Battery monomer, battery pack and power utilization device

Abstract

The invention discloses a battery monomer, a battery pack and a power utilization device, and the battery monomer comprises: a housing, one end of which is provided with an opening; the electrolyte is arranged in the shell; the battery cell assembly comprises a battery cell main body arranged in the shell and a tab which is connected with the battery cell main body and is positioned at one end, close to the opening of the shell, of the battery cell main body; the plastic part is arranged on the opening of the shell in a covering manner, so that an accommodating cavity for accommodating the electrolyte and the battery cell assembly is defined by the plastic part and the shell, and the plastic part comprises a plate-shaped part arranged on the opening of the shell in a covering manner and a convex part arranged on the inner surface, facing the shell, of the plate-shaped part; the first liquid absorption part extends from the plastic part to the battery cell main body, and the distance between one end, far away from the battery cell main body, of the first liquid absorption part and the battery cell main body is equal to or greater than the distance between the inner surface of the plate-shaped part and the battery cell main body.

Description

Technical Field

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

[0002] Battery cells are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc. Battery cells can include nickel-cadmium battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells, etc. In the development of battery technology, how to improve the reliability of battery cells is a technical problem that needs to be solved in battery technology. Summary of the invention

[0003] The present application aims to provide a battery cell, a battery pack and an electrical device that are beneficial to improving the reliability of the battery cell.

[0004] According to one aspect of the present application, a battery cell is provided, which includes: a shell having an opening at one end; an electrolyte disposed in the shell; a battery cell assembly, including a battery cell body disposed in the shell and a pole ear connected to the battery cell body and located at one end of the battery cell body close to the opening of the shell; a plastic part, which covers the opening of the shell to form a accommodating chamber for accommodating the electrolyte and the battery cell assembly with the shell, the plastic part including a plate-like part covering the opening of the shell and a protruding part disposed on the inner surface of the plate-like part facing the shell; and a first liquid absorbing part extending from the plastic part toward the battery cell body, the distance between the end of the first liquid absorbing part away from the battery cell body and the battery cell body being equal to or greater than the distance between the inner surface of the plate-like part and the battery cell body.

[0005] In some embodiments, the plastic part includes a through hole allowing an electrode terminal connected to the tab to pass through, the two through holes are arranged along a first direction and are respectively located at two ends of the plastic part along the first direction, and the first liquid absorbing member is provided at the end of the plastic part along the first direction.

[0006] In some embodiments, the protrusion is provided with an embedding groove connected to the accommodating cavity, the embedding groove extends from one end of the protrusion close to the battery cell body to the plate-like portion, the depth of the embedding groove is greater than or equal to the height of the protrusion protruding from the plate-like portion, and the first liquid absorbent member is embedded in the embedding groove.

[0007] In some embodiments, the battery cell further comprises an end cover disposed on a side of the plastic part away from the battery cell assembly, and the embedding groove extends to a side of the plastic part facing the end cover.

[0008] In some embodiments, the first liquid-absorbing member includes an embedded portion filled in the embedded groove and an overlapping portion connected to the embedded portion and overlapped between the end surface of the protrusion facing the battery cell body and the battery cell body, and the overlapping portion covers one end of the embedded portion close to the battery cell body and part or all of the end surface of the protrusion close to the battery cell body.

[0009] In some embodiments, the first liquid-absorbing member includes an attachment portion attached to the inner surface of the plate-shaped portion.

[0010] In some embodiments, the first liquid absorbent member further includes an overlapping portion connected to the attachment portion and overlapped between the end surface of the protrusion facing the battery cell body and the battery cell body, and the overlapping portion covers part or all of the end surface of the protrusion close to the battery cell body.

[0011] In some embodiments, the first absorbent member further comprises a connecting portion connecting the attaching portion and the overlapping portion, and the connecting portion is attached to a side surface of the protruding portion.

[0012] In some embodiments, the attaching portion extends from the protruding portion toward a through hole of the plate-shaped portion that allows the electrode terminal connected to the tab to pass through.

[0013] In some embodiments, the pole tab is bent toward the middle from one side of the end surface of the battery cell body close to the plastic part, and the battery cell also includes a connector covering the side of the bent pole tab away from the battery cell body and connected to the pole tab, and an electrode terminal connected to the connector, and the first end of the first liquid absorbing member is attached to the side of the connector away from the pole tab, and extends toward the battery cell body along the side of the bent pole tab facing away from the battery cell body.

[0014] In some embodiments, the second end of the first liquid absorbing member away from the connecting member is attached to the side surface of the battery cell body.

[0015] In some embodiments, the plastic member covers a side of the connecting member away from the battery core assembly, and a side of the first liquid absorbing member away from the connecting member is attached to the inner surface of the plate-shaped portion.

[0016] In some embodiments, the battery cell further includes a second liquid absorbing member, a first end of which is attached to a side of the bent pole ear facing the battery cell body and extends along the pole ear toward a side of the battery cell body facing the plastic member.

[0017] In some embodiments, two battery cell assemblies are arranged side by side, the tabs of the two battery cell assemblies are respectively bent toward the junction of the two battery cell assemblies, and the two sides of the connector are respectively connected to the tabs of the two battery cell assemblies.

