Battery monomer, battery and electric device

Abstract

The utility model discloses a battery monomer, a battery and a power utilization device, the battery monomer comprises an electrode assembly, a shell and a pressure relief mechanism, the electrode assembly comprises a straight area and two bending areas, the two bending areas are respectively located at two sides of the straight area along a first direction, the electrode assembly is accommodated in the shell, and the pressure relief mechanism is arranged in the shell. The shell comprises two first walls oppositely arranged in the first direction, the electrode assembly is located between the two first walls in the first direction, and the pressure relief mechanism is arranged on the first walls. According to the battery monomer, the reliability can be improved.

Description

Technical Field

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

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] The development of battery technology must take into account multiple design factors at the same time. For example, how to improve battery reliability is an important research direction in the battery field. Utility Model Content

[0004] The present application provides a battery cell, a battery and an electrical device, which can improve reliability.

[0005] In a first aspect, the present application provides a battery cell including an electrode assembly, a shell and a pressure relief mechanism, wherein the electrode assembly includes a straight area and two bending areas, wherein the two bending areas are respectively located on both sides of the straight area along a first direction, and the electrode assembly is accommodated in the shell, wherein the shell includes two first walls arranged opposite to each other along a first direction, the electrode assembly is located between the two first walls in the first direction, and the pressure relief mechanism is arranged on the first wall.

[0006] In the technical solution of the embodiment of the present application, an electrode assembly is arranged in the outer shell of the battery cell, and the electrode assembly is provided with a bending zone. Due to its own bending shape structure, there is a certain gap between the bending zone and the outer shell. At the same time, a pressure relief mechanism is arranged on the side wall of the outer shell close to the bending zone. When thermal expansion or abnormal gas production occurs inside the battery, the gap between the aforementioned bending zone and the outer shell facilitates the discharge of the generated gas to the position of the pressure relief mechanism so that it can release pressure in time, thereby improving the reliability of the battery cell.

[0007] According to some embodiments of the present application, the battery cell includes a plurality of electrode assemblies, the electrode assemblies are arranged in sequence along the second direction, the second direction intersects with the first direction, and there is a gap between the bending regions of adjacent electrode assemblies; in the first direction, the gap at least partially overlaps with the pressure relief mechanism. In an embodiment in which a plurality of electrode assemblies are provided, the gaps between adjacent electrode assemblies can further assist in the degassing of the gas.

[0008] According to some embodiments of the present application, in the first direction, the orthographic projection of the pressure relief mechanism is located within the orthographic projection of the gap, so that the gap can cover the pressure relief mechanism, so that the gas can flow smoothly to the location of the pressure relief mechanism.

[0009] According to some embodiments of the present application, the electrode assembly includes a first pole piece, a second pole piece and a separator, the separator is sandwiched between the first pole piece and the second pole piece, and the first pole piece, the second pole piece and the separator are wound. Arranging the electrode assembly into a wound structure can conveniently form a bending area with a gap with the shell while maintaining a high energy density.

[0010] According to some embodiments of the present application, the electrode assembly further includes a tab, which protrudes from the straight region in the third direction, and the first direction and the third direction are arranged to intersect. Extending the tab to the side end of the battery cell can improve its safety performance on the basis of making the tab setting space ample and being suitable for different working environments.

[0011] According to some embodiments of the present application, the electrode assembly includes two tabs, which are respectively arranged on two opposite sides of the main body in the third direction. The tabs extend to both sides to further provide a larger arrangement space for components required for the tabs, such as the poles of the battery cell.

[0012] According to some embodiments of the present application, the housing further comprises two second walls arranged opposite to each other along the second direction, the electrode assembly is wound, the bending area is an arc-shaped structure protruding in a direction away from the straight area, and the arc-shaped structure is at least partially spaced apart from the first wall and the second wall. Setting the bending area as an arc-shaped structure enables a gap to exist between the first wall facing it and the second wall on the side, further facilitating the flow of gas.

