Battery monomer, battery device and electric equipment

Abstract

The utility model relates to the technical field of batteries, and provides a single battery, a battery device and electric equipment, the single battery comprises a shell, an electrode assembly and a drainage cap, the shell is provided with a containing cavity, a liquid injection opening communicated with the containing cavity is formed in the top of the shell, and the liquid injection opening is used for injecting electrolyte; the electrode assembly is arranged in the accommodating cavity; the drainage cap is arranged in the containing cavity, located between the liquid injection opening and the electrode assembly and used for guiding the electrolyte injected from the liquid injection opening to the periphery. The flow direction of the electrolyte is effectively guided through the drainage cap, the probability that the electrolyte at the liquid injection port directly makes contact with the top of the electrode assembly is reduced, the electrolyte directionally infiltrates the electrode assembly, gas in the middle of the electrode assembly can be discharged from the top of the electrode assembly, the liquid sealing phenomenon is prevented to a certain degree, and the infiltration effect is improved; the risk of problems such as black spots and / or metal precipitation in the middle of the electrode assembly in the circulation process is reduced, and the performance and the service life of the battery monomer are improved.

Description

Technical Field

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

[0002] Battery cells can be used to store or provide electrical energy. Battery cells can be used in electrical devices. For example, battery cells can be used in vehicles or energy storage devices, etc.

[0003] In the related art, a liquid injection process is required during the production of battery cells. The liquid injection process refers to injecting electrolyte into the battery cells. During the liquid injection process, if the electrolyte fails to fully infiltrate the electrode assembly, resulting in poor infiltration of the electrode assembly, after the battery cell is cycled, the electrode assembly is prone to problems such as black spots and / or metal precipitation, affecting the service life of the battery cell. Utility Model Content

[0004] In view of this, the embodiments of the present application hope to provide a battery cell, a battery device and an electrical equipment, which can effectively guide the flow of electrolyte through a drainage cap, reduce the probability of the electrolyte at the injection port directly contacting the top of the electrode assembly, and improve the wetting effect.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the embodiment of the present application is implemented as follows:

[0006] The present application provides a battery cell, including:

[0007] A shell having a receiving cavity, wherein a liquid injection port communicating with the receiving cavity is formed on the top of the shell, and the liquid injection port is used to inject electrolyte;

[0008] An electrode assembly is disposed in the accommodating cavity;

[0009] A drainage cap is arranged in the accommodating cavity, and the drainage cap is located between the liquid injection port and the electrode assembly. The drainage cap guides the electrolyte injected from the liquid injection port to the periphery.

[0010] In the battery cell provided by the embodiment of the present application, the drainage cap is located between the injection port and the electrode assembly, and the drainage cap guides the electrolyte injected from the injection port to the periphery. During the injection process, the electrolyte passes through the injection port and enters the bottom of the accommodating cavity under the guidance of the drainage cap. Specifically, the electrolyte from the injection port contacts the top surface of the drainage cap and flows along the top surface of the drainage cap to the periphery of the drainage cap. In this way, the drainage cap can block the electrolyte from directly impacting the top of the electrode assembly to a certain extent. The electrolyte flows to the periphery under the guidance of the drainage cap, and the electrolyte flows from the drainage cap and the periphery of the accommodating cavity. The electrolyte flows toward the bottom through the gap between the surfaces, and climbs from the bottom of the electrode assembly to the top and infiltrates the electrode assembly. In this way, the flow direction of the electrolyte is effectively guided by the drainage cap, reducing the probability of the electrolyte at the injection port directly contacting the top of the electrode assembly, allowing the electrolyte to directionally infiltrate the electrode assembly, which is beneficial for the gas in the middle of the electrode assembly to be discharged from the top of the electrode assembly, preventing liquid sealing to a certain extent, improving the infiltration effect, and reducing the risk of black spots and / or metal precipitation in the middle of the electrode assembly during the cycle, thereby improving the performance and service life of the battery cell.

[0011] In some embodiments, taking a plane perpendicular to the top and bottom directions as a projection plane, a projection edge line of the electrode assembly does not exceed a projection edge line of the drainage cap.

[0012] In this embodiment, the projected edge line of the electrode assembly does not exceed the projected edge line of the drainage cap, and the drainage cap can more comprehensively shield the electrode assembly, reducing the probability that the top of the electrode assembly directly contacts the electrolyte from the injection port.

[0013] In some embodiments, taking a plane perpendicular to the top and bottom directions as a projection plane, a distance between a projection edge line of the electrode assembly and a projection edge line of the drainage cap is D1, 0 mm ≤ D1 ≤ 1 mm.

[0014] In this embodiment, in the projection plane perpendicular to the top and bottom directions, D1 is between 0 mm and 1 mm, and the distance between the projection edge line of the electrode assembly and the projection edge line of the drainage cap is small. The drainage cap can minimize the occupied space while taking into account the diversion requirements.

[0015] In some embodiments, the battery cell includes at least two electrode assemblies, and the projection plane is a plane perpendicular to the top and bottom directions, and the projections of all the electrode assemblies are located within the projection edge line of the drainage cap.

[0016] In this embodiment, in the projection plane perpendicular to the top and bottom directions, the projections of all electrode assemblies are located within the projection edge line of the drainage cap, that is, the projection edge line of the drainage cap surrounds the projections of all electrode assemblies. In this way, one drainage cap can basically cover all electrode assemblies, reducing the number of parts.

[0017] In some embodiments, the electrode assembly includes a pole ear, the drainage cap forms a avoidance opening, and the projection of the pole ear is located within the projection contour of the avoidance opening, taking a plane perpendicular to the top and bottom directions as a projection surface.

[0018] In this embodiment, in the projection plane perpendicular to the top and bottom directions, the projection of the pole ear is located within the projection contour of the avoidance opening, so that the pole ear can be electrically connected to the electrode terminal through the avoidance opening, avoiding the drainage cap from blocking the pole ear and reducing the difficulty of assembly.

[0019] In some embodiments, a plane perpendicular to the top and bottom directions is taken as a projection plane, and a distance between a projection of the avoidance opening wall surface and a projection of the pole ear is D2, 0.5 mm ≤ D2 ≤ 10 mm.

