Battery monomer, battery device and electric equipment

Abstract

The embodiment of the utility model provides a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell, an electrode assembly, a pressure relief mechanism and a fire extinguishing structure. The shell comprises a shell body and an end cover connected to the shell body, the shell body is provided with a first wall, the electrode assembly is arranged in the shell, the pressure relief mechanism comprises a pressure relief part, the first wall is connected to the periphery of the pressure relief part, and the at least one fire extinguishing structure is arranged at the pressure relief part. According to the battery monomer, the battery device and the electric equipment provided by the embodiment of the invention, the fire extinguishing structure is arranged at the pressure relief part of the pressure relief mechanism, so that the fire extinguishing structure can perform cooling and fire extinguishing operation at the pressure relief mechanism, and the thermal runaway reaction and heat spreading of the battery monomer can be improved; therefore, the problem of chain reaction of thermal runaway of adjacent battery monomers is solved, the thermal runaway of the whole battery is improved, and the reliability of the battery is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Art

[0002] In the related art, there is a risk of battery cells rapidly generating high temperatures during use, which causes the battery cells to generate high-temperature, high-pressure gas and flames, leading to thermal runaway of the battery cells and then thermal runaway of the entire battery. Utility Model Content

[0003] In view of this, embodiments of the present application aim to provide a battery cell, a battery device, and an electrical device that can improve the thermal runaway problem.

[0004] A first aspect of an embodiment of the present application provides a battery cell, comprising: an outer shell, comprising a shell and an end cover connected to the shell, the shell having a first wall; an electrode assembly, disposed in the outer shell; a pressure relief mechanism, comprising a pressure relief portion, the first wall being connected to the outer periphery of the pressure relief portion; and a fire extinguishing structure, wherein at least one of the fire extinguishing structures is disposed at the pressure relief portion.

[0005] In the battery cells of the embodiments of the present application, a fire extinguishing structure is provided at the pressure relief portion of the pressure relief mechanism, so that the fire extinguishing structure can perform a cooling and fire extinguishing operation at the pressure relief mechanism. This can improve the thermal runaway reaction and heat spread of the battery cells, thereby improving the problem of a chain reaction of thermal runaway occurring in adjacent battery cells, thereby improving the thermal runaway of the entire battery and improving the reliability of the battery.

[0006] Furthermore, it can be understood that the electrode terminals of a battery cell are usually arranged on the end cover, while in the battery cell of the embodiment of the present application, the pressure relief mechanism is arranged on the first wall rather than the end cover, which can simplify the end cover structure of the battery cell.

[0007] In some embodiments, at least one of the fire extinguishing structures provided at the pressure relief portion is in contact with the outer shell; and / or at least one of the fire extinguishing structures provided at the pressure relief portion is in contact with the pressure relief mechanism; and / or at least one of the fire extinguishing structures provided at the pressure relief portion is provided outside the outer shell, spaced from and opposite to the pressure relief portion.

[0008] In this embodiment, a variety of optional configurations of the fire extinguishing structure are provided, all of which can achieve good cooling and fire extinguishing effects.

[0009] In some embodiments, at least one of the fire extinguishing structures disposed at the pressure relief portion is a first fire extinguishing component, the first fire extinguishing component has a through hole, and the pressure relief portion is opposite to the through hole and exposed to the through hole.

[0010] In this embodiment, the first fire extinguishing element is provided with a through hole, thereby improving the problem of the fire extinguishing structure blocking high-temperature, high-pressure gas and flames, and facilitating the release of cooled gas. Especially when the fire extinguishing structure is installed within the housing, the probability of accidents caused by the inability of gas to smoothly exit the housing (for example, the housing expanding and deforming, squeezing other surrounding battery cells) can be reduced.

[0011] In some embodiments, the first fire extinguishing component includes an annular portion arranged outside the pressure relief portion, the annular portion surrounds the through hole, and the minimum distance between any point on the inner edge of the annular portion and the outer peripheral edge of the pressure relief portion is greater than or equal to 0 and less than or equal to 5 mm.

[0012] In this embodiment, the minimum distance between any point on the inner edge of the annular portion and the outer periphery of the pressure relief portion is greater than or equal to zero. This means that the annular portion does not cover the pressure relief portion. This further improves the fire extinguishing structure's ability to block high-temperature, high-pressure gas and flames. The minimum distance between the inner edge of the annular portion and the outer periphery of the pressure relief portion is less than or equal to 5 mm. This reduces the distance between the annular portion and the pressure relief portion, improving the cooling and fire extinguishing effect.

[0013] In some embodiments, the width of the annular portion is greater than or equal to 2 mm; and / or the thickness of the annular portion is greater than or equal to 1 mm and less than or equal to 10 mm.

[0014] It is understood that the annular portion is the part of the fire extinguishing structure that actually performs the fire extinguishing function (e.g., contains the fire extinguishing material). A width of the annular portion greater than or equal to 2 mm and / or a thickness of the annular portion greater than or equal to 1 mm helps improve its cooling and fire extinguishing effect. Furthermore, a thickness of the annular portion less than or equal to 10 mm helps save space within the housing.

[0015] In some embodiments, the end cover is arranged opposite to the first wall, and the outer shell also includes a support plate and a pad arranged between the electrode assembly and the first wall. Along the distribution direction of the electrode assembly and the first wall, the opposite side surfaces of the pad are respectively abutted against the first wall and the support plate, and the annular portion is arranged between the support plate and the first wall, and the thickness of the annular portion is less than or equal to the thickness of the pad.

[0016] In this embodiment, the annular portion is disposed between the support plate and the first wall. This allows for cooling and extinguishing of high-temperature, high-pressure gas and flames before they escape the pressure relief portion, thereby enhancing fire extinguishing effectiveness. Furthermore, it is understood that the fire extinguishing structure having a thickness smaller than that of the spacer reduces the pressure it bears from the electrode assembly, thereby lowering the probability of damage due to pressure, leading to premature release of the fire extinguishing material.

[0017] In some embodiments, at least one of the fire extinguishing structures provided at the pressure relief portion is a second fire extinguishing component, which is provided between the electrode assembly and the first wall. The second fire extinguishing component is provided on one side of the pressure relief portion in a direction perpendicular to the distribution direction of the electrode assembly and the first wall.

[0018] In this embodiment, the second fire extinguishing element is positioned between the electrode assembly and the first wall. This allows for cooling and extinguishing of the high-temperature, high-pressure gas and flames before they escape the pressure relief portion, improving fire extinguishing effectiveness. Furthermore, the second fire extinguishing element is positioned to the side of the pressure relief portion, rather than directly facing it. This alleviates the problem of the fire extinguishing structure blocking the high-temperature, high-pressure gas and flames, facilitating the release of the cooled gas.

[0019] In some embodiments, the end cover is arranged opposite to the first wall, the outer shell also includes a support plate arranged between the electrode assembly and the first wall, the second fire extinguishing component is arranged between the support plate and the first wall, and along the distribution direction of the electrode assembly and the first wall, the opposite side surfaces of the second fire extinguishing component are respectively abutted against the first wall and the support plate.

[0020] In this embodiment, the second fire extinguishing component actually also serves as a spacer, that is, it raises the support plate and the electrode assembly, thereby simplifying the internal structure of the battery cell.

[0021] In some embodiments, the shell includes a second wall connected to the first wall, and at least one of the fire extinguishing structures provided at the pressure relief portion is a third fire extinguishing component, and the third fire extinguishing component is provided between the second wall and the electrode assembly.

[0022] In this embodiment, the third fire extinguishing component is arranged between the second wall and the electrode assembly, rather than between the first wall and the electrode assembly. In this way, the internal space of the shell can be fully utilized to arrange the fire extinguishing structure, thereby achieving a better fire extinguishing effect.

[0023] In some embodiments, the second wall has the largest area among all walls of the housing.

