at least partially overlap each other. In this way, through the overlapping area between the third sub - protrusions, a better constraining effect can be exerted on the electrode assembly in the third direction, reducing the deformation amount of the electrode assembly.

[0025] In some embodiments, in the projection plane perpendicular to the first direction, the edge of the projection of the first wall along the first direction is spaced from the projection of the protrusion along the first direction. In this way, a third gap can be formed by spacing between the protrusion and other inner walls of the housing, so that the emissions generated by the part of the electrode assembly close to other inner walls can enter the third gap and be discharged from the battery cell through the third gap, which is conducive to improving the discharge efficiency of the emissions.

[0026] In some embodiments, the range of the minimum distance between the edge of the projection of the first wall along the first direction and the projection of the protrusion along the first direction is from 3 mm to 12.7 mm. In this way, it is beneficial to reduce the adverse effect of the protrusion on the manufacturing accuracy of the side wall, and it is also beneficial to reduce the part of the electrode assembly that enters the third gap, which is conducive to improving the discharge efficiency; it is beneficial to keep the distance between the connection position of the side wall and the first wall and the electrode assembly within a suitable range, so that the emissions flowing towards the side wall can enter the third gap.

[0027] In some embodiments, the minimum distance between the edge of the projection of the first wall in the first direction and the projection of the protrusion in the first direction ranges from 3 mm to 7 mm. In this way, it is further beneficial to reduce the adverse effect of the protrusion on the manufacturing accuracy of the side wall, and it is beneficial for the emissions flowing towards the side wall to enter the third gap more smoothly.

[0028] In some embodiments, the first wall is located on the bottom side of the battery cell in the direction of gravity. In this way, the protrusion plays a supporting role for the electrode assembly, and reduces the adverse effect of the reduction in the volume of the discharge gap due to the deformation of the electrode assembly under its own gravity.

[0029] An embodiment of the present application further provides a battery device, which includes a box body and the battery cell as described in any one of the foregoing embodiments. An accommodation space is provided in the box body, and the battery cell is located in the accommodation space. In this way, by adopting the battery cell in the foregoing embodiment, it is beneficial to reduce the damage to other components in the battery device caused by the emissions discharged during non-directional pressure relief of the battery cell.

[0030] An embodiment of the present application further provides an electrical device, which includes the battery device as described in the foregoing embodiment, and the battery device is used as the power source of the electrical device. In this way, by adopting the battery device in the foregoing embodiment, it is beneficial to reduce the damage to other components in the electrical device caused by the emissions discharged during non-directional pressure relief of the battery cell. Description of the Drawings

[0031] Figure 1 Schematic diagram of an electrical device being a vehicle in an embodiment of the present application;

[0032] Figure 2 Schematic diagram of a battery device in an embodiment of the present application;

[0033] Figure 3 Schematic diagram of a battery cell in the first embodiment of the present application;

[0034] Figure 4 It is Figure 3 Sectional view at the A-A position in;

[0035] Figure 5 It is Figure 4 Partial enlarged view at the B position in;

[0036] Figure 6 It is Figure 3 Sectional view at the C-C position in;

[0037] Figure 7 Sectional view of the second embodiment of the present application, and the sectional position is the same as the A-A position in Figure 3 ;

[0038] Figure 8 This is a sectional view of the third embodiment of the present application, and the sectional position is the same as that of Figure 3 position A-A in

[0039] Figure 9 This is a schematic diagram of the housing in the fourth embodiment of the present application;

[0040] Figure 10 is Figure 9 a schematic diagram of the embodiment in

[0041] Figure 11 This is a schematic diagram of the housing in the fifth embodiment of the present application, and its perspective is the same as that of Figure 10 ;

[0042] Figure 12 This is a schematic diagram of the housing in the sixth embodiment of the present application, and its perspective is the same as that of Figure 10 ;

[0043] Figure 13 This is a schematic diagram of the housing in the seventh embodiment of the present application, and its perspective is the same as that of Figure 10 ;

[0044] Figure 14 This is a schematic diagram of the housing in the third embodiment of the present application, and its perspective is the same as that of Figure 10 ;

[0045] Figure 15 is Figure 4 a partially enlarged schematic diagram of position D in

[0046] Explanation of reference numerals

[0047] 1000, vehicle; 100, battery device; 200, controller; 300, motor; 10, box body; 11, first box body; 12, second box body; 20, battery cell; 20a, accommodation cavity; 20b, discharge gap; 20c, first gap; 20d, second gap; 20e, third gap; 21, outer shell; 211, first wall; 212, protrusion; 212a, first protrusion; 212b, second protrusion; 2121, first sub-protrusion; 2121a, first bending part; 2121b, second bending part; 2122, second sub-protrusion; 2123, third sub-protrusion; 213, side wall; 214, housing; 215, end cover; 22, electrode assembly; 22a, contact area; 23, pressure relief mechanism. Detailed implementation manners

[0048] It should be noted that, without conflict, the embodiments in this application and the technical features in the embodiments can be combined with each other. The detailed description in the specific implementation manners should be understood as an explanatory illustration of the purpose of this application and should not be regarded as an improper limitation of this application.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0050] In the description of the embodiments of this application, technical terms such as "first", "second", "third", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0051] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0052] In the description of the embodiments of this application, the term "and / or" 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 simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0053] In the description of the embodiments of this application, for ease of explanation, as shown in the accompanying drawings of the specification, the direction in which the arrow X is located is the "first direction"; the direction in which the arrow Y is located is the "second direction"; the direction in which the arrow Z is located is the "reference direction", "third direction".

[0054] In the description of the embodiments of the present application, unless otherwise clearly specified or limited, technical terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0055] In the description of the embodiments of the present application, unless otherwise clearly specified or limited, the technical term "contact" shall be understood in a broad sense. It may be direct contact or contact through an intermediate medium layer. It may be contact with basically no mutual force between the two in contact, or contact with mutual force between the two in contact.

[0056] In the embodiments of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can activate the active material through charging and continue to be used after discharging the battery cell.

[0057] The battery cell may 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-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application do not limit this.

[0058] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, and the separator is disposed between the negative electrode and the positive electrode. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can play a role in preventing short circuit between the positive and negative electrodes and at the same time allow active ions to pass through.

