CN117941119A

CN117941119A - Battery monomer, battery and electric equipment

Info

Publication number: CN117941119A
Application number: CN202280057956.8A
Authority: CN
Inventors: 黄瑛; 刘江; 陈文伟; 姚斌
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-07-26
Filing date: 2022-07-26
Publication date: 2024-04-26
Also published as: WO2024020764A1

Abstract

The embodiment of the application provides a battery monomer (20), a battery (10) and electric equipment. The battery cell (20) includes: an electrode assembly (21); a replenishing electrode (22), the replenishing electrode (22) being used for replenishing alkali metal ions for the battery cell (20); and a separator (23), wherein the separator (23) covers the first surface (221) of the supplemental electrode (22), the first surface (221) is the surface facing the electrode assembly (21), and the separator (23) is used for preventing alkali metal ions from passing through. According to the technical scheme, the capacity of the battery (10) can be improved, the safety of the battery (10) is enhanced, the service life of the battery (10) is prolonged, and therefore the performance of the battery (10) is improved.

Description

Battery monomer, battery and electric equipment

Technical Field

The application relates to the technical field of batteries, in particular to a battery monomer, a battery and electric equipment.

Background

Energy conservation and emission reduction are key to sustainable development of the automobile industry. In this case, the electric vehicle is an important component for sustainable development of the automobile industry due to the advantage of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor for development.

In the development of battery technology, the performance of batteries is a non-negligible problem. The performance of a battery not only affects the development and application of battery-related products, but also affects consumer acceptance of electric vehicles. Therefore, how to improve the performance of the battery is a problem to be solved.

Disclosure of Invention

The embodiment of the application provides a battery monomer, a battery and an electricity utilization device, which can improve the battery capacity, enhance the safety of the battery and prolong the service life of the battery, thereby improving the performance of the battery.

In a first aspect, there is provided a battery cell comprising: an electrode assembly; a supplemental electrode for supplementing the battery cell with alkali metal ions; and the isolating film is covered on the first surface of the supplementary electrode, the first surface is a surface facing the electrode assembly, and the isolating film is used for preventing the alkali metal ions from passing through.

In the embodiment of the application, the battery monomer comprises the supplementary electrode, and the supplementary electrode not only can supplement the loss of the active alkali metal of the battery comprising the battery monomer in the use process, thereby prolonging the service life of the battery, but also can supplement the loss of the active alkali metal of the battery in the first charging process, and improving the energy density of the battery. Further, the first surface of the supplementing electrode facing the electrode assembly is covered with the isolating film, so that the situation that the electrode plate is partially excessively supplemented with alkali metal to produce partial precipitation of the alkali metal due to the fact that alkali metal ions of the supplementing electrode are released from the first surface facing the electrode assembly to be embedded into the electrode plate is avoided, and the safety of the battery is improved. Therefore, the technical scheme of the application can improve the performance of the battery.

In some possible implementations, the alkali metal ion is lithium ion or sodium ion.

Lithium ion batteries are widely used because of their large capacity, strong charge retention capacity, long cycle life, and high safety. The electrode material used by the sodium ion battery is mainly sodium salt, the storage amount of the sodium salt raw material is rich, the price is low, the low-concentration electrolyte is allowed to be used due to the characteristic of the sodium salt, the production cost can be reduced, the sodium ion thermal stability is good, and the safety of the sodium ion battery is ensured.

In some possible implementations, the first face is the face of the supplemental electrode that has the greatest surface area.

The surface with the largest surface area of the supplementary electrode faces the electrode assembly, so that the supplementary electrode and the electrode assembly are more reasonably arranged, the internal space of the battery unit is saved, the volume of the battery unit is reduced, and the energy density of the battery is improved.

In some possible implementations, the surface of the electrode assembly includes a planar portion, and the first face faces the planar portion of the electrode assembly.

