Battery cell, battery, and electric device

Abstract

A battery cell (20), a battery (100), and an electric device. The battery cell (20) comprises: a separator (40) and an electrode piece (30); and an adhesion layer (50), the adhesion layer (50) being provided at the periphery of the electrode piece (30) and adhering to the separator (40).

Description

Battery cells, batteries, and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202323090249.X and application date of November 15, 2023, and claims the priority of the above-mentioned Chinese patent application. The entire content of the above-mentioned Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] In related technologies, dendrites (sodium dendrites for sodium batteries and lithium dendrites for lithium batteries) are prone to self-dissolution in the electrolyte, and the dissolution of dendrites in the electrolyte can be aggravated under the action of an external mechanical field, cavitation generated by ultrasonic oscillation, or mechanical shaking at a certain frequency. Free dendrites will move to the edge of the positive electrode sheet and contact the positive electrode sheet, which will cause a micro-short circuit in the battery cell, affecting the service life of the battery cell.

[0005] Application Contents

[0006] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0007] To this end, the present application proposes a battery cell, in which the probability of dendrites free in the electrolyte contacting the positive electrode sheet is low, which is beneficial to extending the service life of the battery cell.

[0008] In a first aspect, an embodiment of the present application provides a battery cell, comprising:

[0009] diaphragms and pole pieces;

[0010] The bonding layer is provided at the edge of the electrode and bonded to the diaphragm.

[0011] In the above technical solution, by setting the adhesive layer at the edge of the electrode and bonding the adhesive layer to the diaphragm, the probability of dendrites free in the electrolyte contacting the positive electrode can be reduced, thereby reducing the probability of micro-short circuit phenomenon in the battery cell, which is beneficial to extending the service life of the battery cell.

[0012] In a second aspect, an embodiment of the present application further provides a battery comprising the above-mentioned battery cell.

[0013] In a third aspect, an embodiment of the present application further provides an electrical device comprising the above-mentioned battery.

[0014] In a fourth aspect, an embodiment of the present application further provides an energy storage device comprising the above-mentioned battery.

[0015] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0017] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0018] FIG3 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0019] FIG4 is a cross-sectional view of a battery cell provided in some embodiments of the present application (the positive electrode active material layer is omitted);

[0020] FIG5 is a cross-sectional view of a battery cell provided in some embodiments of the present application (the negative electrode active material layer is omitted);

[0021] FIG6 is a cross-sectional view of a positive electrode sheet provided in some embodiments of the present application (the adhesive layer is provided on the active material layer);

[0022] FIG7 is a cross-sectional view of a negative electrode sheet provided in some embodiments of the present application (the adhesive layer is provided on the active material layer);

[0023] FIG8 is a cross-sectional view of a positive electrode sheet provided in some embodiments of the present application (the adhesive layer is provided on the current collector);

[0024] FIG9 is a cross-sectional view of a negative electrode sheet provided in some embodiments of the present application (the adhesive layer is provided on the current collector).

[0025] The figures in the specification are as follows: vehicle 1000; battery 100; casing 10; first casing body 11; second casing body 12; battery cell 20; electrode 30; positive electrode sheet 301; positive electrode current collector 3011; positive electrode active material layer 3012; negative electrode sheet 302; negative electrode current collector 3021; ​​negative electrode active material layer 3022; current collector 31; first surface 312; second surface 313; active material layer 32; first edge 33; second edge 34; third edge 35; fourth edge 36; separator 40; adhesive layer 50; first cavity structure 60; second cavity structure 70. DETAILED DESCRIPTION

[0026] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0028] References to "embodiments" in this application mean 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 appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0029] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0030] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0031] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0032] The term "plurality" used in this application refers to two or more (including two).

[0033] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be flat, rectangular, or in other shapes, and the embodiments of this application do not limit this. Battery cells are generally divided into square battery cells and soft-pack battery cells based on the packaging method, and the embodiments of this application do not limit this.

[0034] The battery referred to in the embodiments of this 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 this application may include a battery module or battery pack. A battery generally includes a casing that encloses one or more battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0035] A battery cell consists of a casing, an electrode assembly, and an electrolyte. The casing is used to hold the electrode assembly and electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The uncoated positive electrode collector protrudes from the coated positive electrode collector, and the uncoated positive electrode collector serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The uncoated negative electrode collector protrudes from the coated negative electrode collector, and the uncoated negative electrode collector serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the positive electrode tabs are multiple and stacked together, and the negative electrode tabs are multiple and stacked together.

[0036] The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0037] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and important role. A battery consists of a housing and multiple cells housed within it. As a core component in new energy vehicles, batteries have high requirements for both reliability and cycle life.

[0038] The battery includes multiple battery cells. Under a quasi-zero electrochemical field, dendrites (sodium dendrites for sodium batteries and lithium dendrites for lithium batteries) are prone to self-dissolution in the electrolyte. Moreover, under the action of an external mechanical field, cavitation generated by ultrasonic oscillation, or mechanical shaking at a certain frequency, the dissolution of dendrites in the electrolyte can be aggravated. Free dendrites will move to the edge of the positive electrode sheet and contact the positive electrode sheet, which will cause a micro-short circuit in the battery cell and affect the service life of the battery cell.

[0039] Based on the above considerations, in order to solve the technical problem that free dendrites may be freed to the edge of the positive electrode sheet and contact the positive electrode sheet, thereby causing a micro short circuit in the battery cell, the present application proposes a battery cell comprising: a separator and a pole piece; and an adhesive layer, the adhesive layer being provided at the edge of the pole piece and bonded to the separator.

[0040] In such a battery cell, by setting an adhesive layer on the edge of the electrode and bonding the adhesive layer to the diaphragm, the probability of dendrites free in the electrolyte contacting the positive electrode can be reduced, thereby reducing the probability of micro-short circuits in the battery cell, which is beneficial to extending the service life of the battery cell.

[0041] The battery disclosed in the embodiments of the present application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. The battery disclosed in the present application can be used to form a power supply system for the electrical device.

[0042] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. 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. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0043] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0044] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0045] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also 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.