[0024] In this embodiment, the second wall is the wall with the largest area among all the walls of the shell, which makes the second wall the wall closest to the pressure relief part except the first wall of the shell, thereby allowing the third fire extinguishing component to be relatively closer to the pressure relief part to obtain a better fire extinguishing effect.

[0025] In some embodiments, along the distribution direction of the electrode assembly and the second wall, the size of the third fire extinguishing element is greater than or equal to 0.2 mm and less than or equal to 5 mm.

[0026] In this embodiment, the dimension of the third fire extinguishing element in the distribution direction between the electrode assembly and the second wall is greater than or equal to 0.2 mm, which helps enhance its cooling and fire extinguishing effectiveness. Furthermore, it is understood that the second wall is the largest wall of all the walls of the housing, meaning that the surface of the electrode assembly facing the third fire extinguishing element is also the largest and relatively fragile surface of all the surfaces of the electrode assembly. In this embodiment, the dimension of the third fire extinguishing element in this direction is less than or equal to 5 mm, which helps reduce the probability of the third fire extinguishing element applying pressure on the large surface of the electrode assembly, causing damage to the electrode assembly. For example, in the case of a lithium battery, this helps reduce the probability of the third fire extinguishing element applying pressure on the large surface of the electrode assembly, causing lithium deposition.

[0027] In some embodiments, an arcuate transition surface is formed between the first wall and the second wall, and an end portion of the third fire extinguishing element is located on an inner side of the arcuate transition surface along a direction of the electrode assembly pointing toward the first wall.

[0028] In this embodiment, the arc-shaped transition surface formed between the first wall and the second wall helps to improve the overall structural strength of the shell and reduce the difficulty of preparing the shell, and the end of the third fire extinguishing component is located on the inner side of the arc-shaped transition surface, which helps to reduce the possibility of interference between the third fire extinguishing component and the arc-shaped transition surface and facilitates assembly.

[0029] In some embodiments, along the direction of the electrode assembly pointing toward the first wall, the distance between the end of the third fire extinguishing element and the first wall is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0030] In this embodiment, the distance between the end of the third fire extinguishing element and the first wall is greater than or equal to 0.5 mm, which helps it avoid the connection between the first wall and the second wall (for example, the arc-shaped transition surface between the first wall and the second wall); the distance between the end of the third fire extinguishing element and the first wall is less than or equal to 2 mm, which helps shorten the distance between the third fire extinguishing element and the pressure relief part, thereby improving its cooling and fire extinguishing effect.

[0031] In some embodiments, the second wall is located on one side of the pressure relief portion in the width direction, and along the length direction of the pressure relief portion, two ends of the third fire extinguishing component exceed two ends of the pressure relief portion.

[0032] In this embodiment, the effective range of the third fire extinguishing component can cover the entire length of the pressure relief portion, which can achieve a better cooling and fire extinguishing effect.

[0033] In some embodiments, the shell includes two second walls arranged opposite to each other, the number of the third fire extinguishing elements is at least two, and at least one third fire extinguishing element is arranged between each second wall and the electrode assembly.

[0034] In this embodiment, a third fire extinguishing component is provided between the second side walls on both sides of the pressure relief portion and the electrode assembly. This can increase the effective range of the third fire extinguishing component and achieve a better cooling and fire extinguishing effect.

[0035] In some embodiments, the battery cell further includes: an insulating structure, the insulating structure being arranged on a side of the first wall away from the electrode assembly and covering the pressure relief portion, at least one of the fire extinguishing structures arranged at the pressure relief portion being a fourth fire extinguishing component, the fourth fire extinguishing component being arranged on a side of the insulating structure away from the pressure relief portion and being arranged opposite to the pressure relief portion, or the fourth fire extinguishing component being arranged between the insulating structure and the pressure relief portion and being arranged opposite to the pressure relief portion.

[0036] In this embodiment, the fourth fire extinguishing component is arranged outside the shell and opposite to the pressure relief part. In this way, it can achieve a better cooling and fire extinguishing effect and will not prevent the high-temperature and high-pressure gas and flame in the shell from breaking through the pressure relief part.

[0037] A second aspect of the embodiments of the present application provides a battery device, comprising: a box; and at least one battery cell according to the first aspect of the embodiments of the present application, disposed in the box.

[0038] A third aspect of the embodiments of the present application provides an electrical device, which is the battery cell of the first aspect of the embodiments of the present application, or the battery device of the second aspect of the embodiments of the present application.

[0039] The battery device and the electrical equipment of the embodiments of the present application have all the advantages of the battery device described in any of the above embodiments, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of an explosion of a battery cell according to an embodiment of the present application;

[0041] Figure 2 This is a schematic diagram of the assembly of the pressure relief mechanism and the housing according to an embodiment of the present application;

[0042] Figure 3 This is a schematic diagram of the end cover structure of a battery cell according to an embodiment of the present application;

[0043] Figure 4 This is a schematic diagram of the assembly of the pressure relief mechanism, the first fire extinguishing component, and the housing according to an embodiment of the present application;

[0044] Figure 5 This is a schematic diagram of the assembly of the first fire extinguishing element, the pressure relief portion, and the first wall according to an embodiment of the present application;

[0045] Figure 6 for Figure 3AA cross-sectional diagram of a battery cell;

[0046] Figure 7 for Figure 6 An enlarged schematic diagram of part B;

[0047] Figure 8 This is a schematic diagram of the assembly of the support plate and the first fire extinguishing component according to an embodiment of the present application;

[0048] Figure 9 A schematic diagram of the assembly of the support plate and the first fire extinguishing element from another perspective of an embodiment of the present application;

[0049] Figure 10 This is a schematic diagram of the assembly of the second fire extinguishing component, the pressure relief portion, and the first wall according to an embodiment of the present application;

[0050] Figure 11 This is a schematic diagram of an explosion of a battery cell according to another embodiment of the present application;

[0051] Figure 12 for Figure 3 CC cross-section diagram of the middle battery cell;

[0052] Figure 13 for Figure 12 An enlarged schematic diagram of part D in the middle;

[0053] Figure 14 This is a schematic diagram of the assembly of the third fire extinguishing element, the pressure relief portion, the first wall, and the second wall of an embodiment of the present application;

[0054] Figure 15 This is a schematic diagram of the assembly of a battery cell and an external structure according to an embodiment of the present application;

[0055] Figure 16 A schematic diagram of the assembly of a battery cell and an external structure from another perspective of an embodiment of the present application;

[0056] Figure 17 for Figure 16 EE cross-sectional diagram;

[0057] Figure 18 for Figure 17 Enlarged schematic diagram of part F.

[0058] Description of Reference Numerals

[0059] 1. Outer shell; 11. End cover; 12. Shell; 121. First wall; 122. Second wall; 123. Arc-shaped transition surface; 13. Support plate; 14. Spacer; 2. Electrode assembly; 21. Pole piece; 22. Insulating film; 23. Adhesive tape; 3. Pressure relief mechanism; 31. Pressure relief portion; 32. Connecting portion; 33. Protective film; 4. Fire extinguishing structure; 4a. First fire extinguishing component; 4b. Second fire extinguishing component; 4c. Third fire extinguishing component; 4d. Fourth fire extinguishing component; 41. Annular portion; 41a. Through hole; 5. Electrode terminal; 6. Insulating structure; Z. Box. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0061] The various specific technical features described in the specific embodiments may be combined in any suitable manner, unless they are inconsistent. For example, different embodiments and technical solutions may be formed by combining different specific technical features. To avoid unnecessary repetition, the various possible combinations of the specific technical features in this utility model will not be described separately.

[0062] In the following description, the terms "first, second, ..." are used solely to distinguish different objects and do not imply any similarities or connections between the objects. It should be understood that the directions "above," "below," "outside," and "inside" refer to directions during normal use. The directions "left" and "right" refer to the left-right directions shown in the corresponding schematic diagrams, which may or may not be the left-right directions during normal use.