[0018] In some embodiments, the second liquid absorbing member extends to the side of the battery cell body, and the second end of the second liquid absorbing member away from the electrode ear is attached to the side of the battery cell body.

[0019] In some embodiments, one end of the first liquid absorbing member away from the plate-shaped portion abuts against or is connected to the battery cell body.

[0020] According to another aspect of the present application, a battery pack is also provided, and the battery pack includes the above-mentioned battery cell.

[0021] According to another aspect of the present application, an electric device is also provided, and the electric device includes the above-mentioned battery pack.

[0022] By applying the technical solution of the present application, after the battery cell is inverted, the end of the first liquid absorbent member away from the battery cell body is no higher than the inner surface of the plate-like portion of the plastic member, so that the electrolyte flowing onto the inner surface of the plate-like portion is guided upwards through capillary action. This is beneficial to improving the problem of reducing the reliability of the battery cell due to the electrolyte flowing to a position closer to the end cover and corroding the weak area of ​​the end cover, and is also beneficial to ensuring the mechanical strength of the battery end cover.

[0023] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 A schematic structural diagram of an electric device disclosed in some embodiments of the present application is shown.

[0026] Figure 2 A schematic diagram of the exploded structure of a battery pack disclosed in some embodiments of the present application is shown.

[0027] Figure 3 A schematic diagram of the exploded structure of a battery cell disclosed in some embodiments of the present application is shown.

[0028] Figure 4 A schematic structural diagram of a battery cell disclosed in some embodiments of the present application is shown.

[0029] Figure 5 A schematic side view of the structure of a battery cell disclosed in some embodiments of the present application is shown.

[0030] Figure 6 A schematic structural diagram of a battery cell shell and a battery cell assembly disclosed in some embodiments of the present application is shown.

[0031] Figure 7 A bottom-up structural schematic diagram of a plastic part and a first liquid-absorbing part of a battery cell disclosed in some embodiments of the present application is shown.

[0032] Figure 8 A schematic side view structure diagram of a plastic part and a first liquid absorbing part of a battery cell disclosed in some embodiments of the present application is shown.

[0033] Fig. 9 Schematic diagrams of the structure of an end cover of a battery cell disclosed in some embodiments of the present application are shown.

[0034] Fig.10 A schematic structural diagram of a battery cell disclosed in some embodiments of the present application is shown.

[0035] Fig.11 A schematic side view of the structure of a battery cell disclosed in some embodiments of the present application is shown.

[0036] Fig.12 A schematic structural diagram of a battery cell shell and a battery cell assembly disclosed in some embodiments of the present application is shown.

[0037] Fig.13 A bottom-up structural schematic diagram of a plastic part and a first liquid-absorbing part of a battery cell disclosed in some embodiments of the present application is shown.

[0038] Fig.14 A schematic side view structure diagram of a plastic part and a first liquid absorbing part of a battery cell disclosed in some embodiments of the present application is shown.

[0039] Fig.15 A schematic diagram of the structure of an end cover of a battery cell disclosed in some embodiments of the present application is shown.

[0040] Fig.16 A schematic structural diagram of a battery cell disclosed in some embodiments of the present application is shown.

[0041] Fig.17 A schematic side view of the structure of a battery cell disclosed in some embodiments of the present application is shown.

[0042] Fig.18 A schematic structural diagram of a battery cell shell and a battery cell assembly disclosed in some embodiments of the present application is shown.

[0043] Fig.19 A bottom-up structural schematic diagram of a plastic part and a first liquid-absorbing part of a battery cell disclosed in some embodiments of the present application is shown.

[0044] Fig. 20A schematic side view structure diagram of a plastic part and a first liquid absorbing part of a battery cell disclosed in some embodiments of the present application is shown.

[0045] Fig.21 A schematic diagram of the structure of an end cover of a battery cell disclosed in some embodiments of the present application is shown.

[0046] Fig. 22 A schematic structural diagram of a battery cell disclosed in some embodiments of the present application is shown.

[0047] Fig.23 Shows Fig. 22 Schematic diagram of the cross-sectional structure at AA in the middle.

[0048] Fig.24 A schematic diagram of the cross-sectional structure of a battery cell disclosed in some other embodiments of the present application is shown.

[0049] Fig.25 A schematic structural diagram of a battery cell shell and a battery cell assembly disclosed in some embodiments of the present application is shown.

[0050] Fig.26 A structural schematic diagram of a first state of an assembly process of a battery cell disclosed in some embodiments of the present application is shown.

[0051] Fig. 27 A side structural schematic diagram of a first state of an assembly process of a battery cell disclosed in some embodiments of the present application is shown.

[0052] Fig.28 Shows Fig. 27 A partial enlarged view of point B in the middle.

[0053] Fig.29 A structural schematic diagram of a second state of an assembly process of a battery cell disclosed in some embodiments of the present application is shown.

[0054] Fig.30 A structural schematic diagram of a third state of an assembly process of a battery cell disclosed in some embodiments of the present application is shown.