[0046] Please refer to Figure 2, which is an exploded view of the structure of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a plurality of battery cells 20, which are intended to be accommodated within the housing 10. The housing 10 is used to provide an assembly space for the battery cells 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12, which cover each other and together define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define an assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, with the open side of the first housing body 11 covering the open side of the second housing body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cube, a rectangular parallelepiped, etc.

[0047] In the battery 100, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 can be constructed by first connecting the multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then connected in series, in parallel, or in a hybrid configuration to form a single structure and housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0048] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be flat, rectangular, or in other shapes.

[0049] The battery cell 20 according to an embodiment of the present application is described below with reference to FIG. 3 to FIG. 9 .

[0050] 4 and 5 , the battery cell 20 according to the embodiment of the present application includes: a separator 40 and a pole piece 30 ; and an adhesive layer 50 , which is provided at the edge of the pole piece 30 and bonded to the separator 40 .

[0051] In some embodiments, the surface of the adhesive layer 50 facing the diaphragm 40 can be bonded to the diaphragm 40. For example, the surface of the adhesive layer 50 facing the diaphragm 40 can be bonded to the surface of the diaphragm 40 facing the adhesive layer 50. The thickness direction of the electrode 30 is the X direction shown in Figure 3, and the adhesive layer 50 can be bonded to the surface of the electrode 30 parallel to the X direction.

[0052] In some embodiments, the bonding layer 50 has two opposite surfaces, one of which is bonded to the surface of the pole piece 30 facing the bonding layer 50, and the other is bonded to the surface of the diaphragm 40 facing the bonding layer 50, that is, the bonding layer 50 is arranged between the pole piece 30 and the diaphragm 40.

[0053] The electrode sheet 30 may be a positive electrode sheet 301 or a negative electrode sheet 302. Referring to FIG. 5 , FIG. 6 , and FIG. 8 , an adhesive layer 50 is provided on the surface of the positive electrode sheet 301 opposite to the separator 40. The adhesive layer 50 is provided at the edge of the positive electrode sheet 301 and is bonded to the separator 40.

[0054] In some embodiments of the present application, an adhesive layer 50 is provided on the surface of the negative electrode sheet 302 opposite to the separator 40 . The adhesive layer 50 is provided at the edge of the negative electrode sheet 302 and adheres to the separator 40 .

[0055] As some embodiments of the present application, an adhesive layer 50 is provided on the surface of the negative electrode sheet 302 opposite to the diaphragm 40, and the adhesive layer 50 is provided on the edge of the negative electrode sheet 302 and bonded to the diaphragm 40, and an adhesive layer 50 is provided on the surface of the positive electrode sheet 301 opposite to the diaphragm 40, and the adhesive layer 50 is provided on the edge of the positive electrode sheet 301 and bonded to the diaphragm 40.

[0056] The surface of the electrode 30 facing the diaphragm 40 is provided with an adhesive layer 50, and the adhesive layer 50 is provided at the edge of the electrode 30. The edge of the electrode 30 can be understood as an approximate quadrilateral frame, and the adhesive layer 50 can be located on at least one side of the quadrilateral frame. For example, as shown in FIG3 , the surface of the electrode 30 facing the diaphragm 40 can have a first edge 33, a second edge 34, a third edge 35, and a fourth edge 36.

[0057] In some embodiments, the adhesive layer 50 is disposed on the first edge 33 of the pole piece 30 , or the adhesive layer 50 is disposed on the second edge 34 of the pole piece 30 , or the adhesive layer 50 is disposed on the third edge 35 of the pole piece 30 , or the adhesive layer 50 is disposed on the fourth edge 36 of the pole piece 30 .

[0058] In some embodiments, the adhesive layer 50 is arranged on the first edge 33 and the second edge 34 of the pole piece 30, or the adhesive layer 50 is arranged on the first edge 33 and the third edge 35 of the pole piece 30, or the adhesive layer 50 is arranged on the first edge 33 and the fourth edge 36 of the pole piece 30, or the adhesive layer 50 is arranged on the second edge 34 and the third edge 35 of the pole piece 30, or the adhesive layer 50 is arranged on the second edge 34 and the fourth edge 36 of the pole piece 30, or the adhesive layer 50 is arranged on the third edge 35 and the fourth edge 36 of the pole piece 30.

[0059] In some embodiments, the adhesive layer 50 is arranged on the first edge 33, the second edge 34, and the third edge 35 of the pole piece 30, or the adhesive layer 50 is arranged on the first edge 33, the second edge 34, and the fourth edge 36 of the pole piece 30, or the adhesive layer 50 is arranged on the first edge 33, the third edge 35, and the fourth edge 36 of the pole piece 30, or the adhesive layer 50 is arranged on the second edge 34, the third edge 35, and the fourth edge 36 of the pole piece 30.

[0060] In some embodiments, as shown in FIG. 3 , the adhesive layer 50 is disposed on the first edge 33 , the second edge 34 , the third edge 35 , and the fourth edge 36 of the pole piece 30 .

[0061] By providing an adhesive layer 50 on the edge of the surface opposite to the positive electrode sheet 301 and the diaphragm 40, and positioning the adhesive layer 50 between the positive electrode sheet 301 and the diaphragm 40, the probability of dendrites dissolved from the negative electrode being liberated into the electrolyte and contacting the positive electrode sheet 301 can be reduced (this can also be understood as the adhesive layer 50 located between the positive electrode sheet 301 and the diaphragm 40 blocking the dendrites from being liberated toward the positive electrode sheet 301), thereby reducing the probability of micro-short circuits occurring in the battery cell 20.

[0062] By providing an adhesive layer 50 at the edge of the surface opposite to the negative electrode sheet 302 and the diaphragm 40, and positioning the adhesive layer 50 between the negative electrode sheet 302 and the diaphragm 40, the probability of dissolved dendrites being released into the electrolyte can be reduced (this can also be understood as, after the dendrites are dissolved, the adhesive layer 50 positioned between the negative electrode sheet 302 and the diaphragm 40 blocks the dendrites from being released into the electrolyte), thereby reducing the probability of dendrites dissolved from the negative electrode being released into the electrolyte and contacting the positive electrode sheet 301, and reducing the probability of micro-short circuits occurring in the battery cell 20.