[0013] According to some embodiments of the present application, at least one first wall is provided with a groove on one side surface close to the electrode assembly, the groove extends along the third direction, and the first direction intersects the third direction. The convenience of gas flow can be further improved by providing the groove.

[0014] According to some embodiments of the present application, at least one first wall is provided with a plurality of grooves, the plurality of grooves extend in parallel and are arranged at equal intervals in the second direction, and the grooves are arranged in connection with the pressure relief mechanism. The plurality of grooves can further improve the uniformity of gas discharge.

[0015] In a second aspect, the present application provides a battery, comprising the battery cell in any embodiment of the first aspect.

[0016] In a third aspect, the present application provides a battery device, comprising the battery in any embodiment of the second aspect, and the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0018] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0019] Figure 2 An exploded schematic diagram of a battery provided in some embodiments of the present application;

[0020] Figure 3 An exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0021] Figure 4 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0022] Figure 5 Schematic diagram of the structure of battery cells provided in other embodiments of the present application.

[0023] Reference numerals:

[0024] 1000-Vehicles;

[0025] 100-battery cell; 200-battery; 300-controller; 400-motor;

[0026] 10-electrode assembly; 20-housing; 30-pressure relief mechanism; 40-box;

[0027] 11-straight area; 12-bending area; 13-ear; 21-first wall; 22-second wall; 41-first box body; 42-second box body; 43-accommodating part;

[0028] 121-gap; 211-groove;

[0029] X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0030] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0032] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0033] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0035] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0036] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. 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 the specific circumstances.

[0038] In the embodiment of the present application, the battery cell may be a secondary battery cell, which refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0039] The battery cells can be lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc., which are not limited in the embodiments of the present application.

[0040] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode.

[0041] In some embodiments, the electrode assembly further includes a separator, which is disposed between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting while allowing active ions to pass through.

[0042] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

[0043] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is disposed on any one or both of the two facing surfaces of the positive electrode current collector.

[0044] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0045] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0046] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode sheet and the negative electrode sheet.

[0047] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0048] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode sheet and the negative electrode sheet and plays the role of transmitting ions and isolating the positive and negative electrodes.

[0049] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0050] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0051] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0052] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0053] 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.

[0054] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0055] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0056] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0057] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0058] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0059] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0060] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery.

[0061] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0062] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0063] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0064] 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.

[0065] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0066] In the battery field, existing battery cells are usually provided with a pressure relief mechanism at the outer shell, which is used to promptly discharge the pressure when a component in the battery cell has a thermal runaway problem, so as to avoid the battery cell from exploding due to excessive internal pressure.

[0067] In the related art, the electrode assembly inside the battery cell is usually close to the pressure relief mechanism, and the cross-sectional area of ​​the gas guide gap between the two is too small. Therefore, when thermal runaway occurs inside the battery cell, the generated gas cannot be promptly discharged to the pressure relief mechanism, resulting in the pressure relief mechanism being unable to release pressure in time, which in turn leads to a decrease in the overall reliability of the battery cell.

[0068] In view of this, an embodiment of the present application provides a technical solution, which generates a gap between the electrode assembly and the outer shell through the structural characteristics of the bending zone in the electrode assembly, so that the gas generated by thermal expansion can be discharged through the gap, thereby achieving timely pressure relief and improving the safety of the battery cell.

[0069] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries, such as mobile phones, portable devices, laptop computers, electric vehicles, electric cars, ships, spacecraft, electric toys and electric tools, etc., wherein spacecrafts include airplanes, rockets, space shuttles and spacecrafts, etc., electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers.