[0063] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising that element. "A plurality" means greater than or equal to two.

[0064] In the description of this application, the orientation or position relationship of "first direction", "second direction" and "third direction" is based on the orientation or position relationship shown in the accompanying drawings, wherein the "first direction" is the direction indicated by the arrow L1 in the accompanying drawings, the "second direction" is the direction indicated by the arrow L2 in the accompanying drawings, and the "third direction" is the direction indicated by the arrow L3 in the accompanying drawings. It should be understood that these orientation terms are only for the convenience of describing this application and simplifying the description, and do 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 this application.

[0065] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0066] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0067] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0068] Embodiments of the present application provide a battery cell, a battery device, and an electrical device.

[0069] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0070] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0071] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator, which is positioned between the positive and negative electrodes. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are intercalated and released between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0072] The electrode assembly may be a wound structure, a laminated structure, or a mixed structure of wound and laminated structures.

[0073] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0074] In some embodiments, the electrode assembly is a laminate structure.

[0075] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0076] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0077] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0078] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0079] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0080] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0081] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0082] In some embodiments, the battery cell may include an outer shell. The outer shell may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film. In some embodiments, the outer shell may be a sealed structure or a non-sealed structure. As an example, when the outer shell is a non-sealed structure, the outer shell serves to protect the electrode assembly, and a sealing bag is further included between the outer shell and the electrode assembly, which 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 outer shell is a sealed structure, it is used to encapsulate components such as the electrode assembly and the electrolyte.

[0083] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0084] In some embodiments, the housing includes an end cap and a shell, wherein the shell has an opening and the end cap covers the opening. The shell may have one or more openings. One or more end caps may also be provided.

[0085] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to the tab. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via a current collecting member. The electrode terminal may be provided on an end cap or on the housing.

[0086] In some embodiments, the housing is provided with a pressure relief mechanism for discharging internal gas of the battery cells.

[0087] For example, a battery cell's internal pressure or temperature reaches a predetermined threshold, triggering the release of internal pressure or temperature. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism activates, or a weakened structure within the pressure relief mechanism is destroyed, thereby creating an opening or channel for the internal pressure or temperature to release. This threshold design varies depending on design requirements. The threshold may depend on the material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell.

[0088] As an example, the pressure relief mechanism may be integrally formed with the housing.

[0089] As an example, the pressure relief mechanism may also be provided separately from and connected to the housing.

[0090] The "activation" mentioned in this application refers to the action of the pressure relief mechanism or its activation to a certain state, so that the internal pressure and temperature of the battery cell can be released. The action produced by the pressure relief mechanism may include but is not limited to: the movement of components in the pressure relief mechanism to form an exhaust channel, at least a part of the pressure relief mechanism rupturing, breaking, tearing or opening, etc. When the pressure relief mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell will be discharged outward from the actuated part as emissions. In this way, the pressure and temperature of the battery cell can be relieved under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0091] In some embodiments, when the outer shell is a non-sealed structure, the pressure relief mechanism can be configured as a through hole for discharging gas from inside the battery cell.

[0092] The emissions from the battery cells mentioned in this application include but are not limited to: electrolyte, dissolved or split positive and negative electrode sheets, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0093] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar.

[0094] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0095] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing multiple battery cells to form an independent module. As an example, the battery module may be formed by bundling multiple battery cells with a cable tie.

[0096] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0097] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0098] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0099] As an example, the housing may include a first housing and a second housing. The first housing and the second housing interlock to form an enclosed space within the housing to house the battery cell assembly. Enclosed here means covered or closed, and can be either sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0100] As an example, the box may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame to form a closed space inside the box to accommodate the battery cell assembly.

[0101] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0102] The technical solutions described in the embodiments of the present application are applicable to various electrical devices that use battery cells, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, for example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc.

[0103] In the related art, there is a risk of battery cells rapidly generating high temperatures during use, which causes the battery cells to generate high-temperature, high-pressure gas and flames, leading to thermal runaway of the battery cells and then thermal runaway of the entire battery.

[0104] To address the above-mentioned issues, a battery cell according to an embodiment of the present application is proposed. The battery cell according to the embodiment of the present application includes a housing, an electrode assembly, a pressure relief mechanism, and a fire extinguishing structure. The housing includes a shell and an end cap connected to the shell. The shell has a first wall. The electrode assembly is disposed within the housing. The pressure relief mechanism includes a pressure relief portion. The first wall is connected to the outer periphery of the pressure relief portion. At least one fire extinguishing structure is disposed at the pressure relief portion.

[0105] In the battery cells of the embodiments of the present application, a fire extinguishing structure is provided at the pressure relief portion of the pressure relief mechanism, so that the fire extinguishing structure can perform a cooling and fire extinguishing operation at the pressure relief portion. This can improve the thermal runaway reaction and heat spread of the battery cells, thereby improving the problem of a chain reaction of thermal runaway occurring in adjacent battery cells, thereby improving the thermal runaway of the entire battery and improving the reliability of the battery.

[0106] Furthermore, it can be understood that the electrode terminals of a battery cell are usually provided on the end cover, while in the battery cell of the embodiment of the present application, the pressure relief portion is provided on the first wall rather than the end cover, thereby simplifying the end cover structure of the battery cell.

[0107] Reference Figure 1-Figure 4 The battery cell of the present embodiment includes a housing 1, an electrode assembly 2, a pressure relief mechanism 3, and a fire extinguishing structure. The housing 1 includes a shell 12 and an end cap 11 connected to the shell 12. The shell 12 has a first wall 121. The electrode assembly 2 is disposed within the housing 1. The pressure relief mechanism 3 includes a pressure relief portion 31. The first wall 121 is connected to the outer periphery of the pressure relief portion 31. At least one fire extinguishing structure 4 is disposed at the pressure relief portion 31.

[0108] The specific structure of the shell 1 is not limited. As an example, the shell 1 can be a prismatic structure, such as a rectangular parallelepiped, or a cylindrical structure. In this application, the shell 12 is mainly described as a rectangular parallelepiped. Furthermore, for the convenience of description, the height direction of the shell 12 is defined as the first direction, the width direction is defined as the second direction, and the length direction is defined as the third direction.

[0109] The housing 1 includes a shell 12 and an end cap 11 connected to the shell 12. As an example, one end of the shell 12 (e.g., the end in the first direction) may have an opening, and the end cap 11 may be installed to cover the opening. The shell 12 has a first wall 121. The first wall 121 may be any wall of the shell 12. Taking the end cap 11 as an example of being installed at the end of the shell 12 along the first direction, the first wall 121 may be a wall arranged opposite to the end cap 11 along the first direction, or a wall arranged adjacent to the end cap 11 (e.g., a wall of the shell 12 along the second direction or the third direction). In this application, the description is mainly based on the example of the end cap 11 and the first wall 121 being arranged opposite to each other along the first direction.

[0110] The electrode assembly 2 is disposed in the housing 1. The specific structure of the electrode assembly 2 is not limited. As an example, the electrode assembly 2 may include a pole piece 21 and an insulating film 22 disposed on the outer surface of the pole piece 21. The pole piece 21 may include a positive pole piece 21 and a negative pole piece 21 and a separator.

[0111] The battery cell may further include an electrode terminal 5 , which is electrically connected to the electrode assembly 2 and is disposed on the end cap 11 .

