Battery monomer, battery device, energy storage device and power utilization device

Abstract

The invention discloses a battery monomer, a battery device, an energy storage device and a power utilization device. The battery cell includes: a housing having an accommodation space; the electrode assembly is accommodated in the accommodating space, the electrode assembly comprises laminated layers, each laminated layer comprises a positive electrode, a negative electrode and a separator, and the separator is arranged between the adjacent positive electrode and negative electrode; the capillary piece is located on the side, away from the shell, of the outer surface of the electrode assembly in the arrangement direction of the positive electrode and the negative electrode. Therefore, the possibility that the electrode assembly is damaged can be reduced under the condition that the infiltration effect of the electrolyte on the electrode assembly is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to battery cells, battery devices, energy storage devices and power-consuming devices. Background Art

[0002] New energy batteries are increasingly used in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, battery devices are increasingly used in the field of energy storage. In new energy vehicles equipped with batteries, battery devices can be used to provide power in whole or in part. In the field of energy storage, battery devices can be installed in energy storage boxes or directly on the user side.

[0003] In the related art, a battery device includes a battery cell, and the battery cell includes an electrode assembly and an electrolyte. The electrolyte is used to wet the electrode assembly. When the wetting effect of the electrolyte on the electrode assembly is improved, the structure of the electrode assembly may be damaged. Summary of the invention

[0004] In order to solve the above technical problems, the embodiments of the present application provide a battery cell, a battery device, an energy storage device and an electrical device to reduce the possibility of damage to the electrode assembly while improving the wetting effect of the electrolyte on the electrode assembly.

[0005] The embodiments of the present application are implemented through the following technical solutions.

[0006] A first aspect of an embodiment of the present application provides a battery cell, which includes: a shell having a accommodating space; an electrode assembly accommodated in the accommodating space, the electrode assembly including a stacked layer, each stacked layer including a positive electrode, a negative electrode and a separator, an separator is arranged between adjacent positive electrodes and negative electrodes, the positive electrode includes a positive electrode body, and the negative electrode includes a negative electrode body; an electrode terminal, wherein the electrode terminal and the electrode assembly are arranged along the direction of gravity; a capillary, along the arrangement direction of the positive and negative electrodes, the capillary is located on the side of the outer surface of the electrode assembly away from the shell, the capillary has a capillary channel, the capillary channel has a preset opening and a preset inlet, and along the direction of gravity, the preset opening is located above the preset inlet, wherein the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the highest position of the separator, and the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the preset opening; the arrangement direction of the capillary and the stacked layers is arranged along the arrangement direction of the positive and negative electrodes.

[0007] Since the capillary is located on the side of the outer surface of the electrode assembly away from the shell, the electrolyte can flow into the interior of the electrode assembly through the capillary, and transport the electrolyte to the position in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and infiltration effect of the difficult-to-infiltrate area of ​​the electrode assembly, thereby improving the performance of the battery cell. Moreover, the structure of the additional capillary is added to the electrode assembly to transport the electrolyte, which can reduce or even eliminate the capillaries on the positive or negative electrode, can better inhibit the loosening or even debonding between the positive active material layer and / or the negative active material layer and the corresponding current collector, can reduce or even eliminate the capillaries on the separator, and the possibility of the insulation function of the separator being damaged is reduced, thereby reducing the possibility of damage to the electrode assembly while improving the infiltration effect of the electrolyte on the electrode assembly. Since the electrode terminal and the electrode assembly are arranged along the direction of gravity, and the preset opening is located above the preset inlet, the capillary can adsorb the electrolyte from the position of the preset inlet to the position of the preset opening along the direction of gravity, that is, the capillary can adsorb the electrolyte to its top, thereby making the electrolyte more effectively infiltrate the middle and / or top of the electrode assembly, which is conducive to further improving the electrolyte retention and wetting performance of the electrode assembly. Since the highest positions of the positive electrode body and the negative electrode body are not only lower than the highest position of the separator but also lower than the preset opening, the electrolyte of the capillary can infiltrate the separator as much as possible, and diffuse between the upper positive electrode body and the negative electrode body through the separator, thereby further improving the electrolyte retention and wetting performance of the electrode assembly.

[0008] In some embodiments, the electrode assembly is configured as a winding structure, and the number of layers stacked along the arrangement direction of the positive and negative electrodes when the electrode assembly is wound is at least two, the number of separators in each stacked layer is at least two, at least one separator is a first separator, and the first separator is located between the positive and negative electrodes when the electrode assembly is unfolded, and at least one separator is a second separator, and the second separator is located outside the positive and negative electrodes when the electrode assembly is unfolded; the capillary member is located on the side of the outer shell away from the outer shell along the arrangement direction of the positive and negative electrodes.

[0009] Since the capillary is located on the side of the outermost stacked layer away from the shell along the arrangement direction of the positive electrode and the negative electrode, the electrolyte can flow into the interior of the electrode assembly of the wound structure through the capillary, and transport the electrolyte to the position in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and infiltration effect of the difficult-to-infiltrate area of ​​the electrode assembly, thereby improving the performance of the battery cell. In addition, the structure of arranging the capillary in the electrode assembly does not require the arrangement of capillary holes on the positive electrode or the negative electrode, and can better inhibit the loosening or even delamination between the positive electrode active material layer and / or the negative electrode active material layer and the corresponding current collector, and does not require the opening of capillary holes at specific positions of the first separator and / or the second separator. For electrode assemblies with different numbers of stacked layers, the first separator and the second separator can be universal, the capillary is an independent structure relative to the first separator and the second separator, and the position of the capillary relative to the first separator and the second separator can be flexibly adjusted according to actual needs, which is conducive to the arrangement of the capillary at a preset position of the electrode assembly after winding.

[0010] In some embodiments, the electrode assembly has a straight area and a corner area, and the corner areas are arranged on opposite sides of the straight area. The arrangement direction of the corner areas on both sides is a first direction that is arranged crosswise with the axial direction of the electrode assembly. The arrangement direction of at least two layers of stacked layers in the straight area is a second direction, and the second direction is arranged crosswise with the first direction and the axial direction of the electrode assembly respectively. At least one capillary member is a first capillary member located in the straight area, and the first capillary member is located between two adjacent layers of stacked layers along the second direction. The first capillary member is located on the inner side of the innermost stacked layer in the straight area.

[0011] Since the first capillary member is located on the inner side of the innermost stacked layer in the straight area, the electrolyte can flow into the inner sides of the innermost stacked layers of the electrode assembly located in the straight area through the first capillary member, thereby improving the electrolyte retention and wetting effect of the innermost layer of the electrode assembly located in the straight area, thereby improving the performance of the battery cell.

[0012] In some embodiments, all the capillary members except the first capillary member are located in the corner area.

[0013] Since not only the first capillary member can be arranged in the straight area, but other capillary members can also be arranged in the corner area, the electrolyte can also flow into the interior of the electrode assembly located in the corner area through other capillary members, which can improve the electrolyte retention and wetting effect of the difficult-to-wet area of ​​the stacked layer located in the corner area, which is beneficial to further improve the performance of the battery cell.

[0014] In some embodiments, the electrode assembly has a straight area and a corner area, and the corner areas are arranged on opposite sides of the straight area. The arrangement direction of the corner areas on both sides is a first direction that is arranged crosswise with the axial direction of the electrode assembly. The arrangement direction of at least two stacked layers in the straight area is a second direction, and the second direction is arranged crosswise with the first direction and the axial direction of the electrode assembly respectively. At least one capillary piece is a second capillary piece located in the corner area.

[0015] The corner area of ​​the electrode assembly has problems such as large gas production and a large distance between adjacent stacked layers along the arrangement direction of the positive and negative electrodes. Therefore, the electrode assembly located in the corner area is more prone to the problem of lack of electrolyte. The second capillary is located in the corner area, which can not only improve the electrolyte retention and wetting performance of the corner area of ​​the electrode assembly, but also can use the inner side of the innermost stacked layer or the gap between two adjacent stacked layers in each corner area to set the second capillary. While improving the electrolyte retention and wetting performance of the electrode assembly, it can also improve the internal space utilization of the battery cell.

[0016] In some embodiments, a second capillary member is disposed on the inner side of the innermost stacked layer in each corner region.

[0017] The inner side of the innermost stacked layer in the corner area of ​​the electrode assembly has a larger gas production and a larger space. The second capillary piece is arranged on the inner side of the innermost stacked layer in each corner area, which can further increase the electrolyte retention and wetting performance in the corner area of ​​the electrode assembly, and further improve the internal space utilization of the battery cell.

[0018] In some embodiments, a second capillary member is disposed between at least two adjacent layers in each corner region.