[0070] The battery cells described in the embodiments of the present application are not limited to being applicable to the electrical devices described above, but for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0071] See also Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 200 may be provided inside the vehicle 1000, and specifically, for example, a battery 200 may be provided at the bottom, front or rear of the vehicle 1000. The battery 200 may be used to power the vehicle 1000, for example, the battery 200 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 300 and a motor 400, and the controller 300 is used, for example, to control the battery to power the motor 400. The battery 200 may be used for starting and navigating the vehicle 1000, and of course, the battery 200 may also be used to drive the vehicle 1000, replacing or partially replacing fuel or natural gas to provide drive for the vehicle 1000.

[0072] Figure 2 Schematic diagram of an explosion of a battery provided in some embodiments of the present application. Figure 2 As shown, the battery 200 includes a case 40 and a battery cell 100 , and the battery cell 100 is accommodated in the case 40 .

[0073] The box body 40 is used to accommodate the battery cell 100, and the box body 40 can be a variety of structures. In some embodiments, the box body 40 may include a first box body portion 41 and a second box body portion 42, the first box body portion 41 and the second box body portion 42 cover each other, and the first box body portion 41 and the second box body portion 42 jointly define a receiving portion 43 for accommodating the battery cell 100. The second box body portion 42 may be a hollow structure with one end open, the first box body portion 41 is a plate-like structure, and the first box body portion 41 covers the open side of the second box body portion 42 to form a box body 40 with a receiving portion 43; the first box body portion 41 and the second box body portion 42 may also be a hollow structure with one side open, and the open side of the first box body portion 41 covers the open side of the second box body portion 42 to form a box body 40 with a receiving portion 43. Of course, the first box body portion 41 and the second box body portion 42 may be a variety of shapes, such as a cylinder, a cuboid, etc.

[0074] In the battery 200, there can be one or more battery cells 100. If there are more than one battery cell 100, the battery cells 100 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that the battery cells 100 are connected in series and in parallel. The battery cells 100 can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the battery cells 100 can be accommodated in the box 40; of course, the battery cells 100 can also be connected in series, in parallel, or in a mixed connection to form a battery module, and then the battery modules can be connected in series, in parallel, or in a mixed connection to form a whole, and then accommodated in the box 40.

[0075] Next, combine with Figure 3 To Attachment Figure 5 The structure of the battery cell 100 is described.

[0076] Please also refer to the attached Figure 3 To Attachment Figure 5 , Figure 3 Schematic diagram of an explosion of a battery cell provided in some embodiments of the present application, Figure 4 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application, Figure 5 Schematic diagram of the structure of battery cells provided in other embodiments of the present application.

[0077] In the first aspect, the present application provides a battery cell 100, including an electrode assembly 10, a shell 20 and a pressure relief mechanism 30, the electrode assembly 10 includes a straight area 11 and two bending areas 12, the two bending areas 12 are respectively located on both sides of the straight area 11 along a first direction X, the electrode assembly 10 is accommodated in the shell 20, the shell 20 includes two first walls 21 arranged opposite to each other along the first direction X, the electrode assembly 10 is located between the two first walls 21 in the first direction X, and the pressure relief mechanism 30 is arranged on the first wall 21.

[0078] The present application provides a battery cell 100 , which includes a housing 20 , an electrode assembly 10 disposed in the housing 20 , and a pressure relief mechanism 30 disposed on the housing 20 .

[0079] Specifically, in the first direction X, the housing 20 has two first walls 21 arranged opposite to each other, and the two first walls 21 may have the same or similar shapes and sizes, so that the housing 20 has a regular shape. At the same time, in the first direction X, the electrode assembly 10 includes a straight region 11 and two bending regions 12 located on both sides of the straight region 11, wherein the straight region 11 may be an entirety extending along the first direction X and having a relatively flat edge, and having two sets of layer structures stacked on each other, and the bending regions 12 are arranged on both sides and may be connected between the aforementioned two layer structures, so that the electrode assembly 10 is connected as a whole, and the two bending regions 12 on both sides of the straight region 11 may be arranged opposite to each other in the first direction X.