The electrode assembly includes a planar portion, which can better utilize the space of the battery cell, thus improving the energy density of the battery; in addition, the first surface of the supplementary electrode faces the plane part of the electrode assembly, so that the supplementary electrode and the electrode assembly are more reasonably arranged, the internal space of the battery unit is saved, the volume of the battery unit is reduced, and the energy density of the battery is further improved.

In some possible implementations, the planar portion is the side of the electrode assembly where the surface area is greatest.

The side surface with the largest surface area of the electrode assembly is opposite to the surface with the largest surface area of the complementary electrode, so that the internal space of the battery unit is further saved, the volume of the battery unit is reduced, and the energy density of the battery is improved.

In some possible implementations, the battery cell includes at least two electrode assemblies arranged along a first direction, the supplemental electrode is disposed between two adjacent electrode assemblies, and the first face is perpendicular to the first direction.

The supplementary electrode is arranged between two adjacent electrode assemblies, so that sufficient alkali metal ions can be ensured in the battery monomer, the content of the alkali metal ions of accessories of each electrode assembly is ensured to be similar, the phenomenon that the alkali metal is locally separated out of an electrode plate due to the excessive local alkali metal ions in the battery monomer is avoided, and the safety of the battery is improved.

In some possible implementations, the separator film is a polymer film that is resistant to electrolyte corrosion. The separator needs to be resistant to electrolyte corrosion so as to avoid corrosion by the electrolyte and not effectively prevent passage of alkali metal ions.

In some possible implementations, the polymer film is a polyester material film or a polyamide resin film.

The polyester material film and the polyamide resin film have good electrical insulation, impact resistance and corrosion resistance.

In some possible implementations, the material of the polyester material film is polyethylene terephthalate (Polyethylene terephthalate, PET).

PET has excellent electrical insulation and good electrical performance even at high temperature and high frequency.

In some possible implementations, the supplemental electrode is sheet-like in shape.

The shape of the supplementary electrode is set to be sheet-shaped, so that the influence on the overall thickness of the battery cell is small, the supplementary electrode does not occupy too much internal space of the battery cell, and the energy density of the battery comprising the battery cell is guaranteed.

In some possible implementations, the supplemental electrode includes a current collector and an alkali metal disposed on a surface of the current collector.

The supplementary electrode performs current transmission with the positive electrode or the negative electrode of the battery cell through the current collector, converts alkali metal into alkali metal ions, and supplements the battery cell with the alkali metal ions.

In a second aspect, there is provided a battery comprising: the battery cell of the first aspect or any possible implementation of the first aspect.

In a third aspect, there is provided a powered device comprising: the battery of the second aspect or any possible implementation of the second aspect, the battery is configured to provide electrical energy.

In the technical scheme of the application, the battery monomer comprises the supplementary electrode, and the supplementary electrode not only can supplement the loss of active alkali metal of the battery comprising the battery monomer in the use process, thereby prolonging the service life of the battery, but also can supplement the loss of active alkali metal of the battery in the first charging process, and improve the energy density of the battery. Further, the first surface of the supplementing electrode facing the electrode assembly is covered with the isolating film, so that the situation that the electrode plate is partially excessively supplemented with alkali metal to produce partial precipitation of the alkali metal due to the fact that alkali metal ions of the supplementing electrode are released from the first surface facing the electrode assembly to be embedded into the electrode plate is avoided, and the safety of the battery is improved. Therefore, the technical scheme of the application can improve the performance of the battery.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of a vehicle according to an embodiment of the present application;

fig. 2 is a schematic view showing the structure of a battery according to an embodiment of the present application;

fig. 3 is a schematic structural view of a battery cell according to an embodiment of the present application;

Fig. 4 is a schematic top view of a battery cell of an embodiment of the application;

FIG. 5 is a schematic view of a partial cross-sectional structure of the battery cell shown in FIG. 4 along the line A-A';

Fig. 6 is an enlarged view of the battery cell shown in fig. 5 at B.

In the drawings, the drawings are not drawn to scale.

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.