[0020] In this embodiment, in the projection plane perpendicular to the top and bottom directions, D2 is between 0.5 mm and 10 mm, and there is a gap between the wall of the avoidance port and the pole ear. In this way, it is convenient to penetrate the pole ear to set the avoidance port, taking into account the manufacturing and assembly requirements. The distance between the wall of the avoidance port and the pole ear is small, and most of the electrolyte is still diverted to the periphery by the drainage cap, and only a small amount of electrolyte leaks to the bottom side through the gap between the wall of the avoidance port and the pole ear.

[0021] In some embodiments, the pole lug is inserted into the avoidance opening; or, the pole lug is located at the bottom side of the avoidance opening.

[0022] In this embodiment, the tab is inserted into the avoidance opening. In this way, the tab is convenient for connecting with the electrode terminal. The tab is located at the bottom side of the avoidance opening. In this way, the tab can be prevented from contacting the wall surface of the avoidance opening, reducing the wear between the structural parts.

[0023] In some embodiments, the number of the avoidance openings is the same as the number of the pole lugs, and each of the avoidance openings is provided with one pole lug.

[0024] In this embodiment, a pole ear is provided through each avoidance opening, which makes it easier to assemble the drainage cap and the electrode assembly.

[0025] In some embodiments, the drainage cap includes at least two guide portions that are spaced apart from each other, and the avoidance opening is formed between two adjacent guide portions.

[0026] In this embodiment, the pole ear is located between two adjacent guide portions, and the drainage cap can be a plurality of discrete guide portions, which can reduce the material usage of the drainage cap and save costs.

[0027] In some embodiments, the drainage cap is an integrally formed structure.

[0028] In this embodiment, the drainage cap has good structural strength and can save assembly steps for the drainage cap.

[0029] In some embodiments, the drainage cap includes two inclined plates, the top ends of the two inclined plates are connected, and the bottom ends of the two inclined plates are far away from each other.

[0030] In this embodiment, the top ends of the two inclined plates are connected, and the bottom ends of the two inclined plates are far away from each other, that is, the drainage cap is roughly in an inverted V shape, so that the electrolyte can flow to the periphery at an accelerated speed under the guidance of the inclined plates.

[0031] In some embodiments, the liquid injection port is located on the top side of the top ends of the two inclined plates.

[0032] In this embodiment, the electrolyte injected from the injection port first contacts the top of the two inclined plates and then flows toward the periphery along the inclined plates. The top of the two inclined plates can divert the electrolyte so that the electrolyte can flow from multiple positions of the drainage cap to the bottom side, and the electrolyte can flow to the bottom of the electrode assembly faster.

[0033] In some embodiments, the drainage cap is a flat plate structure that intersects with the top and bottom directions.

[0034] In this embodiment, the drain cap is a flat plate structure, which is simple and easy to manufacture. The flat plate structure intersects with the top and bottom directions, for example, the flat plate structure intersects with the top and bottom directions perpendicularly, and the drain cap can block the electrolyte from the liquid injection port, and the electrolyte can flow in all directions along the top surface of the drain cap to guide the periphery of the drain cap.

[0035] An embodiment of the present application provides a battery device, comprising at least two battery cells as described above.

[0036] An embodiment of the present application further provides an electrical device, characterized in that it comprises any one of the battery cells or the battery devices described above, wherein the battery cells or the battery devices are used to store or provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of the structure of a vehicle in some embodiments of the present application;

[0038] Figure 2 An exploded schematic diagram of a battery device in some embodiments of the present application;

[0039] Figure 3 A schematic diagram of the structure of a battery cell in some embodiments of the present application;

[0040] Figure 4 for Figure 3 A schematic diagram of a partial structure of a battery cell, wherein the end cover of the housing is not shown;

[0041] Figure 5 Schematic diagram of a partial structure of a battery cell in some other embodiments of the present application;

[0042] Figure 6 for Figure 3 A schematic cross-sectional view of a battery cell;

[0043] Figure 7 Schematic cross-sectional views of battery cells in other embodiments of the present application;

[0044] Figure 8 Schematic cross-sectional views of battery cells in some other embodiments of the present application.

[0045] Description of Reference Numerals

[0046] 1000, vehicle; 100, battery device; 2, housing; 21, first housing; 22, second housing; 200, controller; 300, motor; 1, battery cell; 11, housing; 11a, accommodating chamber; 11b, liquid filling port; 12, electrode assembly; L1, projection edge line of electrode assembly 12; 121, pole ear; 13, drainage cap; L2, projection edge line of drainage cap 13; 13a, avoidance port; 131, guide portion; 132, inclined plate; 14, insulating package. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] In the description of the embodiments of the present application, technical terms such as "first" and "second" 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.

[0050] 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.

[0051] It should be noted that, in the present application, at least two includes a quantity of two and more than two. A plurality includes a quantity of two and more than two. The unit "mm" is millimeter. The first direction, the second direction and the top and bottom directions are perpendicular to each other, the first direction is represented by X, the second direction is represented by Y, the top and bottom directions are represented by Z, the top side and the bottom side are the two sides opposite to the top and bottom directions, the top side is represented by Z1, and the bottom side is represented by Z2.

[0052] See also Figures 1 to 3 To facilitate understanding of the battery cell 1, the battery device 100 and the electrical equipment provided in the embodiment of the present application, some basic structures of the battery cell 1, the battery device 100 and the electrical equipment provided in the embodiment of the present application are first introduced.

[0053] In the embodiment of the present application, the battery cell 1 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 1 is discharged.

[0054] The battery cell 1 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0055] See also Figures 6 to 8 The battery cell 1 generally includes an electrode assembly 12, which includes a positive electrode, a negative electrode, and a separator, and the separator is arranged between the negative electrode and the positive electrode. During the charge and discharge process of the battery cell 1, active ions (such as lithium ions) are embedded and released back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time allow the active ions to pass through.

[0056] 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 disposed on at least one surface of the positive electrode current collector.