[0063] In some embodiments, the present application has no particular limitation on the type of the diaphragm 40 , and any known porous structure diaphragm 40 with good chemical stability and mechanical stability can be selected.

[0064] In some embodiments, the battery cell 20 further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte may be selected based on needs. The electrolyte may be liquid, gel, or solid.

[0065] In the above technical solution, by setting the adhesive layer 50 on the edge of the electrode 30 and bonding the adhesive layer 50 to the diaphragm 40, the probability of dendrites free in the electrolyte contacting the positive electrode 301 can be reduced, thereby reducing the probability of micro-short circuit phenomenon in the battery cell 20, which is beneficial to extending the service life of the battery cell 20.

[0066] According to some embodiments of the present application, as shown in FIG. 3 , the adhesive layer 50 is annular and is disposed along the edge of the pole piece 30 .

[0067] 3 , the surface of the pole piece 30 opposite to the diaphragm 40 may have a first edge 33 , a second edge 34 , a third edge 35 , and a fourth edge 36 , and the first edge 33 , the second edge 34 , the third edge 35 , and the fourth edge 36 are connected end to end in sequence to form a ring, and the adhesive layer 50 may be constructed in a ring shape, and the ring-shaped adhesive layer 50 may be arranged along the first edge 33 , the second edge 34 , the third edge 35 , and the fourth edge 36 of the pole piece 30 .

[0068] As some embodiments of the present application, the adhesive layer 50 can be directly constructed into a ring shape, that is, the ring-shaped adhesive layer 50 is an integrally formed structure, and then the ring-shaped adhesive layer 50 is arranged on the edge of the pole piece 30.

[0069] As some embodiments of the present application, the annular adhesive layer 50 can be multiple split parts. For example, four adhesive layers 50 are respectively arranged on the first edge 33, the second edge 34, the third edge 35, and the fourth edge 36, and the four adhesive layers 50 respectively arranged on the first edge 33, the second edge 34, the third edge 35, and the fourth edge 36 are connected end to end in sequence to form an annular adhesive layer 50.

[0070] In the above technical solution, by constructing the adhesive layer 50 into a ring shape and making the ring-shaped adhesive layer 50 arranged along the edge of the electrode 30, when the adhesive layer 50 is arranged on the surface opposite to the positive electrode 301 and the diaphragm 40, the probability of the dendrites dissolved from the negative electrode being freed into the electrolyte and contacting the positive electrode 301 can be further reduced. When the adhesive layer 50 is arranged on the surface opposite to the negative electrode 302 and the diaphragm 40, the probability of the dissolved dendrites being freed into the electrolyte can be further reduced, thereby further reducing the probability of micro-short circuit phenomenon in the battery cell 20.

[0071] According to some embodiments of the present application, as shown in Figures 6 and 7, the electrode 30 includes: a current collector 31 and an active material layer 32, the current collector 31 has a first surface 312 and a second surface 313 relative to each other (as shown in Figures 6 and 7), the first surface 312 and the second surface 313 are both provided with an active material layer 32, and the adhesive layer 50 is provided on the active material layer 32.

[0072] The electrode piece 30 may be a positive electrode piece 301 , or a negative electrode piece 302 .

[0073] As shown in Figure 6, the positive electrode sheet 301 may include a positive electrode current collector 3011 and a positive electrode active material layer 3012. The positive electrode current collector 3011 may have a first surface 312 and a second surface 313 relative to each other. The first surface 312 and the second surface 313 may both be provided with a positive electrode active material layer 3012. The material of the positive electrode current collector 3011 may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc.

[0074] 7 , the negative electrode sheet 302 may include a negative electrode current collector 3021 and a negative electrode active material layer 3022 . The negative electrode current collector 3021 may have a first surface 312 and a second surface 313 relative to each other. Both the first surface 312 and the second surface 313 may be provided with a negative electrode active material layer 3022 . The material of the negative electrode current collector 3021 may be copper, and the negative electrode active material may be carbon or silicon, etc.

[0075] 6 and 7 , the adhesive layer 50 may be provided on the active material layer 32 . Specifically, the adhesive layer 50 is provided on the surface of the active material layer 32 facing the current collector 31 and the separator 40 , which is away from the current collector 31 .

[0076] In some embodiments, the first surface 312 of the current collector 31 is a surface opposite to the separator 40 , and an adhesive layer 50 is provided on a surface of the active material layer 32 disposed on the first surface 312 facing away from the current collector 31 .

[0077] In some embodiments, the second surface 313 of the current collector 31 is a surface opposite to the separator 40 , and an adhesive layer 50 is provided on a surface of the active material layer 32 disposed on the second surface 313 that faces away from the current collector 31 .

[0078] In some embodiments, the first surface 312 and the second surface 313 of the current collector 31 are both surfaces opposite to the diaphragm 40, the surface of the active material layer 32 arranged on the first surface 312 facing away from the current collector 31 is provided with an adhesive layer 50, and the surface of the active material layer 32 arranged on the second surface 313 facing away from the current collector 31 is provided with an adhesive layer 50.

[0079] In the above technical solution, by providing the adhesive layer 50 on the active material layer 32, the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301 can be reduced, thereby reducing the probability of micro-short circuits in the battery cell 20, which is beneficial for extending the service life of the battery cell 20. Furthermore, when the adhesive layer 50 is provided on the negative electrode active material layer 3022 on the surface of the negative electrode sheet 302, the separator 40, the adhesive layer 50 on the adjacent negative electrode sheet 302, and the negative electrode sheet 302 can jointly define a first cavity structure 60 (see FIG. 5). The first cavity structure 60 can provide sodium or lithium precipitation (if the battery 100 is a sodium battery 100, the first cavity structure 60 can provide sodium precipitation; if the battery 100 is a lithium battery 100, the first cavity structure 60 can provide lithium precipitation), thereby beneficial for improving the capacity of the battery cell 20 and the reliability of the battery cell 20.