[0059] In some embodiments, the battery cell may include a housing. The housing may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite housing), or an aluminum-plastic film, etc. In some embodiments, the housing may be a sealed structure or a non-sealed structure. As an example, when the housing is a non-sealed structure, the housing plays a role in protecting the electrode assembly, and there is also a sealing bag between the housing and the electrode assembly, and the sealing bag is used to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag may be a bag-shaped insulating member or an aluminum-plastic film. When the housing is a sealed structure, it is used to encapsulate components such as the electrode assembly and the electrolyte.

[0060] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch 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 multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal prism battery, etc., and there is no special limitation in this application.

[0061] In some embodiments, the outer casing includes an end cap and a housing. The housing is provided with an opening, and the end cap covers the opening. The housing may be provided with one or more openings. One or more end caps may also be provided.

[0062] In some embodiments, a pressure relief mechanism is provided on the outer casing. The pressure relief mechanism is used to discharge the internal gas of the battery cell.

[0063] As an example, it is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure relief mechanism performs an action or a weak structure provided in the pressure relief mechanism is damaged, thereby forming an opening or a channel for releasing the internal pressure or temperature. This threshold design varies according to different design requirements. The threshold may depend on one or several of the materials of the positive electrode sheet, negative electrode sheet, electrolyte and separator in the battery cell.

[0064] As an example, the pressure relief mechanism can be integrally formed with the outer casing.

[0065] As an example, the pressure relief mechanism can also be separately provided and connected to the outer casing.

[0066] The "actuation" mentioned in this application means that the pressure relief mechanism generates an action or is activated to a certain state, so that the internal pressure and temperature of the battery cell can be released. The actions generated by the pressure relief mechanism may include but are not limited to: the components in the pressure relief mechanism move to form an exhaust channel, at least a part of the pressure relief mechanism breaks, is crushed, is torn or opened, etc. When the pressure relief mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell are discharged outwards from the actuated part as emissions. In this way, the battery cell can be depressurized and cooled under a controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0067] In some embodiments, when the outer casing is a non-sealed structure, the pressure relief mechanism can be set as a through hole for discharging the internal gas of the battery cell.

[0068] The emissions from the battery cell mentioned in this application include but are not limited to: electrolyte, dissolved or split positive and negative electrode sheets, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0069] 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 a plurality of battery cells, and the plurality of battery cells are connected in series, parallel or in a combined series-parallel manner through a busbar component.

[0070] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells.

[0071] As an example, the battery cell assembly may be a battery module, and the battery module 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 with cable ties.

[0072] In some embodiments, the battery apparatus may be a battery pack, and the battery pack includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body.

[0073] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body by fixing the battery module in the box body.

[0074] As an example, the battery cell assembly may also be accommodated in the box body by directly fixing a plurality of battery cells to the box body.

[0075] In some embodiments, the box body may be part of the chassis structure of a vehicle. For example, a part of the box body may become at least a part of the floor of the vehicle, or a part of the box body may become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0076] As an example, referring to Figure 2 , the box body 10 may include a first box body 11 and a second box body 12. The first box body 11 and the second box body 12 are snapped together so that a closed space is formed inside the box body 10 to accommodate the battery cell assembly. The "closed" here means covering or closing, which can be sealed or non-sealed. The first box body 11 may be a top cover or a bottom plate.

[0077] 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.

[0078] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using battery cells, such as mobile phones, portable devices, laptop computers, battery cars, electric toys, electric tools, vehicles, ships and spacecrafts, etc. For example, spacecrafts include airplanes, rockets, space shuttles and spaceships, etc.

[0079] In the following embodiments, for the convenience of description, a power-consuming device in an embodiment of the present application is taken as an example of a vehicle 1000 for illustration. The following is described with reference to the accompanying drawings.

[0080] The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. As Figure 1 shown, a battery device 100 is disposed inside the vehicle 1000, and the battery device 100 can be disposed at the bottom, head or tail of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000. For example, the battery device 100 can be used as an operating power source of the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation and driving of the vehicle 1000.

[0081] In some embodiments of the present application, the battery device 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0082] Next, the embodiments of the present application will be described in detail.

[0083] In the related art, a battery cell includes an electrode assembly and a housing. An accommodation cavity is provided inside the housing, the electrode assembly is located inside the accommodation cavity, and protrusions are provided on the inner wall of the accommodation cavity. The protrusions are used to abut against the electrode assembly so that a discharge gap is formed at an interval between the region of the inner wall of the accommodation cavity without protrusions and the electrode assembly. In a state where the battery cell undergoes thermal runaway, the generated emissions can enter the discharge gap. The emissions flow in the discharge gap and are finally discharged to the outside of the battery cell through a pressure relief mechanism communicated with the discharge gap. The discharge gap can improve the discharge efficiency of the emissions and reduce the risk that the emissions accumulate in the accommodation cavity, resulting in an increase in the pressure in the accommodation cavity and causing the housing to rupture.

[0084] Since the structural strength of the electrode assembly is lower than that of the housing, under the action of factors such as gravity and extrusion force, a part of the electrode assembly can be deformed, thereby reducing the distance between the region of the inner wall of the accommodation cavity without protrusions and the electrode assembly, and thus reducing the cross-sectional area of the discharge gap. In a state where the battery cell undergoes thermal runaway, the flow rate of the emissions that can be discharged to the outside of the battery cell through the discharge gap is reduced, the discharge efficiency of the emissions is reduced, and the risk of housing rupture is increased.

[0085] Based on the above technical problems, the embodiments of the present application provide a battery cell, a battery device, and an electrical device. Among them, the outer shell of the battery cell is provided with a protrusion protruding along a first direction, and the protrusion can be in contact with the electrode assembly. The sum of the maximum dimensions of the contact area between the protrusion and the electrode assembly along a second direction perpendicular to the first direction is a first dimension, and the dimension of the electrode assembly along the second direction is a second dimension. The first dimension is smaller than the second dimension, which is beneficial to reducing the blockage of the flow of emissions by the protrusion when the battery cell is in a state of thermal runaway.

[0086] Specifically, referring to Figures 3 to 6 , the embodiments of the present application provide a battery cell 20, which includes an electrode assembly 22 and an outer shell 21.

