Battery monomer, battery device and electric device

Abstract

The invention belongs to the technical field of batteries, and provides a battery monomer, a battery device and a power utilization device, the battery monomer comprises a shell, an electrode assembly, an electrolyte, an end cover, an insulating film and a plastic part; the shell is provided with an inner cavity; the electrode assembly is arranged in the inner cavity; the electrolyte is arranged in the inner cavity and is used for infiltrating the electrode assembly; the end cover is arranged on the shell and is used for sealing the inner cavity; the insulating film is coated outside the electrode assembly; the plastic part is arranged in the inner cavity and is opposite to the end part of the electrode assembly; wherein at least part of the structure of at least one of the insulating film or the plastic part is a liquid storage structure, the liquid storage structure is used for storing electrolyte, the liquid storage structure and the large surface of the electrode assembly are oppositely arranged, and the liquid storage structure is configured to be extruded by the large surface to release the electrolyte when the large surface of the electrode assembly expands, and the large surface of the electrode assembly is the surface with the largest area of the electrode assembly. The invention aims to increase the storage amount of electrolyte in a battery monomer in the later use period of the battery monomer so as to reduce the risk of poor infiltration of an electrode assembly.

Description

Technical Field

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

[0002] With the rise of new energy devices represented by new energy vehicles, battery devices have become a key source of power. The battery device may include multiple battery cells. The battery cells are the main charging and discharging devices. Electrode assemblies and electrolytes that soak the electrode assemblies are arranged inside the battery cells.

[0003] With the long-term use of the battery device, the electrolyte inside the battery cell is gradually consumed or the electrode assembly is expanded, so that the electrolyte cannot effectively infiltrate the electrode assembly, thereby affecting the normal operation of the battery cell. Summary of the invention

[0004] In view of the above problems, the present application provides a battery cell, a battery device and an electrical device, which aim to increase the electrolyte reserve inside the battery cell in the later stage of battery cell use to reduce the risk of poor wetting of the electrode assembly.

[0005] To solve the above problems, in a first aspect, an embodiment of the present application provides a battery cell, including: a housing having an inner cavity; an electrode assembly, disposed in the inner cavity; An electrolyte, disposed in the inner cavity and used to wet the electrode assembly; An end cover, disposed on the shell and used to close the inner cavity; An insulating film, covering the electrode assembly; and A plastic part, disposed in the inner cavity and opposite to the end of the electrode assembly; Among them, at least a part of the structure of at least one of the insulating film and the plastic part is a liquid storage structure, and the liquid storage structure is used to store electrolyte. The liquid storage structure is arranged opposite to the large surface of the electrode assembly, and the liquid storage structure is configured to be squeezed by the large surface when the large surface of the electrode assembly expands to release the stored electrolyte, wherein the large surface of the electrode assembly is the surface with the largest area of ​​the electrode assembly.

[0006] The effect of this embodiment is that the amount of electrolyte in the battery cell can be increased without occupying the residual space in the battery cell, and the cost is also low. This embodiment provides that the insulating film or plastic part has a relative portion to the large surface of the electrode assembly that expands later, which can enhance the squeezing effect and facilitate the release of the electrolyte.

[0007] In an embodiment of the first aspect, the liquid storage structure is a flexible structure having micropores communicating with the inner cavity, and the micropores are used to adsorb the electrolyte.

[0008] The effect of this embodiment is that the liquid storage structure is designed to be a flexible structure with micropores, so that the liquid storage structure has a strong adsorption effect and can release a large amount of electrolyte with squeezing; when the plastic parts and the insulating film are flexible structures, squeezing between the plastic parts or the insulating film and the electrode assembly will also avoid squeezing damage to the electrode assembly, thereby ensuring the structural stability of the electrode assembly.

[0009] In an embodiment of the first aspect, the liquid storage structure is an elastic structure, a receiving hole connected to the inner cavity is opened on the elastic structure, an elastic liquid storage part is arranged in the receiving hole, and the liquid storage part is configured to release the stored electrolyte after being squeezed.

[0010] The effect of this embodiment is that the liquid storage structure is set to an elastic structure, which will not cause extrusion damage to the electrode assembly when squeezed, because the elastic structure will deform during squeezing, preventing a hard collision with the electrode assembly, and will release the electrolyte stored in the liquid storage component, thereby increasing the amount of electrolyte inside the battery cell.