[0080] According to some embodiments of the present application, as shown in Figures 8 and 9, the electrode 30 includes: a current collector 31 and an active material layer 32, the current collector 31 has a first surface 312 and a second surface 313 relative to each other, the first surface 312 and the second surface 313 are both provided with an active material layer 32, the first surface 312 and / or the second surface 313 are provided with an adhesive layer 50, and the adhesive layer 50 is adjacent to the corresponding active material layer 32.

[0081] The electrode piece 30 may be a positive electrode piece 301 , or a negative electrode piece 302 .

[0082] As shown in Figure 8, the positive electrode sheet 301 may include a positive electrode current collector 3011 and a positive electrode active material layer 3012. The positive electrode current collector 3011 may have a first surface 312 and a second surface 313 relative to each other. The first surface 312 and the second surface 313 may both be provided with a positive electrode active material layer 3012. The material of the positive electrode current collector 3011 may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc.

[0083] 9 , the negative electrode sheet 302 may include a negative electrode current collector 3021 and a negative electrode active material layer 3022 . The negative electrode current collector 3021 may have a first surface 312 and a second surface 313 relative to each other. Both the first surface 312 and the second surface 313 may be provided with a negative electrode active material layer 3022 . The material of the negative electrode current collector 3021 may be copper, and the negative electrode active material may be carbon or silicon, etc.

[0084] 8 and 9 , the first surface 312 and / or the second surface 313 may be provided with an adhesive layer 50. Specifically, the surface of the current collector 31 opposite to the diaphragm 40 may be provided with an adhesive layer 50, and the adhesive layer 50 provided on the surface of the current collector 31 is adjacent to the corresponding active material layer 32. The adjacency between the adhesive layer 50 and the corresponding active material layer 32 can be understood as the end of the adhesive layer 50 close to the active material layer 32 is in contact with the active material layer 32 or has a very small gap.

[0085] In some embodiments, the first surface 312 of the current collector 31 is the surface opposite to the separator 40 , and the first surface 312 may be provided with an adhesive layer 50 . The adhesive layer 50 provided on the first surface 312 may be adjacent to the active material layer 32 provided on the first surface 312 .

[0086] In some embodiments, the second surface 313 of the current collector 31 is the surface opposite to the separator 40 , and the second surface 313 may be provided with an adhesive layer 50 . The adhesive layer 50 provided on the second surface 313 may be adjacent to the active material layer 32 provided on the second surface 313 .

[0087] In some embodiments, the first surface 312 and the second surface 313 of the current collector 31 are both surfaces opposite to the diaphragm 40, and the first surface 312 and the second surface 313 can be provided with an adhesive layer 50. The adhesive layer 50 provided on the first surface 312 can be adjacent to the active material layer 32 provided on the first surface 312, and the adhesive layer 50 provided on the second surface 313 can be adjacent to the active material layer 32 provided on the second surface 313.

[0088] In the above technical solution, by providing an adhesive layer 50 on the first surface 312 and / or the second surface 313 of the current collector 31 and making the adhesive layer 50 adjacent to the corresponding active material layer 32, the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301 can be reduced, thereby reducing the probability of micro-short circuit phenomenon in the battery cell 20, which is beneficial to extending the service life of the battery cell 20.

[0089] According to some embodiments of the present application, the adhesive layer 50 is disposed around the active material layer 32 .

[0090] The surface of the current collector 31 opposite to the separator 40 may be provided with an adhesive layer 50. The adhesive layer 50 provided on the surface of the current collector 31 is adjacent to the corresponding active material layer 32. In addition, the adhesive layer 50 provided on the surface of the current collector 31 may be provided around the corresponding active material layer 32. For example, the adhesive layer 50 may be annular and provided around the outer periphery of the active material layer 32.

[0091] As some embodiments of the present application, the adhesive layer 50 can be directly constructed into a ring shape, that is, the ring-shaped adhesive layer 50 is an integrally formed structure, and then the ring-shaped adhesive layer 50 is sleeved on the outer periphery of the active material layer 32 .

[0092] In some embodiments of the present application, the annular adhesive layer 50 may be a plurality of separate parts. For example, four adhesive layers 50 are connected end to end in sequence to form an annular adhesive layer 50 and are disposed around the periphery of the active material layer 32 .

[0093] In the above technical solution, by setting the adhesive layer 50 around the active material layer 32, when the adhesive layer 50 is set around the positive active material layer 3012 on the surface of the positive electrode sheet 301, the probability of dendrites dissolved from the negative electrode being freed into the electrolyte and contacting the positive electrode sheet 301 can be reduced. When the adhesive layer 50 is set around the negative active material layer 3022 on the surface of the negative electrode sheet 302, the probability of dissolved dendrites being freed into the electrolyte can be reduced, thereby reducing the probability of micro-short circuit phenomenon in the battery cell 20, which is beneficial to improving the service life of the battery cell 20.

[0094] According to some embodiments of the present application, as shown in FIG. 4 , FIG. 5 , FIG. 8 and FIG. 9 , along the thickness direction of the electrode piece 30 , the thickness of the adhesive layer 50 is greater than or equal to the thickness of the corresponding active material layer 32 .

[0095] Among them, the surface of the current collector 31 opposite to the separator 40 may be provided with an adhesive layer 50. The adhesive layer 50 provided on the surface of the current collector 31 is adjacent to the corresponding active material layer 32, and the thickness of the adhesive layer 50 may be greater than the thickness of the corresponding active material layer 32, or the thickness of the adhesive layer 50 may be equal to the thickness of the corresponding active material layer 32. In this regard, the thickness of the adhesive layer 50 and the thickness of the active material layer 32 can be understood as the size of the adhesive layer 50 and the size of the active material layer 32 in the X direction shown in Figure 6. Referring to Figure 6, the thickness of the adhesive layer 50 can be understood as the thickness H shown in Figure 6, and the thickness of the active material layer 32 can be understood as the thickness F shown in Figure 6.

[0096] As some embodiments of the present application, as shown in Figures 4 and 5, the thickness of the bonding layer 50 is equal to the thickness of the corresponding active material layer 32. This arrangement can facilitate bonding the bonding layer 50 to the diaphragm 40, which is beneficial to reducing the manufacturing difficulty of the battery cell 20, and can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301.