[0055] In the figure: 1000, vehicle; 100, battery pack; 110, casing; 111, first part; 112, second part; 120, battery cell; 121, end cover; 121a, electrode terminal; 122, casing; 123, battery cell assembly; 123a, pole ear; 123b, battery cell body; 124, plastic part; 1241, plate-like part; 1242, protruding part; 1243, through hole; 125, first liquid absorption part; 1251, embedded part; 1252, overlapping part; 1253, attaching part; 1254, connecting part; 126, second liquid absorption part; 127, connecting part; 200, controller; 300, motor. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0058] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0059] Further, " scope " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be including end value or not including end value, and can be combined arbitrarily, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a particular parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 listed, and if the maximum range value 3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0060] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0061] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0062] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0063] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0064] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0065] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0066] Figure 1 FIG. 1 shows a schematic diagram of a structure of an electric device using a battery as a power source; Figure 1 As shown, the power-consuming device of this embodiment includes a vehicle 1000, which may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery pack 100 is disposed inside the vehicle 1000, and the battery pack 100 may be disposed at the bottom, head, or tail of the vehicle 1000. The battery pack 100 may be used to power the vehicle 1000, for example, the battery pack 100 may 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 pack 100 to power the motor 300, for example, for the starting, navigation, and working power requirements of the vehicle 1000 during driving.

[0067] In some embodiments of the present application, the battery pack 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0068] Please refer to Figure 2 , Figure 2An exploded view of a battery pack 100 provided for some embodiments of the present application. The battery pack 100 includes a case 110 and a battery module disposed in the case 110, the battery module includes a plurality of battery cells 120, and the battery cells 120 are accommodated in the case 110. Among them, the case 110 is used to provide a storage space for the battery cells 120, and the case 110 can adopt a variety of structures. In some embodiments, the case 110 may include a first portion 111 and a second portion 112, the first portion 111 and the second portion 112 cover each other, and the first portion 111 and the second portion 112 jointly define a storage space for accommodating the battery cells 120. The second part 112 may be a hollow structure with one end open, and the first part 111 may be a plate-like structure, and the first part 111 covers the open side of the second part 112, so that the first part 111 and the second part 112 jointly define a storage space; the first part 111 and the second part 112 may also be hollow structures with one side open, and the open side of the first part 111 covers the open side of the second part 112. Of course, the box body 110 formed by the first part 111 and the second part 112 may be in various shapes, such as a cylinder, a cuboid, etc.

[0069] In the battery pack 100, there may be multiple battery cells 120, and the multiple battery cells 120 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 120 are both connected in series and in parallel. The multiple battery cells 120 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 120 is accommodated in the box 110; of course, the battery pack 100 may also be a battery module formed by connecting multiple battery cells 120 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 110. The battery pack 100 may also include other structures, for example, the battery pack 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 120.

[0070] Each battery cell 120 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 120 may be cylindrical, flat, rectangular, or in other shapes.

[0071] Please refer to Figure 3 , Figure 3 The schematic diagram of the decomposition structure of the battery cell 120 provided in some embodiments of the present application. The battery cell 120 refers to the smallest unit constituting the battery pack 100. Figure 3 The battery cell 120 includes an end cover 121, a shell 122, a battery cell assembly 123 and other functional components.

[0072] The end cap 121 refers to a component that covers the opening of the shell 122 to isolate the internal environment of the battery cell 120 from the external environment. Without limitation, the shape of the end cap 121 can be adapted to the shape of the shell 122 to match the shell 122. Optionally, the end cap 121 can be made of a material with a certain hardness and strength, such as an aluminum alloy, so that the end cap 121 is not easily deformed when squeezed and collided, so that the battery cell 120 can have a higher structural strength and the safety performance can also be improved. Functional components such as electrode terminals 121a can be provided on the end cap 121. The electrode terminal 121a can be used to electrically connect to the battery cell assembly 123 for outputting or inputting electrical energy of the battery cell 120. In some embodiments, the end cap 121 can also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 120 reaches a threshold. The material of the end cap 121 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the present embodiment. In some embodiments, an insulating member can be provided on the inner side of the end cap 121, and the insulating member can be used to isolate the electrical connection components in the housing 122 from the end cap 121 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0073] The shell 122 is a component used to cooperate with the end cap 121 to form the internal environment of the battery cell 120, wherein the formed internal environment can be used to accommodate the battery cell assembly 123, electrolyte and other components. The shell 122 and the end cap 121 can be independent components, and an opening can be set on the shell 122, and the internal environment of the battery cell 120 is formed by covering the opening with the end cap 121 at the opening. Without limitation, the end cap 121 and the shell 122 can also be integrated. Specifically, the end cap 121 and the shell 122 can form a common connection surface before other components are put into the shell, and when it is necessary to encapsulate the interior of the shell 122, the end cap 121 covers the shell 122. The shell 122 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 122 can be determined according to the specific shape and size of the battery cell assembly 123. The shell 122 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special limitation on this.