[0080] The bending region 12 may be a region having a bending structure in the electrode assembly 10. In an embodiment in which the electrode assembly 10 includes a first electrode sheet and a second electrode sheet, the portion of the first electrode sheet located in the bending region 12 and the portion of the second electrode sheet located in the bending region 12 are both bent. For example, the portion of the first electrode sheet located in the bending region 12 and the portion of the second electrode sheet located in the bending region 12 are generally bent into an arc shape, a broken line shape, etc.

[0081] Optionally, only a part of the electrode assembly 10 is the bending area 12, and the electrode assembly 10 may be flat and include a straight area 11 and a bending area 12, and the bending area 12 is connected to the straight area 11. The straight area 11 may be an area where the electrode assembly 10 has a straight structure, and the portion of the first pole piece located in the straight area 11 and the portion of the second pole piece located in the straight area 11 may be substantially straight, that is, extending along a plane.

[0082] The pressure relief mechanism 30 is disposed on the first wall 21. Optionally, the pressure relief mechanism 30 may be in the form of a structure in which a weak portion is formed on the first wall 21 to form an explosion-proof valve. The battery cell 100 may be optionally provided with one or more pressure relief mechanisms 30. In an embodiment in which multiple pressure relief mechanisms 30 are provided, these pressure relief mechanisms 30 may be provided on the same first wall 21, or these pressure relief mechanisms 30 may be provided on two first walls 21 respectively. Under the premise that they do not interfere with other components such as electrode segments on the housing 20, the pressure relief mechanism 30 may be provided at any suitable position on the first wall 21.

[0083] Optionally, the bending zone 12 and the first wall 21 in the electrode assembly 10 can be spaced apart or partially abutted against each other. Through the partial structure of the bending zone 12 itself protruding from the straight zone 11, a gap can be formed between the electrode assembly 10 and the first wall 21. The gap can be connected to the position of the pressure relief mechanism 30. In the event of thermal runaway or abnormal gas production, the generated gas can be diverted to the pressure relief mechanism 30 so that it can be released in time, thereby improving the overall reliability of the battery cell 100.

[0084] In some optional embodiments, the battery cell 100 includes a plurality of electrode assemblies 10, which are arranged in sequence along a second direction Y, the second direction Y intersects with the first direction X, and there is a gap 121 between the bending regions 12 of adjacent electrode assemblies 10; in the first direction X, the gap 121 at least partially overlaps with the pressure relief mechanism 30.

[0085] Optionally, in the battery cell 100, a plurality of electrode assemblies 10 may be disposed inside the housing 20 at the same time, and these electrode assemblies 10 may be arranged in sequence along the second direction Y, and the second direction Y and the first direction X and the axial directions of the electrode assemblies 10 may intersect each other in pairs. Each electrode assembly 10 includes a straight region 11 and a bending region 12, and in the second direction Y, the straight region 11 and the bending region 12 in each electrode assembly 10 may be disposed correspondingly, respectively, that is, the orthographic projections of each electrode assembly 10 in the second direction Y overlap each other.

[0086] Through the setting of its own structural form, the extension dimension of the bending zone 12 in the second direction Y can be smaller than the extension dimension of the straight zone 11 in this direction. Therefore, under the premise that the straight zones 11 are abutted or have a small interval, there is a certain gap 121 between the bending zones 12. The gap 121 extends parallel to the axial direction of the electrode assembly 10 and can partially overlap with the pressure relief mechanism 30, that is, it can be connected with the position of the pressure relief mechanism 30, so that the gas generated by thermal runaway can flow to the pressure relief mechanism 30 through the gap 121.

[0087] Therefore, in an embodiment where a plurality of electrode assemblies 10 are disposed in the battery cell 100 , the gaps 121 between adjacent electrode assemblies 10 can further facilitate the flow of gas to the pressure relief mechanism 30 .