[0087] The outer shell 21 encloses to form a receiving cavity 20a. The outer shell 21 includes a first wall 211. The first wall 211 forms a part of the inner surface of the receiving cavity 20a. A part of the surface of the first wall 211 facing the receiving cavity 20a protrudes along the first direction with respect to other parts to form a protrusion 212. The electrode assembly 22 is located in the receiving cavity 20a and is in contact with the protrusion 212 along the first direction, so that a part of the first wall 211 is spaced apart from the electrode assembly 22 to form an emission gap 20b.

[0088] The sum of the maximum dimensions of the contact area 22a between the protrusion 212 and the electrode assembly 22 along a second direction perpendicular to the first direction is a first dimension, and the dimension of the electrode assembly 22 along the second direction is a second dimension. The first dimension is smaller than the second dimension. That is, referring to Figure 6 , the first dimension is L1, the second dimension is L2, and L1 < L2.

[0089] The number of the first walls 211 included in the outer shell 21 can be one or more.

[0090] The protrusion 212 is in contact with the electrode assembly 22 along the first direction, so that the part of the surface of the first wall 211 facing the receiving cavity 20a that does not have the protrusion 212 can be spaced apart from the electrode assembly 22 along the first direction to form an emission gap 20b for the flow of emissions formed by thermal runaway.

[0091] The number of the protrusions 212 formed on the first wall 211 can be one or more.

[0092] The number of the protrusions 212 in contact with one electrode assembly 22 can be one or more.

[0093] The number of the electrode assemblies 22 in the receiving cavity 20a can be one or more.

[0094] In some embodiments where the number of the electrode assemblies 22 is multiple, referring toFigure 6 , a plurality of electrode assemblies 22 are arranged along the second direction.

[0095] The contact area 22a between the protrusion 212 and the electrode assembly 22 refers to the area of all the protrusions 212 in contact with one electrode assembly 22.

[0096] The sum of the maximum dimensions of the contact area 22a between the electrode assembly 22 and the protrusion 212 along the second direction refers to the sum of the dimensions of the contact areas of all the protrusions 212 in contact with the same electrode assembly 22 along the second direction in a cross-section perpendicular to the reference direction passing through the contact area, where the reference direction, the first direction, and the second direction are perpendicular to each other.

[0097] It should be noted that in an embodiment where the number of protrusions 212 in contact with the electrode assembly 22 is only one, the first dimension is only the maximum dimension of the contact area 22a between the protrusion 212 and the electrode assembly 22 along the second direction. In some embodiments where a plurality of protrusions 212 in contact with the electrode assembly 22 do not overlap with each other along the reference direction, the first dimension is the sum of the maximum dimensions of the contact area 22a between the electrode assembly 22 and each protrusion 212 along the second direction. For example, referring to Figure 7 , the dimension of the contact area 22a between the electrode assembly 22 and a single protrusion 212 along the second direction is L11, and L1 = L11 + L11. In some embodiments where a plurality of protrusions 212 in contact with the electrode assembly 22 overlap with each other at least partially along the reference direction, the first dimension is the sum of the maximum dimensions of the contact area 22a between the electrode assembly 22 and each protrusion 212 along the second direction minus the dimension of all the overlapping parts along the second direction. For example, referring to Figure 8 , the dimension of the overlapping part along the second direction is L12, and L1 = L11 + L11 - L12.

[0098] In the battery cell 20 according to the embodiment of the present application, by limiting the first dimension and the second dimension within a reasonable range, it is beneficial to reduce the adverse effect of the deformation of the electrode assembly 22 on the reduction of the volume of the discharge gap 20b, and it is beneficial to reduce the blockage of the protrusion 212 to the flow of the discharge in the state of thermal runaway of the battery cell 20, and it can allow a larger flow of discharge to enter the discharge gap 20b and be discharged from the battery cell 20 through the discharge gap 20b, which is beneficial to suppressing the increase in pressure or reducing the rate of increase in pressure in the accommodation cavity 20a, and reducing the risk of non-directional pressure relief of the outer shell 21.

[0099] Non-directional pressure relief refers to the situation where, in the state of thermal runaway of the battery cell 20, in addition to the pressure relief mechanism 23 being able to discharge the discharge to achieve the purpose of pressure relief, there is also pressure relief at other parts of the outer shell 21. The rupture of the outer shell 21 will cause non-directional pressure relief of the outer shell 21.

[0100] In some embodiments, the ratio range of the first dimension to the second dimension is from 0.4 to 0.8. That is, referring to Figure 6 , the first dimension is L1, the second dimension is L2, and 0.4 ≤ L1 / L2 ≤ 0.8.

[0101] When L1 / L2 < 0.4, the support and restraint effect of the protrusion 212 on the end face of the electrode assembly 22 facing the first wall 211 is insufficient, making the part of the electrode assembly 22 not in contact with the protrusion 212 prone to deform towards the first wall 211, thereby reducing the volume of the discharge gap 20b and being unfavorable for the discharge of emissions; when L1 / L2 > 0.8, although the support and restraint effect of the protrusion 212 on the end face of the electrode assembly 22 facing the first wall 211 can achieve a good effect, however, the volume occupied by the protrusion 212 itself increases. When the total volume in the battery cell 20 is a fixed value, the volume of the discharge gap 20b correspondingly decreases, which is also unfavorable for the discharge of emissions.

[0102] In this way, it is beneficial to both reduce the occupation of the space of the discharge gap 20b by the protrusion 212 itself and reduce the adverse effect of the deformation of the electrode assembly 22 on the reduction of the volume of the discharge gap 20b. It is beneficial when the battery cell 20 is in a state of thermal runaway, and it is beneficial to reduce the blockage of the protrusion 212 to the flow of emissions, allowing a larger flow of emissions to enter the discharge gap 20b and be discharged from the battery cell 20 through the discharge gap 20b, which is beneficial to suppressing the increase in pressure or reducing the rate of pressure increase in the accommodation cavity 20a, and reducing the risk of non-directional pressure relief of the outer shell 21.

[0103] The specific value of the ratio of the first dimension to the second dimension can be 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, etc.