[0019] Thus, the space between two adjacent layers in the corner area can be more fully utilized to arrange the second capillary member, further improving the electrolyte retention and wetting performance in the corner area of ​​the electrode assembly and the space utilization rate inside the battery cell.

[0020] In some embodiments, at least two second capillary members are disposed in each corner region, and along the arrangement direction of the positive electrode and the negative electrode, the number of stacked layers between every two adjacent second capillary members in each corner region is at least two.

[0021] Since there are at least two layers of stacked layers between two adjacent second capillary members in each corner area along the arrangement direction of the positive and negative electrodes, the amount of capillary members can be reduced as much as possible while satisfying the electrolyte transport capacity as much as possible, thereby improving the energy density.

[0022] In some embodiments, the electrode assembly is configured as a laminate structure, wherein the separator, the positive electrode, the separator, and the negative electrode are sequentially stacked.

[0023] Since the electrode assembly is constructed as a stacked structure, the electrolyte can flow into the interior of the electrode assembly of the stacked structure through the capillary parts, and transport the electrolyte to the locations in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and wetting effect in the difficult-to-wet areas of the electrode assembly, and thereby improving the performance of the battery cells.

[0024] In some embodiments, the capillary member has an ion channel.

[0025] Since the capillary has an ion channel, the ion channel can transport ions and enable active ions to be embedded and released back and forth between the positive electrode and the negative electrode.

[0026] In some embodiments, the porosity of the capillary member is in the range of 40% to 70%.

[0027] By limiting the porosity of the capillary, the liquid absorption rate of the capillary can be increased while taking into account the strength of the capillary, thereby increasing the rate at which the electrolyte flows from the capillary into the interior of the electrode assembly, thereby improving the electrolyte retention and wetting performance of the electrode assembly.

[0028] In some embodiments, the average pore size of the capillary is in the range of 0.05 um to 8 um.

[0029] By limiting the average pore size of the capillary element, the liquid absorption capacity of the capillary element can be improved, thereby improving the electrolyte retention and wetting performance of the electrode assembly.

[0030] In some embodiments, the specific surface area of ​​the capillary element is 12 m 2 / g to 225m 2 / g range.

[0031] By limiting the specific surface area of ​​the capillary, the adsorption capacity of the capillary can be enhanced, so that more electrolyte can flow from the capillary into the interior of the electrode assembly, thereby improving the electrolyte retention and wetting performance of the electrode assembly.

[0032] In some embodiments, the material of the capillary element is at least one of polytetrafluoroethylene and polystyrene.

[0033] Both polytetrafluoroethylene and polystyrene have high corrosion resistance and good electrochemical stability. The capillary member is made of at least one of polytetrafluoroethylene and polystyrene, which can make the capillary member have high corrosion resistance and good electrochemical stability, which is beneficial to improving the overall performance of the battery cell. In some embodiments, the capillary channel extends along the direction of gravity.

[0034] Since the capillary channel extends in the direction of gravity, the flow path of the electrolyte adsorbed by the capillary to its top is shorter, which can speed up the speed of the electrolyte reaching the top of the capillary, and speed up the delivery of the electrolyte to the position in the electrode assembly where the electrolyte is lacking or the electrolyte wetting effect is poor, thereby more effectively improving the electrolyte retention and wetting effect in the difficult-to-wet areas of the electrode assembly.

[0035] In some embodiments, the highest position of the isolation member is lower than the preset opening.

[0036] Since the highest position of the isolating member is lower than the preset opening, the top of the isolating member can be more effectively infiltrated by the capillary member, thereby increasing the electrolyte retention and wetting effect on the top of the isolating member, thereby further increasing the electrolyte retention and wetting performance of the electrode assembly.

[0037] A second aspect of the present application provides a battery device, which includes a plurality of battery cells provided according to the first aspect.

[0038] Since the battery device includes the battery cell, the electrolyte retention and the wetting effect of the electrode assembly can be improved, the overall performance of the battery cell can be improved, and the overall performance of the battery device can be improved.

[0039] A third aspect of the present application provides an energy storage device, which includes a plurality of battery cells provided according to the first aspect or a plurality of battery devices provided according to the second aspect, and the battery cells or battery devices are used to store or provide electrical energy.

[0040] Since the energy storage device includes the above-mentioned battery cell or battery device, the electrolyte retention and infiltration effect of the electrode assembly in the energy storage device can be improved, the overall performance of the battery cell or the battery device can be improved, and the overall performance of the energy storage device can be improved.

[0041] A fourth aspect of the present application provides an electrical device, which includes a battery cell provided according to the first aspect, a battery device provided in the second aspect, or an energy storage device provided in the third aspect, wherein the battery cell or the battery device is used to store or provide electrical energy.

[0042] Since the electrical device includes the above-mentioned battery cell, battery device or energy storage device, the electrolyte retention and infiltration effect of the electrode assembly can be improved, the overall performance of the battery cell, battery device or energy storage device can be improved, and the overall performance of the electrical device can be improved.

[0043] The beneficial effects of the present application include: the electrolyte can flow into the interior of the electrode assembly through the capillary, and the electrolyte is transported to the position in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and infiltration effect of the difficult-to-infiltrate area of ​​the electrode assembly, thereby improving the performance of the battery cell. Moreover, the structure of the additional capillary in the electrode assembly to transport the electrolyte can reduce or even eliminate the capillaries on the positive or negative electrode, can better inhibit the loosening or even delamination between the positive active material layer and / or the negative active material layer and the corresponding current collector, can reduce or even eliminate the capillaries on the separator, and the possibility of the insulation function of the separator being damaged is reduced, thereby reducing the possibility of damage to the electrode assembly while improving the infiltration effect of the electrolyte on the electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings: Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application; Figure 2 A three-dimensional exploded schematic diagram of a battery device provided in some embodiments of the present application; Figure 3 A three-dimensional exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 4 A schematic diagram of the structure of an electrode assembly with a wound structure provided in some embodiments of the present application; Figure 5 A schematic diagram of a structure of an electrode assembly of a winding structure provided in some other embodiments of the present application; Figure 6 A schematic diagram of the structure of an electrode assembly of a winding structure provided in some further embodiments of the present application; Figure 7 A schematic diagram of a structure of an electrode assembly with a wound structure provided in some other embodiments of the present application; Figure 8 A schematic diagram of the structure of an electrode assembly with a wound structure in an unfolded state provided by some embodiments of the present application; Fig. 9 A schematic structural diagram of an electrode assembly of a laminate structure provided for some embodiments of the present application.

[0045] Description of Reference Numerals 1000 vehicle; 100 battery device; 200 controller; 300 motor; 10 battery cell; 20 casing; 20a first casing; 20b second casing; 1 shell; 11 accommodating space; 2 electrode assembly; 21 stacked layers; 211 positive electrode; 212 negative electrode; 213 separator; 213a first separator; 213b second separator; 3 capillary; 31 first capillary; 32 second capillary; 4 electrode terminal; 5 pole ear; X first direction; Y second direction; Z axial direction of the electrode assembly. DETAILED DESCRIPTION

[0046] 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.

[0047] 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 of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions.

[0048] 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.

[0049] 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.

[0050] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. 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.

[0051] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "circumferential" are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limitations on the embodiments of the present application.

[0052] 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.

[0053] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0054] Below, this application is described in detail.

[0055] In the related art, the electrolyte may gather in some areas of the electrode assembly, so that other areas inside the electrode assembly may have problems such as low electrolyte retention and poor electrolyte infiltration effect. A separator is set between the positive and negative electrodes of the electrode assembly, and an ion channel is set on the separator to enable charged particles to move between the positive and negative electrodes. The separator exceeds the positive and negative electrodes to a certain extent to ensure good insulation between the positive and negative electrodes. It is difficult to set capillaries on the separator to transport electrolyte. If the capillaries are slightly improperly arranged, the insulation function of the separator may be damaged. Processing capillaries on the active material of the positive electrode and / or the active material of the negative electrode will reduce the amount of active material, which may cause looseness between the active material layer and the corresponding positive electrode current collector and / or the negative electrode current collector, and even the active material layer may be delaminated, resulting in poor structural stability of the electrode assembly.

[0056] Through research, it is found that a capillary is added to the side of the outer surface of the electrode assembly facing away from the outer shell. Therefore, the electrolyte can flow into the interior of the electrode assembly through the capillary, and the electrolyte is transported to the position in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor. The structure of the additional capillary is added to the electrode assembly to transport the electrolyte, which can reduce or even eliminate the capillaries on the positive or negative electrode, and can better inhibit the loosening or even peeling of the positive active material layer and / or the negative active material layer and the corresponding current collector. The capillary pores on the isolation member can be reduced or even eliminated, and the possibility of damage to the insulating function of the isolation member is reduced. The possibility of damage to the insulating function of the isolation member is reduced, thereby reducing the possibility of damage to the electrode assembly while improving the wetting effect of the electrolyte on the electrode assembly.