[0057] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0058] As an example, the positive electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium or silver, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0059] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO 4 (also referred to as LFP), composite materials of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), at least one of a composite material of lithium manganese phosphate and carbon, a composite material of lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0060] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0061] As an example, the negative electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel, titanium or silver, etc., may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0062] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0063] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0064] As an example, the negative electrode active material may adopt the negative electrode active material for battery cell 1 known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for battery cell 1 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0065] 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.

[0066] 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.

[0067] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be coated on the surface of the separator.

[0068] In some embodiments, the battery cell 1 further includes an electrolyte, which plays a role in conducting 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.

[0069] The electrolyte solution may include an electrolyte salt and a solvent.

[0070] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0071] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent can also be selected from ether solvents. Ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0072] In some embodiments, the electrolyte may also optionally include additives. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell 1, such as additives that improve the overcharge / fast charge performance of the battery cell 1, additives that improve the high temperature performance of the battery cell 1, and additives that improve the low temperature performance of the battery cell 1.

[0073] The electrode assembly 12 may be a wound structure, a laminated structure, or a mixed structure of a wound structure and a laminated structure.

[0074] In some embodiments, the electrode assembly 12 is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0075] In some embodiments, the electrode assembly 12 is a laminate structure.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] In some embodiments, the shape of the electrode assembly 12 can be cylindrical, flat, or polygonal.

[0082] In some embodiments, see Figures 6 to 8The electrode assembly 12 is provided with a pole ear 121, and the pole ear 121 can lead the current from the electrode assembly 12. The pole ear 121 includes a positive pole ear 121 and a negative pole ear 121.

[0083] In some embodiments, the battery cell 1 may include a housing 11. The housing 11 may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), or a composite metal housing (such as a copper-aluminum composite housing).

[0084] As an example, the battery cell 1 can be a cylindrical battery cell, a prismatic 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 cell. The polygonal battery cell is, for example, a hexagonal battery cell, etc. There is no special limitation in this application.

[0085] In some embodiments, the housing 11 includes an end cap and a shell, the shell is provided with an opening, and the end cap is provided to cover the opening. The shell may be provided with one or more openings. One or more end caps may also be provided.

[0086] In some embodiments, at least one electrode terminal is disposed on the housing 11, and the electrode terminal is electrically connected to the tab 121. The electrode terminal may be directly connected to the tab 121, or may be indirectly connected to the tab 121 through a current collecting member. The electrode terminal may be disposed on an end cap or on the housing.

[0087] In some embodiments, a pressure relief mechanism is provided on the housing 11 , and is used to discharge the internal gas of the battery cell 1 .

[0088] As an example, when the internal pressure or temperature of the battery cell 1 reaches a predetermined threshold, it is actuated to release the internal pressure or temperature. When the internal pressure or temperature of the battery cell 1 reaches a predetermined threshold, the pressure relief mechanism performs an action or a weak structure provided in the pressure relief mechanism is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released. The threshold design varies according to different design requirements. The threshold may depend on one or more materials of the positive electrode sheet, negative electrode sheet, electrolyte and separator in the battery cell 1.

[0089] As an example, the pressure relief mechanism may be integrally formed with the housing 11 .

[0090] As an example, the pressure relief mechanism may also be separately provided and connected to the housing 11 .

[0091] The "actuation" mentioned in this application means that the pressure relief mechanism is in action or activated to a certain state, so that the internal pressure and temperature of the battery cell 1 can be released. The action produced by the pressure relief mechanism may include but is not limited to: the components in the pressure relief mechanism move to form an exhaust channel, at least a part of the pressure relief mechanism ruptures, breaks, is torn or opened, etc. When the pressure relief mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell 1 will be discharged from the actuated part as emissions. In this way, the battery cell 1 can be depressurized and cooled under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0092] See also Figure 2 An embodiment of the present application provides a battery device 100, and the battery device 100 includes at least two battery cells 1 in any one embodiment of the present application.

[0093] The battery apparatus 100 mentioned in the embodiment of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells 1 .

[0094] A plurality of battery cells 1 can be connected in series, in parallel or in mixed connection through a busbar component. The busbar component is used to realize electrical connection between at least two battery cells 1.

[0095] Exemplarily, hybrid connection means that at least two battery cells 1 are both connected in series and in parallel. At least two battery cells 1 can be directly connected in series, in parallel, or in hybrid connection; of course, at least two battery cells 1 can be first connected in series, in parallel, or in hybrid connection to form a module, and the module can then be connected in series, in parallel, or in hybrid connection to form a whole.

[0096] In some embodiments, a battery cell assembly (Battery Cell Assembly) is generally formed by arranging a plurality of battery cells 1 .

[0097] As an example, the battery cell assembly may be a battery module (Battery Module), and the battery module is formed by arranging and fixing a plurality of battery cells 1 to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells 1 by a cable tie.

[0098] In some embodiments, see Figure 2 The battery device 100 may be a battery pack, which includes a box body 2 and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the box body 2 .

[0099] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body 2 by fixing the battery module in the box body 2 .

[0100] As an example, the battery cell assembly may also be accommodated in the box body 2 by directly fixing a plurality of battery cells 1 to the box body 2 .

[0101] As an example, see Figure 2 The box body 2 may include a first box body 21 and a second box body 22. The first box body 21 and the second box body 22 are buckled together to form a closed space inside the box body 2 to accommodate the battery monomer assembly. The closed space here means to cover or close, which can be sealed or unsealed. The first box body 21 can be a top cover or a bottom plate.

[0102] As an example, the box body 2 may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body 2 to accommodate the battery monomer assembly.

[0103] In some embodiments, the box 2 can be used as a part of the chassis structure of the vehicle. For example, part of the box 2 can become at least a part of the floor of the vehicle, or part of the box 2 can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0104] An embodiment of the present application provides an electrical device, which includes a battery cell 1 in any embodiment of the present application or a battery device 100 in any embodiment of the present application, and the battery cell 1 or the battery device 100 is used to store or provide electrical energy.