In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like are merely used for convenience in describing the present application and to simplify the description, and do not denote or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.

The directional terms appearing in the following description are those directions shown in the drawings and do not limit the specific structure of the application. In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present application can be understood as appropriate by those of ordinary skill in the art.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the described embodiments of the application may be combined with other embodiments.

In the embodiment of the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiment of the present application. The battery cell may be in a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, which is not limited in this embodiment of the application. The battery cells are generally classified into three types according to the packaging method: the cylindrical battery cell, the square battery cell and the soft package battery cell are not limited in this embodiment.

Reference to a battery in accordance with an embodiment of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, or the like. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The battery cell may include an electrode assembly and an electrolyte, the electrode assembly being composed of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly relies on metal ions to move between the positive and negative electrode plates to operate. The positive plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the current collector without the positive electrode active material layer protrudes out of the current collector coated with the positive electrode active material layer, and the current collector without the positive electrode active material layer is used as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the current collector without the negative electrode active material layer protrudes out of the current collector with the coated negative electrode active material layer, and the current collector without the negative electrode active material layer is used as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be graphite, carbon, silicon, or the like. In order to ensure that the high current is passed without fusing, the number of positive electrode lugs is multiple and stacked together, and the number of negative electrode lugs is multiple and stacked together. The separator may be made of polypropylene (PP) or Polyethylene (PE). In addition, the electrode assembly may be a roll-to-roll structure or a lamination structure, and embodiments of the present application are not limited thereto.

The development of battery technology is taking into consideration various design factors such as energy density, cycle life, discharge capacity, charge-discharge rate, safety, etc.

A general problem existing in the battery at present is that a large amount of alkali metal ions extracted from the positive electrode are consumed in the first charging process to form a solid electrolyte interface (solid electrolyte interphase, SEI) film on the surface of the negative electrode, and the irreversible consumption of the positive electrode alkali metal ions in the first charging process is usually more than 10%, so that the first-period charging and discharging efficiency is low, thereby reducing the energy density of the battery. On the other hand, the battery also continuously consumes active alkali metal during normal use, resulting in a greatly reduced service life of the battery.

In view of this, embodiments of the present application provide a battery cell including an electrode assembly, a supplemental electrode, and a separator. The supplementary electrode is used for supplementing alkali metal ions for the battery cell, the isolating film covers the first surface of the supplementary electrode, the first surface is a surface facing the electrode assembly, and the isolating film is used for preventing the alkali metal ions from passing through. In the technical scheme of the application, the battery monomer comprises the supplementary electrode, and the supplementary electrode not only can supplement the loss of active alkali metal of the battery comprising the battery monomer in the use process, thereby prolonging the service life of the battery, but also can supplement the loss of active alkali metal of the battery in the first charging process, and improve the energy density of the battery. Further, the first surface of the supplementing electrode facing the electrode assembly is covered with the isolating film, so that the situation that the electrode plate is partially excessively supplemented with alkali metal to produce partial precipitation of the alkali metal due to the fact that alkali metal ions of the supplementing electrode are released from the first surface facing the electrode assembly to be embedded into the electrode plate is avoided, and the safety of the battery is improved. Therefore, the technical scheme of the application can improve the performance of the battery.

The technical scheme described by the embodiment of the application is suitable for various devices using batteries. For example, cell phones, portable devices, notebook computers, battery cars, electric toys, electric tools, electric vehicles, ships, and spacecraft, etc., for example, spacecraft including airplanes, rockets, space shuttles, and spacecraft, etc.

It should be understood that the technical solutions described in the embodiments of the present application are not limited to the above-described devices, but may be applied to all devices using batteries, but for simplicity of description, the following embodiments are described by taking an electric vehicle as an example.