[0057] Based on such a design concept, an embodiment of the present application provides a battery cell, which includes: a shell having a accommodating space; an electrode assembly accommodated in the accommodating space, the electrode assembly including a stacked layer, each stacked layer including a positive electrode, a negative electrode and a separator, an separator is arranged between adjacent positive electrodes and negative electrodes, the positive electrode includes a positive electrode body, and the negative electrode includes a negative electrode body; an electrode terminal, wherein the electrode terminal and the electrode assembly are arranged along the direction of gravity; a capillary, along the arrangement direction of the positive electrode and the negative electrode, the capillary is located on the side of the outer surface of the electrode assembly away from the shell, the capillary has a capillary channel, the capillary channel has a preset opening and a preset inlet, and along the direction of gravity, the preset opening is located above the preset inlet, wherein the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the highest position of the separator, and the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the preset opening; the arrangement direction of the capillary and the stacked layers is arranged along the arrangement direction of the positive electrode and the negative electrode.

[0058] Since the capillary is located on the side of the outer surface of the electrode assembly away from the shell, the electrolyte can flow into the interior of the electrode assembly through the capillary, and the electrolyte is transported to the position in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and infiltration effect of the difficult-to-infiltrate area of ​​the electrode assembly, thereby improving the performance of the battery cell. Moreover, the structure of the additional capillary is added to the electrode assembly to transport the electrolyte, which can reduce or even eliminate the capillaries on the positive or negative electrode, can better inhibit the loosening or even debonding between the positive active material layer and / or the negative active material layer and the corresponding current collector, can reduce or even eliminate the capillaries on the separator, and the possibility of the insulation function of the separator being damaged is reduced, thereby reducing the possibility of damage to the electrode assembly while improving the infiltration effect of the electrolyte on the electrode assembly.

[0059] The battery cells and battery devices provided in the embodiments of the present application can be used, but are not limited to, in electrical devices such as energy storage devices, vehicles, ships, or aircraft.

[0060] The present application also provides an electric device including the above-mentioned battery device, which may be, but not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0061] An embodiment of the present application also provides an energy storage device including the above-mentioned battery device, and the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0062] In the following embodiments, for the convenience of description, an electric device according to an embodiment of the present application is taken as a vehicle 1000 as an example.

[0063] Figure 1 The schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended range vehicle. Figure 1 As shown, a battery device 100 is disposed inside the vehicle 1000, and the battery device 100 can be disposed at the bottom, head, or tail of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000, for example, the battery device 100 can be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to power the motor 300, for example, for the starting, navigation, and working power requirements of the vehicle 1000 during driving.

[0064] 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.

[0065] Figure 2 A three-dimensional exploded schematic diagram of a battery device 100 provided in some embodiments of the present application; the battery device (Battery Apparatus) mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly (Battery Cell Assembly) may include a plurality of battery cells 10, and the plurality of battery cells 10 are connected in series, in parallel, or in mixed connection through a busbar component.

[0066] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells 10; as an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells 10 to form an independent module. As an example, a battery module may be formed by bundling a plurality of battery cells 10 by a cable tie.

[0067] In some embodiments, the battery device 100 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.

[0068] 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.

[0069] As an example, the battery cell assembly may also be housed in the case 20 by directly fixing the plurality of battery cells 10 to the case 20 .

[0070] As an example, the box 20 may include a first box 20a and a second box 20b. The first box 20a and the second box 20b are buckled together to form a closed space inside the box 20 to accommodate the battery cell 10 assembly. The closed here means covered or closed, which can be sealed or unsealed. The first box 20a can be a top cover or a bottom plate.

[0071] In the embodiment of the present application, the battery cell 10 may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell 10 is discharged.

[0072] The battery cell 10 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0073] The battery cell 10 generally includes an electrode assembly 2 (see Figure 3 ).For example Figures 4 to 9 As shown, the electrode assembly 2 includes a positive electrode 211, a negative electrode 212, and a separator 213. During the charge and discharge process of the battery cell 10, active ions are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting and allow the active ions to pass through. For example, the active ions can be lithium ions.

[0074] In some embodiments, the positive electrode 211 may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode collector and a positive electrode active material disposed on at least one surface of the positive electrode collector.

[0075] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0076] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material on a polymer material substrate.

[0077] Exemplarily, the metal material may be aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.

[0078] For example, the polymer material substrate may be a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like.

[0079] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the embodiments of the present application are not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0080] In some embodiments, the positive electrode 211 may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, a foamed alloy, etc. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0081] In some embodiments, the negative electrode 212 may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0082] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. The composite current collector may be formed by forming a metal material on a polymer material substrate. In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0083] Exemplarily, the metal material may be copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, silver alloy, etc.

[0084] For example, the polymer material substrate may be a substrate such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.

[0085] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0086] In some embodiments, the separator is a separator. The present invention has no particular restrictions on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0087] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0088] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0089] In some embodiments, the battery cell 10 further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application embodiment has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0090] In some embodiments, the electrode assembly 2 is a wound structure in which the positive electrode and the negative electrode are wound into a wound structure.

[0091] As an example, the separator may be disposed continuously and disposed between any adjacent positive electrode sheets or negative electrode sheets by winding.

[0092] In some embodiments, the electrode assembly 2 is a laminate structure.

[0093] As an example, a plurality of positive electrodes and a plurality of negative electrodes may be provided respectively, and the plurality of positive electrodes and the plurality of negative electrodes may be alternately stacked.

[0094] In some embodiments, the shape of the electrode assembly 2 can be cylindrical, flat, or polygonal.

[0095] In some embodiments, the electrode assembly 2 is provided with tabs, which can lead current out of the electrode assembly 2. The tabs include a positive tab and a negative tab.

[0096] In some embodiments, the battery cell 10 may include a housing 1. The housing 1 encapsulates the electrode assembly 2 and components such as electrolyte. The housing 1 may be a steel shell, an aluminum shell, a plastic shell, a composite metal shell, or an aluminum-plastic film.

[0097] As an example, the battery cell 10 can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, and a polygonal prismatic battery cell. The polygonal prismatic battery cell is, for example, a hexagonal prismatic battery cell, etc. There is no particular limitation in the embodiments of the present application.

[0098] In some embodiments, Figure 3 As shown, the housing 1 includes an end cap assembly and a shell, the shell is provided with an opening, and the end cap assembly closes the opening to form a closed space for accommodating the electrode assembly 2 and electrolyte and other substances. The shell may be provided with one or more openings. One or more end cap assemblies may also be provided.

[0099] In some embodiments, at least one electrode terminal 4 is provided on the housing 1, and the electrode terminal 4 is electrically connected to the tab 5. The electrode terminal 4 can be directly connected to the tab 5, or can be indirectly connected to the tab through a transition component. The electrode terminal 4 can be provided on the end cap assembly, or can be provided on the housing.

[0100] In some embodiments, a pressure relief mechanism (not shown) is disposed on the housing 1 , and is used to release the internal pressure of the battery cell 10 .

[0101] Below, refer to Figures 3 to 9 Some embodiments of the present application are described in detail.

[0102] Figure 3 A three-dimensional exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 4 A schematic diagram of the structure of an electrode assembly with a wound structure provided in some embodiments of the present application; Figure 5 A schematic diagram of a structure of an electrode assembly of a winding structure provided in some other embodiments of the present application; Figure 6 A schematic diagram of the structure of an electrode assembly of a winding structure provided in some further embodiments of the present application; Figure 7 A schematic diagram of a structure of an electrode assembly with a wound structure provided in some other embodiments of the present application; Figure 8A schematic diagram of the structure of an electrode assembly with a wound structure in an unfolded state provided by some embodiments of the present application; Fig. 9 A schematic diagram of the structure of an electrode assembly of a laminated structure provided for some embodiments of the present application. In the description of the embodiments of the present disclosure, for ease of explanation, the direction of arrow X represents the "first direction X", the direction of arrow Y represents the "second direction Y", and the direction of arrow Z represents the "axial direction of the electrode assembly of the winding structure".

[0103] A first aspect of the present application provides a battery cell 10, such as Figure 3 As shown, the battery cell 10 includes a housing 1, an electrode assembly 2, a capillary member 3 and an electrode terminal. The housing 1 has a receiving space 11. The electrode assembly 2 is received in the receiving space 11. Figure 3 , Figure 4 and Fig. 9 As shown, the electrode assembly 2 is accommodated in the accommodation space 11, and the electrode assembly 2 includes a stacked layer, each stacked layer 21 includes a positive electrode 211, a negative electrode 212 and a separator 213, and a separator 213 is provided between adjacent positive electrodes 211 and negative electrodes 212, and the positive electrode 211 includes a positive electrode body, and the negative electrode 212 includes a negative electrode body. Along the arrangement direction of the positive electrode and the negative electrode, the capillary member is located on the side of the outer surface of the electrode assembly away from the shell, and the arrangement direction of the capillary member 3 and the stacked layer 21 is arranged along the arrangement direction of the positive electrode 211 and the negative electrode 212.