[0105] Electrical equipment includes, but is not limited to, energy storage devices, mobile phones, tablets, laptops, electric toys, electric tools, vehicles, ships or spacecraft, etc. Vehicles may include battery vehicles and electric cars, electric toys may include battery vehicle toys and electric car toys, etc., fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles and spacecraft, etc.

[0106] Energy storage equipment includes but is not limited to energy storage containers or energy storage cabinets, etc.

[0107] In the following embodiments, for the convenience of description, an electric device according to an embodiment of the present application is taken as an example of a vehicle 1000. The following is a description with reference to the accompanying drawings.

[0108] Figure 1 The schematic diagram of the structure of a vehicle 1000 provided in 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. Figure 1 As shown, a battery device 100 is disposed inside the vehicle 1000, and the battery device 100 can be disposed at the bottom of the vehicle 1000 or at the front or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000, for example, the battery device 100 can be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to power the motor 300, for example, for the starting, navigation, and working power requirements of the vehicle 1000 during driving.

[0109] In some embodiments of the present application, the battery device 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0110] In the related art, during the process of injecting electrolyte, the electrolyte directly impacts the top of the electrode assembly. When the electrolyte infiltrates from the top, bottom and surrounding areas to the middle, liquid sealing is likely to occur in the middle of the electrode assembly, resulting in difficulty in discharging the gas in the middle. Moreover, taking positive pressure injection as an example, a large amount of electrolyte impacting the top of the electrode assembly is likely to cause excessive spacing between the electrode layers, and the middle area of ​​the electrode is not infiltrated or is not fully infiltrated, resulting in poor infiltration and affecting the embedding of active ions. After the battery cell is cycled, black spots and / or metal precipitation are likely to occur in the middle of the electrode assembly, affecting the performance and service life of the battery cell. In severe cases, there are safety risks such as fire and explosion.

[0111] In view of this, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and a drainage cap. The shell has a accommodating cavity, and a liquid injection port connected to the accommodating cavity is formed on the top of the shell, and the liquid injection port is used to inject electrolyte; the electrode assembly is arranged in the accommodating cavity; the drainage cap is arranged in the accommodating cavity, and the drainage cap is located between the liquid injection port and the electrode assembly, and the drainage cap guides the electrolyte injected from the liquid injection port to the periphery.

[0112] In the battery cell provided by the embodiment of the present application, the drainage cap is located between the injection port and the electrode assembly, and the drainage cap guides the electrolyte injected from the injection port to the periphery. During the injection process, the electrolyte passes through the injection port and enters the bottom of the accommodating cavity under the guidance of the drainage cap. Specifically, the electrolyte from the injection port contacts the top surface of the drainage cap and flows along the top surface of the drainage cap to the periphery of the drainage cap. In this way, the drainage cap can block the electrolyte from directly impacting the top of the electrode assembly to a certain extent. The electrolyte flows to the periphery under the guidance of the drainage cap, and the electrolyte flows from the drainage cap and the periphery of the accommodating cavity. The electrolyte flows toward the bottom through the gap between the surfaces, and climbs from the bottom of the electrode assembly to the top and infiltrates the electrode assembly. In this way, the flow direction of the electrolyte is effectively guided by the drainage cap, reducing the probability of the electrolyte at the injection port directly contacting the top of the electrode assembly, allowing the electrolyte to directionally infiltrate the electrode assembly, which is beneficial for the gas in the middle of the electrode assembly to be discharged from the top of the electrode assembly, preventing liquid sealing to a certain extent, improving the infiltration effect, and reducing the risk of black spots and / or metal precipitation in the middle of the electrode assembly during the cycle, thereby improving the performance and service life of the battery cell.

[0113] The following further describes the battery cell 1 provided in the embodiment of the present application in conjunction with the accompanying drawings. Figures 3 to 8 The embodiment of the present application provides a battery cell 1, which includes a housing 11, an electrode assembly 12 and a drainage cap 13. The housing 11 has a housing cavity 11a, and a liquid injection port 11b connected to the housing cavity 11a is formed on the top of the housing 11, and the liquid injection port 11b is used to inject electrolyte. The electrode assembly 12 is disposed in the housing cavity 11a; the drainage cap 13 is disposed in the housing cavity 11a, and the drainage cap 13 is located between the liquid injection port 11b and the electrode assembly 12, and the drainage cap 13 guides the electrolyte injected from the liquid injection port 11b to the periphery.

[0114] The housing 11 is used to encapsulate the electrode assembly 12 , electrolyte, drainage cap 13 and other structures, and provide protection for the electrode assembly 12 and drainage cap 13 and other structures.

[0115] The drainage cap 13 is located between the liquid injection port 11 b and the electrode assembly 12 , that is, the drainage cap 13 is located at the bottom side Z2 of the liquid injection port 11 b , and the drainage cap 13 is located at the top side Z1 of the electrode assembly 12 .

[0116] The drainage cap 13 shields the electrode assembly 12. The drainage cap 13 can block the electrolyte injected from the injection port 11b from impacting the electrode assembly 12 to a certain extent. The drainage cap 13 is used to guide the electrolyte injected from the injection port 11b to the periphery. The periphery of the drainage cap 13 refers to the peripheral part of the drainage cap 13 surrounding the top and bottom direction Z.

[0117] There may be a gap between the periphery of the drainage cap 13 and the circumferential surface of the accommodating chamber 11a, and the electrolyte flows toward the bottom side Z2 through the gap. Exemplarily, in some embodiments, the periphery of the drainage cap 13 and the circumferential surface of the accommodating chamber 11a may be spaced apart from each other to form a gap. In some embodiments, the periphery of the drainage cap 13 is partially in contact with the circumferential surface of the accommodating chamber 11a, and the periphery of the drainage cap 13 has a notch, which is a gap. In some embodiments, the periphery of the drainage cap 13 is partially in contact with the circumferential surface of the accommodating chamber 11a, and the circumferential surface of the accommodating chamber 11a has a notch, which is a gap.