[0104] The specific method for measuring the first dimension can be to cut the battery cell 20 to form a cross-section perpendicular to the second direction, project along the normal direction of the cross-section through a projection measuring instrument, and obtain the total dimension along the second direction of the projection along the first direction of the contact area 22a between the protrusion 212 and the electrode assembly 22 on the screen of the projection measuring instrument to obtain the first dimension; the dimension along the second direction of the projection along the first direction of the electrode assembly 22 on the screen of the projection measuring instrument. The normal direction of the cross-section is the aforementioned reference direction.

[0105] In some embodiments, the ratio range of the first dimension to the second dimension is from 0.5 to 0.7.

[0106] In this way, it is further beneficial to reduce the occupation of the space of the discharge gap 20b by the protrusion 212 itself, further beneficial to reduce the adverse effect of the deformation of the electrode assembly 22 on the reduction of the volume of the discharge gap 20b, and further reduce the risk of non-directional pressure relief of the housing 21.

[0107] It can be understood that the number of electrode assemblies 22 in the accommodation cavity 20a can be one or more; one protrusion 212 can be in contact with one electrode assembly 22, or can be in contact with multiple electrode assemblies 22 respectively.

[0108] In some embodiments, referring to Figure 6 , the number of electrode assemblies 22 is two, the two electrode assemblies 22 are arranged along the second direction, the protrusion 212 includes a first protrusion 212a and a second protrusion 212b, the first protrusion 212a abuts against one electrode assembly 22 along the first direction, and the maximum dimension of the contact area between the two along the second direction is a third dimension, and the ratio range of the third dimension to the second dimension is 0.4 to 0.8; the second protrusion 212b abuts against the other electrode assembly 22 along the first direction, and the maximum dimension of the contact area between the two along the second direction is a fourth dimension, and the ratio range of the fourth dimension to the second dimension is 0.4 to 0.8.

[0109] Referring to Figure 6 , the third dimension is L3, 0.4 ≤ L3 / L2 ≤ 0.8; the third dimension is L4, 0.4 ≤ L4 / L2 ≤ 0.8.

[0110] In this way, the two electrode assemblies 22 can be respectively supported by the first protrusion 212a and the second protrusion 212b. At the same time, it is beneficial to reduce the adverse effect of the deformation of the two electrode assemblies 22 on the discharge of the discharge material, and reduce the risk of non-directional pressure relief of the housing 21.

[0111] The specific manner of forming the protrusion 212 is not limited. Exemplarily, it is stamped on one side surface of the first wall 211 along the first direction to form the protrusion 212 on the other side.

[0112] In some embodiments, the dimension of the end face of the electrode assembly 22 in contact with the protrusion 212 along the second direction is the second dimension.

[0113] The end face of the electrode assembly 22 in contact with the protrusion 212, that is, the end face of the electrode assembly 22 facing the first wall 211.

[0114] It can be understood that the arrangement manner of the protrusion 212 is adapted to the specific shape of the first wall 211.

[0115] In some embodiments, referring to Figures 6 to 8 , the battery cell 20 is a square shell battery cell, and one of the width directions of the battery cell 20 is the second direction.

[0116] In this way, it is beneficial to enable the protrusion 212 on the first wall 211 to better support and constrain the electrode assembly 22, and it is beneficial to reduce the deformation of the part of the electrode assembly 22 that is not abutted by the protrusion 212 towards the first wall 211.

[0117] In some other embodiments, the battery cell 20 is a cylindrical battery cell, and the radial direction of the cylinder is the second direction.

[0118] In this way, it is beneficial to enable the protrusion 212 on the first wall 211 to better support and constrain the electrode assembly 22.

[0119] In some embodiments, referring to Figures 10 to 14 , the battery cell 20 further includes a pressure relief mechanism 23, and the pressure relief mechanism 23 is disposed on the outer shell 21 and can be selectively communicated with the accommodation cavity 20a.

[0120] In the normal working state of the battery cell 20, the pressure relief mechanism 23 is in a sealed state to reduce the probability of leakage of the electrolyte in the accommodation cavity 20a; in the state of thermal runaway of the battery cell 20, the pressure relief mechanism 23 is in an open state so that the accommodation cavity 20a is communicated with the outside of the battery cell 20 through the pressure relief mechanism 23, and the emissions in the accommodation cavity 20a can be discharged to the outside of the battery cell 20.

[0121] In some embodiments, referring to Figures 10 to 14 , the pressure relief mechanism 23 is disposed in the area where the first wall 211 does not form the protrusion 212.

[0122] In this way, under the limiting action of the protrusion 212, it is beneficial to form a gap between the pressure relief mechanism 23 and the electrode assembly 22 so that the emissions in the accommodation cavity 20a can enter the pressure relief mechanism 23 through the gap, and it is beneficial to reduce the adverse effect on the emission efficiency of the emissions due to the shielding of the electrode assembly 22 itself.

[0123] It can be understood that the gap formed between the pressure relief mechanism 23 and the electrode assembly 22 is communicated with the discharge gap 20b.

[0124] It can be understood that the protrusion 212 plays a constraining role in the flow of the emissions so as to guide the emissions to the pressure relief mechanism 23 in the state of thermal runaway of the battery cell 20.

[0125] In some embodiments, referring to Figures 10 to 13, the plurality of protrusions 212 include first sub-protrusions 2121, at least two first sub-protrusions 2121 are located on one side of the pressure relief mechanism 23 along the third direction, the third direction is perpendicular to the first direction and intersects with the second direction, a first gap 20c is formed between the two first sub-protrusions 2121 at intervals, and an opening is formed on one side of the first gap 20c along the third direction to be in fluid communication with the pressure relief mechanism 23.

[0126] The opening on one side of the first gap 20c along the third direction being in fluid communication with the pressure relief mechanism 23 means that the fluid medium in the first gap 20c, such as the emissions, can flow out of the first gap 20c through the opening on one side of the first gap 20c along the third direction and flow towards the pressure relief mechanism 23.

[0127] It can be understood that the space of the first gap 20c can form at least part of the discharge gap 20b.

[0128] In this way, the emissions entering the first gap 20c can flow towards the pressure relief mechanism 23 under the constraint of the first sub-protrusions 2121, so as to improve the efficiency of discharging the emissions from the battery cell 20 when the battery cell 20 undergoes thermal runaway, and reduce the risk of non-directional pressure relief.