[0104] like Figure 3 As shown, the battery cell 10 includes a shell 1. The shell 1 can be a steel shell, an aluminum shell, a plastic shell, a composite metal shell or an aluminum-plastic film, etc. The battery cell 10 also includes an electrode assembly 2. In some embodiments, the shell 1 can be a sealed structure or a non-sealed structure. As an example, when the shell 1 is a non-sealed structure, the shell 1 plays a role in protecting the electrode assembly 2, and a sealed bag can also be included between the shell 1 and the electrode assembly 2, and the sealed bag is used to encapsulate the electrode assembly 2 and the electrolyte. Specifically, the sealed bag can be a bag-shaped insulating member or an aluminum-plastic film. When the shell 1 is a sealed structure, it is used to encapsulate components such as the electrode assembly 2 and the electrolyte.

[0105] Exemplarily, the composite metal shell may be a copper-aluminum composite shell.

[0106] Exemplarily, the material of the plastic shell may be polypropylene.

[0107] In some embodiments, Figure 3 As shown, the housing 1 includes a plurality of housing walls, a portion of which encloses a space having an opening, and the opening can be closed by another housing wall to form a receiving space 11 for receiving the electrode assembly 2 and electrolyte and other substances. The housing 1 can be provided with one or more openings. The housing wall that closes the opening can also be configured as a top cover.

[0108] like Figures 4 to 7 As shown, the battery cell 10 includes an electrode assembly 2. The electrode assembly 2 includes a positive electrode 211, a negative electrode 212 and a separator 213. During the charge and discharge process of the battery cell 10, active ions are embedded and released back and forth between the positive electrode 211 and the negative electrode 212. The separator 213 is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting, and at the same time allow the active ions to pass through.

[0109] Exemplarily, the active ions may be lithium ions.

[0110] In some embodiments, the positive electrode includes a positive electrode body and a positive electrode tab connected to each other, and the negative electrode includes a negative electrode body and a negative electrode tab connected to each other.

[0111] In some embodiments, Figure 3 As shown, the housing 1 is provided with an electrode terminal 4, which is electrically connected to the pole tab 5, and can be directly connected to the pole tab 5, or indirectly connected to the pole tab 5 through a switching component. The pole tab 5 is a positive pole tab or a negative pole tab. The pole tab 5 can import or export the current of the electrode assembly.

[0112] Optionally, the electrode assembly 2 may be a laminate structure or a winding structure.

[0113] Exemplarily, the electrode assembly 2 is a laminate structure, such as Fig. 9 As shown, the separator 213, the positive electrode 211, the separator 213, and the negative electrode 212 are stacked in sequence, and the separator 213, the positive electrode 211, the separator 213, and the negative electrode 212 in the same stacking layer are bonded together, and there are capillaries between adjacent different stacking layers. There can be capillaries between each adjacent different stacking layer, or there can be capillaries between some adjacent different stacking layers.

[0114] Exemplarily, the electrode assembly 2 is a winding structure, such as Figures 4 to 7 As shown, the electrode assembly 2 has a corner area and a straight area. The capillary element may be located only in the corner area, or only in the straight area, or the capillary element may be provided in the corner area or also in the straight area.

[0115] The capillary element 3 and the stacking layer 21 are arranged along the arrangement direction of the positive electrode 211 and the negative electrode 212. No capillary element 3 is arranged between the positive electrode 211 and the negative electrode 212 of the same stacking layer 21, and the capillary element 3 is located outside the positive electrode and the negative electrode of the same stacking layer.

[0116] Capillary component 3 refers to a component with capillary phenomenon. Capillary phenomenon refers to when liquid enters a tiny pipe or tiny pore, due to the effect of surface tension, the liquid presents a series of special physical phenomena, including the phenomenon that the liquid rises in the capillary. That is, capillary component 3 refers to a component that has a strong attraction to the contact surface with the liquid and can make the liquid flow along the capillary component 3. For example, capillary component 3 can be made of polytetrafluoroethylene and / or polystyrene material injected into a specific mold to form a structure with a certain porosity, average pores or specific surface area. Of course, capillary component 3 can also be made of other corrosion-resistant materials.

[0117] Exemplarily, the liquid may be an electrolyte.

[0118] In some embodiments, in the same projection plane projected along the arrangement direction of the positive electrode and the negative electrode, the projection of the capillary member 3, the projection of the positive electrode 211 and the projection of the negative electrode 212 at least partially overlap, and further, the projection of the capillary member 3, the projection of the positive electrode 211, the projection of the negative electrode 212 and the projection of the insulating member 213 at least partially overlap.

[0119] Since the capillary is located on the side of the outer surface of the electrode assembly away from the shell, the electrolyte can flow into the interior of the electrode assembly 2 through the capillary 3, and transport the electrolyte to the position in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and infiltration effect of the difficult-to-infiltrate area of ​​the electrode assembly, thereby improving the performance of the battery cell. In addition, the structure of the additional capillary is added to the electrode assembly to transport the electrolyte, which can reduce or even eliminate the capillaries on the positive or negative electrode, can better inhibit the loosening or even debonding between the positive active material layer and / or the negative active material layer and the corresponding current collector, can reduce or even eliminate the capillaries on the separator, and reduce the possibility of the insulation function of the separator being damaged, thereby reducing the possibility of damage to the electrode assembly while improving the infiltration effect of the electrolyte on the electrode assembly.

[0120] In some embodiments, the electrode assembly 2 includes a winding structure, and the number of layers of the stacked layers 21 stacked along the arrangement direction of the positive electrode 211 and the negative electrode 212 when the electrode assembly 2 is wound is at least two, and the number of separators 213 in each stacked layer 21 is at least two, at least one separator 213 is a first separator 213a, and the first separator 213a is located between the positive electrode 211 and the negative electrode 212 when the electrode assembly 2 is unfolded, and at least one separator 213 is a second separator 213b, and the second separator 213b is located outside the positive electrode 211 and the negative electrode 212 when the electrode assembly 2 is unfolded. The capillary member 3 is located on the side of the outermost stacked layer 21 away from the outer casing 1 along the arrangement direction of the positive electrode 211 and the negative electrode 212. Figure 8As shown, in the unfolded state of the electrode assembly 2, the first isolation member 213a is located between the positive electrode 211 and the negative electrode 212, the second isolation member 213b is located on the side of the positive electrode 211 away from the negative electrode 212 along the arrangement direction of the positive and negative electrodes, or the second isolation member 213b is located on the side of the negative electrode 212 away from the positive electrode 211 along the arrangement direction of the positive and negative electrodes.

[0121] The positive electrode 211, the negative electrode 212, the first separator 213a and the second separator 213b can be stacked. The stack formed by the positive electrode 211, the negative electrode 212, the first separator 213a and the second separator 213b is wound around the winding center axis to form a winding structure, and the winding structure includes at least two layers of stacking layers 21, and each stacking layer 21 includes the positive electrode 211, the negative electrode 212, the first separator 213a and the second separator 213b. That is, the electrode assembly 2 is stacked and laid into the shape of the winding structure in the unfolded state by the positive electrode 211, the first separator 213a, the negative electrode 212 and the second separator 213b, and then the whole is wound to form the electrode assembly 2. Since the positive electrode 211, the first separator 213a, the negative electrode 212 and the second separator 213b are stacked and laid in the unfolded state, the positive electrode 211, the first separator 213a, the negative electrode 212 and the second separator 213b in the same stacking layer 21 of the electrode assembly 2 formed after winding are closely attached and have a small gap, but there is a large gap between adjacent stacking layers 21 in the electrode assembly 2 formed after winding, and the gap between the positive electrode 211 and the first separator 213a, the gap between the first separator and the negative electrode and the gap between the negative electrode 212 and the second separator 213b in the same stacking layer 21 of the electrode assembly 2 formed after winding are all the first gaps, and the gap between adjacent stacking layers 21 in the electrode assembly 2 formed after winding is the second gap, which is larger than the first gap. Therefore, the capillary member 3 can be arranged between adjacent stacking layers 21 inside the electrode assembly 2, and the electrolyte wetting performance of the electrode assembly 2 can be improved without changing the outer contour size of the electrode assembly 2 as much as possible, and the space utilization rate in the housing 1 can be improved.