[0118] During the injection process, the electrolyte passes through the injection port 11b and enters the accommodating chamber 11a under the guidance of the drainage cap 13. Specifically, the electrolyte from the injection port 11b contacts the top surface of the drainage cap 13 and flows along the top surface of the drainage cap 13 to the periphery of the drainage cap 13. In this way, the drainage cap 13 can, to a certain extent, block the electrolyte from directly impacting the top of the electrode assembly 12. The electrolyte flows toward the periphery under the guidance of the drainage cap 13. The electrolyte flows from the gap between the drainage cap 13 and the circumferential surface of the accommodating chamber 11a to the bottom side Z2, or the electrolyte flows along the circumferential surface of the accommodating chamber 11a to the bottom side Z2. Under the capillary action, the electrolyte climbs from the bottom of the electrode assembly 12 to the top side Z1 and infiltrates the electrode assembly 12. In this way, the electrolyte can achieve directional infiltration of the electrode assembly 12 from the bottom to the top.

[0119] It should be noted that the circumferential surface of the accommodating cavity 11 a refers to the wall surface of the accommodating cavity 11 a surrounding the top and bottom direction Z.

[0120] Taking the square-shell battery cell 1 as an example, the circumferential surface of the shell 11 has two large surfaces and two side surfaces. The large surface of the shell 11 is the surface with the largest area of ​​the shell 11, and the side surface of the shell 11 is the surface connected to the large surface along the circumferential direction. The electrolyte can flow along the large surface and / or the side surface toward the bottom side Z2.

[0121] The number of electrode assemblies 12 is not limited, and the number of electrode assemblies 12 can be one, two, three or more.

[0122] In the battery cell 1 provided in the embodiment of the present application, the drainage cap 13 is located between the injection port 11b and the electrode assembly 12. The drainage cap 13 guides the electrolyte injected from the injection port 11b to the periphery. During the injection process, the electrolyte passes through the injection port 11b and enters the bottom of the accommodating chamber 11a under the guidance of the drainage cap 13. Specifically, the electrolyte from the injection port 11b contacts the top surface of the drainage cap 13 and flows along the top surface of the drainage cap 13 to the periphery of the drainage cap 13. In this way, the drainage cap 13 can block the electrolyte from directly impacting the top of the electrode assembly 12 to a certain extent. The electrolyte flows to the periphery under the guidance of the drainage cap 13, and the electrolyte flows from the drainage cap 13 to the electrode assembly 12. The electrolyte flows through the gap between the circumferential surface of the accommodating cavity 11a toward the bottom side Z2, and climbs from the bottom of the electrode assembly 12 toward the top side Z1 and infiltrates the electrode assembly 12. In this way, the flow direction of the electrolyte is effectively guided by the drainage cap 13, and the probability of the electrolyte at the injection port 11b directly contacting the top of the electrode assembly 12 is reduced, so that the electrolyte directionally infiltrates the electrode assembly 12, which is beneficial for the gas in the middle of the electrode assembly 12 to be discharged from the top of the electrode assembly 12, preventing the occurrence of liquid sealing to a certain extent, improving the infiltration effect, and reducing the risk of black spots and / or metal precipitation in the middle of the electrode assembly 12 during the cycle, thereby improving the performance and service life of the battery cell 1.

[0123] In some embodiments, the drainage cap 13 can be connected to the housing 11. For example, the drainage cap 13 can be connected to the end cap, and the injection port 11b can be formed on the end cap. The specific connection method is not limited, and the drainage cap 13 can be detachably connected to the housing 11 or non-detachably connected.

[0124] In the embodiments of the present application, unless otherwise stated, the non-detachable connection includes but is not limited to welding or bonding, etc. The detachable connection includes but is not limited to snap connection, screw connection or bolt connection, etc.

[0125] For some examples, see Figures 4 to 5 The battery cell 1 includes an insulating wrapping member 14, and the insulating wrapping member 14 wraps the electrode assembly 12. It is understandable that the insulating wrapping member 14 can avoid the tab 121, that is, the insulating wrapping member 14 does not wrap the tab 121, so that the tab 121 is connected to the electrode terminal. The insulating wrapping member 14 insulates and isolates the electrode assembly 12 from the housing 11, and protects the electrode assembly 12.

[0126] The insulating wrapping member 14 has an insulating function. The insulating wrapping member 14 may be made of an insulating material. For example, the insulating wrapping member 14 may be made of a Mylar film.

[0127] Mylar film is also called Mylar film. Mylar is a polyester polymer with good surface smoothness, transparency and mechanical flexibility. Mylar film is a translucent flexible film.

[0128] For some examples, see Figures 4 to 8 , taking the plane perpendicular to the top-bottom direction Z as the projection plane, the projection edge line L1 of the electrode assembly 12 does not exceed the projection edge line L2 of the drainage cap 13 .

[0129] The projection edge line L1 of the electrode assembly 12 refers to the outer contour line of the electrode assembly 12 projected on the projection plane.

[0130] The projection edge line L2 of the drainage cap 13 refers to the outer contour line of the drainage cap 13 projected on the projection plane.

[0131] The projected edge line L1 of the electrode assembly 12 does not exceed the projected edge line L2 of the drainage cap 13. The projected edge line L1 of the electrode assembly 12 may coincide with the projected edge line L2 of the drainage cap 13, or the projected edge line L1 of the electrode assembly 12 may be located on the inner side of the projected edge line L2 of the drainage cap 13.

[0132] In this embodiment, the projected edge line L1 of the electrode assembly 12 does not exceed the projected edge line L2 of the drainage cap 13. The drainage cap 13 can more comprehensively shield the electrode assembly 12, reducing the probability that the top of the electrode assembly 12 directly contacts the electrolyte from the injection port 11b.

[0133] For some examples, see Figure 4 and Figure 5 , taking the plane perpendicular to the top-bottom direction Z as the projection plane, the projection edge line L2 of the drainage cap 13 does not exceed the projection edge line of the insulation package 14. In this way, the drainage cap 13 has a moderate size so as to be easily assembled into the accommodating cavity 11a.

[0134] For some examples, see Figure 7 , taking the plane perpendicular to the top-bottom direction Z as the projection plane, the distance between the projection edge line L1 of the electrode assembly 12 and the projection edge line L2 of the drainage cap 13 is D1, 0mm≤D1≤1mm. Preferably, 0.5mm≤D1≤1mm.