For example, as shown in fig. 1, a schematic structural diagram of a vehicle 1 according to an embodiment of the present application is shown, where the vehicle 1 may be a fuel-oil vehicle, a gas-fired 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. The vehicle 1 may be provided with a motor 40, a controller 30 and a battery 10, the controller 30 being arranged to control the battery 10 to supply power to the motor 40. For example, the battery 10 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, e.g. the battery 10 may be used as an operating power source for the vehicle 1, for electrical circuitry of the vehicle 1, e.g. for start-up, navigation and operational power requirements of the vehicle 1. In another embodiment of the present application, the battery 10 may be used not only as an operating power source for the vehicle 1 but also as a driving power source for the vehicle 1, instead of or in part instead of fuel oil or natural gas, to supply driving power to the vehicle 1.

To meet different power usage requirements, the battery 10 may include a plurality of battery cells. For example, as shown in fig. 2, a battery 10 according to an embodiment of the present application may include a plurality of battery cells 20. The battery 10 may further include a case 11, in which the case 11 has a hollow structure, and a plurality of battery cells 20 are accommodated in the case 11. For example, a plurality of battery cells 20 are connected in parallel or in series-parallel combination with each other and then placed in the case 11.

Alternatively, the battery 10 may further include other structures, which are not described in detail herein. For example, the battery 10 may further include a bus member for making electrical connection between the plurality of battery cells 20, such as parallel or series-parallel connection. Specifically, the bus member may realize electrical connection between the battery cells 20 by connecting electrode terminals of the battery cells 20. Further, the bus member may be fixed to the electrode terminals of the battery cells 20 by welding. The electrical energy of the plurality of battery cells 20 may be further drawn through the housing by a conductive mechanism. Alternatively, the conductive means may also belong to the bus bar member.

The number of battery cells 20 may be set to any number according to different power requirements. The plurality of battery cells 20 may be connected in series, parallel, or series-parallel to achieve a larger capacity or power. Since the number of battery cells 20 included in each battery 10 may be large, the battery cells 20 may be arranged in groups for easy installation, and each group of battery cells 20 constitutes a battery module. The number of battery cells 20 included in the battery module is not limited, and may be set according to requirements. The battery may include a plurality of battery modules, which may be connected in series, parallel, or series-parallel.

Fig. 3 is a schematic structural diagram of a battery cell 20 according to an embodiment of the present application. The battery cell 20 includes an electrode assembly 21, a supplemental electrode 22, and a separator 23. The supplemental electrode 22 is used for supplementing the battery cell 20 with alkali metal ions, the first surface 221 of the supplemental electrode 22 is covered by the isolating film 23, the first surface 221 is a surface facing the electrode assembly 21, and the isolating film 23 is used for preventing the alkali metal ions of the supplemental electrode 22 from passing through.

The separator 23 is a separator that does not allow alkali metal ions to pass through, and in the embodiment of the present application, the separator 23 covers the first surface 221 of the supplemental electrode 22, so that the separator 23 only ensures that alkali metal ions of the supplemental electrode 22 cannot be released from the first surface 221 of the supplemental electrode 22 into the electrolyte, and does not affect the release of alkali metal ions of the supplemental electrode 22 into the electrolyte at other surfaces not covered by the separator 23. That is, the separator 23 in the present application controls the alkali metal ion release path by covering the specific position of the surface of the electrode 22, thereby avoiding the phenomenon of localized alkali metal precipitation caused by localized excessive alkali metal replenishment of the electrode sheet.

The property of the separation membrane 23 to separate alkali metal ions can be detected by chemical reaction. Specifically, the opening of the beaker was covered with the separator 23, and a solution containing alkali metal ions was poured into the beaker whose opening was covered with the separator 23, and whether or not the solution filtered through the separator 23 contained alkali metal ions was detected. For example, alkali metal ions are detected by flame reaction, precipitation reaction, or the like of the alkali metal ions.