[0122] In some embodiments, along the arrangement direction of the positive and negative electrodes, the capillary 3 is located on the side of the outermost laminated layer 21 away from the shell 1, that is, along the arrangement direction of the positive and negative electrodes, the capillary 3 is located on the inner side of the electrode assembly 2 and is adjacent to at least one layer of the laminated layer 21. As a result, the electrolyte can enter the interior of the electrode assembly 2 through the capillary 3, thereby increasing the electrolyte retention and wetting effect of the electrolyte-difficult-to-wet area inside the electrode assembly 2. It should be noted that the inside and outside of the present application refer to the arrangement direction of the positive and negative electrodes, the inner side is toward the winding center, and the outer side is away from the winding center, that is, the outer side of the laminated layer 21 points to the inner side from the outermost position of the outer shell 1 to the electrode assembly 2.

[0123] Optionally, the capillary element 3 can be one or more and can be arranged between any two adjacent stacking layers 21 along the arrangement direction of the positive electrode and the negative electrode. When there are multiple capillary elements 3, there can be one or more stacking layers 21 between adjacent capillary elements 3 along the arrangement direction of the positive electrode and the negative electrode.

[0124] In some implementations, the electrode assembly 2 has a straight region and a corner region, such as Figures 4 to 7 As shown, the straight area of ​​the electrode assembly 2 refers to the area where the electrode assembly is located between the dotted line L1 and the dotted line L2, and the corner area refers to the area where the electrode assembly is located away from the straight area and located on the dotted line L1 or the dotted line L2, wherein the dotted line L1 and the dotted line L2 are respectively parallel to the arrangement direction of the stacked layers located in the straight area and respectively pass through the winding center of the corner area adjacent to it along the arrangement direction of the corner area.

[0125] The positive electrode 211, the first separator 213a, the negative electrode 212 and the second separator 213b in the straight area are generally arranged along the first direction X, and the positive electrode 211, the first separator 213a, the negative electrode 212 and the second separator 213b in the corner area are generally arranged along the second direction Y. The capillary member 3 can be located between the stacked layers 21 in the straight area of ​​the electrode assembly 2, and / or, the capillary member 3 can be located between the stacked layers 21 in the corner area of ​​the electrode assembly 2. The first direction X, the second direction Y and the axial direction Z of the electrode assembly intersect each other and the first direction X, the second direction Y and the axial direction Z of the electrode assembly are not coplanar, and further, the first direction X, the second direction Y and the axial direction Z of the electrode assembly are perpendicular to each other.

[0126] In some embodiments, the outer contour of the capillary member 3 may be similar to the gap between the stacked layers 21 of the electrode assembly 2 , thereby making it easier to dispose the capillary member 3 between the stacked layers 21 .

[0127] In some embodiments, the outer contour of the capillary member 3 may be rounded, thereby helping to reduce the probability of the capillary member 3 causing damage to the laminated layer 21 .

[0128] In some embodiments, for example, the first isolation member 213a is an isolation membrane, and the maximum thickness of the capillary member is greater than the thickness of the isolation membrane, thereby facilitating the processing and manufacturing of the capillary member.

[0129] In some embodiments, the capillary member 3 is located on the side of the outermost stacked layer 21 away from the outer shell 1 along the arrangement direction of the positive electrode 211 and the negative electrode 212, and the capillary holes may not be opened at the specific position of the first insulating member 213a and / or the second insulating member 213b. The specific position may refer to the position of the first insulating member 213a and / or the second insulating member 213b located in the straight area or the corner area.

[0130] Since the capillary member 3 is located on the side of the outermost stacked layer 21 away from the outer casing 1 along the arrangement direction of the positive and negative electrodes, the electrolyte can flow into the interior of the electrode assembly 2 through the capillary member 3, and transport the electrolyte to the position in the electrode assembly 2 where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and wetting effect of the difficult-to-wet area of ​​the electrode assembly 2, and thereby improving the performance of the battery cell. Moreover, the structure of setting the capillary 3 in the electrode assembly does not need to arrange capillaries on the positive electrode 211 or the negative electrode 212, which can better suppress the loosening or even peeling of the positive electrode active material layer and / or the negative electrode active material layer and the corresponding current collector. There is no need to open capillaries at specific positions of the first separator 213a and / or the second separator 213b. For electrode assemblies with different numbers of stacked layers, the first separator and the second separator can be used interchangeably. The capillary is an independent structure relative to the first separator and the second separator. The position of the capillary relative to the first separator and the second separator can be flexibly adjusted according to actual needs, which is conducive to arranging the capillary at a preset position of the electrode assembly after winding.

[0131] In some embodiments, Figure 3 and Figure 4 As shown, the electrode assembly 2 has a straight area and a corner area, and the corner areas are arranged on opposite sides of the straight area. The arrangement direction of the corner areas on both sides is a first direction X that is arranged crosswise with the axial direction Z of the electrode assembly. The arrangement direction of at least two layers of laminated layers 21 in the straight area is a second direction Y, and the second direction Y is arranged crosswise with the first direction X and the axial direction Z of the electrode assembly respectively. At least one capillary member 3 is a first capillary member 31 located in the straight area, and the first capillary member 31 is located between two adjacent layers of laminated layers 21 along the second direction Y. The first capillary member 31 is located on the inner side of the innermost laminated layer 21 in the straight area. Among them, the first direction X, the second direction Y and the axial direction Z of the electrode assembly intersect each other, and the first direction X, the second direction Y and the axial direction Z of the electrode assembly are not coplanar. Further, the first direction X, the second direction Y and the axial direction Z of the electrode assembly are perpendicular to each other.

[0132] In some embodiments, the straight region is provided with corner regions on opposite sides along the first direction X, the stacked layers 21 located in the straight region are arranged along the second direction Y, the first direction X, the second direction Y and the axial direction Z of the electrode assembly intersect each other, and the planes formed between the two are not coplanar. The capillary member 3 includes a first capillary member 31, which is located between two adjacent stacked layers 21 in the straight region along the second direction Y, and along the first direction X, the opposite ends of the first capillary member 31 do not exceed the opposite ends of the stacked layers 21 located in the straight region. Of course, there may also be other capillary members 3 between the stacked layers 21 located in the corner region. The first capillary member 31 may also be provided only between the stacked layers 21 located in the straight region.

[0133] In some embodiments, all the stacked layers 21 located in the corner region are arranged along the second direction Y across two opposite sides of the first capillary element 31 .

[0134] In a specific embodiment, a first capillary member 31 is disposed inside the innermost stacked layer 21 of the straight region, which is beneficial to improving the electrolyte retention and wetting effect of the innermost stacked layer 21 of the straight region.

[0135] Optionally, in the straight area, the first capillary member 31 may be located between any two adjacent laminated layers 21 along the second direction Y, or may be located on the inner side of the innermost laminated layer 21 .

[0136] Since the first capillary member 31 is located on the inner side of the innermost stacked layer 21 in the straight area, the electrolyte can flow into the inner side of the innermost stacked layer 21 of the electrode assembly 2 located in the straight area through the first capillary member 31, thereby improving the electrolyte retention and wetting effect at the innermost side of the electrode assembly located in the straight area, thereby improving the performance of the battery cell 10.

[0137] In some embodiments, Figures 4 to 7 As shown, among all the capillary members 3 except the first capillary member 31 , the remaining capillary members 3 are all located in the corner area.

[0138] Optionally, the capillary member 3 may be arranged only in the straight area, or in both the straight area and the corner area. Of course, the capillary member 3 may also be arranged only in the corner area.

[0139] In a specific embodiment, the first capillary member 31 is located on the inner side of the innermost stacked layer 21 in the straight area, and the remaining capillary members 3 are all located in the corner area. All the stacked layers 21 located in the corner area are arranged on opposite sides of the first capillary member 31 along the second direction Y. Therefore, by arranging the capillary member 3 in the area with a large gap between the stacked layers 21, the outer contour size of the electrode assembly 2 can be reduced, and then the outer contour size of the battery cell 10 can be reduced, thereby improving the space utilization rate inside the outer shell 1 of the battery cell 10.

[0140] Since not only the first capillary member 31 can be arranged in the straight area, but other capillary members 3 can also be arranged in the corner area, the electrolyte can also flow into the interior of the electrode assembly 2 located in the corner area through other capillary members 3, which can improve the electrolyte retention and wetting effect of the difficult-to-wet area of ​​the stacked layer 21 located in the corner area, which is beneficial to further improve the performance of the battery cell 10.

[0141] In some embodiments, Figures 5 to 7As shown, the electrode assembly 2 has a straight area and a corner area. The corner areas are arranged on opposite sides of the straight area. The arrangement direction of the corner areas on both sides is a first direction X that crosses the axial direction Z of the electrode assembly. The arrangement direction of at least two layers of stacked layers 21 in the straight area is a second direction Y. The second direction Y crosses the first direction X and the axial direction Z of the electrode assembly respectively. At least one capillary member 3 is a second capillary member 32 located in the corner area.