[0135] Illustratively, D1 may be 0 mm, 0.1 mm, 0.2 mm, 0.25 mm, 0.5 mm, 0.7 mm, 0.9 mm or 1 mm, etc.

[0136] In this embodiment, in the projection plane perpendicular to the top-bottom direction Z, D1 is between 0 mm and 1 mm, and the distance between the projection edge line L1 of the electrode assembly 12 and the projection edge line L2 of the drainage cap 13 is small. The drainage cap 13 can minimize the occupied space while taking into account the diversion requirements.

[0137] The drain cap 13 may be an insulating structure. For example, the drain cap 13 may be made of insulating material. Preferably, the drain cap 13 may be made of insulating and heat-resistant materials. The drain cap 13 may be made of hard materials or materials with certain flexibility. The drain cap 13 can maintain its shape under the impact of the electrolyte. For example, the drain cap 13 may be made of hard materials such as plastic or ceramics, or may be made of flexible materials such as Mylar film.

[0138] For some examples, see Figure 6 , the drainage cap 13 can abut against the electrode assembly 12. In this way, the electrode assembly 12 can provide support for the drainage cap 13, and the drainage cap 13 has better structural stability, which is conducive to maintaining the shape of the drainage cap 13. Of course, the drainage cap 13 can also be spaced apart from the electrode assembly 12.

[0139] For some examples, see Figure 3 and Figure 5 The battery cell 1 includes at least two electrode assemblies 12 , and the projection plane is a plane perpendicular to the top-bottom direction Z. The projections of all electrode assemblies 12 are located within the projection edge line L2 of the drainage cap 13 .

[0140] As an example, see Figure 3 and Figure 5 At least two electrode assemblies 12 may be stacked along a first direction X, and the first direction X is perpendicular to the top-bottom direction Z. Taking the square-shell battery cell 1 as an example, the first direction X may be perpendicular to the large surface of the shell 11 .

[0141] In this embodiment, in the projection plane perpendicular to the top-bottom direction Z, the projections of all electrode assemblies 12 are located within the projection edge line L2 of the drainage cap 13, that is, the projection edge line L2 of the drainage cap 13 surrounds the projections of all electrode assemblies 12, so that one drainage cap 13 can basically cover all electrode assemblies 12, reducing the number of parts.

[0142] For some examples, see Figure 4 and Figure 5 The electrode assembly 12 includes a pole ear 121, and the drainage cap 13 forms an avoidance opening 13a. Taking the plane perpendicular to the top-bottom direction Z as the projection surface, the projection of the pole ear 121 is located within the projection outline of the avoidance opening 13a.

[0143] The projection contour of the avoidance opening 13 a refers to a figure formed by the edge lines of the avoidance opening 13 a projected on the projection plane.

[0144] In this embodiment, in the projection plane perpendicular to the top-bottom direction Z, the projection of the pole ear 121 is located within the projection contour of the avoidance opening 13a, so that the pole ear 121 can be electrically connected to the electrode terminal through the avoidance opening 13a, avoiding the drainage cap 13 from blocking the pole ear 121, thereby reducing the difficulty of assembly.

[0145] It is understandable that the tab 121 and the electrode terminal may be directly connected, for example, the tab 121 and the electrode terminal are welded; or the tab 121 and the electrode terminal are indirectly connected via a conductive structure, which is not limited in the present application.

[0146] In some embodiments, the electrolyte cannot penetrate the drain cap 13. In other words, the drain cap 13 does not have micropores at the micron level, and the drain cap 13 can be made of dense materials. Except for the macro openings on the drain cap 13, such as the avoidance port 13a, the electrolyte cannot penetrate the drain cap 13 along the top-to-bottom direction Z to the top of the electrode assembly 12, but is diverted to the periphery of the drain cap 13. It can be understood that the avoidance port 13a is a macro opening on the drain cap 13, and the size of the avoidance port 13a is much larger than the micron level.

[0147] For some examples, see Figure 5 , taking the plane perpendicular to the top-bottom direction Z as the projection plane, the distance between the projection of the wall surface of the avoidance opening 13a and the projection of the pole ear 121 is D2, 0.5mm≤D2≤10mm. Preferably, 1mm≤D2≤5mm.

[0148] Illustratively, D2 may be 0.5 mm, 1 mm, 2 mm, 5 mm, 5 mm, 7 mm, 8 mm or 10 mm, etc.

[0149] In this embodiment, in the projection plane perpendicular to the top-bottom direction Z, D2 is between 0.5 mm and 10 mm, and there is a gap between the wall of the avoidance port 13a and the pole ear 121. In this way, it is convenient for the pole ear 121 to pass through the avoidance port 13a, taking into account the manufacturing and assembly requirements. The distance between the wall of the avoidance port 13a and the pole ear 121 is small, and most of the electrolyte is still diverted to the periphery by the drainage cap 13, and only a small amount of electrolyte leaks to the bottom side Z2 through the gap between the wall of the avoidance port 13a and the pole ear 121.

[0150] In some embodiments, in the projection plane perpendicular to the top-bottom direction Z, the distance D2 between the projection of the wall of the avoidance opening 13a and the projection of the pole tab 121 may also be 0 mm. In other words, the wall of the avoidance opening 13a fits the pole tab 121, so that the probability of leakage from the gap between the wall of the avoidance opening 13a and the pole tab 121 can be reduced.

[0151] For some examples, see Figure 6 to Figure 7 The pole tab 121 is inserted into the avoidance opening 13a. In this way, it is convenient to connect the pole tab 121 with the electrode terminal, for example, the pole tab 121 and the electrode terminal are welded.

[0152] For some examples, see Figure 8, the pole lug 121 is located at the bottom side Z2 of the avoidance opening 13a. In this way, the pole lug 121 can be prevented from contacting the wall surface of the avoidance opening 13a, reducing the wear between the structural parts.

[0153] For some examples, see Figure 4 The number of the avoidance openings 13 a is the same as the number of the pole lugs 121 , and one pole lug 121 is passed through each avoidance opening 13 a .