In the embodiment of the application, the battery cell 20 comprises the supplementary electrode 22, and the supplementary electrode 22 not only can supplement the loss of the active alkali metal of the battery 10 comprising the battery cell 20 in the use process, thereby prolonging the service life of the battery 10, but also can supplement the loss of the active alkali metal of the battery 10 in the primary charging process, and improve the energy density of the battery 10. Further, the first surface 221 of the supplemental electrode 22 facing the electrode assembly 21 is covered with the isolating film 23, so as to avoid the situation that the electrode sheet is partially excessively supplemented with alkali metal to generate partial precipitation of the alkali metal due to the release of the alkali metal ions of the supplemental electrode 22 from the first surface 221 facing the electrode assembly 21. Therefore, the technical scheme of the application can improve the performance of the battery 10.

With continued reference to fig. 3, the battery cell 20 may further include a housing 241 and a cover 242. The case 241 and the cover 242 form an outer case or a battery 10 case. The wall of the case 241 and the cover plate 242 are referred to as the wall of the battery cell 20, wherein for a rectangular parallelepiped type battery cell 20, the wall of the case 241 includes a bottom wall and four side walls. The case 241 is dependent on the shape of the combined one or more electrode assemblies 21, for example, the case 241 may be a hollow rectangular parallelepiped or square or cylindrical body, and one face of the case 241 has an opening so that one or more electrode assemblies 21 may be placed in the case 241. For example, when the case 241 is a hollow rectangular parallelepiped or square, one of the planes of the case 241 is an open face, i.e., the plane has no wall so that the inside and outside of the case 241 communicate. When the housing 241 may be a hollow cylinder, an end surface of the housing 241 is an opening surface, i.e., the end surface has no wall body so that the inside and the outside of the housing 241 communicate. The cap plate 242 covers the opening and is connected with the case 241 to form a closed cavity in which the electrode assembly 21 is placed. The case 241 is filled with an electrolyte, such as an electrolytic solution.

The battery cell 20 may further include two electrode terminals 243, and the two electrode terminals 243 may be disposed on the cap plate 242. The cap plate 242 is generally in the shape of a flat plate, and two electrode terminals 243 are fixed to the flat plate surface of the cap plate 242, the two electrode terminals 243 being a positive electrode terminal 243a and a negative electrode terminal 243b, respectively. One connection member 25, or may also be referred to as a current collecting member 25, is provided for each electrode terminal 243, which is located between the cap plate 242 and the electrode assembly 21, for electrically connecting the electrode assembly 21 and the electrode terminal 243.

As shown in fig. 3, each electrode assembly 21 has a first tab 211a and a second tab 212a. The polarities of the first tab 211a and the second tab 212a are opposite. For example, when the first tab 211a is a positive tab, the second tab 212a is a negative tab. The first tab 211a of one or more electrode assemblies 21 is connected to one electrode terminal through one connection member 25, and the second tab 212a of one or more electrode assemblies 21 is connected to the other electrode terminal through the other connection member 25. For example, the positive electrode terminal 243a is connected to the positive electrode tab by one connection member 25, and the negative electrode terminal 243b is connected to the negative electrode tab by the other connection member 25.

A pressure relief mechanism 244 may also be provided on the battery cell 20. The pressure release mechanism 244 is used to actuate to release the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a threshold.

The pressure relief mechanism 244 may be any of a variety of possible pressure relief structures, and embodiments of the present application are not limited in this regard. For example, pressure relief mechanism 244 may be a temperature-sensitive pressure relief mechanism configured to melt when the internal temperature of battery cell 20 provided with pressure relief mechanism 244 reaches a threshold; and/or the pressure relief mechanism 244 may be a pressure sensitive pressure relief mechanism configured to rupture when the internal air pressure of the battery cell 20 provided with the pressure relief mechanism 244 reaches a threshold.

Alternatively, in embodiments of the present application, the alkali metal ions may be lithium ions or sodium ions.

Specifically, in the lithium ion battery, the supplementary electrode is an electrode comprising metal lithium, and lithium ions are supplemented for a battery cell in the lithium ion battery; in a sodium ion battery, the supplemental electrode is an electrode comprising metallic sodium, which supplements sodium ions to the cells in the sodium ion battery.