[0074] The cell assembly 123 is a component where electrochemical reactions occur in the battery cell 120. The housing 122 may contain one or more cell assemblies 123. The cell assembly 123 is mainly formed by winding or stacking pole sheets, wherein the pole sheets include a positive pole sheet and a negative pole sheet, and a separator is usually provided between the positive pole sheet and the negative pole sheet.

[0075] The electrode sheet mainly includes a thin sheet-shaped current collector and an active material coated on the current collector. The parts of the positive electrode sheet, cathode electrode sheet and the negative electrode sheet, anode electrode sheet with active materials constitute the main body of the battery cell assembly, and the parts of the positive electrode sheet and negative electrode sheet without active materials each constitute a tab 123a. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery pack 100, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab 123a connects the electrode terminal to form a current loop.

[0076] In a general placement state of the battery cell, the opening of the shell 122 of the battery cell 120 faces upward, the end cover 121 covers the top of the opening of the shell 122, the battery cell assembly 123 is accommodated in the accommodating cavity of the shell 122, and the electrode terminal 121a is connected to the pole ear 123a of the battery cell assembly 123 and passes through the end cover 121 and extends to the top of the end cover 121.

[0077] In some cases, the battery cell 120 needs to be inverted. When the battery cell 120 is inverted, the end cap 121 is located below the shell 122, and the opening of the shell 122 faces downward. After the battery cell is inverted, the electrolyte inside the battery cell will flow along the battery cell assembly 123 to a position closer to the end cap 121, corroding the weak areas of the end cap 121, such as the explosion-proof valve at the end cap 121, the area near the electrode terminal 121a, and the weld. Electrolyte corrosion of the end cap 121 will weaken the mechanical strength of the end cap 121 and seriously affect the reliability of the battery cell. In addition, superimposed corrosion will continuously consume electrolyte, and the effective electrolyte in the battery cell will become less and less. During the use of the battery cell, due to the aggravation of poor electrolyte infiltration, the cycle performance of the battery cell will deteriorate.

[0078] In order to improve the above problems, the present application provides a battery cell, see Figures 4 to 7 In some embodiments of the present application, the battery cell includes a shell 122 , an electrolyte, a battery cell assembly 123 , a plastic part 124 and a first liquid absorbing part 125 .

[0079] An opening is provided at one end of the housing 122. The electrolyte is disposed in the housing 122. The battery cell assembly 123 includes a battery cell body 123b disposed in the housing 122 and a tab 123a connected to the battery cell body 123b and located at one end of the battery cell body 123b close to the opening of the housing 122. The plastic part 124 is covered on the opening of the housing 122 to form a containing cavity for containing the electrolyte and the battery cell assembly 123 with the housing 122. The plastic part 124 includes a plate-like portion 1241 covering the opening of the housing 122 and a protrusion 1242 disposed on the inner surface of the plate-like portion 1241 facing the housing 122.

[0080] The first liquid absorbent member 125 extends from the plate-shaped portion 1241 toward the cell body 123b, and the distance between one end of the first liquid absorbent member 125 away from the cell body 123b and the cell body 123b is equal to or greater than the distance between the inner surface of the plate-shaped portion 1241 and the cell body 123b.

[0081] Therefore, after the battery cell 120 is inverted, the end of the first liquid absorbent member 125 away from the battery cell body 123b is no higher than the inner surface of the plate-like portion 1241 of the plastic member 124, so that the electrolyte flowing onto the inner surface of the plate-like portion 1241 is guided upwards through capillary action. This is beneficial to improving the problem of reducing the reliability of the battery cell 120 by causing the electrolyte to flow to a position closer to the end cover 121 and corroding the weak area of ​​the end cover 121. It is also beneficial to ensuring the mechanical strength of the battery end cover 121.

[0082] The first liquid absorbent member 125 extends from the plate-shaped portion 1241 toward the battery cell body 123b and is connected to and abuts against the battery cell body 123b. After the battery is inverted, the electrolyte flowing toward the plate-shaped portion 1241 of the plastic member 124 can be absorbed by the first liquid absorbent member 125 under the capillary action and transported toward the battery cell body 123b, thereby improving the problem of poor cycle performance of the battery cell 120 caused by the reduction of electrolyte.

[0083] The material of the liquid-absorbing component is preferably a fibrous material, and the material can be selected from common high-liquid-absorbing materials such as polyethylene oxide (PEO), polyacrylamide (PAM), polyvinyl alcohol (PVA), etc.

[0084] In some embodiments, the first liquid absorbent member 125 is connected to or abuts against one end of the plate-like portion 1241 of the accommodating cavity close to the plastic member 124, so that the distance between the end of the first liquid absorbent member 125 away from the battery cell body 123b and the battery cell body 123b is equal to the distance between the inner surface of the plate-like portion 1241 and the battery cell body 123b, so that the first liquid absorbent member 125 absorbs the electrolyte above the plate-like portion 1241 of the inverted battery cell 120, which helps to prevent the problem of electrolyte remaining on the plate-like portion 1241.