[0088] In some optional embodiments, the electrode assembly 10 includes a first pole piece, a second pole piece, and an isolating member, the isolating member is sandwiched between the first pole piece and the second pole piece, and the first pole piece, the second pole piece, and the isolating member are wound.

[0089] Optionally, the electrode assembly 10 may include a first electrode sheet, a second electrode sheet, and a separator that are stacked. In the stacking direction, the first electrode sheet and the second electrode sheet may be alternately arranged, and a separator is sandwiched between every two layers of the first electrode sheet and the second electrode sheet. Subsequently, the stacked first electrode sheet, the second electrode sheet, and the separator are wound to form the electrode assembly 10, that is, the electrode assembly 10 can be manufactured by winding.

[0090] By setting the electrode assembly 10 as a winding structure, it is possible to easily form a straight area 11 and a bending area 12 having a gap with the outer shell 20, that is, the winding structure can naturally form a bending area 12 with a corner, so that the bending area 12 is at least partially spaced apart from the first wall 21, thereby forming the required additional air conduction gap without reducing the size of the electrode assembly 10 in the first direction X, thereby allowing the battery cell 100 to maintain a higher energy density.

[0091] In some optional embodiments, in the first direction X, the orthographic projection of the pressure relief mechanism 30 is located within the orthographic projection of the gap 121.

[0092] By adjusting the structure and size of the bending area 12, the shape and size of the gap 121 between the electrode assemblies 10 can be adjusted accordingly, so that it extends in the same direction as the axial direction of the electrode assembly 10, and its position in the second direction Y can correspond to the position of the pressure relief mechanism 30. By making the orthographic projection of the gap 121 cover the pressure relief mechanism 30, the smoothness and convenience of gas flow can be further improved, and in the case of blockage problems in some areas of the gap 121, the battery cell 100 can still maintain good reliability.

[0093] In some optional embodiments, the electrode assembly 10 further includes a pole ear 13, and at least one of the two opposite ends of the straight region 11 in the third direction Z is protruding with a pole ear 13, and the first direction X, the second direction Y and the third direction Z are intersected in pairs.

[0094] The electrode assembly 10 may include a straight area 11 and a bent area 12 formed by stacking and winding the aforementioned first electrode sheet, the second electrode sheet and the isolation member, and a pole ear 13 protruding from the first pole sheet and the second pole sheet respectively. The pole ear 13 may be protruded from at least one of the two ends of the electrode assembly 10 in its own axial direction, that is, in the third direction Z, and be led out to the electrode terminal by at least one of the two side walls opposite to each other in the third direction Z of the outer shell 20, so as to facilitate electrical connection with the outside world.

[0095] Extending the tab 13 to the third direction Z of the battery cell 100, that is, to the side end, can improve its safety performance on the basis of making the arrangement space of the tab 13 ample and suitable for different working environments. At the same time, in the embodiment where the tab 13 is led out from the end in the third direction Z, the extension dimension of the battery cell 100 in the third direction Z is usually large. By providing the electrode assembly 10 with the bending area 12 in the battery cell 100 of this structural form, the convenience of gas circulation in the third direction Z can be effectively increased, thereby effectively improving the reliability of the battery cell 100.

[0096] In some optional embodiments, the electrode assembly 10 includes two electrode tabs 13 , and the two electrode tabs 13 are respectively disposed on two opposite sides of the straight region 11 in the third direction Z.

[0097] Optionally, the electrode assembly 10 may have two pole tabs 13, which are respectively connected to the first pole piece and the second pole piece, and each pole tab 13 may be formed by stacking a plurality of prepared pole tabs. Further, the pole tabs 13 may be respectively protruded from opposite ends of the straight region 11 in the third direction Z, and terminal assemblies are respectively provided on the corresponding two side walls of the housing 20.

[0098] By extending the pole ears 13 to both sides in the third direction Z, the components required for the external electrical connection of the pole ears 13, such as the terminal assembly of the battery cell 100, can have a larger installation space, reducing the possibility of mutual interference and influence among the components on the shell 20, thereby further improving the reliability of the battery cell 100.