Alternatively, in an embodiment of the present application, the first face 221 is the face where the surface area of the supplemental electrode 22 is greatest.

The surface of the greatest surface area of the supplementary electrode 22 faces the electrode assembly 21, so that the supplementary electrode 22 and the electrode assembly 21 are more reasonably arranged, the internal space of the battery cell 20 is saved, the volume of the battery cell 20 is reduced, and the energy density of the battery 10 is improved.

Alternatively, in the embodiment of the present application, the surface of the electrode assembly 21 includes the flat surface portion 213, and the first surface 221 faces the flat surface portion 213 of the electrode assembly 21.

The electrode assembly 21 includes the flat surface part 213, which can better utilize the space of the battery cell 20, thus improving the energy density of the battery 10; in addition, the first surface 221 of the supplemental electrode 22 faces the planar portion 213 of the electrode assembly 21, so that the supplemental electrode 22 and the electrode assembly 21 are more reasonably arranged, the internal space of the battery cell 20 is saved, the volume of the battery cell 20 is reduced, and the energy density of the battery 10 is further improved.

Alternatively, in the embodiment of the present application, the flat portion 213 is the side where the surface area of the electrode assembly 21 is maximized.

The side surface of the electrode assembly 21 having the largest surface area is disposed opposite to the surface of the supplemental electrode 22 having the largest surface area, thereby further saving the internal space of the battery cell 20, reducing the volume of the battery cell 20, and improving the energy density of the battery 10.

Alternatively, in the embodiment of the present application, the battery cell 20 includes at least two electrode assemblies 21, at least two electrode assemblies 21 are arranged along the first direction x, the supplemental electrode 22 is disposed between two adjacent electrode assemblies 21, the first surface 221 is perpendicular to the first direction x, and fig. 3 illustrates that two independent electrode assemblies 21 are disposed in the battery cell 20.

It should be understood that the supplemental electrode 22 includes two first faces 221 disposed opposite to each other in the first direction x, and when the supplemental electrode 22 is disposed between two adjacent electrode assemblies 21, the two first faces 221 are respectively opposite to the two electrode assemblies 21.

The supplemental electrode 22 is disposed between two adjacent electrode assemblies 21, so as to ensure that sufficient alkali metal ions exist in the battery unit 20, ensure that the content of alkali metal ions in the accessories of each electrode assembly 21 is similar, avoid the phenomenon that the partial alkali metal ions in the battery unit 20 are excessive to generate electrode pole piece to partially separate out alkali metal, and improve the safety of the battery 10.

Alternatively, in the embodiment of the present application, the separator 23 is a polymer film resistant to corrosion by an electrolyte. The separator 23 needs to be resistant to electrolyte corrosion so as to avoid corrosion by the electrolyte and not effectively prevent passage of alkali metal ions.

Alternatively, in an embodiment of the present application, the polymer film is a polyester material film or a polyamide resin film.

The polyester material film is made of a polyester material, and the polyester material is a polymer material obtained by polycondensation of polyalcohol and polybasic acid, and has good fiber forming property, mechanical property, wear resistance, corrosion resistance, low water absorption and electrical insulation property. The polyester material may include PET, polybutylene terephthalate (Polybutylene terephthalate, PBT), polyarylate, and the like.

The polyamide resin film is made of polyamide resin material, polyamide resin commonly called nylon is a polycondensation type high molecular compound with a-CONH structure in molecules, is usually obtained by polycondensation of dibasic acid and diamine, and has good mechanical strength, wear resistance, corrosion resistance and electrical insulation property. The polyamide resin may include nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 46, nylon 1010, and the like.

Alternatively, in the embodiment of the present application, the material of the polyamide resin film is PET. PET has excellent electrical insulation and good electrical performance even at high temperature and high frequency.

Alternatively, in the embodiment of the present application, the supplementary electrode 22 is in the shape of a sheet.