[0112] The pressure relief mechanism 3 is disposed on the first wall 121. The specific structure of the pressure relief mechanism 3 is not limited. The pressure relief mechanism 3 is a mechanism capable of releasing the internal pressure of the battery cell when the internal pressure or temperature of the battery cell reaches a threshold value. For example, when the battery cell is operating normally, the gas pressure inside the battery cell is less than the opening pressure value of the pressure relief mechanism 3, the pressure relief mechanism 3 is in a closed state, and the gas inside the battery cell is not connected to the gas outside. When the battery cell experiences thermal runaway due to internal and external factors such as overcharge, overdischarge, overheating, and mechanical collision, a large amount of high-temperature and high-pressure gas is generated inside the battery cell, causing the internal pressure of the battery cell to exceed the opening pressure value of the pressure relief mechanism 3. The pressure relief mechanism 3 then switches from a closed state to an open state, and the high-temperature and high-pressure gas inside the battery cell can be discharged to the outside of the battery cell through the pressure relief mechanism 3.

[0113] The pressure relief mechanism 3 may be a structure having at least a portion thereof lower structural strength than the housing 12, or the pressure relief mechanism 3 may be a pressure valve, etc. In this way, when a battery cell experiences thermal runaway, the high-temperature, high-pressure gas and flame generated inside the battery cell can break through the pressure relief mechanism 3 and be released outside the battery cell.

[0114] The pressure relief portion 31 is the portion of the pressure relief mechanism 3 used for pressure relief. The pressure relief portion 31 may be a hole structure formed in the first wall 121 , that is, the pressure relief portion 31 may not have a physical structure. Alternatively, the pressure relief portion 31 may be a diaphragm-like structure that can be broken by high-temperature, high-pressure gas and flames. Specifically, during thermal runaway of a battery cell, the high-temperature, high-pressure gas and flames inside the battery cell can break through the pressure relief portion 31, thereby achieving pressure relief.

[0115] The first wall 121 is connected to the outer periphery of the pressure relief portion 31. Specifically, the first wall 121 is disposed around the outer periphery of the pressure relief portion 31 and is connected to the pressure relief portion 31. The first wall 121 can be directly connected to the pressure relief portion 31; alternatively, the pressure relief mechanism 3 further includes a connecting portion 32 disposed around the outer periphery of the pressure relief portion 31 and connected to the pressure relief portion 31, with the first wall 121 connected to the first connecting portion 32. In some embodiments, the pressure relief mechanism 3 may further include a protective film 33 disposed on the side of the pressure relief portion 31 facing away from the electrode assembly 2.

[0116] Fire extinguishing structure 4 is a structure made of fire-extinguishing material that has a fire-extinguishing function. Specifically, fire extinguishing structure 4 can suppress the generation and spread of flames and, during operation, remove heat from high-temperature, high-pressure gas and flames to achieve a cooling and fire-extinguishing function. In other words, fire extinguishing structure 4 is primarily used for cooling and fire-extinguishing.

[0117] As an example, the fire extinguishing structure 4 includes a fire extinguishing layer and an adhesive layer, the sum of the thicknesses of the fire extinguishing layer and the adhesive layer is greater than or equal to 0.2 mm and less than or equal to 10 mm; and / or the thickness of the fire extinguishing layer is greater than or equal to 0.1 mm and less than or equal to 8 mm, and / or the thickness of the adhesive layer is greater than or equal to 0.02 mm and less than or equal to 2 mm, and / or the ratio of the thickness of the fire extinguishing layer to the thickness of the adhesive layer is greater than or equal to 2 and less than or equal to 5.

[0118] The fire extinguishing layer is specifically a portion of the fire extinguishing structure 4 used to achieve the cooling and fire extinguishing functions, while the bonding layer is used to achieve bonding and fixing of the fire extinguishing structure 4 to other structures.

[0119] The thickness of the fire extinguishing layer and the adhesive layer specifically refers to the thickness of the fire extinguishing layer and the adhesive layer along the arrangement direction of the two. The fire extinguishing structure 4 may include only one adhesive layer, or it may include two adhesive layers respectively arranged on both sides of the thickness direction of the fire extinguishing layer. In this case, the thickness of the adhesive layer refers to the total thickness of the two adhesive layers.

[0120] The fire extinguishing layer may specifically be a coating formed by a microcapsule structure. The capsule shell of the microcapsule may be made of a polymer material, and the capsule core may be a fire extinguishing material, such as perfluorohexanone.

[0121] At least one fire extinguishing structure 4 is located at the pressure relief portion 31, meaning that the at least one fire extinguishing structure 4 is located in a position capable of cooling and extinguishing the pressure relief portion 31. The at least one fire extinguishing structure 4 located at the pressure relief portion 31 can be positioned adjacent to the pressure relief portion 31, or it can be located adjacent to the pressure relief portion 31 and spaced apart from the pressure relief portion 31. In other words, the fire extinguishing structure 4 can be used to cool and extinguish the pressure relief portion 31, which can be understood as being located at the pressure relief portion 31.

[0122] It should be noted that the battery cell may include two or more fire extinguishing structures 4, and a part of the fire extinguishing structures 4 may be arranged at other positions of the battery cell instead of at the pressure relief mechanism 3. For example, the shell 1 and / or the electrode assembly 2 may have a weak structure. The weak structure here specifically refers to a structure that is easily damaged under thermal runaway (such as the weld of the shell 12, the melting position of the electrode 21, etc.), and the fire extinguishing structure 4 can be arranged at these weak structures.

[0123] In the battery cell of the embodiment of the present application, a fire extinguishing structure 4 is provided at the pressure relief portion 31 of the pressure relief mechanism 3, so that the fire extinguishing structure 4 can perform a cooling and fire extinguishing operation at the pressure relief mechanism 3, thereby improving the thermal runaway reaction and heat spread of the battery cell, thereby improving the problem of a chain reaction of thermal runaway occurring in adjacent battery cells, thereby improving the thermal runaway of the entire battery and improving the reliability of the battery.

[0124] Furthermore, it can be understood that the electrode terminal 5 of the battery cell is usually arranged on the end cover 11, while in the battery cell of the embodiment of the present application, the pressure relief mechanism 3 is arranged on the first wall 121 rather than the end cover 11, so that the structure of the end cover 11 of the battery cell can be simplified.

[0125] In some embodiments, at least one fire extinguishing structure 4 provided at the pressure relief portion 31 is in contact with the outer shell 1; and / or at least one fire extinguishing structure 4 provided at the pressure relief portion 31 is in contact with the pressure relief mechanism 3; and / or at least one fire extinguishing structure 4 provided at the pressure relief portion 31 is provided outside the outer shell 1, spaced apart from and opposite to the pressure relief portion 31.

[0126] The abutment here specifically refers to direct contact with essentially no gap. The two abutting parts may be in contact with essentially no interaction force, or in contact with interaction force (for example, the fire extinguishing structure 4 may generate interaction force between the two parts by means of an adhesive layer).

[0127] In the embodiment where the fire extinguishing structure 4 is abutted against the housing 1, the fire extinguishing structure 4 can be abutted against any wall of the housing 1, such as the first wall 121, other walls, or multiple walls of the housing 1 at the same time. The fire extinguishing interface can be abutted against the side surface of the housing 1 facing the electrode assembly 2, or against the side surface of the housing 1 facing away from the electrode assembly 2.

[0128] In the embodiment where the fire extinguishing structure 4 is abutted against the pressure relief mechanism 3, the fire extinguishing structure 4 can be abutted against any position of the pressure relief mechanism 3, such as against the pressure relief portion 31, against the connecting portion 32, or against both the pressure relief portion 31 and the connecting portion 32. The fire extinguishing structure 4 can be abutted against the surface of the pressure relief mechanism 3 facing the electrode assembly 2, or against the surface of the pressure relief mechanism 3 facing away from the electrode assembly 2.

[0129] In embodiments where the fire extinguishing structure 4 is disposed outside the housing 1, the fire extinguishing structure 4 may be abutted against an external structure, such as the battery device housing Z. Alternatively, the fire extinguishing structure 4 may be abutted against the housing 1 or other structures of the battery cell. It is sufficient that the fire extinguishing structure 4 is disposed opposite the pressure relief mechanism 3.

[0130] Those skilled in the art may select one or more of the above-mentioned configuration methods to configure the fire extinguishing structure 4 according to actual use requirements, and there is no limitation to this.