[0011] In an embodiment of the first aspect, the liquid storage member is a flexible structure having micropores communicating with the inner cavity, and the micropores are used to absorb the electrolyte.

[0012] The effect of this embodiment is that the liquid storage member is also configured as a flexible structure, which is low-cost and has obvious effects.

[0013] In an embodiment of the first aspect, the material of the flexible structure includes at least one of silicone rubber, styrene-butadiene copolymer, polyurethane, polyurethane-polyether copolymer, polypyrrole polymer, polythiophene polymer, polyimidazole polymer, polytriazine polymer, styrene hypercross-linked polymer, and polyaniline polymer.

[0014] This embodiment provides a variety of flexible structural materials, which not only have good flexibility and can be squeezed without hard contact with the electrode assembly, but also have high structural stability and functional stability when generating more micropores, have high liquid absorption and storage effects, and are low in price and cost.

[0015] In an embodiment of the first aspect, the flexible structure includes at least one of cotton fabric, rubber product, sponge, foam, and liquid absorbent cloth. These structures have good liquid absorption effect, can store a large amount of electrolyte, and are all made of flexible materials. When squeezed, they can be flexibly squeezed between the electrode assembly, effectively protecting the electrode assembly, and are low in price to reduce costs.

[0016] In an embodiment of the first aspect, at least a portion of the plastic part is the liquid storage structure, and the plastic part is disposed at one end of the electrode assembly adjacent to the end cover and between the end cover and the electrode assembly.

[0017] The effect of this embodiment is that the plastic part is set as a liquid storage structure, and there is no need to set up an additional structure to store liquid separately, so that the plastic part has the functions of storing liquid and preventing the end cover and the electrode assembly from being squeezed, which not only reduces the cost but also does not affect the residual space in the battery cell.

[0018] In an embodiment of the first aspect, the liquid storage structure includes a first part and a second part, the first part is farther away from the middle of the end cover in the length direction than the second part, and the liquid absorption per unit volume of the first part is less than the liquid absorption per unit volume of the second part.

[0019] This embodiment can reduce the back absorption of the electrolyte.

[0020] In one embodiment of the first aspect, the porosity of the flexible structure of the first portion is smaller than the porosity of the flexible structure of the second portion, and / or the average volume of the micropores of the flexible structure of the first portion is larger than the average volume of the micropores of the flexible structure of the second portion.

[0021] The effect of this embodiment is that it provides an implementation form in which the liquid absorption capacity of the first part is designed to be smaller than that of the second part.

[0022] In an embodiment of the first aspect, the liquid storage structure is located at the top or bottom end of the battery cell in the gravity direction.

[0023] This embodiment provides a design of the end cap at the top or bottom of the battery unit in the gravity direction, which can realize the storage and extrusion release of electrolyte. It should be noted that the liquid storage structure that is in an extrusion deformation state after being squeezed will not absorb the electrolyte or the amount of electrolyte absorbed is very small.

[0024] In an embodiment of the first aspect, an opening of the accommodating hole faces one side of the electrode assembly, the elastic structure is provided with a plurality of the accommodating holes, and the plurality of the accommodating holes are arranged in an array.

[0025] The effect of this embodiment is that the opening direction of the accommodating hole enables the electrolyte to flow to the electrode assembly quickly and effectively, and the multi-row and multi-column array arrangement allows the electrolyte to flow out of each site, which is beneficial to the balanced infiltration of the electrolyte into the electrode assembly.

[0026] In an embodiment of the first aspect, the inner wall surface of the accommodating hole is an arc-shaped surface.

[0027] The effect of this embodiment is that the inner wall surface of the accommodating hole adopts an arc surface. When the elastic structure is squeezed, the accommodating hole with an arc surface is not easy to produce dead corners that are not completely squeezed when compressed. For example, when the inner wall surface of the accommodating hole is a non-arc surface, such as a plane, the corner where the two planes meet may produce an extrusion gap when squeezed, and the flexible structure in the gap is squeezed to a lower degree, and the electrolyte is not completely released.