[0142] In some embodiments, the second capillary member 32 is located in a corner region. Optionally, the second capillary member 32 may be disposed in any corner region arranged along the first direction X, for example Figure 5 In the orientation shown, the second capillary member 32 may be disposed in the left corner region or the right corner region; or the second capillary member 32 may be disposed in both corner regions arranged along the first direction X, for example Figure 5 In the orientation shown, the second capillary member 32 may be disposed in the left corner region and the right corner region.

[0143] Alternatively, if Figure 6 and Figure 7 As shown, in one of the corner regions, the second capillary member 32 may be located between any two adjacent stacked layers 21 in the corner regions along the first direction X, as shown in FIG. Figures 5 to 7 As shown, in one of the corner regions, the second capillary member 32 may also be located inside the innermost laminate layer 21 of the corner region. The arrangement of the second capillary member 32 in the other corner region may be similar to that in one of the corner regions, and will not be described in detail.

[0144] The corner area of ​​the electrode assembly 2 has problems such as large gas production and a large distance between adjacent stacked layers 21 along the arrangement direction of the positive electrode 211 and the negative electrode 212. Therefore, the electrode assembly 2 located in the corner area is more likely to have a problem of lack of electrolyte. The second capillary 32 is located in the corner area, which can not only improve the electrolyte retention and wetting performance of the corner area of ​​the electrode assembly 2, but also can use the inner side of the innermost stacked layer or the gap between two adjacent stacked layers in each corner area to set the second capillary 32. While improving the electrolyte retention and wetting performance of the electrode assembly 2, it can also improve the internal space utilization of the battery cell 10.

[0145] In some embodiments, Figures 5 to 7 As shown, a second capillary member 32 is disposed on the inner side of the innermost laminate layer 21 in each corner region.

[0146] Along the first direction X, the second capillary members 32 are disposed on the inner sides of the innermost laminated layers 21 in the corner regions at the two opposite sides of the straight region.

[0147] The inner side of the innermost stacking layer 21 in the corner area of ​​the electrode assembly 2 has a larger gas production volume and a larger space. The second capillary member 32 is arranged on the inner side of the innermost stacking layer 21 in each corner area, which can further improve the electrolyte retention and wetting performance in the corner area of ​​the electrode assembly 2, and further improve the internal space utilization rate of the battery cell 10.

[0148] In some embodiments, Figure 6 and Figure 7 As shown, a second capillary member 32 is disposed between at least two adjacent laminated layers 21 in each corner region.

[0149] Alternatively, if Figure 6 and Figure 7 As shown, in each corner region, there may be one or more second capillary members 32. In each corner region, a portion of the stacked layers 21 adjacent along the first direction X may have a second capillary member 32; or in the corner region, any two stacked layers 21 adjacent along the first direction X may have a second capillary member 32 between them.

[0150] Optionally, the number of second capillary members 32 in one corner area and the number of second capillary members 32 in another corner area may be the same or different. The specific location of the second capillary members 32 in one corner area and the specific location of the second capillary members 32 in another corner area may be the same or different. Taking the case where each side corner has a plurality of capillary members 3 as an example, the number of layers of laminated layers 21 between adjacent second capillary members 32 along the first direction X in one corner area and the number of layers of laminated layers 21 between adjacent second capillary members 32 along the first direction X in another corner area may be the same or different.

[0151] Thus, the space between two adjacent stacked layers 21 in the corner area can be more fully utilized to arrange the second capillary member 32 , further improving the electrolyte retention and wetting performance in the corner area of ​​the electrode assembly 2 and the space utilization rate inside the battery cell 10 .

[0152] In some embodiments, each Figure 7 As shown, at least two second capillary members 32 are arranged in each corner region, and along the arrangement direction of the positive and negative electrodes, the number of the stacking layers 21 between every two adjacent second capillary members 32 in each corner region is at least two.

[0153] like Figure 7 As shown, at least two second capillary members 32 are arranged in each side corner area. Taking one side corner area as an example, along the arrangement direction of the positive electrode and the negative electrode, the number of layers of the stacking layer 21 between two adjacent second capillary members 32 is at least two layers, which can be two layers, three layers, four layers, six layers or more layers, etc. Figure 7It is only shown that along the arrangement direction of the positive and negative electrodes, the number of stacked layers 21 between each two adjacent second capillary members 32 in the corner area on one side is at least two layers; it is also possible that along the arrangement direction of the positive and negative electrodes, the number of stacked layers 21 between each two adjacent second capillary members 32 in the corner area on the other side is at least two layers.

[0154] Since the number of stacked layers 21 between each two adjacent second capillary members 32 in each corner area along the arrangement direction of the positive and negative electrodes is at least two, the amount of capillary members can be reduced as much as possible while satisfying the electrolyte transport capacity as much as possible, thereby improving the energy density.

[0155] In some embodiments, Fig. 9 As shown, the electrode assembly 2 is constituted as a laminate structure, and the separator 213, the positive electrode 211, the separator 213, and the negative electrode 212 are stacked in sequence.

[0156] Along the arrangement direction of the positive electrode 211 and the negative electrode 212 , the capillary member 3 is located between the positive electrode 211 and the negative electrode 212 .

[0157] In some embodiments, in the same projection plane projected along the arrangement direction of the positive electrode 211 and the negative electrode 212, the projection of the capillary member 3, the projection of the positive electrode 211, and the projection of the negative electrode 212 at least partially overlap. Further, along the arrangement direction of the positive electrode 211 and the negative electrode 212, the outer contour of the capillary member 3 is located within the range of the outer contour of the positive electrode 211, and the outer contour of the capillary member 3 is located within the range of the outer contour of the negative electrode 212.

[0158] Since the electrode assembly 2 is constructed as a stacked structure, the electrolyte can flow into the interior of the electrode assembly of the stacked structure through the capillary parts, and transport the electrolyte to the locations in the electrode assembly where the electrolyte is lacking or the electrolyte infiltration effect is poor, thereby improving the electrolyte retention and wetting effect in the difficult-to-wet areas of the electrode assembly, and thereby improving the performance of the battery cells.

[0159] In some embodiments, the capillary member 3 has an ion channel.

[0160] Since the capillary member 3 has an ion channel, the ion channel can play a role in transmitting ions, and can enable active ions to be embedded and released back and forth between the positive electrode and the negative electrode.

[0161] In some embodiments, the porosity of the capillary member 3 is in the range of 40% to 70%.

[0162] Optionally, the porosity of the capillary member 3 may be 40%, 45%, 50%, 55%, 60%, 65% or 70%, etc., and of course, may also be other values ​​within the above range.

[0163] Porosity measurement method: true density method and porosity analysis method.

[0164] The calculation formula of porosity is: porosity = (apparent volume of sample - true volume of sample) / apparent volume of sample × 100%.

[0165] The apparent area of ​​a sample refers to the surface area of ​​the sample under specific conditions, and is usually used to characterize the contact area between the sample and the external environment. For example, in porous materials, the apparent volume refers to the total volume including pores, while the true volume refers to the solid volume excluding pores. Porosity refers to the percentage of the volume of pores in a porous material to the apparent volume.

[0166] Table 1

[0167] Note: Among the samples selected in Examples 1 to 4 and Comparative Example 1, only the porosity is different, and the other parameters remain unchanged.

[0168] It can be seen from Table 1 that the liquid absorption rate of the capillary 3 with a porosity of 40% to 70% is significantly higher than that of the capillary 3 with a porosity of 30%, and the liquid absorption rate of the capillary 3 with a porosity of 60% is optimal. Therefore, in order to increase the liquid absorption rate of the capillary 3, a capillary 3 with a porosity of 50% to 70% can be used, thereby increasing the liquid absorption rate of the capillary 3, thereby increasing the liquid retention amount and wetting effect of the electrolyte of the electrode assembly 2.

[0169] By limiting the porosity of the capillary, the liquid absorption rate of the capillary 3 can be increased while taking into account the strength of the capillary 3, thereby increasing the rate at which the electrolyte flows from the capillary 3 into the electrode assembly 2, thereby increasing the electrolyte retention and wetting performance of the electrode assembly 2.

[0170] In some embodiments, the average pore size of the capillary member 3 is in the range of 0.05 um to 8 um.

[0171] Optionally, the average pore size of the capillary member 3 may be 0.05um, 0.08um, 0.1um, 0.2um, 0.3um, 0.5um, 0.8um, 1um, 1.5um, 2um, 2.5um, 3um, 3.5um, 4um, 4.5um, 4.8um, 5um, 6um, 7um or 8um, etc. Of course, it may also be other values ​​within the above range.