[0131] In this embodiment, a variety of optional configurations of the fire extinguishing structure 4 are provided, all of which can achieve better cooling and fire extinguishing effects.

[0132] In some embodiments, reference Figure 4-Figure 9 At least one fire extinguishing structure 4 provided at the pressure relief portion 31 is a first fire extinguishing component 4a. The first fire extinguishing component 4a has a through hole 41a. The pressure relief portion 31 is opposite to the through hole 41a and is exposed to the through hole 41a.

[0133] Specifically, in the direction of distribution between the first wall 121 and the electrode assembly 2, the first fire extinguishing element 4a is provided with a through hole 41a extending therethrough. The pressure relief portion 31 is opposite the through hole 41a and is exposed within the through hole 41a. Thus, the first fire extinguishing element 4a is disposed at the pressure relief portion 31. As an example, the distribution direction between the first wall 121 and the electrode assembly 2 is the first direction.

[0134] The pressure relief portion 31 is exposed in the through hole 41 a , which may mean that a portion of the pressure relief portion 31 is exposed in the through hole 41 a , or the pressure relief portion 31 is completely exposed in the through hole 41 a .

[0135] In this embodiment, the first fire extinguishing element 4a can be disposed within the housing 12 (e.g., abutting the side of the first wall 121 facing the electrode assembly 2), or can be disposed outside the housing 12 (e.g., abutting the side of the first wall 121 facing away from the electrode assembly 2), without limitation. Alternatively, there can be two first fire extinguishing elements 4a, one disposed within the housing 12 and the other disposed outside the housing 12.

[0136] In this embodiment, the first fire extinguishing element 4a is provided with a through hole 41a, thereby improving the problem of the fire extinguishing structure 4 blocking high-temperature, high-pressure gas and flames, and facilitating the release of the cooled gas. In particular, when the fire extinguishing structure 4 is disposed within the housing 12, the probability of accidents caused by the inability of gas to smoothly exit the housing 12 (for example, the housing 12 expanding and deforming, squeezing other surrounding battery cells) is reduced.

[0137] In some embodiments, the first fire extinguishing component 4a includes an annular portion 41 arranged on the outside of the pressure relief portion 31, the annular portion 41 is surrounded by a through hole 41a, and the minimum distance between any point on the inner edge of the annular portion 41 and the outer peripheral edge of the pressure relief portion 31 is greater than or equal to 0 and less than or equal to 5 mm.

[0138] Specifically, refer to Figure 5 The annular portion 41 can extend along the outer periphery of the pressure relief portion 31 to form a closed annular structure. The annular portion 41 can be a structure of equal width or a structure of unequal width, which is not limited.

[0139] Figure 5 The first dimension D1 indicated in FIG. 1 is the minimum distance between one point on the inner periphery of the annular portion 41 and the outer periphery of the pressure relief portion 31 . The minimum distances between different points on the inner periphery of the annular portion 41 and the outer periphery of the pressure relief portion 31 may be the same or different, and there is no limitation on this.

[0140] For any point on the inner periphery of the annular portion 41, the minimum distance between it and the outer periphery of the pressure relief portion 31 can be 0, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0141] In this embodiment, the minimum distance between any point on the inner edge of the annular portion 41 and the outer periphery of the pressure relief portion 31 is greater than or equal to zero. In other words, the pressure relief portion 31 is completely exposed to the through hole 41a. This further improves the fire extinguishing structure 4's ability to block high-temperature, high-pressure gas and flames. The minimum distance between the inner edge of the annular portion 41 and the outer periphery of the pressure relief portion 31 is less than or equal to 5 mm. This reduces the distance between the annular portion 41 and the pressure relief portion 31, improving the cooling and fire extinguishing effect.

[0142] In some embodiments, reference Figure 5 , the width of the annular portion 41 is greater than or equal to 2 mm. And / or, refer to Figure 7 The thickness of the annular portion 41 is greater than or equal to 1 mm and less than or equal to 10 mm.

[0143] Figure 5 The second dimension D2 indicated in the figure is the width of one position of the annular portion 41. The width of the annular portion 41 specifically refers to the distance between the inner edge and the outer edge of the annular portion 41. The annular portion 41 may be of equal width or unequal width.

[0144] The width of the annular portion 41 is greater than or equal to 2 mm, which means that the width of any position of the annular portion 41 is greater than or equal to 2 mm, and can be 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc. The maximum width of the annular portion 41 can depend on the size of the housing 12 (such as the length and width of the first wall 121), which is not limited thereto.

[0145] Figure 9 The third dimension D3 indicated in the figure is the thickness of the annular portion 41 at one location. The thickness of the annular portion 41 refers to the dimension of the annular portion 41 along the distribution direction of the first wall 121 and the electrode assembly 2. As an example, the distribution direction of the first wall 121 and the electrode assembly 2 is the first direction. The annular portion 41 can have a uniform thickness or a unequal thickness.

[0146] The thickness of the annular portion 41 is greater than or equal to 1 mm and less than or equal to 10 mm, which means that the thickness at any position of the annular portion 41 is greater than or equal to 1 mm and less than or equal to 10 mm, such as 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, etc.

[0147] It is understood that the annular portion 41 is the portion of the fire extinguishing structure 4 that actually performs the fire extinguishing function (e.g., accommodates the fire extinguishing material). A width of the annular portion 41 greater than or equal to 2 mm and / or a thickness of the annular portion 41 greater than or equal to 1 mm help enhance its cooling and fire extinguishing effectiveness. Furthermore, a thickness of the annular portion 41 less than or equal to 10 mm helps conserve space within the housing 12.

[0148] In some embodiments, reference Figure 1 、 Figure 6-Figure 9 The end cap 11 is disposed opposite the first wall 121. The battery cell further includes a support plate 13 and a spacer 14 disposed between the electrode assembly 2 and the first wall 121. Along the distribution direction of the electrode assembly 2 and the first wall 121, annular portions 41 on opposite sides of the spacer 14 are disposed between the support plate 13 and the first wall 121. The thickness of the annular portion 41 is less than or equal to the thickness of the spacer 14.

[0149] As an example, the end cap 11 and the first wall 121 are arranged relative to each other along the first direction, and the support plate 13 is used to support the electrode assembly 2. The electrode assembly 2 and the support plate 13 can be relatively fixed by bonding, for example, referring to Figure 1 The electrode assembly 2 and the support plate 13 can be bonded and fixed by an adhesive tape 23, and the adhesive tape 23 can be blue glue.

[0150] The spacers 14 are used to raise the support plate 13 and the electrode assembly 2 so that the electrode assembly 2 can fit more closely with the end cap 11. The two opposite sides of the spacers 14 along the first direction are in contact with the first wall 121 and the support plate 13 respectively. The specific number of spacers 14 is not limited. For example, refer to Figure 8 A pad 14 can be provided at each of the four corners of the support plate 13.

[0151] Figure 9 The fourth dimension D4 indicated in the figure is the thickness of the spacer 14. The thickness of the spacer 14 refers to the thickness of the spacer 14 along the distribution direction of the support plate 13 and the first wall 121, that is, the thickness along the first direction. The thickness of the annular portion 41 is less than or equal to the thickness of the spacer 14, which means that the thickness of the annular portion 41 at any position is less than the thickness of the spacer 14.

[0152] In this embodiment, the annular portion 41 may be in contact with either the support plate 13 or the first wall 121, or may be in contact with both the support plate 13 and the first wall 121 simultaneously, without limitation. In the case where the annular portion 41 is in contact with both the support plate 13 and the first wall 121 simultaneously, the annular portion 41 may be bonded to either the support plate 13 or the first wall 121, or may be bonded to both the support plate 13 and the first wall 121 simultaneously, or may be in contact with only the support plate 13 and the first wall 121 without being bonded.