[0028] In an embodiment of the first aspect, the material of the elastic structure includes at least one of polyurethane, polyethylene, silicone rubber, and polytetrafluoroethylene. The material selection of the elastic structure has a good deformation effect, can be smoothly extruded, and has stable material performance, no chemical reaction, and has a good anti-collision effect.

[0029] In a second aspect, the present application further provides a battery device, comprising any one of the battery cells described.

[0030] In a third aspect, the present application further provides an electrical device, comprising any one of the battery cells or the battery device described.

[0031] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 any creative work.

[0033] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application; Figure 2 A schematic diagram of the structure of a battery device provided in some embodiments of the present application; Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application; Figure 4 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application; Figure 5 for Figure 4 A schematic diagram of the enlarged structure at A in the middle; Figure 6 A schematic cross-sectional view of a battery cell provided in some embodiments of the present application; Figure 7 for Figure 6 A schematic diagram of the enlarged structure at B in the middle; Figure 8 Schematic diagram of the exploded structure of the electrode assembly and the insulating film provided in some embodiments of the present application.

[0034] The reference numerals in the specific implementation manner are as follows: 1000. Vehicles; 100, battery device; 200, controller; 300, motor; 10. Battery cell; 11. Shell; 12. Electrode assembly; 13. End cap; 14. Insulating film; 15. Plastic part; 16. Liquid storage structure; 17. Flexible structure; 18. Micropores; 19. Elastic structure; 20. Accommodating hole; 21. Liquid storage part; 22. First part; 23. Second part. DETAILED DESCRIPTION

[0035] 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.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0037] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0038] 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.

[0039] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0040] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0041] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0042] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0043] At present, from the perspective of market development, the application of battery devices is becoming more and more extensive. Battery devices 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 battery application fields, its market demand is also constantly expanding.

[0044] The battery device is a complete structural unit, including a box body, and multiple battery cells are arranged inside the box body. In some special scenarios, one battery cell can also be arranged inside the box body. When there are multiple battery cells, the battery cells in the same row can be formed into a battery cell assembly.

[0045] The battery apparatus provided in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, in parallel or in hybrid connection through a busbar component, where hybrid connection refers to a mixture of series connection and parallel connection.

[0046] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0047] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0048] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0049] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0050] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0051] As an example, the box may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0052] As an example, the box body may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0053] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0054] like Figure 2 The embodiment of the present application also provides an electrical device having a battery device 100, that is, an electrical device that uses the battery device 100 as a power source.

[0055] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using the battery device 100, wherein the electrical devices may be vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. The spacecraft includes airplanes, rockets, space shuttles, and spacecrafts, etc. The electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. The electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0056] The battery device 100 disclosed in the embodiment of the present application can be used in, but not limited to, electrical devices such as vehicles, ships, or aircraft. The electrical device can use a power supply system having the battery device 100 disclosed in the present application, which is conducive to improving the reliability of the electrical device.

[0057] For the convenience of description, the following embodiments are described by taking the electric device provided in the embodiments of the present application as a vehicle 1000 as an example.

[0058] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 may be used to power the vehicle 1000, for example, the battery device 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 device 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0059] 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.

[0060] The battery cell 10 in the battery device 100 is the main energy storage component for charging and discharging. An electrode assembly 12 is arranged inside the battery cell 10. The electrode assembly 12 is soaked in electrolyte. The electrode assembly 12 includes positive and negative electrode sheets and a separator. The electrode assembly 12 can be arranged in a winding form or in a stacked form. As the use time increases, the electrolyte may be consumed, resulting in a decrease in the amount of electrolyte inside the battery cell 10, or, due to the expansion of the electrode assembly 12 at a later stage, the electrolyte cannot effectively and fully soak the electrode assembly 12.

[0061] Based on this, the present application provides a battery cell 10, which aims to increase the amount of electrolyte stored inside the battery cell 10 during the later use of the battery cell 10.

[0062] See also Figure 3-Figure 8 A battery cell 10 of the present embodiment includes a shell 11, an electrode assembly 12, an electrolyte, an end cover 13, an insulating film 14, and a plastic part 15.