[0097] As some embodiments of the present application, as shown in Figures 8 and 9, the thickness of the bonding layer 50 is greater than the thickness of the corresponding active material layer 32. This arrangement can facilitate the bonding of the bonding layer 50 to the diaphragm 40, which is beneficial to reducing the manufacturing difficulty of the battery cell 20. Moreover, this arrangement can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301. In addition, when the bonding layer 50 is provided on the negative electrode sheet 302, the diaphragm 40 and the bonding layer 50 and the negative electrode sheet 302 on the adjacent negative electrode sheet 302 can jointly define a first cavity structure 60, and the first cavity structure 60 can provide sodium or lithium precipitation.

[0098] In the above technical solution, by making the thickness of the adhesive layer 50 equal to the thickness of the corresponding active material layer 32, it is convenient to bond the adhesive layer 50 to the diaphragm 40, which is beneficial to reduce the manufacturing difficulty of the battery cell 20, and can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301.

[0099] By making the thickness of the adhesive layer 50 greater than the thickness of the corresponding active material layer 32, it is convenient to bond the adhesive layer 50 to the separator 40, which is beneficial to reducing the manufacturing difficulty of the battery cell 20, and can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301. In addition, when the adhesive layer 50 is provided on the negative electrode sheet 302, the separator 40 and the adhesive layer 50 and the negative electrode sheet 302 on the adjacent negative electrode sheet 302 can jointly define a first cavity structure 60. The first cavity structure 60 can provide sodium or lithium precipitation (if the battery 100 is a sodium battery 100, the first cavity structure 60 can provide sodium precipitation, and if the battery 100 is a lithium battery 100, the first cavity structure 60 can provide lithium precipitation), which is beneficial to improving the capacity of the battery cell 20 and the reliability of the battery cell 20.

[0100] According to some embodiments of the present application, as shown in FIG. 3 , along a first direction perpendicular to the thickness direction of the pole piece 30 , the width of the adhesive layer 50 is greater than 0 mm and less than or equal to 3 mm.

[0101] Among them, the thickness direction of the pole piece 30 can be the X direction shown in Figure 6. Along the first direction perpendicular to the X direction shown in Figure 6, the width dimension of the adhesive layer 50 is greater than 0 mm and less than or equal to 3 mm. That is, the width dimension of the adhesive layer 50 can be any size between greater than 0 mm and less than or equal to 3 mm. For example, the width dimension of the adhesive layer 50 can be but not limited to 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0102] It should be explained that the width dimension of the adhesive layer 50 can be understood as the dimension from the end of the adhesive layer 50 away from the center point of the pole piece 30 to the end of the adhesive layer 50 close to the center point of the pole piece 30. As shown in Figure 3, the width dimension of the adhesive layer 50 can be understood as the width D shown in Figure 3.

[0103] In the above technical solution, by making the width dimension of the adhesive layer 50 greater than 0 mm and less than or equal to 3 mm, the width dimension of the adhesive layer 50 can be set reasonably, which can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301, thereby reducing the probability of micro-short circuit in the battery cell 20. Moreover, such a setting can minimize or even avoid the negative impact of the adhesive layer 50 on the capacitance of the battery cell 20 and other parameters of the battery cell 20.

[0104] According to some embodiments of the present application, the thickness of the adhesive layer 50 is greater than or equal to 2 μm and less than or equal to 50 μm.

[0105] In the X direction shown in FIG6 , the thickness of the adhesive layer 50 is greater than or equal to 2 μm and less than or equal to 50 μm. In other words, the thickness of the adhesive layer 50 can be any size between greater than or equal to 2 μm and less than or equal to 50 μm. For example, the thickness of the adhesive layer 50 can be, but is not limited to, 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, etc.

[0106] As some embodiments of the present application, the thickness of the adhesive layer 50 arranged on the positive electrode sheet 301 can be greater than or equal to 2μm and less than or equal to 5μm. For example, the thickness of the adhesive layer 50 arranged on the positive electrode sheet 301 can be but not limited to 2μm, 3μm, 4μm, 5μm, etc. Such a setting can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301.

[0107] As some embodiments of the present application, the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 can be greater than or equal to 5μm and less than or equal to 50μm. For example, the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 can be but not limited to 5μm, 10μm, 15μm, 20μm, 30μm, 40μm, 50μm, etc. Such a setting can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301, and the diaphragm 40 and the adhesive layer 50 on the adjacent negative electrode sheet 302 and the negative electrode sheet 302 can jointly define a first cavity structure 60. The first cavity structure 60 can provide sodium or lithium precipitation, which is beneficial to improving the capacity of the battery cell 20 and the reliability of the battery cell 20.

[0108] As some embodiments of the present application, the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 can be greater than or equal to 10 μm and less than or equal to 30 μm. For example, the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 can be but is not limited to 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc.

[0109] In the above technical solution, by making the thickness of the adhesive layer 50 greater than or equal to 2μm and less than or equal to 50μm, the thickness of the adhesive layer 50 can be reasonably set, which can effectively reduce the probability of dendrites free in the electrolyte contacting the positive electrode sheet 301, thereby reducing the probability of micro-short circuit phenomenon in the battery cell 20. In addition, by making the thickness of the adhesive layer 50 arranged on the negative electrode sheet 302 greater than or equal to 5μm and less than or equal to 50μm, the diaphragm 40 and the adhesive layer 50 and the negative electrode sheet 302 on the adjacent negative electrode sheet 302 can jointly define a first cavity structure 60. The first cavity structure 60 can provide sodium or lithium precipitation, which is beneficial to improving the capacity of the battery cell 20 and the reliability of the battery cell 20.

[0110] According to some embodiments of the present application, the adhesive layer 50 is configured as an insulating member having adhesive properties.

[0111] As some embodiments of the present application, the surface of the adhesive layer 50 facing the pole piece 30 is adhesive, and the surface of the adhesive layer 50 facing the diaphragm 40 is also adhesive. This makes it easy to set the adhesive layer 50 and to bond the adhesive layer 50 to the diaphragm 40, thereby facilitating the production of the battery cell 20.