[0153] In this embodiment, the annular portion 41 is disposed between the support plate 13 and the first wall 121. This allows for cooling and extinguishing of the high-temperature, high-pressure gas and flames before they escape the pressure relief portion 31, thereby enhancing the fire extinguishing effect. Furthermore, it will be appreciated that the thickness of the fire extinguishing structure 4 being smaller than that of the spacer 14 reduces the pressure it bears from the electrode assembly 2, thereby reducing the probability of damage to the electrode assembly under pressure, which could lead to the premature release of the fire extinguishing material.

[0154] In some embodiments, reference Figure 10 At least one of the fire extinguishing structures 4 arranged at the pressure relief portion 31 is a second fire extinguishing component 4b. The second fire extinguishing component 4b is arranged between the electrode assembly 2 and the first wall 121. The second fire extinguishing component 4b is arranged on one side of the pressure relief portion 31 along a direction perpendicular to the distribution direction of the electrode assembly 2 and the first wall 121.

[0155] As an example, the distribution direction of the electrode assembly 2 and the first wall 121 is the first direction, and the second fire extinguishing component 4b can be arranged on one side of the pressure relief portion 31 along the second direction or the third direction. Of course, it can also be arranged on one side of the pressure relief portion 31 along other directions perpendicular to the first direction.

[0156] In this embodiment, the second fire extinguishing element 4b is disposed between the electrode assembly 2 and the first wall 121. This allows for cooling and extinguishing of the high-temperature, high-pressure gas and flames before they escape the pressure relief portion 31, thereby enhancing fire extinguishing effectiveness. Furthermore, the second fire extinguishing element 4b is disposed to the side of the pressure relief portion 31, rather than directly facing it. This alleviates the problem of the fire extinguishing structure 4 blocking the high-temperature, high-pressure gas and flames, facilitating the release of the cooled gas.

[0157] In some embodiments, still referring to Figure 10 The end cover 11 is arranged opposite to the first wall 121, and the housing 1 also includes a support plate 13 arranged between the electrode assembly 2 and the first wall 121. The second fire extinguishing element 4b is arranged between the support plate 13 and the first wall 121. Along the distribution direction of the electrode assembly 2 and the first wall 121, the opposite side surfaces of the second fire extinguishing element 4b are respectively abutted against the first wall 121 and the support plate 13.

[0158] As an example, the distribution direction of the electrode assembly 2 and the first wall 121 is the first direction. The number of the second fire extinguishing element 4b is multiple, for example, Figure 10 In the illustrated embodiment, there are four second fire extinguishing elements 4 b , which are respectively disposed at the four corners of the first wall 121 .

[0159] In this embodiment, the second fire extinguishing element 4b actually also serves as a spacer 14, that is, it raises the support plate 13 and the electrode assembly 2, thereby simplifying the internal structure of the battery cell.

[0160] It should be noted that, in this embodiment, the cushion block 14 and the second fire extinguishing element 4 b may be provided at the same time, or only the second fire extinguishing element 4 b may be provided without the cushion block 14 .

[0161] It should also be noted that, in this embodiment, the first fire extinguishing element 4a and the second fire extinguishing element 4b may be provided at the same time, or only the second fire extinguishing element 4b may be provided.

[0162] In some embodiments, reference Figure 11-14 The shell 12 includes a second wall 122 connected to the first wall 121 , and the at least one fire extinguishing structure 4 provided at the pressure relief portion 31 is a third fire extinguishing component 4 c , which is provided between the second wall 122 and the electrode assembly 2 .

[0163] As an example, the distribution direction of the electrode assembly 2 and the first wall 121 is the first direction, and the second wall 122 may be a wall of the shell 12 along the second direction or the third direction.

[0164] The third fire extinguishing element 4c may be attached to the second wall 122, or to the electrode assembly 2 (eg, to the insulating film 22 of the electrode assembly 2), or to both at the same time, which is not limited.

[0165] In this embodiment, the third fire extinguishing component 4c is arranged between the second wall 122 and the electrode assembly 2, rather than between the first wall 121 and the electrode assembly 2. In this way, the internal space of the shell 12 can be fully utilized to arrange the fire extinguishing structure 4, thereby obtaining a better fire extinguishing effect.

[0166] In some embodiments, the second wall 122 is the wall with the largest area among all the walls of the housing 1 .

[0167] Taking the distribution direction of the electrode assembly 2 and the first wall 121 as the first direction as an example, the second wall 122 may be a wall of the housing 12 along the second direction.

[0168] In this embodiment, the second wall 122 is the wall with the largest area among all the walls of the shell 12, which makes the second wall 122 the wall closest to the pressure relief portion 31 except for the first wall 121 of the shell 12, thereby allowing the third fire extinguishing element 4c to be relatively closer to the pressure relief portion 31, thereby obtaining a better fire extinguishing effect.

[0169] In some embodiments, along the distribution direction of the electrode assembly 2 and the second wall 122 , the size of the third fire extinguishing element 4 c is greater than or equal to 0.2 mm and less than or equal to 5 mm.

[0170] Taking the second wall 122 as the wall with the largest area among all the walls of the shell 12 as an example, the distribution direction of the electrode assembly 2 and the second wall 122 is the second direction.

[0171] Figure 13 The fifth dimension D5 indicated in the figure is the dimension of a portion of the third fire extinguishing element 4c along the distribution direction of the electrode assembly 2 and the second wall 122. The third fire extinguishing element 4c can be of equal or unequal dimensions in this direction. The dimension of the third fire extinguishing element 4c in this direction is greater than or equal to 0.2 mm and less than or equal to 5 mm, which means that the dimension of any position of the third fire extinguishing element 4c in this direction is greater than or equal to 0.2 mm and less than or equal to 5 mm. For example, the dimension can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0172] In this embodiment, the dimension of the third fire extinguishing element 4c in the distribution direction between the electrode assembly 2 and the second wall 122 is greater than or equal to 0.2 mm, which helps improve its cooling and fire extinguishing effect. Furthermore, it can be understood that the second wall 122 is the largest wall of all the walls of the housing 12, meaning that the surface of the electrode assembly 2 facing the third fire extinguishing element 4c is also the largest surface of all the surfaces of the electrode assembly 2 and is also a relatively fragile surface. In this embodiment, the dimension of the third fire extinguishing element 4c in this direction is less than or equal to 5 mm, which helps reduce the probability of the third fire extinguishing element 4c applying pressure to the large surface of the electrode assembly 2, causing damage to the electrode assembly 2. For example, in the case of a lithium battery, this helps reduce the probability of the third fire extinguishing element 4c applying pressure to the large surface of the electrode assembly 2, causing lithium deposition.

[0173] In some embodiments, reference Figure 13 An arcuate transition surface 123 is formed between the first wall 121 and the second wall 122 . The end of the third fire extinguishing element 4 c is located on the inner side of the arcuate transition surface 123 along the direction of the electrode assembly 2 pointing to the first wall 121 .

[0174] The end of the third fire extinguishing element 4c is located on the inner side of the arc-shaped transition surface 123 . Specifically, in the direction of the electrode assembly 2 pointing to the first wall 121 , the end of the third fire extinguishing element 4c is located on the side of the arc-shaped transition surface 123 away from the first wall 121 .

[0175] In this embodiment, the arcuate transition surface 123 formed between the first wall 121 and the second wall 122 helps to improve the overall structural strength of the shell 12 and reduce the difficulty of preparing the shell 12, and the end of the third fire extinguishing component 4c is located on the inner side of the arcuate transition surface 123, which helps to reduce the possibility of interference between the third fire extinguishing component 4c and the arcuate transition surface 123, thereby facilitating assembly.

[0176] In some embodiments, along the direction of the electrode assembly 2 pointing to the first wall 121, the distance between the end of the third fire extinguishing element 4c and the first wall 121 is greater than or equal to 0.5 mm and less than or equal to 2 mm.