[0063] Among them, the shell 11 has an inner cavity, the electrode assembly 12 is arranged in the inner cavity, the electrolyte is arranged in the inner cavity and is used to infiltrate the electrode assembly 12, the end cover 13 is arranged on the shell 11 and is used to close the inner cavity, the insulating film 14 is coated on the outside of the electrode assembly 12, and the plastic part 15 is arranged in the inner cavity and is arranged opposite to the end of the electrode assembly 12. It can be arranged at one end of the electrode assembly 12 adjacent to the end cover 13, and / or at one end of the electrode assembly 12 opposite to the end cover 13.

[0064] In this embodiment, at least a portion of at least one of the insulating film 14 and the plastic part 15 is a liquid storage structure 16 , which is used to store electrolyte and is configured to be squeezed by the electrode assembly 12 to release the stored electrolyte when the electrode assembly 12 expands.

[0065] Specifically, the housing 11 has an inner cavity, which is used to accommodate the electrode assembly 12 and store the electrolyte so that the electrolyte can infiltrate the electrode assembly 12 to perform a charge and discharge reaction. The end cap 13 is used to seal the housing 11 to maintain a closed environment for the internal electrochemical reaction. The insulating film 14 is also disposed inside the housing 11, which is used to wrap the electrode assembly 12.

[0066] The battery cell 10 of this embodiment also includes a plastic part 15, which can be arranged at an end adjacent to the electrode assembly 12 and the end cover 13, that is, squeezed between the end cover 13 and the electrode assembly 12 to play a role of buffering extrusion. In some cases, the plastic part 15 can also be arranged at an end opposite to the electrode assembly 12 and the end cover 13. In this case, the plastic part 15 can be arranged between the bottom plate and the electrode assembly 12.

[0067] When the electrode assembly 12 expands, it will squeeze the insulating film 14 or the plastic part 15, so in this embodiment, at least part of the structure of the insulating film 14 and / or the plastic part 15 is configured as a liquid storage structure 16. The liquid storage structure 16 is arranged opposite to the electrode assembly 12 to withstand the squeezing of the electrode assembly 12. The liquid storage structure 16 is configured to store a certain amount of electrolyte, which can be specifically achieved in the form of adsorbing electrolyte. When the electrode assembly 12 expands and squeezes the liquid storage structure 16, the stored electrolyte is released into the shell 11, which can increase the electrolyte reserve in the shell 11.

[0068] Furthermore, the liquid storage structure 16 of the present embodiment is not a new structure added inside the battery cell 10, but is formed based on the existing structure. For example, part or all of the plastic part 15 is set as the liquid storage structure 16, or part or all of the insulating film 14 is set as the liquid storage structure 16. This will not occupy additional residual space inside the battery cell 10 and save costs.

[0069] Therefore, the effect of this embodiment is that the amount of electrolyte stored in the battery cell 10 can be increased without occupying the residual space in the battery cell 10 , and the cost is also low.

[0070] In this embodiment, the liquid storage structure 16 is arranged opposite to the large surface of the electrode assembly 12, and the liquid storage structure 16 is configured to be squeezed by the large surface when the large surface of the electrode assembly 12 expands to release the stored electrolyte, wherein the large surface of the electrode assembly 12 is the surface with the largest area of ​​the electrode assembly 12.

[0071] The electrode assembly 12 is composed of a positive electrode sheet, a negative electrode sheet and a separator, all of which are in sheet form. The three can be arranged in a stacked form or in a wound form. Since the three are in sheet form, they include a large surface and a side surface, with a smaller area on the side surface and a larger area on the large surface. Therefore, the electrode assembly 12 formed also includes a large surface, which can be specifically understood as follows: when the electrode assembly 12 is in a wound form, the large surface of the electrode assembly 12 is the large surface of the outermost electrode sheet, and the liquid storage structure 16 can be arranged opposite to it, and can be arranged opposite to only a part of the large surface, which can be the part where the large surface is bent or the plane part. When the electrode assembly 12 is in a stacked form, the large surface of the electrode assembly 12 is the large surface of the electrode sheet at both ends in the stacking direction. When the electrode assembly 12 expands in the later stage of use, it is mainly the large surface that expands, that is, it expands in a direction perpendicular to the large surface. A pole is generally arranged on the end cover 13. When the end cover 13 and the plastic part 15 arranged on one side of the end cover 13 are opposite to the large surface of the electrode assembly 12, that is, the pole ear of the electrode assembly 12 is away from the pole, in this case, the pole ear can be connected to the pole with the help of a structure such as an adapter.