[0129] In some embodiments, the third direction is the above-mentioned reference direction, and the third direction is perpendicular to the second direction.

[0130] The specific number of the first gaps 20c is not limited, and it can be one or multiple.

[0131] In some embodiments, referring to Figures 10 to 13 , openings are formed on both sides of the first gap 20c along the third direction. In this way, it is beneficial for the emissions in the first gap 20c to flow out of the first gap 20c faster, so as to reduce the risk of pressure increase caused by the accumulation of emissions in the first gap 20c.

[0132] It can be understood that the gap between the pressure relief mechanism 23 and the electrode assembly 22 is in communication with the first gap 20c.

[0133] In some embodiments, referring to Figure 10 , the first sub-protrusion 2121 includes a first bending portion 2121a, the first bending portion 2121a is located on the side of the first sub-protrusion 2121 along the third direction close to the pressure relief mechanism 23, and along the direction pointing towards the pressure relief mechanism 23 along the third direction, among the two first sub-protrusions 2121 forming the first gap 20c, the distance between the first bending portion 2121a of one first sub-protrusion 2121 and the first bending portion 2121a of the other first sub-protrusion 2121 gradually increases.

[0134] That is to say, among the two first sub-protrusions 2121 that form the first gap 20c, for the portion of the first gap 20c between the two first bending portions 2121a, the closer it is to the pressure relief mechanism 23, the larger the cross-section of this portion of the first gap 20c in the direction perpendicular to the third direction.

[0135] In this way, it is beneficial to reduce the flow velocity of the emissions in the first gap 20c as they gradually approach the pressure relief mechanism 23 along the third direction, and reduce the impact on the pressure relief mechanism 23.

[0136] In some embodiments where both sides of the first gap 20c are open along the third direction, referring to Figure 10 , the first sub-protrusion 2121 includes a second bending portion 2121b. The second bending portion 2121b is located on the side of the first sub-protrusion 2121 that is away from the pressure relief mechanism 23 along the third direction. Along the direction away from the pressure relief mechanism 23 along the third direction, among the two first sub-protrusions 2121 that form the first gap 20c, the distance between the second bending portion 2121b of one first sub-protrusion 2121 and the second bending portion 2121b of the other first sub-protrusion 2121 gradually increases.

[0137] That is to say, among the two first sub-protrusions 2121 that form the first gap 20c, for the portion of the first gap 20c between the two second bending portions 2121b, the farther it is from the pressure relief mechanism 23, the larger the cross-section of this portion of the first gap 20c in the direction perpendicular to the third direction.

[0138] In this way, it is beneficial to reduce the flow velocity of the emissions in the first gap 20c as they flow out of the first gap 20c along the third direction, and reduce the impact on the outer shell 21.

[0139] The specific manner of forming the first bending portion 2121a and the second bending portion 2121b is not limited.

[0140] Exemplarily, referring to Figures 10 to 12 , both side surfaces of the two ends of the first sub-protrusion 2121 along the third direction, which are close to the side surface of another adjacent first sub-protrusion 2121, are arc surfaces, and the arc surfaces protrude towards the other first sub-protrusion 2121. Among them, one end along the third direction close to the pressure relief mechanism 23 forms the first bending portion 2121a, and the other end forms the second bending portion 2121b.

[0141] It can be understood that the arc surface forms a part of the inner wall of the first gap 20c.

[0142] The specific manner of forming the arc surface is not limited.

[0143] For example, referring to Figure 12, in a projection plane perpendicular to the first direction, the projection of the first sub-protrusion 2121 along the first direction is a waist-shaped; for another example, refer to Figure 10 , in a projection plane perpendicular to the first direction, the projection of the first sub-protrusion 2121 along the first direction is an arc-shaped strip, and the first sub-protrusion 2121 protrudes toward another first sub-protrusion 2121 that jointly encloses the first gap 20c with it.

[0144] In some embodiments, refer to Figure 13 , two first sub-protrusions 2121 that form the first gap 20c are a group, and multiple groups of first sub-protrusions 2121 are arranged at intervals along the third direction and the first gaps 20c in each group communicate with each other.

[0145] In this way, it is beneficial for the emissions of other parts in the accommodation space to enter the first gap 20c through the gap between adjacent two groups, and flow toward the pressure relief mechanism 23 under the guiding action of the first sub-protrusions 2121, which is beneficial to improving the discharge efficiency of the emissions.

[0146] It can be understood that multiple groups of first sub-protrusions 2121 with the first gaps 20c communicating with each other are located on the same side of the pressure relief mechanism 23 along the third direction.

[0147] In some embodiments, refer to Figures 10 to 13 , multiple first sub-protrusions 2121 are divided into at least two groups, the two groups of first sub-protrusions 2121 are respectively located on one side of the pressure relief mechanism 23 along the third direction, and the number of first sub-protrusions 2121 in each group is multiple and forms at least one first gap 20c.

[0148] In this way, it is beneficial for the emissions on both sides of the pressure relief mechanism 23 along the third direction to enter the pressure relief mechanism 23 through the first gap 20c, which is beneficial to improving the discharge efficiency of the emissions.

[0149] The specific number of first sub-protrusions 2121 in each group can be two, three, four, five, six, seven, eight, nine, ten, etc.

[0150] In some embodiments where the two groups of first sub-protrusions 2121 are respectively located on one side of the pressure relief mechanism 23 along the third direction, refer to Figure 7 and Figure 8 , both groups of first sub-protrusions 2121 are in contact with the same electrode assembly 22.

[0151] That is to say, one group of first sub-protrusions 2121 is in contact with one side of an electrode assembly 22 along the third direction, and the other group of first sub-protrusions 2121 is in contact with the other side of the electrode assembly 22 along the third direction, so that the electrode assembly 22 straddles one side of the pressure relief mechanism 23 along the first direction.

[0152] Thus, it is beneficial to enable the emissions generated by the electrode assembly 22 to directly enter the pressure relief mechanism 23 along the first direction, which is beneficial to improving the discharge efficiency of the emissions.

[0153] In some embodiments, referring to Figures 10 to 13 , the first sub-protrusion 2121 extends along the third direction, so that the first gap 20c extends along the third direction.