[0112] In addition, the adhesive layer 50 is constructed as an insulating part. For example, the adhesive layer 50 can be constructed as but not limited to a fluorine-free adhesive material or a fluorine-containing adhesive material. By constructing the adhesive layer 50 as an insulating part, the reliability of the battery cell 20 can be improved and the probability of short circuit of the battery cell 20 can be reduced.

[0113] In the above technical solution, by constructing the adhesive layer 50 as an insulating part with adhesive properties, it is convenient to set the adhesive layer 50 and to produce the battery cell 20, which is beneficial to improve the production efficiency of the battery cell 20, and can improve the reliability of the battery cell 20 and reduce the probability of short circuit of the battery cell 20.

[0114] According to some embodiments of the present application, the adhesive layer 50 is made of one of ethylene propylene rubber materials, fluorine-free adhesive materials, and fluorine-containing adhesive materials.

[0115] Ethylene propylene diene monomer (EPDM) rubber materials include, but are not limited to, EPDM materials (a certain amount of EPDM rubber and a certain amount of adhesive resin), EPDM materials, etc. Fluorine-free adhesive materials include, but are not limited to, polyacrylate materials, epoxy resin materials, silicone resin materials, etc. Fluorine-containing adhesive materials include, but are not limited to, polyvinylidene fluoride materials, polytetrafluoroethylene materials, etc.

[0116] Ethylene propylene rubber materials, fluorine-free adhesive materials, and fluorine-containing adhesive materials have adhesive properties. By making the adhesive layer 50 from one of these materials, it is possible to facilitate the provision of the adhesive layer 50 and the bonding of the adhesive layer 50 to the separator 40, thereby facilitating the production of the battery cell 20. Furthermore, ethylene propylene rubber materials, fluorine-free adhesive materials, and fluorine-containing adhesive materials have strong reduction resistance. By making the adhesive layer 50 from one of these materials, fluorine-free adhesive materials, and fluorine-containing adhesive materials, the probability of the adhesive layer 50 being reduced by sodium or lithium can be reduced, thereby improving the reliability of the adhesive layer 50.

[0117] In the above technical solution, by making the adhesive layer 50 from one of an EPDM rubber material, a fluorine-free adhesive material, and a fluorine-containing adhesive material, it is possible to facilitate the provision of the adhesive layer 50 and the bonding of the adhesive layer 50 to the separator 40, thereby facilitating the production of the battery cell 20. Furthermore, the probability of the adhesive layer 50 being reduced by sodium or lithium can be reduced, thereby improving the reliability of the adhesive layer 50.

[0118] According to some embodiments of the present application, as shown in FIG. 5 , the electrode sheet 30 includes a negative electrode sheet 302 , and the separator 40 , the adhesive layer 50 adjacent to the negative electrode sheet 302 , and the negative electrode sheet 302 together define a first cavity structure 60 .

[0119] In some embodiments of the present application, the negative electrode sheet 302 may include a negative electrode current collector 3021 and a negative electrode active material layer 3022. The adhesive layer 50 may be disposed on the negative electrode active material layer 3022. Specifically, the adhesive layer 50 is disposed on the surface of the negative electrode active material layer 3022 disposed on the surface of the negative electrode current collector 3021 opposite the separator 40. The separator 40, the adhesive layer 50 on the adjacent negative electrode sheet 302, and the negative electrode sheet 302 may collectively define a first cavity structure 60.

[0120] In some embodiments of the present application, the negative electrode sheet 302 may include a negative electrode current collector 3021 and a negative electrode active material layer 3022. The negative electrode current collector 3021 may have a first surface 312 and a second surface 313 facing each other. The first surface 312 and the second surface 313 may both be provided with the negative electrode active material layer 3022. The first surface 312 and / or the second surface 313 may be provided with an adhesive layer 50. Along the thickness direction of the electrode sheet 30, the thickness of the adhesive layer 50 is greater than the thickness of the corresponding negative electrode active material layer 3022. The separator 40, the adhesive layer 50 on the adjacent negative electrode sheet 302, and the negative electrode sheet 302 may collectively define a first cavity structure 60.

[0121] The first cavity structure 60 can provide sodium or lithium precipitation (if the battery 100 is a sodium battery 100, the first cavity structure 60 can provide sodium precipitation; if the battery 100 is a lithium battery 100, the first cavity structure 60 can provide lithium precipitation).

[0122] In the above technical solution, the diaphragm 40, the adhesive layer 50 on the adjacent negative electrode sheet 302, and the negative electrode sheet 302 jointly define a first cavity structure 60. The first cavity structure 60 can provide sodium or lithium precipitation (if the battery 100 is a sodium battery 100, the first cavity structure 60 can provide sodium precipitation; if the battery 100 is a lithium battery 100, the first cavity structure 60 can provide lithium precipitation), which is beneficial to improving the capacity of the battery cell 20 and the reliability of the battery cell 20.

[0123] According to some embodiments of the present application, as shown in FIG. 7 , the negative electrode sheet 302 includes a negative electrode current collector 3021 and a negative electrode active material layer 3022 . The negative electrode active material layer 3022 is disposed on the surface of the negative electrode current collector 3021 , and the thickness of the negative electrode active material layer 3022 is greater than or equal to 2 μm and less than or equal to 10 μm.

[0124] As shown in FIG7 , the negative electrode current collector 3021 may have a first surface 312 and a second surface 313 facing each other. A negative electrode active material layer 3022 may be provided on both the first surface 312 and the second surface 313. The negative electrode current collector 3021 may be made of copper, and the negative electrode active material may be carbon, silicon, or the like. In the X direction shown in FIG7 , the thickness of the negative electrode active material layer 3022 is greater than or equal to 2 μm and less than or equal to 10 μm. In other words, the thickness of the negative electrode active material layer 3022 may be any dimension between greater than or equal to 2 μm and less than or equal to 10 μm. For example, the thickness of the negative electrode active material layer 3022 may be, but is not limited to, 2 μm, 4 μm, 6 μm, 8 μm, or 10 μm. This configuration ensures a reasonable thickness for the negative electrode active material layer 3022, which helps improve the reliability of the battery cell 20.