[0072] Based on the expansion direction of the electrode assembly 12, this embodiment provides a portion where the insulating film 14 or the plastic part 15 has a relative portion to the large surface of the electrode assembly 12 that expands later, which can enhance the squeezing effect and facilitate the release of the electrolyte.

[0073] In some embodiments, Figure 4 and Figure 5 The liquid storage structure 16 is a flexible structure 17 having micropores 18 communicating with the inner cavity, and the micropores 18 are used to absorb the electrolyte.

[0074] Specifically, the liquid storage structure 16 itself is made of a material that can absorb liquid and has micropores 18. The micropores 18 are used to absorb electrolyte. The electrolyte entering the micropores 18 will not fall off by itself when not squeezed because the resistance of the electrolyte in the micropores 18 to flow out of the micropores 18 is greater than the electrolyte's own weight.

[0075] In this embodiment, the liquid storage structure 16 is configured as a micropore 18 structure as a whole, that is, it has a large number of micropores 18, and adopts a flexible structure 17, and the micropores 18 can be squeezed by extrusion to squeeze out the internal electrolyte.

[0076] The effect of this embodiment is that the liquid storage structure 16 is designed as a flexible structure 17 with micropores 18, so that the liquid storage structure 16 has a strong adsorption effect and can release a large amount of electrolyte with squeezing; when the plastic part 15 or the insulating film 14 is a flexible structure 17, squeezing occurs between the plastic part 15 or the insulating film 14 and the electrode assembly 12, which will also avoid squeezing damage to the electrode assembly 12 and ensure the structural stability of the electrode assembly 12.

[0077] In some embodiments, Figure 6 and Figure 7 The liquid storage structure 16 is an elastic structure 19, and a receiving hole 20 communicating with the inner cavity is provided on the elastic structure 19. An elastic liquid storage member 21 is provided in the receiving hole 20, and the liquid storage member 21 is configured to release the stored electrolyte after being squeezed.

[0078] The present embodiment provides that the liquid storage structure 16 itself can be an elastic structure 19, can have a certain elastic deformation, and can restore its original shape after the elastic deformation. However, the elastic structure 19 provided in the present embodiment cannot be used to store liquid and does not have the property of storing liquid. The structure for storing liquid is a liquid storage part 21 located in the receiving hole 20 inside the elastic structure 19.

[0079] The receiving hole 20 is a hole-shaped structure provided on the elastic structure 19, has a certain receiving space, and is an open hole, that is, it is not a closed hole provided inside the elastic structure 19, and is connected to the inner cavity, that is, to the internal space of the battery cell 10 for storing electrolyte. A liquid storage member 21 is provided inside the receiving hole 20, and the liquid storage member 21 is used to store electrolyte, and can release the electrolyte when the extrusion is deformed during squeezing.

[0080] In the later stage of the use of the battery cell 10, due to the expansion of the electrode assembly 12, the electrode assembly 12 will squeeze the elastic structure 19, and the elastic structure 19 will be deformed, so that the receiving hole 20 will be deformed, and then the liquid storage part 21 in the receiving hole 20 will be squeezed, so that the liquid storage part 21 releases the electrolyte stored in it.

[0081] The effect of this embodiment is that the liquid storage structure 16 is set to an elastic structure 19, which will not cause extrusion damage to the electrode assembly 12 when squeezed, because the elastic structure 19 will deform during squeezing to prevent a hard collision with the electrode assembly 12, and will release the electrolyte stored in the liquid storage part 21, thereby increasing the amount of electrolyte inside the battery cell 10.

[0082] In some embodiments, Figure 6 and Figure 7 The liquid storage member 21 is a flexible structure 17 having micropores 18 communicating with the inner cavity, and the micropores 18 are used to absorb the electrolyte.

[0083] Specifically, the liquid storage member 21 adopts a flexible structure 17 with open micropores 18, which can be made of the same material as the flexible structure 17 of the liquid storage structure 16 in the above embodiment and also has the function of storing liquid. The micropores 18 are also used to absorb electrolyte.