[0099] In some optional embodiments, the housing 20 further includes two second walls 22 arranged opposite to each other along the second direction Y, the bending area 12 is an arc-shaped structure protruding away from the straight area 11, and the arc-shaped structure is at least partially spaced apart from the first wall 21 and the second wall 22.

[0100] The housing 20 also includes two second walls 22 arranged opposite to each other in the second direction Y. The two second walls 22 may have the same or similar structure and size so that the overall shape of the housing 20 is regular. As mentioned above, the electrode assembly 10 may be made of a winding structure. By winding and shaping, the bending area 12 may be an arc-shaped structure, so that the overall cross-section of the electrode assembly 10 may be in a shape similar to a waist-shaped hole. Thus, in an embodiment where the electrode assembly 10 abuts against the first wall 21, a gap area with a gradually decreasing size in the second direction Y may be formed between the edge of the arc-shaped structure that shrinks toward the straight area 11 and the first wall 21, and the airflow may pass through the gap area more smoothly.

[0101] Optionally, in the second direction Y, the gap between the electrode assembly 10 and the second wall 22 can be 0-5mm to save space inside the housing 20. Optionally, on the basis of the limited extension dimension of the housing 20 in the second direction Y, as the number of electrode assemblies 10 increases, the gap between the bending areas 12 of adjacent electrode assemblies 10 tends to decrease. Specifically, the spacing between the two second walls 22 is recorded as c, the minimum spacing between the edgemost electrode assembly 10 and the second wall 22 is recorded as n, and the number of electrode assemblies 10 is recorded as y, then the gap cross-sectional area D between the electrode assembly 10 at the edge and the first wall 21 and the second wall 22 is calculated as D = [(C-2n) / (2*y)+n]^2-Π / 2*[(C-2n) / (2*y)+n]. Therefore, on the basis of meeting the electrical performance standards of the battery cell 100, the number of electrode assemblies 10 can be less, for example, less than or equal to 10, and can be optionally 1-6.

[0102] In some optional embodiments, a groove 211 is further provided on a surface of at least one side of the first walls 21 close to the electrode assembly 10 , and the groove 211 extends along the third direction Z.

[0103] The first wall 21 may also be provided with a groove 211, which starts from a side surface of the first wall 21 close to the electrode assembly 10 and is recessed in a direction away from the electrode assembly 10. The ratio between the depth of the groove 211 and the thickness of the first wall 21 may be 0.2-0.5, for example, one of 0.2, 0.3, 0.4, and 0.5 may be selected, so that the groove 211 has a certain cross-sectional area on the basis of ensuring the structural strength of the first wall 21, so as to facilitate gas flow. Optionally, the cross section of the groove 211 may be rectangular, arc-shaped, triangular, etc.

[0104] Optionally, the groove 211 can be arranged on the same side as the pressure relief mechanism 30. In an embodiment where the pressure relief mechanism 30 is arranged on one of the first walls 21, the groove 211 and the pressure relief mechanism 30 are arranged on the same side of the first wall 21 to ensure smooth gas flow.

[0105] By providing the groove 211 on the first wall 21 , the gas flow convenience along the third direction Z can be further improved, thereby further improving the reliability of the battery cell 100 .

[0106] In some optional embodiments, at least one first wall 21 is provided with a plurality of grooves 211 , the plurality of grooves 211 extend in parallel and are arranged at equal intervals in the second direction Y, and the grooves 211 are arranged in connection with the pressure relief mechanism 30 .