The shape of the supplemental electrode 22 is set to be a sheet shape, which has less influence on the overall thickness of the battery cell 20, so that the supplemental electrode 22 does not occupy too much of the internal space of the battery cell 20, which is advantageous for ensuring the energy density of the battery 10 including the battery cell 20.

Or the shape of the supplemental electrode 22 may be a block, and in general, the thicker the supplemental electrode 22 is, the better the supplemental alkali metal effect is, i.e., the supplemental electrode 22 is provided in a block shape, so that the capability of the supplemental electrode 22 for supplementing alkali metal can be ensured, and the effect of the supplemental electrode 22 for supplementing alkali metal is greatly improved.

Fig. 4 is a schematic top view of the battery cell 20, fig. 5 is a schematic view of a partial cross-sectional structure of the battery cell 20 along A-A' shown in fig. 4, and fig. 6 is an enlarged view of the battery cell 20 at B shown in fig. 5.

Alternatively, in the embodiment of the present application, as shown in fig. 6, the supplemental electrode 22 includes a current collector 222 and an alkali metal 223, and the alkali metal 223 is disposed on the surface of the current collector 222.

The supplementary electrode 22 performs current transmission with the positive electrode or the negative electrode of the battery cell 20 through the current collector 222, converts alkali metal into alkali metal ions, and supplements the battery cell 20 with the alkali metal ions.

The embodiment of the present application also provides a battery 10, and the battery 10 may include the battery cells 20 in the foregoing embodiments. In some embodiments, the battery 10 may further include a case, a bus member, and other structures, which are not described in detail herein.

An embodiment of the present application also provides a powered device that may include the battery 10 of the previous embodiment. Alternatively, the electric device may be the vehicle 1, the ship, the spacecraft, or the like, but the embodiment of the application is not limited thereto.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

A battery cell (20), characterized by comprising:

an electrode assembly (21);

-a supplementary electrode (22), the supplementary electrode (22) being for supplementing the battery cell (20) with alkali metal ions;

-a separator (23), the separator (23) covering a first face (221) of the supplementary electrode (22), the first face (221) being the face facing the electrode assembly (21), the separator (23) being adapted to prevent the passage of the alkali metal ions.
The battery cell (20) of claim 1, wherein the alkali metal ion is lithium ion or sodium ion.
The battery cell (20) according to claim 1 or 2, wherein the first face (221) is a face of the supplemental electrode (22) having the largest surface area.
The battery cell (20) of claim 3, wherein the surface of the electrode assembly (21) includes a planar portion (213), the first face (221) facing the planar portion (213) of the electrode assembly (21).
The battery cell (20) of claim 4, wherein the planar portion (213) is a side of the electrode assembly (21) where the surface area is greatest.
The battery cell (20) according to any one of claims 1 to 5, wherein the battery cell (20) comprises at least two of the electrode assemblies (21), the at least two of the electrode assemblies (21) being arranged along a first direction (x), the supplemental electrode (22) being disposed between adjacent two of the electrode assemblies (21), the first face (221) being perpendicular to the first direction (x).
The battery cell (20) of any one of claims 1 to 6, wherein the separator (23) is a polymer film resistant to electrolyte corrosion.
The battery cell (20) of claim 7, wherein the polymer film is a polyester material film or a polyamide resin film.
The battery cell (20) of claim 8, wherein the material of the polyester material film is polyethylene terephthalate, PET.
The battery cell (20) of any one of claims 1 to 9, wherein the supplemental electrode (22) is sheet-like in shape.
The battery cell (20) of any one of claims 1 to 10, wherein the supplemental electrode (22) comprises a current collector (222) and an alkali metal (223), the alkali metal (223) being disposed on a surface of the current collector (222).
A battery (10), characterized by comprising: the battery cell (20) according to any one of claims 1 to 11.
A powered device, comprising: the battery (10) according to claim 12, the battery (10) being adapted to provide electrical energy.