[0125] As some embodiments of the present application, the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 can be greater than or equal to 5 μm and less than or equal to 50 μm. For example, the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 can be but is not limited to 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, etc. By making the thickness of the negative electrode active material layer 3022 greater than or equal to 2 μm and less than or equal to 10 μm, and making the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 greater than or equal to 5 μm and less than or equal to 50 μm, the thickness relationship between the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 and the thickness of the negative electrode active material layer 3022 can be made reasonable, and the first cavity structure 60 can have a reasonable size along the thickness direction of the electrode sheet 30 to provide sodium or lithium precipitation (if the battery 100 is a sodium battery 100, the first cavity structure 60 can provide sodium precipitation, and if the battery 100 is a lithium battery 100, the first cavity structure 60 can provide lithium precipitation).

[0126] In the above technical solution, by ensuring that the thickness of the negative electrode active material layer 3022 is greater than or equal to 2 μm and less than or equal to 10 μm, the thickness of the negative electrode active material layer 3022 can be optimized, which is beneficial for improving the reliability of the battery cell 20. Furthermore, by ensuring that the thickness of the negative electrode active material layer 3022 is greater than or equal to 2 μm and less than or equal to 10 μm, and by ensuring that the thickness of the adhesive layer 50 provided on the negative electrode sheet 302 is greater than or equal to 5 μm and less than or equal to 50 μm, the thickness relationship between the adhesive layer 50 provided on the negative electrode sheet 302 and the thickness of the negative electrode active material layer 3022 can be optimized, thereby ensuring that the first cavity structure 60 has a reasonable size along the thickness direction of the electrode sheet 30 to allow for sodium or lithium precipitation (if the battery 100 is a sodium battery 100, the first cavity structure 60 can provide for sodium precipitation, and if the battery 100 is a lithium battery 100, the first cavity structure 60 can provide for lithium precipitation).

[0127] According to some embodiments of the present application, as shown in Figure 4, the electrode sheet 30 also includes a positive electrode sheet 301, and the diaphragm 40 is arranged between the negative electrode sheet 302 and the positive electrode sheet 301. The diaphragm 40 and the adhesive layer 50 on the adjacent positive electrode sheet 301 and the positive electrode sheet 301 jointly define a second cavity structure 70.

[0128] The negative electrode sheet 302 , the positive electrode sheet 301 and the separator 40 may be assembled together to form a wound electrode assembly or a stacked electrode assembly.

[0129] In some embodiments of the present application, the positive electrode sheet 301 may include a positive electrode current collector 3011 and a positive electrode active material layer 3012. The adhesive layer 50 may be disposed on the positive electrode active material layer 3012. Specifically, the adhesive layer 50 is disposed on the surface of the positive electrode active material layer 3012 disposed on the surface of the positive electrode current collector 3011 opposite the separator 40. The separator 40, the adhesive layer 50 on the adjacent positive electrode sheet 301, and the positive electrode sheet 301 collectively define a second cavity structure 70.

[0130] In some embodiments of the present application, the positive electrode sheet 301 may include a positive electrode current collector 3011 and a positive electrode active material layer 3012. The positive electrode active material layer 3012 may be provided on both opposing surfaces of the positive electrode sheet 301, and an adhesive layer 50 may be provided on at least one of the opposing surfaces of the positive electrode sheet 301. Along the thickness direction of the electrode sheet 30, the thickness of the adhesive layer 50 is greater than the thickness of the corresponding positive electrode active material layer 3012. The separator 40, the adhesive layer 50 on the adjacent positive electrode sheet 301, and the positive electrode sheet 301 together define a second cavity structure 70.

[0131] It should be explained that when sodium or lithium is precipitated in the first cavity structure 60, the diaphragm 40 will protrude toward the positive electrode sheet 301. By making the diaphragm 40 and the adhesive layer 50 on the adjacent positive electrode sheet 301 and the positive electrode sheet 301 jointly define the second cavity structure 70, space can be reserved for the diaphragm 40 to protrude toward the positive electrode sheet 301. In other words, by making the diaphragm 40 and the adhesive layer 50 on the adjacent positive electrode sheet 301 and the positive electrode sheet 301 jointly define the second cavity structure 70, the diaphragm 40 that protrudes toward the positive electrode sheet 301 can be avoided.

[0132] In the above technical solution, by making the diaphragm 40 and the adhesive layer 50 on the adjacent positive electrode sheet 301 and the positive electrode sheet 301 jointly define the second cavity structure 70, space can be reserved for the diaphragm 40 to protrude toward the positive electrode sheet 301, and the diaphragm 40 protruding toward the positive electrode sheet 301 can be avoided, which is beneficial to improving the reliability of the battery cell 20.

[0133] According to some embodiments of the present application, the battery cell 20 is a sodium metal battery.

[0134] It is understandable that metallic sodium has more active chemical properties than metallic lithium. Under a quasi-zero electrochemical field, sodium dendrites are extremely prone to self-dissolution in the electrolyte. Moreover, under the action of an external mechanical field, ultrasonic oscillation to generate cavitation, or mechanical shaking at a certain frequency, the dissolution of dendrites in the electrolyte can be aggravated. The ablation of sodium dendrites will further aggravate the polarization of the battery, and the free dendrites will be free to the edge of the positive electrode sheet 301 and contact the positive electrode sheet 301, thereby causing a micro-short circuit in the battery cell 20.

[0135] As some embodiments of the present application, the active material of the active material layer 32 of the battery cell 20 of the sodium metal battery may be, but is not limited to, sodium iron phosphate, sodium iron pyrophosphate, sodium vanadium phosphate, and the like.

[0136] By providing an adhesive layer 50 on the surfaces opposite to the electrode 30 and the diaphragm 40 of the sodium metal battery, and providing the adhesive layer 50 at the edge of the electrode 30, and bonding the adhesive layer 50 to the diaphragm 40, the probability of sodium dendrites free in the electrolyte contacting the positive electrode 301 can be reduced.

[0137] As some embodiments of the present application, the battery cell 20 may also be a lithium battery.