[0172] Method for measuring average pore size: gas adsorption method.

[0173] Among them, the gas adsorption method mainly uses the principle of capillary condensation phenomenon and volume equivalent substitution. Under the premise of assuming that the shape of the pore is cylindrical and tubular, a capillary condensation model is established to estimate the pore size distribution characteristics and pore volume of the sample. By measuring the adsorption amount of the sample under different pressure conditions, the isothermal adsorption and desorption curves are drawn, and the average pore size can be obtained through different theoretical methods.

[0174] Table 2

[0175] Note: Among the samples selected in Examples 5 to 9 and Comparative Example 2, only the average pore diameter is different, and the other parameters remain unchanged.

[0176] It can be seen from Table 2 that the liquid absorption rate of the capillary 3 with an average pore size of 0.05um~8um is significantly higher than the liquid absorption rate of the capillary 3 with an average pore size of 0.01um, and the liquid absorption rate of the capillary 3 with an average pore size of 1um is optimal. Therefore, in order to increase the liquid absorption rate of the capillary 3, a capillary 3 with an average pore size of 0.1um~5um can be used, thereby increasing the liquid absorption rate of the capillary 3, thereby increasing the liquid retention capacity and wetting effect of the electrolyte of the electrode assembly 2.

[0177] By limiting the average pore size of the capillary member, the liquid absorption capacity of the capillary member 3 can be improved, thereby improving the electrolyte retention and wetting performance of the electrode assembly 2.

[0178] In some embodiments, the specific surface area of ​​the capillary element 3 is about 12 m 2 / g to 225m 2 / g range.

[0179] Optionally, the specific surface area of ​​the capillary member 3 may be 12 m 2 / g, 13m 2 / g, 14m 2 / g, 15m 2 / g, 20m 2 / g, 25m 2 / g, 30m 2 / g, 40m 2 / g, 50m 2 / g, 80m 2 / g、100m 2 / g, 120m 2 / g, 150m 2 / g, 180m 2 / g, 190m 2 / g, 200m 2 / g, 205m 2 / g, 210m 2 / g, 212m2 / g, 214m 2 / g, 216m 2 / g, 220m 2 / g、m 2 / g, 222m 2 / g, 224m 2 / g or 225m 2 Of course, it can also be other values ​​within the above range.

[0180] Specific surface area measurement method: BET (Brunauer Emmett Teller) specific surface area detection method test.

[0181] Among them, the measurement method of specific surface area can be a continuous flow method or a static volumetric method. For example, the continuous flow method refers to placing the powder sample to be tested in a U-shaped sample tube, allowing a mixed gas containing a certain proportion of adsorbent to flow through the sample, and determining the adsorption amount of the adsorbent molecules by the sample to be tested based on the change in gas concentration before and after adsorption.

[0182] Table 3

[0183] Note: Among the samples selected in Examples 10 to 14 and Comparative Example 3, only the specific surface area is different, and the other parameters remain unchanged.

[0184] From Table 1, we can see that the specific surface area is 12 m 2 / g ~225 m 2 / g of capillary 3 has a significantly higher liquid absorption rate than that of the capillary 3 with a specific surface area of ​​5m 2 / g of the liquid absorption rate of the capillary 3, and when the specific surface area of ​​the capillary 3 is 12 m 2 / g ~225 m 2 / g range, as the specific surface area of ​​the capillary 3 increases, the liquid absorption rate of the capillary 3 increases. Therefore, in order to increase the liquid absorption rate of the capillary 3, a specific surface area of ​​12 m 2 / g ~225 m 2 / g of capillary member 3, thereby increasing the liquid absorption rate of the capillary member 3, and further increasing the liquid retention amount and wetting effect of the electrolyte of the electrode assembly 2.

[0185] By limiting the specific surface area of ​​the capillary member 3 , the adsorption capacity of the capillary member 3 can be enhanced, so that more electrolyte can flow from the capillary member 3 into the interior of the electrode assembly 2 , thereby improving the electrolyte retention and wetting performance of the electrode assembly 2 .

[0186] In some embodiments, the porosity of the capillary element 3 is in the range of 40% to 70%, the average pore size of the capillary element is in the range of 0.05 um to 8 um, and the specific surface area of ​​the capillary element is in the range of 12 m 2 / g to 225m 2 / g range.

[0187] In some embodiments, the capillary member 3 is made of at least one of polytetrafluoroethylene and polystyrene.

[0188] Both polytetrafluoroethylene and polystyrene have high corrosion resistance and good electrochemical stability. The material of the capillary member 3 is at least one of polytetrafluoroethylene and polystyrene, which can make the capillary member 3 have high corrosion resistance and good electrochemical stability, which is beneficial to improving the overall performance of the battery cell 10.

[0189] In some embodiments, the battery cell further includes an electrode terminal, the electrode terminal and the electrode assembly are arranged along the direction of gravity, the capillary member has a capillary channel, the capillary channel has a preset opening and a preset inlet, and along the direction of gravity, the preset opening is located above the preset inlet.

[0190] like Figure 3 As shown, a pole ear 5 is provided on one side of the electrode assembly 2 along the direction of gravity, and the pole ear 5 is connected to the electrode terminal 4. For example, a pole ear 5 can be provided at the upper end of the electrode assembly along the direction of gravity. The pole ear 5 can import or export current from the electrode assembly 2. Since the pole ear is usually provided on the upper side of the electrode assembly, due to the effect of gravity, the electrolyte retention at the position where the pole ear 5 of the electrode assembly 2 and its surroundings is low and the infiltration effect is poor. The capillary can adsorb the electrolyte to the area of ​​the electrode assembly 2 where the pole ear 5 is provided, thereby increasing the electrolyte retention in the area of ​​the electrode assembly 2 where the pole ear 5 is provided and its surrounding parts, reducing the speed at which the electrolyte near the pole ear 5 at one end of the electrode assembly 2 loses to the other end of the electrode sheet, and reducing the risk of lithium deposition in the part of the electrode sheet near the pole ear 5.

[0191] In some embodiments, the capillary channel has a preset opening and a preset inlet that are interconnected. The preset inlet can be in contact with the bottom electrolyte. The preset inlet can absorb the electrolyte into the capillary channel. The electrolyte flows along the capillary channel to the preset opening and flows out from the preset opening, thereby wetting the electrode assembly.

[0192] Since the electrode terminals and the electrode assembly are arranged along the direction of gravity, and the preset opening is located above the preset inlet, the capillary 3 can adsorb the electrolyte from the position of the preset inlet to the position of the preset opening along the direction of gravity, that is, the capillary can adsorb the electrolyte to its top, thereby allowing the electrolyte to more effectively infiltrate the middle and / or top of the electrode assembly 2, which is beneficial to further improve the electrolyte retention and wetting performance of the electrode assembly 2.

[0193] In some embodiments, the capillary channel extends in the direction of gravity.

[0194] Optionally, the capillary channel may extend generally in the direction of gravity, may be a straight channel extending in the direction of gravity, or may be a channel with an arc, for example, projected in a direction perpendicular to the direction of gravity, the projection of the capillary channel may be a curve with a certain thickness.

[0195] Since the capillary channel extends in the direction of gravity, the flow path of the electrolyte adsorbed by the capillary to its top is shorter, which can speed up the speed of the electrolyte reaching the top of the capillary, and speed up the delivery of the electrolyte to the position in the electrode assembly where the electrolyte is lacking or the electrolyte wetting effect is poor, thereby more effectively improving the electrolyte retention and wetting effect in the difficult-to-wet areas of the electrode assembly.

[0196] In some embodiments, the capillary channel may not extend in the direction of gravity, as long as the electrolyte can be adsorbed to the liquid-deficient position of the electrode assembly.

[0197] In some embodiments, Figure 3 and Figure 4 As shown, the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the highest position of the separator 213, and the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the preset opening (not shown).

[0198] In some embodiments, the electrolyte can flow along the capillary channel of the capillary member 3 under the action of the adsorption force, and the electrolyte in the capillary channel can flow out from the preset opening (not shown) of the capillary channel (not shown), and the electrolyte flowing out from the preset opening can infiltrate the electrode assembly 2. The capillary member 3 has multiple capillary channels, and the preset opening can refer to an opening where a part of the capillary channels are located at the top, or can also refer to an opening where all the capillary channels are located at the top. Along the gravity direction, the preset openings of different channels can be located substantially flush or not flush.

[0199] Along the gravity direction, the highest position of the separator 213 is higher than the highest position of the positive electrode body and the highest position of the negative electrode body; and the preset opening of the capillary channel is higher than the highest position of the positive electrode body and the highest position of the negative electrode body. Of course, there may also be other capillary channel openings below the highest position of the positive electrode body and / or the negative electrode body.