[0154] In some embodiments, referring to Figure 10 and Figure 13 , the plurality of protrusions 212 includes a second sub-protrusion 2122. The second sub-protrusion 2122 is located in the first gap 20c and at the open position of the first gap 20c. The second sub-protrusion 2122 is spaced apart from both of the first sub-protrusions 2121 that form the first gap 20c.

[0155] The second sub-protrusion 2122 is spaced apart from the first sub-protrusion 2121 along the second direction.

[0156] Thus, the second sub-protrusion 2122 can achieve a better constraining effect on the electrode assembly 22, reducing the part of the electrode assembly 22 that enters the first gap 20c due to deformation, which is beneficial to increasing the space of the discharge gap 20b and improving the discharge efficiency of the emissions.

[0157] In some embodiments, referring to Figure 10 and Figure 13 , the second sub-protrusion 2122 extends along the second direction.

[0158] In some embodiments, referring to Figure 10 and Figure 13 , one end of the second sub-protrusion 2122 close to the first sub-protrusion 2121 is an arc surface. Thus, it is beneficial to reduce the resistance suffered by the emissions during the process of passing through the gap between the first sub-protrusion 2121 and the second sub-protrusion 2122, and it is beneficial to reduce the adverse impact on the flow rate of the emissions.

[0159] In some embodiments, referring to Figure 10 and Figure 13 , in the projection plane perpendicular to the first direction, the projection of the second sub-protrusion 2122 along the first direction is an oval shape, so that one end of the second sub-protrusion 2122 close to the first sub-protrusion 2121 is an arc surface.

[0160] In some embodiments, referring to Figure 14 , the plurality of protrusions 212 includes a third sub-protrusion 2123. The plurality of third sub-protrusions 2123 are located on one side of the pressure relief mechanism 23 along the third direction and are spaced apart from each other along the third direction. In the projection plane perpendicular to the third direction, the projections of the respective third sub-protrusions 2123 along the third direction at least partially overlap each other.

[0161] A second gap 20d is formed between two adjacent third sub-protrusions 2123, and the emissions formed by the electrode assembly 22 can enter the second gap 20d.

[0162] It can be understood that the second gap 20d forms at least part of the emission gap 20b.

[0163] In this way, through the overlapping area between the third sub-protrusions 2123, a better constraining effect can be exerted on the electrode assembly 22 in the third direction, reducing the deformation amount of the electrode assembly 22.

[0164] In some embodiments, the electrode assembly 22 abuts against a plurality of third sub-protrusions 2123.

[0165] In some embodiments, referring to Figure 14 , in the projection plane perpendicular to the first direction, the projection of the third sub-protrusion 2123 along the first direction is waist-shaped, so that one end of the third sub-protrusion 2123 along its extending direction close to one side surface of another adjacent third sub-protrusion 2123 is an arc surface.

[0166] In this way, it is beneficial to reduce the resistance suffered by the emissions during the process of passing through the gap between two adjacent third sub-protrusions 2123, and it is beneficial to reduce the adverse effect on the flow rate of the emissions.

[0167] It can be understood that, referring to Figure 9 and Figure 10 , a plurality of side walls 213 are provided around the edge of the first wall 211, and the first wall 211 and the side walls 213 together enclose a receiving cavity 20a.

[0168] The side wall 213 can be the first wall 211 or not the first wall 211.

[0169] In some embodiments, referring to Figures 10 to 15 , in the projection plane perpendicular to the first direction, the edge of the projection of the first wall 211 along the first direction and the projection of the protrusion 212 along the first direction are spaced apart from each other.

[0170] In this way, a third gap 20e can be formed between the protrusion 212 and other inner walls of the housing 21 at intervals, so that the emissions generated by the part of the electrode assembly 22 close to other inner walls can enter the third gap 20e and be discharged from the battery cell 20 through the third gap 20e, which is beneficial to improving the discharge efficiency of the emissions.

[0171] It can be understood that the third gap 20e forms at least part of the emission gap 20b.

[0172] In some embodiments, referring to Figure 15, the minimum distance between the edge of the projection of the first wall 211 in the first direction and the projection of the protrusion 212 in the first direction ranges from 3 mm to 12.7 mm. That is, 3 mm ≤ L3 ≤ 12.7 mm.

[0173] When the minimum distance between the edge of the projection of the first wall 211 in the first direction and the projection of the protrusion 212 in the first direction is less than 3 mm, the distance between the protrusion 212 and the adjacent side wall 213 is too close. During the manufacturing process of the protrusion 212, due to manufacturing errors, the edge of the protrusion 212 will squeeze the side wall 213, easily causing the side wall 213 to deform and not meeting the design requirements; when the minimum distance between the edge of the projection of the first wall 211 in the first direction and the projection of the protrusion 212 in the first direction is greater than 12.7 mm, the restraint effect on the deformation of the battery assembly is weakened, and more parts of the electrode assembly 22 can enter the third gap 20e between the protrusion 212 and the adjacent side wall 213, which is not conducive to the discharge of sheet emissions and increases the risk of non-directional pressure relief of the battery cell 20 in the state of thermal runaway.

[0174] In this way, it is beneficial to reduce the adverse impact of the protrusion 212 on the manufacturing accuracy of the side wall 213, and also beneficial to reduce the part of the electrode assembly 22 entering the third gap 20e, which is beneficial to improving the discharge efficiency; it is beneficial to keep the distance between the connection position between the side wall 213 and the first wall 211 and the electrode assembly 22 within a suitable range, so that the emissions flowing towards the side wall 213 can enter the third gap 20e.

[0175] Refer to Figure 15 , the distance between the connection position between the side wall 213 and the first wall 211 and the electrode assembly 22 is L4.

[0176] The minimum distance between the edge of the projection of the first wall 211 and the projection of the protrusion 212 can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 12.7 mm, etc.

[0177] In some embodiments, refer to Figure 15 , the minimum distance between the edge of the projection of the first wall 211 in the first direction and the projection of the protrusion 212 in the first direction ranges from 3 mm to 7 mm. That is, 3 mm ≤ L3 ≤ 7 mm.

[0178] In this way, it is further beneficial to reduce the adverse impact of the protrusion 212 on the manufacturing accuracy of the side wall 213, and beneficial to the emissions flowing towards the side wall 213 to more smoothly enter the third gap 20e.