[0177] Figure 13The sixth dimension D6 indicated in the figure is the distance from a point on the end of the third fire extinguishing element 4c to the first wall 121. In this direction, the distances from different points on the end of the third fire extinguishing element 4c to the first wall 121 can be the same or different. The distance between the end of the third fire extinguishing element 4c and the first wall 121 is greater than or equal to 0.5mm and less than or equal to 2mm. Specifically, the distance between any point on the end of the third fire extinguishing element 4c and the surface of the first wall 121 facing the electrode assembly 2 is greater than or equal to 0.5mm and less than or equal to 2mm, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, etc.

[0178] In this embodiment, the distance between the end of the third fire extinguishing element 4c and the first wall 121 is greater than or equal to 0.5 mm, which helps it avoid the connection between the first wall 121 and the second wall 122 (for example, the arc-shaped transition surface 123 between the first wall 121 and the second wall 122); the distance between the end of the third fire extinguishing element 4c and the first wall 121 is less than or equal to 2 mm, which helps shorten the distance between the third fire extinguishing element 4c and the pressure relief portion 31, thereby improving its cooling and fire extinguishing effect.

[0179] In some embodiments, reference Figure 14 The second wall 122 is located on one side of the pressure relief portion 31 in the width direction. Along the length direction of the pressure relief portion 31 , both ends of the third fire extinguishing element 4 c exceed both ends of the pressure relief portion 31 .

[0180] The two ends of the third fire extinguishing element 4c extending beyond the two ends of the pressure relief portion 31 specifically means that, along the length direction of the pressure relief portion 31, both ends of the third fire extinguishing element 4c are located outside the ends of the pressure relief portion 31. In other words, along the length direction of the pressure relief portion 31, the third fire extinguishing element 4c completely covers the pressure relief portion 31.

[0181] In this embodiment, the effective range of the third fire extinguishing element 4c can cover the entire length of the pressure relief portion 31, which can achieve a better cooling and fire extinguishing effect.

[0182] Of course, in some other embodiments, multiple third fire extinguishing elements 4 c may be provided along the length direction of the pressure relief portion 31 , so that the multiple third fire extinguishing elements 4 c together cover the entire length of the pressure relief portion 31 .

[0183] In some embodiments, still referring to Figure 14 The shell 12 includes two second walls 122 arranged opposite to each other, the number of the third fire extinguishing elements 4c is at least two, and at least one third fire extinguishing element 4c is arranged between each second wall 122 and the electrode assembly 2.

[0184] In this embodiment, only one third fire extinguishing member 4c may be provided between each second wall 122 and the electrode assembly 2, or multiple third fire extinguishing members 4c may be provided, which is not limited.

[0185] In this embodiment, third fire extinguishing components 4c are provided between the second side walls on both sides of the pressure relief portion 31 and the electrode assembly 2. This can increase the effective range of the third fire extinguishing components 4c and achieve a better cooling and fire extinguishing effect.

[0186] In some embodiments, reference Figure 15-18 The battery cell also includes an insulating structure 6, which is arranged on the side of the first wall 121 away from the electrode assembly 2 and covers the pressure relief portion 31. At least one of the fire extinguishing structures 4 arranged at the pressure relief portion 31 is a fourth fire extinguishing component 4d, and the fourth fire extinguishing component 4d is arranged on the side of the insulating structure 6 away from the pressure relief portion 31 and is arranged opposite to the pressure relief portion 31. Alternatively, the fourth fire extinguishing component 4d is arranged between the insulating structure 6 and the pressure relief portion 31 and is arranged opposite to the pressure relief portion 31.

[0187] The insulating structure 6 can be, for example, an insulating cover, a blister film, etc., which is not limited thereto, and is mainly used to insulate the outer shell 1 of the battery cell from an external structure (such as a box Z of a battery device).

[0188] Taking the insulating structure 6 as an example, each battery cell can include a blister film, or a plurality of battery cells can share a blister film, without limitation. The blister film can be connected to the housing 1 or to an external structure, as long as it can be maintained in a position covering the pressure relief portion 31.

[0189] The fourth fire extinguishing component 4d can be arranged on the side of the insulating structure 6 away from the pressure relief portion 31. In this case, the fourth fire extinguishing component 4d can be attached to the insulating structure 6, or to an external structure (such as the box Z of the battery device), or to both at the same time.

[0190] The fourth fire extinguishing element 4d can also be arranged on the side of the insulating structure 6 facing the pressure relief portion 31. In this case, the fourth fire extinguishing element 4d can be attached to the insulating structure 6, the pressure relief mechanism 3 and / or the housing 1, or all of the above.

[0191] Alternatively, the number of fourth fire extinguishing elements 4d may be at least two, at least one fourth fire extinguishing element 4d being arranged on the side of the insulating structure 6 away from the pressure relief portion 31 , and at least one fourth fire extinguishing element 4d being arranged on the side of the insulating structure 6 facing the pressure relief portion 31 .

[0192] The fourth fire extinguishing element 4d is arranged opposite to the pressure relief portion 31 in that, along the distribution direction of the pressure relief portion 31 and the fourth fire extinguishing element 4d, the fourth fire extinguishing element 4d at least partially covers the pressure relief portion 31.

[0193] In this embodiment, the fourth fire extinguishing component 4d is arranged outside the shell 1 and opposite to the pressure relief portion 31. In this way, it can achieve a better cooling and fire extinguishing effect and will not prevent the high-temperature and high-pressure gas and flame in the shell 1 from breaking through the pressure relief portion 31.

[0194] The battery cells involved in one or more of the above embodiments will be described in more detail and specifically in conjunction with several specific embodiments below.

[0195] Example 1

[0196] Reference Figures 1-9 The battery cell includes a shell 1, an electrode assembly 2, a pressure relief mechanism 3 and a fire extinguishing structure 4.

[0197] The housing 1 is a square housing, and its height direction is defined as a first direction, its width direction is defined as a second direction, and its length direction is defined as a third direction.

[0198] The outer shell 1 includes an end cover 11 and a shell 12. The end cover 11 is arranged at one end (top end) of the shell 12 along the first direction. The shell 12 includes a first wall 121 (that is, the bottom wall of the shell 12) arranged opposite to the end cover 11 along the first direction, and also includes two second walls 122 arranged opposite to each other along the second direction (the second wall 122 is the wall with the largest area among all the walls of the outer shell 1).

[0199] The pressure relief mechanism 3 includes a pressure relief portion 31 , which is disposed on the first wall 121 .

[0200] At least one fire extinguishing structure 4 is a first fire extinguishing element 4a. The first fire extinguishing element 4a has a through hole 41a. The pressure relief portion 31 is opposite to the through hole 41a and is exposed to the through hole 41a. Specifically, the first fire extinguishing element 4a includes an annular portion 41 disposed outside the pressure relief portion 31, and the annular portion 41 surrounds the through hole 41a.

[0201] The minimum distance between any point on the inner edge of the annular portion 41 and the outer periphery of the pressure relief portion 31 is greater than or equal to 0 and less than or equal to 5 mm. The width of the annular portion 41 is greater than or equal to 2 mm, and the thickness of the annular portion 41 is greater than or equal to 1 mm and less than or equal to 10 mm.

[0202] The housing 1 further includes a support plate 13 and a spacer 14. The support plate 13 is disposed between the electrode assembly 2 and the first wall 121. The spacer 14 is disposed between the support plate 13 and the first wall 121, with opposite side surfaces along the first direction respectively abutting against the support plate 13 and the first wall 121. The thickness of the annular portion 41 is less than that of the spacer 14.

[0203] Example 2

[0204] Reference Figure 1-Figure 3 、 Figure 10 The difference from the first embodiment is that in the second embodiment, at least one fire extinguishing structure 4 is a second fire extinguishing element 4b, which replaces the spacer 14 in the first embodiment. The second fire extinguishing element 4b is respectively abutted against the support plate 13 and the spacer 14 on two opposite sides along the first direction.