[0138] In the above technical solution, by providing an adhesive layer 50 on the surface opposite to the electrode 30 and the diaphragm 40 of the sodium metal battery, and providing the adhesive layer 50 at the edge of the electrode 30, and bonding the adhesive layer 50 to the diaphragm 40, the probability of sodium dendrites free in the electrolyte contacting the positive electrode 301 can be reduced, which is beneficial to extending the service life of the sodium metal battery.

[0139] In some embodiments of the present application, the high-temperature static period after the battery cell 20 is injected with liquid needs to be extended to reduce or even avoid the effect of the adhesive layer 50 on the wetting.

[0140] According to some embodiments of the present application, the present application further provides a battery 100 , which includes the battery cell 20 in the above embodiment.

[0141] According to some embodiments of the present application, the present application further provides an electrical device, which includes the battery 100 in the above embodiment, and the battery 100 is used to provide electrical energy to the electrical device.

[0142] The power-consuming device may be any of the aforementioned devices or systems using the battery 100 .

[0143] According to some embodiments of the present application, the present application further provides an energy storage device, which includes the battery 100 in the above embodiment.

[0144] According to some embodiments of the present application, referring to FIG. 3 to FIG. 9 , the present application provides a battery cell 20 , which includes a diaphragm 40 , a pole piece 30 and an adhesive layer 50 . The adhesive layer 50 is provided at the edge of the pole piece 30 and is bonded to the diaphragm 40 .

[0145] The electrode sheet 30 includes a negative electrode sheet 302 and a positive electrode sheet 301. The positive electrode sheet 301 may include a positive electrode current collector 3011 and a positive electrode active material layer 3012. The positive electrode current collector 3011 may have a first surface 312 and a second surface 313 relative to each other. The first surface 312 and the second surface 313 may both be provided with the positive electrode active material layer 3012. The negative electrode sheet 302 may include a negative electrode current collector 3021 and a negative electrode active material layer 3022. The negative electrode current collector 3021 may have a first surface 312 and a second surface 313 relative to each other. The first surface 312 and the second surface 313 may both be provided with the negative electrode active material layer 3022.

[0146] The adhesive layer 50 can be provided on the active material layer 32. Specifically, the adhesive layer 50 is provided on the surface of the active material layer 32 facing away from the current collector 31. The separator 40, the adhesive layer 50 on the adjacent negative electrode sheet 302, and the negative electrode sheet 302 can jointly define a first cavity structure 60. The first cavity structure 60 can provide for the precipitation of sodium or lithium (if the battery 100 is a sodium battery 100, the first cavity structure 60 can provide for the precipitation of sodium; if the battery 100 is a lithium battery 100, the first cavity structure 60 can provide for the precipitation of lithium), thereby facilitating the improvement of the capacity of the battery cell 20 and the reliability of the battery cell 20.

[0147] The diaphragm 40, the adhesive layer 50 on the adjacent positive electrode sheet 301, and the positive electrode sheet 301 together define a second cavity structure 70. The second cavity structure 70 can reserve space for the diaphragm 40 to protrude toward the positive electrode sheet 301, and can avoid the diaphragm 40 protruding toward the positive electrode sheet 301, thereby helping to improve the reliability of the battery cell 20.

[0148] By setting the adhesive layer 50 at the edge of the electrode 30 and bonding the adhesive layer 50 to the diaphragm 40, the probability of dendrites free in the electrolyte contacting the positive electrode 301 can be reduced, thereby reducing the probability of micro-short circuit phenomenon in the battery cell 20, which is beneficial to extending the service life of the battery cell 20.

[0149] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0150] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: Diaphragms and pole pieces; An adhesive layer is provided at the edge of the pole piece and is bonded to the diaphragm.

2. The battery cell according to claim 1, characterized in that: The bonding layer is annular and is arranged along the edge of the pole piece.

3. The battery cell according to claim 1 or 2, characterized in that: The pole piece comprises: a current collector and an active material layer, the current collector has a first surface and a second surface opposite to each other, the first surface and the second surface are both provided with the active material layer, and the adhesive layer is provided on the active material layer.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The pole piece includes: a current collector and an active material layer, the current collector has a first surface and a second surface relative to each other, the first surface and the second surface are both provided with the active material layer, the first surface and / or the second surface are provided with the adhesive layer, and the adhesive layer is adjacent to the corresponding active material layer.

5. The battery cell according to claim 4, characterized in that: The adhesive layer is disposed around the active material layer.

6. The battery cell according to claim 4 or 5, characterized in that: Along the thickness direction of the pole piece, the thickness dimension of the bonding layer is greater than or equal to the thickness dimension of the corresponding active material layer.

7. The battery cell according to any one of claims 1 to 6, characterized in that: Along a first direction perpendicular to the thickness direction of the pole piece, a width dimension of the adhesive layer is greater than 0 mm and less than or equal to 3 mm.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The thickness of the adhesive layer is greater than or equal to 2 μm and less than or equal to 50 μm.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The adhesive layer is configured as an insulating member having adhesiveness.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The adhesive layer is made of one of ethylene propylene rubber materials, fluorine-free adhesive materials and fluorine-containing adhesive materials.

11. The battery cell according to any one of claims 1 to 10, characterized in that: The electrode sheet includes a negative electrode sheet, and the separator, the adhesive layer adjacent to the negative electrode sheet, and the negative electrode sheet together define a first cavity structure.

12. The battery cell according to claim 11, characterized in that: The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is arranged on the surface of the negative electrode current collector, and the thickness of the negative electrode active material layer is greater than or equal to 2 μm and less than or equal to 10 μm.

13. The battery cell according to claim 11 or 12, characterized in that: The electrode sheet further includes a positive electrode sheet, the separator is disposed between the negative electrode sheet and the positive electrode sheet, and the separator, the adhesive layer adjacent to the positive electrode sheet, and the positive electrode sheet together define a second cavity structure.

14. The battery cell according to any one of claims 1 to 13, characterized in that: The battery cell is a sodium metal battery.

15. A battery, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 14.

16. An electrical device, characterized in that: Comprising a battery according to claim 15.

17. An energy storage device, characterized in that: Comprising a battery according to claim 15.

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