[0084] The effect of this embodiment is that the liquid storage member 21 is also configured as the flexible structure 17, which has low cost and obvious effect.

[0085] In some embodiments, the material of the flexible structure 17 includes at least one of silicone rubber, styrene-butadiene copolymer, polyurethane, polyurethane-polyether copolymer, polypyrrole polymer, polythiophene polymer, polyimidazole polymer, polytriazine polymer, styrene hypercrosslinked polymer, and polyaniline polymer.

[0086] Specifically, this embodiment provides materials for the flexible structure 17 , including materials that can be used for the flexible structure 17 when the liquid storage structure 16 provided in the above embodiment is the flexible structure 17 and when the liquid storage member 21 is the flexible structure 17 .

[0087] This embodiment provides a variety of materials for the flexible structure 17, which not only have good flexibility and can be squeezed without hard contact with the electrode assembly 12, but also have high structural stability and functional stability when generating more micropores 18, have high liquid absorption and storage effects, and are low in price and cost.

[0088] In some embodiments, the flexible structure 17 includes at least one of cotton fabric, rubber product, sponge, foam, and absorbent cloth.

[0089] This embodiment provides specific materials of the flexible structure 17 .

[0090] Specifically, they include cotton fabrics, rubber products, sponges, foams, and absorbent cloths. These structures have good liquid absorption effects, can store a large amount of electrolyte, and are all made of flexible materials. When squeezed, they can be flexibly squeezed between the electrode assembly 12, effectively protecting the electrode assembly 12, and are low in price to reduce costs.

[0091] In some embodiments, Figure 4 and Figure 5 or Figure 6 and Figure 7 The plastic part 15 is at least partially a liquid storage structure 16 . The plastic part 15 is disposed at one end of the electrode assembly 12 adjacent to the end cover 13 and between the end cover 13 and the electrode assembly 12 .

[0092] Specifically, this embodiment provides a liquid storage structure 16 disposed on the plastic part 15 , that is, a part or the entire structure of the plastic part 15 is the liquid storage structure 16 .

[0093] Specifically, the plastic part 15 is arranged between the end cover 13 and the electrode assembly 12. While realizing the function of storing liquid, the plastic part 15 is also arranged between the end cover 13 and the electrode assembly 12. When the battery cell 10 is in use, it can avoid hard collision between the end cover 13 and the electrode assembly 12. Therefore, in addition to the liquid storage function, the plastic part 15 still maintains its original function.

[0094] The plastic part 15 faces the electrode assembly 12 . When the electrode assembly 12 expands later, it will effectively squeeze the plastic part 15 , thereby effectively releasing the electrolyte stored in the plastic part 15 .

[0095] The effect of this embodiment is that the plastic part 15 is set as a liquid storage structure 16, and there is no need to set up an additional structure to store liquid. The plastic part 15 has the functions of storing liquid and preventing the end cover 13 and the electrode assembly 12 from being squeezed. This not only reduces the cost, but also does not affect the residual space in the battery cell 10.

[0096] In some embodiments, Figure 4 and Figure 5The liquid storage structure 16 includes a first part 22 and a second part 23. The first part 22 is farther away from the middle of the end cover 13 in the length direction than the second part 23. The liquid absorption per unit volume of the first part 22 is less than the liquid absorption per unit volume of the second part 23.

[0097] Specifically, the middle of the end cap 13 in the length direction faces the middle of the electrode assembly 12, and the two sides of the end cap 13 in the length direction face the two sides of the electrode assembly 12. When the electrode assembly 12 expands, the central area expands first, and the two sides expand subsequently. The overall expansion degree of the two sides is smaller than that of the middle, so that the first part 22 is squeezed to a lesser extent or partially not squeezed. For example, when the plastic part 15 is located at the top of the battery cell 10 in the gravity direction, as the electrolyte increases after squeezing, the first part 22 that is squeezed to a lesser extent or not squeezed may contact the electrode liquid and may absorb the electrolyte. The two side areas of the electrode assembly 12 are the main locations for infiltration of the electrolyte. In order to prevent the phenomenon of back-absorption after the electrolyte is released in this area, the liquid absorption capacity of the first part 22 is designed to be smaller than the liquid absorption capacity of the second part 23. Because after the electrolyte is released, the first part 22 may absorb the electrolyte inside the battery cell 10, and the local absorption phenomenon has a certain impact on the local electrolyte storage, so the liquid absorption capacity of the first part 22 of this embodiment is smaller than that of the second part 23, and the electrolyte absorption is also weaker. If the liquid absorption capacity of the first part 22 is designed to be very large, the electrolyte stored in it may not reach its storage upper limit, and the electrolyte may be absorbed back. At the same time, the liquid storage capacity of the second part 23 is set to be stronger, which also increases the liquid storage of the entire plastic part 15 and the overall release of the electrolyte after it is all squeezed.