[0154] As an example, the positive electrode tabs 121 and the negative electrode tabs 121 are arranged at intervals along the second direction Y, all the positive electrode tabs 121 are arranged along the first direction X, and all the negative electrode tabs 121 are arranged along the first direction X.

[0155] In this embodiment, a pole ear 121 is provided through each avoidance opening 13 a, which makes it easier to assemble the drainage cap 13 and the electrode assembly 12 .

[0156] For some examples, see Figure 5 , the number of avoidance openings 13a is less than the number of pole ears 121, and each avoidance opening 13a corresponds to at least two pole ears 121. Exemplarily, the number of avoidance openings 13a is two, all positive pole ears 121 correspond to one avoidance opening 13a, and all negative pole ears 121 correspond to the other avoidance opening 13a. All positive pole ears 121 can be arranged along the first direction X, and all negative pole ears 121 can be arranged along the first direction X. In this way, the structure of the drainage cap 13 can be simplified and the manufacturing difficulty can be reduced.

[0157] It can be understood that the positive electrode tab 121 is connected to the positive electrode, and the negative electrode tab 121 is connected to the negative electrode.

[0158] For some examples, see Figure 5 The drainage cap 13 includes at least two guide portions 131 disposed at intervals, and a avoidance opening 13 a is formed between two adjacent guide portions 131 .

[0159] Exemplarily, at least two guide portions 131 may be spaced apart along the second direction Y, and the first direction X, the second direction Y, and the top-bottom direction Z may be perpendicular to each other.

[0160] As an example, at least one guide portion 131 is located on the bottom side Z2 of the injection port 11b. The guide portion 131 located on the bottom side Z2 of the injection port 11b can block the electrolyte from the injection port 11b, and other guide portions 131 can prevent the electrolyte from splashing to the top of the electrode assembly 12 to a certain extent.

[0161] In this embodiment, the pole ear 121 is located between two adjacent guide portions 131 , and the drainage cap 13 can be a plurality of separate guide portions 131 , which can reduce the material usage of the drainage cap 13 and save costs.

[0162] For some examples, see Figure 4 and Figure 6 The drainage cap 13 is an integrally formed structure. The integrally formed structure refers to a structure manufactured by an integrally formed process. In this way, the drainage cap 13 has good structural strength and can also save assembly steps of the drainage cap 13.

[0163] In some embodiments, a plurality of independent parts may be connected to form the drainage cap 13. An independent part refers to a structural part that is manufactured separately and independently, and the independent parts may be connected in a non-detachable manner or in a detachable manner to form the drainage cap 13.

[0164] For some examples, see Figure 4 , Figure 6 and Figure 7 The drainage cap 13 includes two inclined plates 132 , the top ends of the two inclined plates 132 are connected, and the bottom ends of the two inclined plates 132 are far away from each other.

[0165] As an example, the two inclined plates 132 may be formed by bending the plates relative to each other.

[0166] In this embodiment, the top ends of the two inclined plates 132 are connected, and the bottom ends of the two inclined plates 132 are far away from each other, that is, the drainage cap 13 is roughly in an inverted V shape, so that the electrolyte can flow to the periphery at an accelerated speed under the guidance of the inclined plates 132.

[0167] For some examples, see Figure 6 to Figure 7 The liquid injection port 11 b is located at the top side Z1 of the top ends of the two inclined plates 132 .

[0168] In this embodiment, the electrolyte injected into the injection port 11b first contacts the top of the two inclined plates 132, and then flows toward the periphery along the inclined plates 132. The top of the two inclined plates 132 can divert the electrolyte, so that the electrolyte can flow from multiple positions of the drainage cap 13 to the bottom side Z2, and the electrolyte can flow to the bottom of the electrode assembly 12 faster.

[0169] For some examples, see Figure 8 The drainage cap 13 is a flat plate structure intersecting with the top-bottom direction Z.

[0170] The flat plate structure means that the flow cap 13 is substantially in the shape of a flat plate.

[0171] The flat plate structure intersects the top-bottom direction Z means that the flat plate structure may intersect perpendicularly or obliquely with the top-bottom direction Z. In other words, the drainage cap 13 is not parallel to the top-bottom direction Z. In other words, the thickness direction of the drainage cap 13 is parallel to or obliquely intersects with the top-bottom direction Z.

[0172] In this embodiment, the drain cap 13 is a flat plate structure, and the drain cap 13 has a simple structure and is easy to manufacture. The flat plate structure intersects with the top-bottom direction Z, for example, the flat plate structure intersects with the top-bottom direction Z perpendicularly, and the drain cap 13 can block the electrolyte from the injection port 11b, and the electrolyte can flow in all directions along the top surface of the drain cap 13 to guide the periphery of the drain cap 13.

[0173] In some embodiments, a drainage groove may be formed on the top surface of the drainage cap 13, and the drainage groove may penetrate the periphery of the drainage cap 13. The drainage groove may limit the flow direction of the electrolyte and direct the electrolyte to a set position around the drainage cap 13.

[0174] The following is a specific example to further illustrate the battery cell 1 provided in the present application. Figures 3 to 7 The battery cell 1 provided in the embodiment of the present application includes a housing 11, an electrode assembly 12 and a drainage cap 13. The housing 11 has a receiving cavity 11a. The top of the housing 11 forms a liquid injection port 11b connected to the receiving cavity 11a. The liquid injection port 11b is used to inject electrolyte. The electrode assembly 12 is arranged in the receiving cavity 11a. The drainage cap 13 is arranged in the receiving cavity 11a, and the drainage cap 13 is located between the liquid injection port 11b and the electrode assembly 12. The battery cell 1 includes at least two electrode assemblies 12. The projection plane is a plane perpendicular to the top-bottom direction Z. The projections of all electrode assemblies 12 are located within the projection edge line L2 of the drainage cap 13. The electrode assembly 12 includes a pole ear 121. The drainage cap 13 forms an avoidance port 13a. The projection plane is a plane perpendicular to the top-bottom direction Z. The projection of the pole ear 121 is located within the projection outline of the avoidance port 13a. The housing 11 may be square, at least two electrode assemblies 12 may be stacked along a first direction X, the positive electrode ear 121 and the negative electrode ear 121 may be spaced apart along a second direction Y, and the first direction X, the second direction Y, and the top and bottom directions Z may be perpendicular to each other. The drainage cap 13 is an integrally formed structure, and the drainage cap 13 includes two inclined plates 132, the top ends of the two inclined plates 132 are connected, and the bottom ends of the two inclined plates 132 are away from each other.