[0085] In other embodiments, the distance between the end of the first liquid absorbent member 125 of the plastic member 124 away from the battery cell body 123b and the battery cell body 123b is greater than the distance between the inner surface of the plate-shaped portion 1241 and the battery cell body 123b. Specifically, a recessed portion is provided on the inner surface of the plate-shaped portion 1241, and the end of the first liquid absorbent member 125 away from the battery cell body 123b is embedded in the recessed portion. The electrolyte of the inverted battery cell 120 flowing toward the plate-shaped portion 1241 can converge toward the above-mentioned recessed portion and be guided toward the battery cell through the capillary action of the first liquid absorbent member 125, thereby improving the problem of reduced reliability of the battery cell 120 due to corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 due to the reduction of the electrolyte.

[0086] In some embodiments, the plastic part 124 includes a through hole 1243 that allows the electrode terminal 121a connected to the tab 123a to pass through, and the two through holes 1243 are arranged along the first direction and are respectively located at two ends of the plastic part 124 along the first direction, and the first liquid absorbing member 125 is provided at the end of the plastic part 124 along the first direction. Specifically, the two through holes 1243 are respectively located on the inner side of the protrusions 1242 provided at two ends of the plate-shaped part 1241 along the first direction.

[0087] The first liquid absorbing member 125 is disposed near the electrode terminal to guide the electrolyte near the electrode terminal 121a toward the battery cell body 123b, which is beneficial to prevent the electrolyte from corroding the welding part of the electrode terminal 121a. Further, the problem of the reliability of the battery cell 120 being reduced due to the corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of the poor cycle performance of the battery cell 120 due to the reduction of the electrolyte are improved.

[0088] In some embodiments, see Figure 5As well as 7 and 8, the protruding portion 1242 is provided with an embedding groove connected to the accommodating cavity, the embedding groove extends from one end of the protruding portion 1242 close to the battery body 123b to the plate-shaped portion 1241, the depth of the embedding groove is greater than or equal to the height of the protruding portion 1242 protruding from the plate-shaped portion 1241, the first liquid absorbent member 125 is at least partially embedded in the embedding groove, and the distance between one end of the first liquid absorbent member 125 facing the bottom of the embedding groove and the battery body 123b is greater than or equal to the distance between the inner surface of the plate-shaped portion 1241 and the battery body 123b, that is, When the battery cell is inverted, the end of the first liquid absorbent member 125 away from the battery cell body 123b is lower than the inner surface of the plate-like portion 1241 or is flush with the inner surface of the plate-like portion 1241, which is beneficial for the first liquid absorbent member 125 to guide the electrolyte flowing toward the plate-like portion 1241 to the battery cell body 123b under capillary action, thereby improving the problem of reduced reliability of the battery cell 120 due to corrosion of the end cover of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 due to the reduction of the electrolyte.

[0089] In some embodiments, the embedding groove extends to the side of the plastic part 124 facing the end cap 121. The two ends of the first liquid absorbent member 125 are respectively connected to the inner surface of the battery cell body 123b of the end cap 121. When the electrolyte level of the inverted battery cell is low, the first liquid absorbent member 125 can transfer the electrolyte to the battery cell body 123b.

[0090] Furthermore, the first liquid absorbing member 125 is embedded in the embedding groove of the protruding portion 1242 and does not occupy the space in the height direction of the battery cell 120 .

[0091] Furthermore, a groove is provided on the protruding portion 1242 of the plastic member 124 to accommodate the first liquid absorbent member 125, which is beneficial to avoid occupying additional space (such as height space) due to the provision of the first liquid absorbent member 125, has little impact on the original structure of the battery cell 120, and is also beneficial to making the structure of the battery cell 120 compact and realizing miniaturization of the battery.

[0092] Combination Figures 4 to 9 As shown, the battery cell 120 includes two battery cell assemblies 123 arranged side by side along the second direction, wherein the second direction is perpendicular to the first direction, and two protrusions 1242 arranged at both ends of the plastic part 124 along the first direction extend along the second direction at both ends of the plastic part 124. Among them, the two first liquid absorbing members 125 are arranged along the second direction. The two embedded first liquid absorbing members 125 are respectively located in the middle of the two battery cell assemblies 123 along the second direction.

[0093] The first liquid absorbent member 125 is placed between the end cap 121 and the battery body 123b to provide a path for transferring electrolyte; the first liquid absorbent member 125 is embedded in the embedding groove of the plastic member 124, and the first liquid absorbent member 125 is placed in the center relative to the battery body 123b. The number of the first liquid absorbent members 125 is not limited to 2, and can be 1 or more.

[0094] In some embodiments, see Figures 10 to 15 The first liquid absorbent member 125 includes an embedding portion 1251 filled in the embedding groove. Optionally, the end of the embedding portion 1251 away from the battery cell body 123b abuts against the bottom of the embedding groove, and the end of the embedding portion 1251 close to the battery cell body 123b abuts against or is connected to the battery cell body 123b. The embedding groove is open on the side facing the accommodating cavity, so that the embedding portion 1251 guides the electrolyte toward the battery cell body 123b through capillary action, which is beneficial to avoid the extra space occupied by the first liquid absorbent member 125, has little impact on the original structure of the battery cell 120, and is also beneficial to make the structure of the battery cell 120 compact and realize the miniaturization of the battery.