[0098] In some embodiments, Figure 4 and Figure 5 , the porosity of the flexible structure 17 of the first portion 22 is smaller than the porosity of the flexible structure 17 of the second portion 23 , and / or the average volume of the micropores 18 of the flexible structure 17 of the first portion 22 is larger than the average volume of the micropores 18 of the flexible structure 17 of the second portion 23 .

[0099] Specifically, for the flexible structure 17, the porosity and the volume of the pores are two factors that affect the liquid absorption capacity. The higher the porosity, the stronger the liquid absorption capacity, and the smaller the volume of the pores, the stronger the liquid absorption capacity.

[0100] Therefore, in order to reduce the liquid absorption capacity of the first part 22 , the porosity of the first part 22 is designed to be smaller than that of the second part 23 , or the average volume of the micropores 18 is larger than the average volume of the micropores 18 of the second part 23 .

[0101] The effect of this embodiment is that it provides an implementation form in which the liquid absorption capacity of the first part 22 is designed to be smaller than that of the second part 23.

[0102] In some embodiments, the liquid storage structure 16 is located at the top or bottom of the battery cell 10 in the gravity direction.

[0103] Specifically, this embodiment provides a design of the top or bottom of the liquid storage structure 16 in the gravity direction of the battery cell 10, which can realize the storage and extrusion release of the electrolyte. It should be noted that the liquid storage structure 16 that is in an extrusion deformation state after being squeezed will not absorb the electrolyte or the amount of electrolyte absorbed is very small.

[0104] In some embodiments, Figure 6 and Figure 7 The opening of the receiving hole 20 faces one side of the electrode assembly 12 , and the elastic structure 19 is provided with a plurality of receiving holes 20 , which are arranged in an array.

[0105] The accommodating holes 20 are arranged on the elastic structure 19 in an array form of multiple rows and columns.

[0106] Specifically, when the plastic part 15 or the insulating film 14 is an elastic structure 19, a receiving hole 20 is arranged on the elastic structure 19. The receiving hole 20 is an open hole with its opening facing the side of the electrode assembly 12. This is beneficial for the electrolyte to flow to the electrode assembly 12 after being squeezed, and the receiving holes 20 are arranged in multiple rows and columns. Specifically, the receiving holes 20 can be arranged in parallel along one direction and in parallel along another vertical direction to form multiple rows and columns.

[0107] The effect of this embodiment is that the opening direction of the receiving hole 20 enables the electrolyte to flow to the electrode assembly 12 quickly and effectively, and the multi-row and multi-column array form allows the electrolyte to flow out of each site, which is beneficial to the balanced infiltration of the electrode assembly 12 with the electrolyte.

[0108] In some embodiments, Figure 6 and Figure 7 The inner wall surface of the accommodating hole 20 is an arc surface.

[0109] Specifically, the arc-shaped surface may be a spherical surface.

[0110] The effect of this embodiment is that the inner wall surface of the accommodating hole 20 is an arc-shaped surface. When the elastic structure 19 is squeezed, the accommodating hole 20 with the arc-shaped surface is not easy to produce dead corners that are not completely squeezed when compressed. For example, when the inner wall surface of the accommodating hole 20 is a non-arc-shaped surface, such as a plane, the corner where the two planes meet may produce an extrusion gap when squeezed, and the flexible structure 17 in the gap is squeezed to a lower degree, and the electrolyte is not completely released.