[0179] In some embodiments, the outer shell 21 includes a housing 214 and an end cap 215. A receiving space is provided in the housing 214, and one side of the receiving space is open in a first direction. The end cap 215 is disposed at the open position in the first direction to jointly enclose a receiving cavity 20a with the housing 214.

[0180] In some embodiments, the first wall 211 is located at the bottom side of the battery cell 20 along the gravity direction.

[0181] That is to say, the first direction is the same as the gravity direction.

[0182] In this way, the protrusion 212 plays a supporting role for the electrode assembly 22, and the adverse effect that the volume of the discharge gap 20b is reduced due to the deformation of the electrode assembly 22 under its own gravity is reduced.

[0183] The battery cell 20 in a specific embodiment of the present application is described as follows:

[0184] The battery cell 20 includes a pressure relief mechanism 23, an electrode assembly 22, and a housing 21. The housing 21 encloses to form a receiving cavity 20a. The housing 21 includes a first wall 211. The first wall 211 forms a part of the inner surface of the receiving cavity 20a. A part of the surface of the first wall 211 facing the receiving cavity 20a protrudes in a first direction from other parts to form a protrusion 212. The electrode assembly 22 is located in the receiving cavity 20a and abuts against the protrusion 212 in the first direction, so that a part of the first wall 211 is spaced from the electrode assembly 22 to form a discharge gap 20b. The sum of the maximum dimensions of the contact area 22a between the protrusion 212 and the electrode assembly 22 in a second direction perpendicular to the first direction is a first dimension. The dimension of the electrode assembly 22 in the second direction is a second dimension. The ratio range of the first dimension to the second dimension is from 0.4 to 0.8. The battery cell 20 is a square shell battery cell, and the width direction of the battery cell 20 is the second direction. The pressure relief mechanism 23 is provided in an area of the first wall 211 where the protrusion 212 is not formed. The plurality of protrusions 212 include a first sub-protrusion 2121 and a second sub-protrusion 2122. At least two first sub-protrusions 2121 are located on one side of the pressure relief mechanism 23 in a third direction perpendicular to the first direction and intersecting the second direction. A first gap 20c is formed between the two first sub-protrusions 2121 at intervals. An opening is formed on one side of the first gap 20c in the third direction to be in fluid communication with the pressure relief mechanism 23. The first sub-protrusion 2121 includes a first bending portion 2121a and a second bending portion 2121b. The first bending portion 2121a is located on the side of the first sub-protrusion 2121 closer to the pressure relief mechanism 23 in the third direction. In the direction pointing closer to the pressure relief mechanism 23 in the third direction, among the two first sub-protrusions 2121 forming the first gap 20c, the distance between the first bending portion 2121a of one first sub-protrusion 2121 and the first bending portion 2121a of the other first sub-protrusion 2121 gradually increases. The second bending portion 2121b is located on the side of the first sub-protrusion 2121 farther from the pressure relief mechanism 23 in the third direction. In the direction pointing farther from the pressure relief mechanism 23 in the third direction, among the two first sub-protrusions 2121 forming the first gap 20c, the distance between the second bending portion 2121b of one first sub-protrusion 2121 and the second bending portion 2121b of the other first sub-protrusion 2121 gradually increases. The two first sub-protrusions 2121 forming the first gap 20c are a group. Multiple groups of first sub-protrusions 2121 are arranged at intervals in the third direction and the first gaps 20c in each group communicate with each other. The multiple first sub-protrusions 2121 are divided into at least two groups. The two groups of first sub-protrusions 2121 are respectively located on one side of the pressure relief mechanism 23 in the third direction. The number of first sub-protrusions 2121 in each group is multiple and forms at least one first gap 20c. The two groups of first sub-protrusions 2121 both abut against the same electrode assembly 22.The plurality of protrusions 212 include second sub-protrusions 2122. The second sub-protrusions 2122 are located in the first gap 20c and at the open position of the first gap 20c. The second sub-protrusions 2122 are spaced apart from both of the two first sub-protrusions 2121 that form the first gap 20c. In a projection plane perpendicular to the first direction, the edge of the projection of the first wall 211 along the first direction and the projection of the protrusion 212 along the first direction are spaced apart from each other. The range of the minimum distance between the edge of the projection of the first wall 211 along the first direction and the projection of the protrusion 212 along the first direction is from 3 mm to 12.7 mm.

[0185] Example 1:

[0186] (1) Provide the battery cell 20:

[0187] (11) Dimensions of the battery cell 20:

[0188] A rectangular shell cell with a length of 275 mm, a width of 71 mm, and a height of 171 mm. Among them, the first direction is the height direction, the width direction is the second direction, and the length direction is the third direction.

[0189] (12) Type of the battery cell 20:

[0190] Lithium iron phosphate or sodium ion.

[0191] (13) Arrangement of the electrode assembly 22:

[0192] The number of the electrode assemblies 22 is four, and they are arranged along the width direction of the battery cell 20.

[0193] (14) Arrangement relationship between the protrusion 212 and the electrode assembly 22:

[0194] For the number and shape of the protrusions 212, refer to Figure 12 , and for the relationship between the first dimension and the second dimension, refer to Table 1.

[0195] Examples 2 to 7:

[0196] Prepare the battery cell 20 with a scheme similar to that of Example 1, except that: for the first dimension and the second dimension, refer to Table 1.

[0197] Comparative Examples 1 to 7:

[0198] Prepare the battery cell 20 with a scheme similar to that of Example 1, except that for the first dimension and the second dimension, refer to Table 1.

[0199] Test of directional pressure relief:

[0200] A heating film is placed between two adjacent battery cell assemblies. The heating film is externally connected to a voltage of 40V (Voltage) and a current of 10A (Ampere) to trigger thermal runaway of the battery cell assemblies, and the test results are recorded in Table 1.

[0201] Table 1

[0202]

[0203] Examples 8 to 10:

[0204] The minimum distance between the protrusion 212 and the side wall 213 is shown in Table 2.

[0205] Comparative Example 8:

[0206] The minimum distance between the protrusion 212 and the side wall 213 is shown in Table 2.

[0207] Test on the distance between the connection position between the side wall 213 and the first wall 211 and the electrode assembly 22:

[0208] Apply an air pressure of 0.9 Mpa (Megapascal) in the accommodation cavity 20a, and the test results are recorded in Table 2.