[0095] In some embodiments, the first liquid absorbent member 125 further includes an embedded portion 1251 filled in the embedded groove and an overlapped portion 1252 connected to the embedded portion 1251 and overlapped between the end surface of the protrusion 1242 facing the battery cell body 123b and the battery cell body 123b. The overlapped portion 1252 covers one end of the embedded portion 1251 close to the battery cell body 123b and part or all of the end surface of the protrusion 1242 close to the battery cell body 123b. This is beneficial to increase the contact area between the first liquid absorbent member 125 and the battery cell body 123b. The overlapped portion 1252 covers the end surfaces of the protrusion 1242 at both ends of the plastic member 124 facing the battery cell body 123b, and the electrolyte can be transferred to the battery cell body 123b more evenly.

[0096] In some embodiments, see Figures 16 to 21 The first liquid absorbing member 125 includes an attaching portion 1253 attached to the inner surface of the plate-shaped portion 1241. The attaching portion 1253 can effectively absorb the electrolyte on the inner surface of the plate-shaped portion 1241, thereby improving the problem of reduced reliability of the battery cell 120 due to corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 due to the reduction of the electrolyte.

[0097] See also Fig.16 , 1921, in some embodiments, the attachment portion 1253 extends from the protrusion 1242 toward the through hole 1243 of the plate-shaped portion 1241 that allows the electrode terminal 121a connected to the pole ear 123a to pass through, and the attachment portion 1253 is arranged near the electrode terminal to guide the electrolyte near the electrode terminal 121a toward the battery body 123b, which is conducive to preventing the electrolyte from corroding the welding part of the electrode terminal 121a. Further, the problem of reduced reliability of the battery cell 120 due to corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 due to the reduction of the electrolyte are improved.

[0098] In some embodiments, the first liquid absorbent member 125 further includes an overlapping portion 1252 connected to the attachment portion 1253 and overlapped between the end surface of the protrusion 1242 facing the battery cell body 123b and the battery cell body 123b. The overlapping portion 1252 covers one end of the embedded portion 1251 close to the battery cell body 123b and part or all of the end surface of the protrusion 1242 close to the battery cell body 123b. This is beneficial to increase the contact area between the first liquid absorbent member 125 and the battery cell body 123b. The overlapping portion 1252 covers the end surfaces of the protrusion 1242 at both ends of the plastic member 124 facing the battery cell body 123b, and the electrolyte can be transferred to the battery cell body 123b more evenly.

[0099] In some embodiments, the first absorbent member 125 further includes a connecting portion 1254 connecting the attaching portion 1253 and the overlapping portion 1252, and the connecting portion 1254 is attached to the side of the protruding portion 1242, see Fig.21 This is beneficial to avoid the first liquid absorbing member 125 occupying additional space, has little impact on the original structure of the battery cell 120, and is also beneficial to making the structure of the battery cell 120 compact and realizing the miniaturization of the battery.

[0100] See also Fig.16 , 19 21, the first liquid absorbing member 125 includes an overlapping portion 1252 covering the end surface of the protruding portion 1242 facing the battery cell body 123b, a connecting portion 1254 attached to the side surface of the protruding portion 1242 adjacent to the through hole 1243, and an attaching portion 1253 attached to the inner surface of the plate-shaped portion 1241. The overlapping portion 1252, the connecting portion 1254 and the attaching portion are sequentially connected and arranged in a Z-shape, which can effectively guide the electrolyte near the electrode terminal 121a to the battery cell body 123b, thereby improving the problem of reduced reliability of the battery cell 120 due to corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 due to the reduction of the electrolyte.

[0101] The first liquid absorbing member 125 is attached to the outer surface of the plastic member, connecting the end surface of the protruding portion 1242 of the plastic member 124 facing the battery cell body 123b and the inner surface of the sunken portion, and is attached to the surface of the plastic member, with sufficient contact area and simple assembly. Fig.16 and 19 .

[0102] In some embodiments, see Figures 22 to 25 , the pole tab 123a is bent toward the middle from one side of the end surface of the battery body 123b close to the plastic part 124, the battery cell 120 further includes a connector 127 that covers the side of the bent pole tab 123a away from the battery body 123b and connected to the pole tab 123a, and an electrode terminal 121a connected to the connector 127, the first end of the first liquid absorbing member 125 is attached to the side of the connector 127 away from the pole tab 123a, and extends toward the battery body 123b along the side of the bent pole tab 123a that is away from the battery body 123b. In some embodiments, the side of the connector 127 away from the battery body 123b is welded to the electrode terminal 121a.

[0103] The first liquid absorbing member 125 is disposed near the electrode terminal to guide the electrolyte near the electrode terminal 121 a toward the battery cell body 123 b , which is beneficial to preventing the electrolyte from corroding the welding portion of the electrode terminal 121 a .

[0104] In some embodiments, the second end 125a of the first liquid absorbent member 125 away from the connector 127 is attached to the side of the battery cell body 123b to increase the contact area between the liquid absorbent member and the battery cell body. The first liquid absorbent member 125 is attached to the outer surface of the tab 123a, and the electrolyte at the welding mark of the electrode terminal 121a and the tab 123a can be guided to the battery cell body 123b, thereby improving the problem of reduced reliability of the battery cell 120 due to corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 due to the reduction of the electrolyte.