[0205] Example 3

[0206] Reference Figure 11-14 The difference from the first embodiment is that in the third embodiment, at least one fire extinguishing structure 4 is a third fire extinguishing component 4 c , and a third fire extinguishing component 4 c is provided between each second wall 122 and the electrode assembly 2 .

[0207] Along the first direction, the distance between the end of the third fire extinguishing element 4c and the first wall 121 is greater than or equal to 0.5 mm and less than or equal to 2 mm. Along the second direction, the dimension of the third fire extinguishing element 4c is greater than or equal to 0.2 mm and less than or equal to 5 mm. Along the third direction, both ends of the third fire extinguishing element 4c extend beyond both ends of the pressure relief portion 31.

[0208] An arcuate transition surface 123 is formed between the first wall 121 and the second wall 122 . Along the direction of the electrode assembly 2 pointing toward the first wall 121 , the end of the third fire extinguishing element 4 c is located on the inner side of the arcuate transition surface 123 .

[0209] Example 4

[0210] Reference Figure 15-18 The difference from the first embodiment is that in the fourth embodiment, at least one fire extinguishing structure 4 is a fourth fire extinguishing component 4d.

[0211] The battery cell further includes an insulating structure 6, which is disposed on a side of the first wall 121 away from the electrode assembly 2 and covers the pressure relief portion 31. A fourth fire extinguishing element 4d is disposed on a side of the insulating structure 6 away from the pressure relief portion 31 and opposite to the pressure relief portion 31.

[0212] Example 5

[0213] Reference Figures 1-18 The difference from the first to fourth embodiments is that in the fifth embodiment, at least two of the first fire extinguishing element 4a, the second fire extinguishing element 4b, the third fire extinguishing element 4c and the fourth fire extinguishing element 4d are simultaneously provided in the battery cell.

[0214] Example 6

[0215] The difference from Examples 1 to 5 is that in Example 6, at least one fire extinguishing structure 4 is arranged at a weak structure of the shell 12 and / or the electrode assembly 2. The weak structure of the shell 12 includes, for example, a weld of the shell 12, and the weak structure of the electrode assembly 2 includes, for example, a fuse position on the electrode assembly 2.

[0216] An embodiment of the present application further provides a battery device, comprising a box Z, and at least one battery cell as described in any of the above embodiments, wherein the battery cell is disposed in the box Z.

[0217] An embodiment of the present application further provides an electrical device, which includes a battery cell or a battery device as described in any of the above embodiments.

[0218] The battery device and the electrical equipment of the embodiments of the present application have all the advantages of the battery device described in any of the above embodiments, which will not be repeated here.

[0219] In the description of this application, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine different embodiments or examples described in this application and features of different embodiments or examples without contradiction.

[0220] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: The battery cell comprises: A housing comprising a shell and an end cap connected to the shell, wherein the shell has a first wall; an electrode assembly, disposed in the housing; The pressure relief mechanism includes a pressure relief portion, the first wall being connected to an outer periphery of the pressure relief portion; and Fire extinguishing structure, wherein at least one of the fire extinguishing structures is arranged at the pressure relief portion.

2. The battery cell according to claim 1, wherein: At least one of the fire extinguishing structures provided at the pressure relief portion is abutted against the housing; and / or At least one of the fire extinguishing structures provided at the pressure relief portion is abutted against the pressure relief mechanism; and / or At least one fire extinguishing structure disposed at the pressure relief portion is disposed outside the housing and is spaced apart from and opposite to the pressure relief portion.

3. The battery cell according to claim 1 or 2, characterized in that: At least one of the fire extinguishing structures provided at the pressure relief portion is a first fire extinguishing component. The first fire extinguishing component has a through hole. The pressure relief portion is opposite to the through hole and is exposed to the through hole.

4. The battery cell according to claim 3, characterized in that The first fire extinguishing component includes an annular portion arranged outside the pressure relief portion, the annular portion surrounds the through hole, and the minimum distance between any point on the inner edge of the annular portion and the outer peripheral edge of the pressure relief portion is greater than or equal to 0 and less than or equal to 5 mm.

5. The battery cell according to claim 4, characterized in that The width of the annular portion is greater than or equal to 2 mm; and / or The thickness of the annular portion is greater than or equal to 1 mm and less than or equal to 10 mm.

6. The battery cell according to claim 4, characterized in that The end cap is arranged opposite to the first wall, and the housing further includes a support plate and a spacer block arranged between the electrode assembly and the first wall. Along the distribution direction of the electrode assembly and the first wall, the opposite side surfaces of the pad are respectively abutted against the first wall and the support plate, the annular portion is arranged between the support plate and the first wall, and the thickness of the annular portion is less than or equal to the thickness of the pad.

7. The battery cell according to claim 1 or 2, characterized in that: At least one of the fire extinguishing structures arranged at the pressure relief portion is a second fire extinguishing component, and the second fire extinguishing component is arranged between the electrode assembly and the first wall. The second fire extinguishing component is arranged on one side of the pressure relief portion along a direction perpendicular to the distribution direction of the electrode assembly and the first wall.

8. The battery cell according to claim 7, characterized in that The end cover is arranged opposite to the first wall, and the outer shell also includes a support plate arranged between the electrode assembly and the first wall. The second fire extinguishing component is arranged between the support plate and the first wall. Along the distribution direction of the electrode assembly and the first wall, the opposite side surfaces of the second fire extinguishing component are respectively abutted against the first wall and the support plate.

9. The battery cell according to claim 1 or 2, characterized in that: The housing includes a second wall connected to the first wall, and the at least one fire extinguishing structure provided at the pressure relief portion is a third fire extinguishing component, and the third fire extinguishing component is provided between the second wall and the electrode assembly.

10. The battery cell according to claim 9, characterized in that: The second wall has the largest area among all the walls of the housing.

11. The battery cell according to claim 10, characterized in that Along the distribution direction of the electrode assembly and the second wall, the size of the third fire extinguishing element is greater than or equal to 0.2 mm and less than or equal to 5 mm.

12. The battery cell according to claim 10, characterized in that An arcuate transition surface is formed between the first wall and the second wall. Along the direction of the electrode assembly pointing toward the first wall, the end of the third fire extinguishing element is located on the inner side of the arcuate transition surface.

13. The battery cell according to claim 10 or 12, characterized in that: Along the direction of the electrode assembly pointing toward the first wall, the distance between the end of the third fire extinguishing element and the first wall is greater than or equal to 0.5 mm and less than or equal to 2 mm.

14. The battery cell according to claim 10, characterized in that The second wall is located on one side of the pressure relief portion in the width direction, and along the length direction of the pressure relief portion, two ends of the third fire extinguishing component exceed two ends of the pressure relief portion.

15. The battery cell according to claim 9, characterized in that The housing includes two second walls arranged opposite to each other, the number of the third fire extinguishing elements is at least two, and at least one third fire extinguishing element is arranged between each second wall and the electrode assembly.

16. The battery cell according to claim 1 or 2, characterized in that: The battery cell further comprises: an insulating structure, the insulating structure being arranged on a side of the first wall away from the electrode assembly and covering the pressure relief portion, and at least one of the fire extinguishing structures arranged at the pressure relief portion being a fourth fire extinguishing component, The fourth fire extinguishing component is arranged on a side of the insulating structure away from the pressure relief portion and is arranged opposite to the pressure relief portion, or the fourth fire extinguishing component is arranged between the insulating structure and the pressure relief portion and is arranged opposite to the pressure relief portion.

17. A battery device, characterized in that: The battery device comprises: cabinet; and At least one battery cell according to any one of claims 1 to 16 is disposed in the box.

18. An electrical device, characterized in that: The electrical equipment comprises the battery cell according to any one of claims 1 to 16, or the battery device according to claim 17.

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