[0200] In some embodiments, the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the highest position of the first separator 213 a and the highest position of the second separator 213 b .

[0201] Since the highest positions of the positive electrode body and the negative electrode body are not only lower than the highest positions of the isolation piece but also lower than the preset opening, the preset opening of the capillary piece can be made higher than the portion of the positive electrode body and / or the negative electrode body connected to the pole ear. Thus, along the direction of gravity, the capillary piece can adsorb the electrolyte from the position of the preset inlet to the position of the preset opening, that is, the capillary piece can adsorb the electrolyte to its top, thereby making the electrolyte more effectively infiltrate the top of the inside of the electrode assembly. The electrolyte can infiltrate the portion of the positive electrode body and / or the negative electrode body connected to the pole ear through the capillary piece, thereby increasing the electrolyte retention and infiltration effect in the area of ​​the electrode assembly where the pole ear is provided and the surrounding area, reducing the speed at which the electrolyte near one end of the pole ear in the electrode assembly loses to the other end of the pole piece, and reducing the risk of lithium plating in the portion of the pole piece near the pole ear.

[0202] In some embodiments, the highest position of the isolation member is lower than the preset opening.

[0203] In some embodiments, the highest position of the first isolating member 213a and the highest position of the second isolating member 213b are both lower than the preset opening, that is, along the direction of gravity, the preset opening is higher than the highest position of the first isolating member 213a and higher than the highest position of the second isolating member 213b.

[0204] Since the highest position of the isolating member is lower than the preset opening, the top of the isolating member can be more effectively infiltrated by the capillary member 3, thereby increasing the electrolyte retention and wetting effect on the top of the isolating member, thereby further increasing the electrolyte retention and wetting performance of the electrode assembly 2.

[0205] A second aspect of the present application provides a battery device, which includes a plurality of battery cells 10 provided according to the first aspect.

[0206] Since the battery device includes the battery cell 10 , the electrolyte retention and the wetting effect of the electrode assembly 2 can be improved, and the overall performance of the battery cell 10 can be improved, thereby improving the overall performance of the battery device.

[0207] A third aspect of the present application provides an energy storage device, which includes a plurality of battery cells 10 provided according to the first aspect or a plurality of battery devices 100 provided according to the second aspect, and the battery cells 10 or the battery devices are used to store or provide electrical energy.

[0208] Since the energy storage device includes the above-mentioned battery cell 10 or battery device, the electrolyte retention and infiltration effect of the electrode assembly 2 in the energy storage device can be improved, the overall performance of the battery cell 10 or the overall performance of the battery device can be improved, and the overall performance of the energy storage device can be improved.

[0209] The fourth aspect of the present application provides an electrical device, which includes the battery cell 10 provided according to the first aspect, the battery device 100 provided in the second aspect, or the energy storage device provided in the third aspect, and the battery cell 10 or the battery device 100 is used to store or provide electrical energy.

[0210] Since the electrical device includes the above-mentioned battery cell 10, battery device or energy storage device, the electrolyte retention and infiltration effect of the electrode assembly 2 in the electrical device can be improved, the overall performance of the battery cell 10, battery device or energy storage device can be improved, and the overall performance of the electrical device can be improved.

[0211] Below, refer to the following figure Figures 3 to 7 A specific example of an embodiment of the present application is described in detail.

[0212] A porous lamellar component, such as a capillary component 3, is added to the inside of the electrode assembly 2. The capillary force thereof is used to strengthen the electrolyte transport capability of the electrode assembly 2 from bottom to top along the gravity direction. The lamellar component can be arranged inside the innermost laminated layer 21 of the straight area, inside the innermost laminated layer 21 of the corner area, or between adjacent laminated layers 21 of any one or two corner areas. The capillary component 3 can be made of polytetrafluoroethylene or polystyrene, etc., and polystyrene can constitute a polystyrene nanoarray.

[0213] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced 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 present application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment 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 present application.

Claims

1. A battery cell, characterized in that: include: A housing having a receiving space; an electrode assembly, contained in the containing space, the electrode assembly comprising stacked layers, each stacked layer comprising a positive electrode, a negative electrode and a separator, the separator being disposed between adjacent positive electrodes and negative electrodes, the positive electrode comprising a positive electrode body, and the negative electrode comprising a negative electrode body; An electrode terminal, wherein the electrode terminal and the electrode assembly are arranged along a gravity direction; A capillary member, along the arrangement direction of the positive electrode and the negative electrode, the capillary member is located on a side of the outer surface of the electrode assembly away from the shell, the capillary member has a capillary channel, the capillary channel has a preset opening and a preset inlet, along the gravity direction, the preset opening is located above the preset inlet, Among them, the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the highest position of the isolation member, and the highest position of the positive electrode body and the highest position of the negative electrode body are both lower than the preset opening; the arrangement direction of the capillary member and the stacking layer is arranged along the arrangement direction of the positive electrode and the negative electrode.

2. The battery cell according to claim 1, characterized in that: The electrode assembly is configured as a winding structure, the number of layers of the stacked layers stacked along the arrangement direction of the positive electrode and the negative electrode when the electrode assembly is wound is at least two, the number of separators in each stacked layer is at least two, at least one of the separators is a first separator, and the first separator is located between the positive electrode and the negative electrode when the electrode assembly is unfolded, and at least one of the separators is a second separator, and the second separator is located outside the positive electrode and the negative electrode when the electrode assembly is unfolded; The capillary member is located at a side of the outermost stacked layer away from the outer shell along the arrangement direction of the positive electrode and the negative electrode.

3. The battery cell according to claim 2, characterized in that: The electrode assembly has a straight region and a corner region, the corner regions are arranged on opposite sides of the straight region, the arrangement direction of the corner regions on both sides is a first direction intersecting with the axial direction of the electrode assembly, and the arrangement direction of at least two layers of the stacked layers in the straight region is a second direction, and the second direction is intersecting with the first direction and the axial direction of the electrode assembly, respectively. At least one of the capillary members is a first capillary member located in the straight region, the first capillary member is located between two adjacent laminated layers along the second direction, and the first capillary member is located on the inner side of the innermost laminated layer in the straight region.

4. The battery cell according to claim 3, characterized in that: Except for the first capillary member, all other capillary members among the capillary members are located in the corner area.

5. The battery cell according to claim 2, characterized in that: The electrode assembly comprises a straight area and a corner area, wherein the corner areas are arranged on opposite sides of the straight area, wherein the arrangement direction of the corner areas on both sides is a first direction intersecting with the axial direction of the electrode assembly, and the arrangement direction of at least two layers of the stacked layers in the straight area is a second direction intersecting with the first direction and the axial direction of the electrode assembly, respectively, and at least one of the capillaries is a second capillary located in the corner area.

6. The battery cell according to claim 5, characterized in that: The second capillary member is disposed on the inner side of the innermost stacked layer in the corner area on each side.

7. The battery cell according to claim 5, characterized in that: The second capillary member is arranged between at least two adjacent stacked layers in the corner area on each side.

8. The battery cell according to claim 5, characterized in that: At least two second capillary members are arranged in the corner area on each side, and along the arrangement direction of the positive electrode and the negative electrode, the number of stacked layers between every two adjacent second capillary members in the corner area on each side is at least two.

9. The battery cell according to claim 1, characterized in that: The electrode assembly is configured as a laminate structure, wherein the separator, the positive electrode, the separator, and the negative electrode are sequentially stacked.

10. The battery cell according to claim 9, characterized in that: The capillary member has an ion channel.

11. The battery cell according to any one of claims 1 to 10, characterized in that: The porosity of the capillary element is in the range of 40% to 70%.

12. The battery cell according to any one of claims 1 to 10, characterized in that: The average pore size of the capillary element is in the range of 0.05 um to 8 um.

13. The battery cell according to any one of claims 1 to 10, characterized in that: The specific surface area of ​​the capillary element is 12m 2 / g to 225m 2 / g range.

14. The battery cell according to any one of claims 1 to 10, characterized in that: The material of the capillary piece is at least one of polytetrafluoroethylene and polystyrene.

15. The battery cell according to any one of claims 1 to 10, characterized in that: The capillary channel extends along the direction of gravity.

16. The battery cell according to any one of claims 1 to 10, characterized in that: The highest position of the isolation member is lower than the preset opening.

17. A battery device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 16.

18. An energy storage device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 16 or a plurality of battery devices according to claim 17, wherein the battery cells or the battery devices are used for storing or providing electric energy.

19. An electrical device, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 16, a battery device according to claim 17 or an energy storage device according to claim 18, wherein the battery cell or the battery device is used for storing or providing electrical energy.

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