[0105] In some embodiments, the plastic member 124 covers the side of the connector 127 away from the battery cell assembly 123, and the side of the first liquid absorbent member 125 away from the connector 127 is attached to the inner surface of the plate-like portion 1241, so that the first liquid absorbent member 125 absorbs the electrolyte above the plate-like portion 1241 of the inverted battery cell 120, which helps to prevent the problem of electrolyte remaining on the plate-like portion 1241.

[0106] In some embodiments, the battery cell further includes a second liquid absorbing member 126, the first end of which is attached to a side of the bent pole ear 123a facing the battery cell body 123b, and extends along a side of the pole ear 123a facing the battery cell body 123b facing the plastic member 124. The second liquid absorbing member 126 can guide the electrolyte above the connector 127 of the inverted battery cell toward the battery cell body 123b, which is beneficial to improve the problem of electrolyte corrosion of the connection between the connector 127 and the pole ear 123a (e.g., welding mark) and the connection between the connector 127 and the electrode terminal 121a (e.g., welding mark), thereby improving the problem of reduced reliability of the battery cell 120 due to corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 due to the reduction of the electrolyte.

[0107] In some embodiments, the second liquid absorbing member 126 extends to the side of the battery cell body 123b, and the second end 126a of the second liquid absorbing member 126 away from the pole ear 123a is attached to the side of the battery cell body 123b, which is located on the side of the end surface of the battery cell body 123b facing the plastic part 124, see Fig.23 , so as to increase the contact area between the second liquid absorbent member 126 and the battery body 123b, so as to quickly and efficiently transfer the electrolyte to the battery body 123b. Of course, the second liquid absorbent member 126 may also extend to the edge of the end surface of the battery body 123b facing the plastic member 124.

[0108] The first liquid absorbing member 125 and the second liquid absorbing member 126 are respectively attached to the outer surface and the inner surface of the electrode tab 123 a , so as to transfer electrolyte and protect the electrode tab 123 a from contacting the shell 122 (aluminum shell) or the end cover 121 .

[0109] In some embodiments, two battery cell assemblies 123 are arranged side by side, and the tabs 123a of the two battery cell assemblies 123 are bent toward the junction of the two battery cell assemblies 123, and the two sides of the connector 127 are respectively connected to the tabs 123a of the two battery cell assemblies 123. The number of battery cell assemblies 123 is not limited to two bare battery cell structures, and the battery cell assemblies 123 are not limited to bare battery cells with a winding structure, and are also applicable to laminated battery cells.

[0110] The assembly process of the battery cell 120 of this embodiment is as follows.

[0111] First, two battery cell assemblies 123 are arranged side by side along the height direction of the battery cell assemblies 123, and the tabs 123a of the two battery cell assemblies 123 are arranged opposite to each other. Then, the tabs 123a of the two battery cell assemblies 123 are connected by a connector 127. Then, a first liquid absorbing member 125 and a second liquid absorbing member 126 are attached to both sides of the connector 127 and the tab 123a, respectively. Figures 26 to 28.

[0112] Then, the plastic part 124 is covered on the above-mentioned connecting part 127. The plastic part 124 can be as follows Figures 4 to 9 The first liquid-absorbing member 125 or the Figures 10 to 15 A first liquid absorbing member 125 or Figures 16 to 21 A first liquid absorbing member 125 is provided, see Fig.29 .

[0113] Then, after the end cap 121 and the electrode terminal 121a are arranged on the plastic part 124, the two battery cell components 123 are bent to Fig.23 The structure shown, see Fig.30 .

[0114] The first liquid absorbing member 125 is placed on the outer surface of the pole ear, and the second liquid absorbing member 126 is placed on the surface of the innermost pole ear 123a to transfer the electrolyte at the welding position. The first liquid absorbing member 125 is placed on the surface of the outer pole ear 123a, and on the top surface of the connecting member 127, transfers the electrolyte at the contact position between the connecting member 127 and the plastic member 124, such as Fig.23 . Fig.24 The second end of the second liquid absorbing member 126 may not be placed between the two battery cell assemblies 123 , but may be connected to the end surface of the battery cell body 123 b .

[0115] The above are merely exemplary embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing (122) having an opening at one end; An electrolyte is disposed in the housing (122); A battery cell assembly (123), comprising a battery cell body (123b) disposed in the shell (122) and a pole ear (123a) connected to the battery cell body (123b) and located at one end of the battery cell body (123b) close to the opening of the shell (122); a plastic part (124) covering the opening of the shell (122) to enclose, together with the shell (122), a containing cavity for containing the electrolyte and the battery cell assembly (123); the plastic part (124) comprising a plate-shaped portion (1241) covering the opening of the shell (122) and a protruding portion (1242) provided on the inner surface of the plate-shaped portion (1241) facing the shell (122); and A first liquid absorbing member (125) extends from the plastic member (124) toward the battery cell body (123b), and a distance between an end of the first liquid absorbing member (125) away from the battery cell body (123b) and the battery cell body (123b) is equal to or greater than a distance between an inner surface of the plate-shaped portion (1241) and the battery cell body (123b).