[0107] Optionally, a plurality of grooves 211 may be provided on the same first wall 21 at the same time. These grooves 211 may have the same shape and size and may extend parallel to each other along the third direction Z. At the same time, these grooves 211 may be arranged at equal intervals in the second direction Y. Optionally, the connecting arrangement here means that the groove 211 can be connected to the pressure relief mechanism 30, or extend to the specific position where the pressure relief mechanism 30 is located. Each groove 211 may be connected to the pressure relief mechanism 30, and may be connected by directly overlapping, or may be connected by adding a conducting groove body between the plurality of grooves 211.

[0108] The provision of a plurality of grooves 211 can further improve the uniformity and convenience of gas exhaust, thereby further improving the overall reliability of the battery cell 100 .

[0109] In a second aspect, the present application provides a battery 200 , comprising the battery cell 100 in any embodiment of the first aspect.

[0110] In a third aspect, the present application provides a battery device, comprising the battery 200 in any embodiment of the second aspect, and the battery 200 is used to provide electrical energy.

[0111] The battery 200 and the electrical device provided in the embodiment of the present application have all the beneficial effects of the battery cell 100 in any of the embodiments of the first aspect mentioned above. For details, please refer to the specific description of the battery cell 100 in the above embodiments, and this embodiment will not be repeated here.

[0112] The present application provides a battery cell 100, including an electrode assembly 10, a shell 20 and a pressure relief mechanism 30. The electrode assembly 10 includes a straight area 11 and two bending areas 12, and the two bending areas 12 are respectively located on both sides of the straight area 11 along the first direction X. The electrode assembly 10 is accommodated in the shell 20, and the shell 20 includes two first walls 21 arranged oppositely along the first direction X and two second walls 22 arranged oppositely along the second direction Y. The electrode assembly 10 is located between the two first walls 21 in the first direction X, and the pressure relief mechanism 30 is arranged on the first wall 21. The electrode assembly 10 includes a first pole sheet, a second pole sheet and a separator, and the three are wound. The electrode assembly 10 includes a straight area 11 and a plurality of pole ears 13, and the plurality of pole ears 13 are respectively protruded from both sides of the straight area 11 in the third direction Z.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, comprising a straight region and two bending regions, wherein the two bending regions are respectively located on two sides of the straight region along a first direction; a housing, the electrode assembly being accommodated in the housing, the housing comprising two first walls arranged opposite to each other along the first direction, the electrode assembly being located between the two first walls in the first direction; The pressure relief mechanism is arranged on the first wall.

2. The battery cell according to claim 1, characterized in that: The battery cell comprises a plurality of electrode assemblies, the electrode assemblies are arranged in sequence along a second direction, the second direction intersects with the first direction, and there is a gap between the bending regions of adjacent electrode assemblies; In the first direction, the gap at least partially overlaps with the pressure relief mechanism.

3. The battery cell according to claim 2, characterized in that: In the first direction, the orthographic projection of the pressure relief mechanism is located within the orthographic projection of the gap.

4. The battery cell according to claim 1, characterized in that: The electrode assembly further includes a pole ear, which protrudes from the straight region in a third direction, and the first direction and the third direction are arranged to intersect.

5. The battery cell according to claim 4, characterized in that: The electrode assembly includes two electrode tabs, which are respectively arranged on two opposite sides of the straight area in the third direction.

6. The battery cell according to claim 1, characterized in that: The shell also includes two second walls arranged opposite to each other along a second direction. The electrode assembly is wound, and the bending area is an arc-shaped structure protruding away from the straight area. The arc structure is at least partially spaced apart from the first wall and the second wall.

7. The battery cell according to claim 1, characterized in that: A groove is provided on a surface of at least one of the first walls close to the electrode assembly, and the groove extends along a third direction, and the first direction intersects with the third direction.

8. The battery cell according to claim 7, characterized in that: The first wall is provided with a plurality of grooves, the plurality of grooves extend in parallel and are arranged at equal intervals in the second direction, and the grooves are connected to the pressure relief mechanism.

9. A battery, characterized in that: The invention comprises at least one battery cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: Comprising a battery as claimed in claim 9, the battery is used to provide electrical energy.

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