[0111] In some embodiments, Figure 6 and Figure 7 The accommodating holes 20 are evenly arranged on the elastic structure 19 . In this way, the electrolyte is evenly stored on the elastic structure 19 , which is conducive to evenly infiltrating the electrode assembly 12 .

[0112] In some embodiments, the material of the elastic structure 19 includes at least one of polyurethane, polyethylene, silicone rubber, and polytetrafluoroethylene.

[0113] The material selection of the elastic structure 19 has a good deformation effect, can smoothly realize extrusion, and the material performance is stable, no chemical reaction occurs, and has a good anti-collision effect.

[0114] The present application also provides a specific embodiment of a battery device 100 , including the battery cell 10 provided in any one of the above embodiments.

[0115] The present application also provides an electrical device, comprising the battery cell 10 provided by any one of the above embodiments or the battery device 100 provided by the above embodiments.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing having an inner cavity; an electrode assembly, disposed in the inner cavity; An electrolyte, disposed in the inner cavity and used to wet the electrode assembly; An end cover, disposed on the shell and used to close the inner cavity; An insulating film, covering the outside of the electrode assembly; as well as A plastic part, disposed in the inner cavity and opposite to the end of the electrode assembly; Among them, at least a part of the structure of at least one of the insulating film and the plastic part is a liquid storage structure, and the liquid storage structure is used to store electrolyte. The liquid storage structure is arranged opposite to the large surface of the electrode assembly, and the liquid storage structure is configured to be squeezed by the large surface when the large surface of the electrode assembly expands to release the stored electrolyte, wherein the large surface of the electrode assembly is the surface with the largest area of ​​the electrode assembly.

2. The battery cell according to claim 1, characterized in that: The liquid storage structure is a flexible structure having micropores communicating with the inner cavity, and the micropores are used for absorbing electrolyte.

3. The battery cell according to claim 1, characterized in that: The liquid storage structure is an elastic structure, a receiving hole communicating with the inner cavity is provided on the elastic structure, an elastic liquid storage member is provided in the receiving hole, and the liquid storage member is configured to release the stored electrolyte after being squeezed.

4. The battery cell according to claim 3, characterized in that: The liquid storage member is a flexible structure having micropores communicating with the inner cavity, and the micropores are used for absorbing electrolyte.

5. The battery cell according to claim 2 or 4, characterized in that: The material of the flexible structure includes at least one of silicone rubber, styrene-butadiene copolymer, polyurethane, polyurethane-polyether copolymer, polypyrrole polymer, polythiophene polymer, polyimidazole polymer, polytriazine polymer, styrene hypercrosslinked polymer and polyaniline polymer.

6. The battery cell according to claim 2 or 4, characterized in that: The flexible structure includes at least one of cotton fabric, rubber product, sponge, foam, and liquid-absorbing cloth.

7. The battery cell according to claim 2 or 4, characterized in that: At least a portion of the plastic component is the liquid storage structure. The plastic component is disposed at one end of the electrode assembly adjacent to the end cover and between the end cover and the electrode assembly.

8. The battery cell according to claim 7, characterized in that: The liquid storage structure includes a first part and a second part, the first part is farther away from the middle of the end cover in the length direction than the second part, and the liquid absorption per unit volume of the first part is smaller than the liquid absorption per unit volume of the second part.

9. The battery cell according to claim 8, characterized in that: The porosity of the flexible structure of the first portion is smaller than that of the flexible structure of the second portion, and / or the average volume of the micropores of the flexible structure of the first portion is larger than that of the flexible structure of the second portion.

10. The battery cell according to any one of claims 1 to 4, characterized in that: The liquid storage structure is located at the top or bottom of the battery cell in the gravity direction.

11. The battery cell according to claim 3 or 4, characterized in that: The opening of the accommodating hole faces one side of the electrode assembly, and the elastic structure is provided with a plurality of the accommodating holes, which are arranged in an array.

12. The battery cell according to claim 3 or 4, characterized in that: The inner wall surface of the accommodating hole is an arc-shaped surface.

13. The battery cell according to claim 3 or 4, characterized in that: The material of the elastic structure includes at least one of polyurethane, polyethylene, silicone rubber and polytetrafluoroethylene.

14. A battery device, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 13.

15. An electrical device, 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.

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