2. The battery cell according to claim 1, characterized in that: The plastic part (124) comprises a through hole (1243) allowing an electrode terminal (121a) connected to the electrode tab (123a) to pass through, two through holes (1243) are arranged along a first direction and are respectively located at two ends of the plastic part (124) along the first direction, and the first liquid absorbing part (125) is provided at an end of the plastic part (124) along the first direction.

3. The battery cell according to claim 1, characterized in that: The protruding portion (1242) is provided with an embedding groove connected to the accommodating cavity, the embedding groove extending from an end of the protruding portion (1242) close to the battery cell body (123b) toward the plate-like portion (1241), the depth of the embedding groove being greater than or equal to the height of the protruding portion (1242) protruding from the plate-like portion (1241), and the first liquid absorbing member (125) being embedded in the embedding groove.

4. The battery cell according to claim 3, characterized in that: It also comprises an end cover (121) which is arranged on a side of the plastic part (124) away from the battery cell assembly (123), and the embedding groove extends to a side of the plastic part (124) facing the end cover (121).

5. The battery cell according to claim 3, characterized in that: The first liquid absorbing member (125) comprises an embedded portion (1251) filled in the embedded groove and an overlapping portion (1252) connected to the embedded portion (1251) and overlapped between the end surface of the protruding portion (1242) facing the battery cell body (123b) and the battery cell body (123b), wherein the overlapping portion (1252) covers one end of the embedded portion (1251) close to the battery cell body (123b) and part or all of the end surface of the protruding portion (1242) close to the battery cell body (123b).

6. The battery cell according to any one of claims 1 to 4, characterized in that: The first liquid-absorbing member (125) comprises an attachment portion (1253) attached to the inner surface of the plate-shaped portion (1241).

7. The battery cell according to claim 6, characterized in that: The first liquid absorbent member (125) further comprises an overlapping portion (1252) connected to the attachment portion (1253) and overlapping between the end surface of the protruding portion (1242) facing the battery cell body (123b) and the battery cell body (123b), wherein the overlapping portion (1252) covers part or all of the end surface of the protruding portion (1242) close to the battery cell body (123b).

8. The battery cell according to claim 7, characterized in that: The first liquid-absorbing member (125) further comprises a connecting portion (1254) connecting the attaching portion (1253) and the overlapping portion (1252), wherein the connecting portion (1254) is attached to a side surface of the protruding portion (1242).

9. The battery cell according to claim 6, characterized in that: The attachment portion (1253) extends from the protruding portion (1242) toward a through hole (1243) of the plate-shaped portion (1241) that allows the electrode terminal (121a) connected to the electrode tab (123a) to pass through.

10. The battery cell according to claim 1, characterized in that: The pole ear (123a) is bent toward the middle from one side of the end surface of one end of the battery body (123b) close to the plastic part (124); the battery cell (120) further comprises a connector (127) which is covered on a side of the bent pole ear (123a) away from the battery body (123b) and connected to the pole ear (123a), and an electrode terminal (121a) connected to the connector (127); a first end of the first liquid absorbing member (125) is attached to a side of the connector (127) away from the pole ear (123a), and extends toward the battery body (123b) along a side of the bent pole ear (123a) facing away from the battery body (123b).

11. The battery cell according to claim 10, characterized in that: The second end (125a) of the first liquid absorbing member (125) away from the connecting member (127) is attached to the side surface of the battery core body (123b).

12. The battery cell according to claim 10, characterized in that: The plastic part (124) covers a side of the connecting part (127) away from the battery core assembly (123), and a side of the first liquid absorbent part (125) away from the connecting part (127) is attached to the inner surface of the plate-shaped part (1241).

13. The battery cell according to claim 10, characterized in that: It also includes a second liquid absorbing member (126), wherein a first end of the second liquid absorbing member (126) is attached to a side of the bent pole ear (123a) facing the battery cell body (123b), and extends along the pole ear (123a) toward a side of the battery cell body (123b) facing the plastic member (124).

14. The battery cell according to any one of claims 10 to 13, characterized in that: The two battery cell assemblies (123) are arranged side by side, the pole ears (123a) of the two battery cell assemblies (123) are respectively bent towards the junction of the two battery cell assemblies (123), and the two sides of the connecting member (127) are respectively connected to the pole ears (123a) of the two battery cell assemblies (123).

15. The battery cell according to claim 13, characterized in that: The second liquid absorbing member (126) extends to the side of the battery core body (123b), and the second end of the second liquid absorbing member (126) away from the pole ear (123a) is attached to the side of the battery core body (123b).

16. The battery cell according to claim 1, characterized in that: One end of the first liquid absorbing member (125) away from the plate-shaped portion (1241) abuts against or is connected to the battery core body (123b).

17. A battery pack, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 16.

18. An electrical device, characterized in that: A battery pack comprising the battery pack of claim 17.

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