[0209] Table 2

[0210]

[0211] The embodiment of the present application further provides a battery device 100, refer to Figure 2 , the battery device 100 includes a box body 10 and the battery cell 20 in any one of the foregoing embodiments. There is an accommodation space in the box body 10, and the battery cell 20 is located in the accommodation space.

[0212] In this way, by adopting the battery cell 20 in the foregoing embodiment, it is beneficial to reduce the damage to other devices in the battery device 100 caused by the emissions discharged during non-directional pressure relief of the battery cell 20.

[0213] The embodiment of the present application further provides an electrical device. The electrical device includes the battery device 100 in the foregoing embodiment, and the battery device 100 is used as the power source of the electrical device.

[0214] In this way, by adopting the battery device 100 in the foregoing embodiment, it is beneficial to reduce the damage to other devices in the electrical device caused by the emissions discharged during non-directional pressure relief of the battery cell 20.

[0215] The various embodiments / implementations provided in the present application can be combined with each other without contradiction.

[0216] The above are only the preferred embodiments of the present application and are not used to limit the embodiments in the present application. For those skilled in the art, the embodiments of the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present application shall be included within the protection scope of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: Electrode assembly; a housing, enclosing a receiving cavity, the housing comprising a first wall, the first wall forming a portion of an inner surface of the receiving cavity, a portion of a surface of the first wall facing the receiving cavity protruding from other portions along a first direction to form a protrusion, the electrode assembly being located in the receiving cavity and abutting against the protrusion along the first direction, so that a portion of the first wall is spaced from the electrode assembly to form a discharge gap; The sum of the maximum dimensions of the contact area between the protrusion and the electrode assembly along a second direction is a first dimension, the second direction is perpendicular to the first direction, the dimension of the electrode assembly along the second direction is a second dimension, and the first dimension is smaller than the second dimension; Pressure relief mechanism; The plurality of protrusions include first sub-protrusions, at least two of the first sub-protrusions are located on one side of the pressure relief mechanism along a third direction, the third direction is perpendicular to the first direction and intersects with the second direction, a first gap is formed between the two first sub-protrusions, and the first gap forms an opening along one side of the third direction to be in fluid communication with the pressure relief mechanism; The first sub-protrusion includes a first curved portion, which is located on a side of the first sub-protrusion close to the pressure relief mechanism along the third direction, and is close to the direction of the pressure relief mechanism along the third direction. Among the two first sub-protrusions forming the first gap, the distance between the first curved portion of one first sub-protrusion and the first curved portion of the other first sub-protrusion gradually increases; and / or, the first sub-protrusion includes a second curved portion, which is located on a side of the first sub-protrusion away from the pressure relief mechanism along the third direction, and is away from the direction of the pressure relief mechanism along the third direction. Among the two first sub-protrusions forming the first gap, the distance between the second curved portion of one first sub-protrusion and the second curved portion of the other first sub-protrusion gradually increases.

2. The battery cell according to claim 1, characterized in that: The ratio of the first size to the second size ranges from 0.4 to 0.

8.

3. The battery cell according to claim 1, characterized in that: The ratio of the first size to the second size ranges from 0.5 to 0.

7.

4. The battery cell according to claim 1, characterized in that: The number of the electrode assemblies is two, the two electrode assemblies are arranged along the second direction, the protrusions include a first protrusion and a second protrusion, the first protrusion abuts against one of the electrode assemblies along the first direction, and the maximum dimension of the contact area between the first protrusion and the second direction is a third dimension, and the ratio of the third dimension to the second dimension is in a range of 0.4 to 0.8; The second protrusion abuts against another electrode assembly along the first direction, and a maximum dimension of a contact area therebetween along the second direction is a fourth dimension, and a ratio of the fourth dimension to the second dimension ranges from 0.4 to 0.

8.

5. The battery cell according to claim 1, characterized in that: The battery cell is a square-shell battery cell, and the width direction of the battery cell is the second direction.

6. The battery cell according to claim 1, characterized in that: The pressure relief mechanism is arranged in an area of ​​the first wall where the protrusion is not formed.

7. The battery cell according to claim 1, characterized in that: Two first sub-protrusions forming the first gap form a group, and a plurality of groups of the first sub-protrusions are arranged at intervals along the third direction, and the first gaps in each group are connected to each other.

8. The battery cell according to claim 1, characterized in that: The multiple first sub-protrusions are divided into at least two groups, and the two groups of the first sub-protrusions are respectively located on one side of the pressure relief mechanism along the third direction. The number of the first sub-protrusions in each group is multiple and forms at least one first gap, and the two groups of the first sub-protrusions are both in contact with the same electrode assembly.

9. The battery cell according to claim 1, characterized in that: The plurality of protrusions include a second sub-protrusion, the second sub-protrusion is located in the first gap and at an open position of the first gap, and the second sub-protrusion is spaced apart from the two first sub-protrusions forming the first gap.

10. The battery cell according to claim 1, characterized in that: The multiple protrusions include a third sub-protrusion, and the multiple third sub-protrusions are located on one side of the pressure relief mechanism along the third direction and are spaced apart from each other along the third direction. In a projection plane perpendicular to the third direction, projections of each third sub-protrusion along the third direction at least partially overlap with each other.

11. The battery cell according to claim 1, characterized in that: In a projection plane perpendicular to the first direction, an edge of a projection of the first wall along the first direction and a projection of the protrusion along the first direction are spaced apart from each other.

12. The battery cell according to claim 11, characterized in that: A minimum distance between an edge of a projection of the first wall along the first direction and a projection of the protrusion along the first direction ranges from 3 mm to 12.7 mm.

13. The battery cell according to claim 11, characterized in that: A minimum distance between an edge of a projection of the first wall along the first direction and a projection of the protrusion along the first direction ranges from 3 mm to 7 mm.

14. The battery cell according to claim 1, characterized in that: The first wall is located at a bottom side of the battery cell along a gravity direction.

15. A battery device, characterized in that: The battery device comprises a box body and a battery cell according to any one of claims 1 to 14, wherein a receiving space is provided in the box body, and the battery cell is located in the receiving space.

16. An electrical device, characterized in that: The electric device comprises the battery device according to claim 15, and the battery device is used as a power source for the electric device.

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