[0175] In this embodiment, the drainage cap 13 is located between the injection port 11b and the electrode assembly 12. The drainage cap 13 guides the electrolyte injected from the injection port 11b to the periphery. During the injection process, the electrolyte passes through the injection port 11b and enters the bottom of the accommodating chamber 11a under the guidance of the drainage cap 13. Specifically, the electrolyte from the injection port 11b contacts the top surface of the drainage cap 13 and flows along the top surface of the drainage cap 13 to the periphery of the drainage cap 13. In this way, the drainage cap 13 can prevent the electrolyte from directly impacting the top of the electrode assembly 12 to a certain extent. The electrolyte flows to the periphery under the guidance of the drainage cap 13, and the electrolyte flows from the drainage cap 13 and the accommodating chamber 11a. The electrolyte flows from the gap between the circumferential surfaces of the electrode assembly 1a to the bottom side Z2, and crawls from the bottom of the electrode assembly 12 to the top side Z1 and infiltrates the electrode assembly 12. In this way, the electrolyte flow direction is effectively guided by the drainage cap 13, reducing the probability that the electrolyte at the injection port 11b directly contacts the top of the electrode assembly 12, so that the electrolyte infiltrates the electrode assembly 12 in a directional manner, which is conducive to the gas in the middle of the electrode assembly 12 being discharged from the top of the electrode assembly 12, preventing the occurrence of liquid sealing to a certain extent, improving the infiltration effect, reducing the risk of black spots and / or metal precipitation in the middle of the electrode assembly 12 during the cycle, and improving the performance and service life of the battery cell 1. In the projection plane perpendicular to the top and bottom direction Z, the projections of all electrode assemblies 12 are located within the projection edge line L2 of the drainage cap 13, that is, the projection edge line L2 of the drainage cap 13 surrounds the projections of all electrode assemblies 12, so that one drainage cap 13 can basically cover all electrode assemblies 12, reducing the number of parts. In the projection plane perpendicular to the top-bottom direction Z, the projection of the pole ear 121 is located within the projection contour of the avoidance port 13a, so that the pole ear 121 can be electrically connected to the electrode terminal through the avoidance port 13a, avoiding the drain cap 13 from blocking the pole ear 121, and reducing the difficulty of assembly. The drain cap 13 has good structural strength and can also save assembly steps of the drain cap 13. The top ends of the two inclined plates 132 are connected, and the bottom ends of the two inclined plates 132 are far away from each other, that is, the drain cap 13 is roughly in an inverted V shape, so that the electrolyte can be accelerated to flow to the periphery under the guidance of the inclined plate 132.

[0176] 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. 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. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way.

Claims

1. A battery cell, characterized in that: include: A shell having a receiving cavity, wherein a liquid injection port communicating with the receiving cavity is formed on the top of the shell, and the liquid injection port is used to inject electrolyte; An electrode assembly is disposed in the accommodating cavity; A drainage cap is arranged in the accommodating cavity, and the drainage cap is located between the liquid injection port and the electrode assembly. The drainage cap guides the electrolyte injected from the liquid injection port to the periphery.

2. The battery cell according to claim 1, characterized in that: Taking the plane perpendicular to the top and bottom directions as the projection plane, the projection edge line of the electrode assembly does not exceed the projection edge line of the drainage cap.

3. The battery cell according to claim 2, characterized in that: Taking the plane perpendicular to the top and bottom directions as the projection plane, the distance between the projection edge line of the electrode assembly and the projection edge line of the drainage cap is D1, 0mm≤D1≤1mm.

4. The battery cell according to claim 1, characterized in that: The battery cell includes at least two electrode assemblies, and the projection plane is a plane perpendicular to the top and bottom directions, and the projections of all the electrode assemblies are located within the projection edge line of the drainage cap.

5. The battery cell according to claim 1, characterized in that: The electrode assembly includes a pole ear, and the drainage cap forms an avoidance opening. The projection surface is a plane perpendicular to the top and bottom directions, and the projection of the pole ear is located within the projection contour of the avoidance opening.

6. The battery cell according to claim 5, characterized in that: Taking the plane perpendicular to the top and bottom directions as the projection plane, the distance between the projection of the avoidance wall surface and the projection of the pole ear is D2, 0.5mm≤D2≤10mm.

7. The battery cell according to claim 5, characterized in that: The pole lug is inserted into the avoidance opening; or, the pole lug is located at the bottom side of the avoidance opening.

8. The battery cell according to claim 5, characterized in that: The number of the avoidance openings is the same as the number of the pole lugs, and one pole lug is passed through each of the avoidance openings.

9. The battery cell according to claim 5, characterized in that: The drainage cap comprises at least two guide parts which are arranged at intervals, and the avoidance opening is formed between two adjacent guide parts.

10. The battery cell according to claim 1, characterized in that: The drainage cap is an integrally formed structure.

11. The battery cell according to any one of claims 1 to 10, characterized in that: The drainage cap comprises two inclined plates, the top ends of the two inclined plates are connected, and the bottom ends of the two inclined plates are far away from each other.

12. The battery cell according to claim 11, characterized in that: The liquid injection port is located at the top side of the top ends of the two inclined plates.

13. The battery cell according to any one of claims 1 to 10, characterized in that: The drainage cap is in the form of a flat plate structure intersecting with the top and bottom directions.

14. A battery device, characterized in that: Comprising at least two battery cells according to any one of claims 1 to 13.

15. An electrical equipment, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 13 or the battery device according to claim 14, wherein the battery cell or the battery device is used for storing or providing electrical energy.

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