CN218586129U - Battery cell, battery and power consumption device - Google Patents

Abstract

The application provides a battery monomer, battery and power consumption device, above-mentioned battery monomer include casing and electrode subassembly, and casing and electrode subassembly all are prismatic structure, and electrode subassembly holds in the casing, and each lateral surface of electrode subassembly and each medial surface one-to-one just to and parallel arrangement of casing. The battery monomer that this application embodiment provided is through all setting up casing and electrode subassembly into prismatic structure to each medial surface one-to-one just and parallel arrangement of each lateral surface that makes electrode subassembly and casing, so, electrode subassembly can utilize the inner space of casing according to practical application needs furthest, thereby has effectively increased electrode subassembly's volume, has effectively promoted the free energy of battery.

Description

Battery cell, battery and power consumption device

Technical Field

The application belongs to the technical field of batteries, and more particularly relates to a single battery, a battery and an electric device.

Background

At present, the battery cell with a prismatic structure gradually appears on the market, the shell of the battery cell is in a prismatic structure, the electrode assembly of the battery cell is accommodated in the shell, and the energy of the battery cell is reduced due to the fact that more space exists between the inner peripheral side of the shell and the outer peripheral side of the electrode assembly.

SUMMERY OF THE UTILITY MODEL

An embodiment of the present application aims to provide a battery cell, a battery and an electric device, so as to solve a technical problem that in the related art, the energy of the battery cell is reduced due to the fact that a large space exists between the inner circumference side of a casing and the outer circumference side of an electrode assembly in the battery cell with a prism structure.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions: the utility model provides a battery monomer, includes casing and electrode subassembly, the casing with electrode subassembly all is prismatic structure, electrode subassembly hold in the casing, each lateral surface of electrode subassembly with each medial surface one-to-one just to and parallel arrangement of casing.

The battery monomer that this application embodiment provided has following beneficial effect at least: the battery monomer that this application embodiment provided is through all setting up casing and electrode subassembly into prismatic structure to each medial surface one-to-one just and parallel arrangement of each lateral surface that makes electrode subassembly and casing, so, electrode subassembly can utilize the inner space of casing according to practical application needs furthest, thereby has effectively increased electrode subassembly's volume, has effectively promoted the free energy of battery.

In some embodiments of the present application, the battery cell further includes an elastic restraining member wrapping an outer circumferential side of the electrode assembly.

Through adopting above-mentioned technical scheme, under the elastic action of elasticity constraint piece, effectively cushioned electrode subassembly at the produced bulging force of charge-discharge in-process to effectively reduced electrode subassembly's expansion amplitude, effectively improved the condition that leads to battery monomer inflation deformation because of electrode subassembly inflation back and casing extrude each other, thereby effectively promoted above-mentioned battery monomer's safety in utilization.

In some embodiments of the present application, the elastic restraint is a restraining band that is provided around an outer circumferential side of the electrode assembly.

Through adopting above-mentioned technical scheme, the binding area can effectively cushion electrode subassembly produced bulging force at the charge-discharge in-process, has effectively reduced electrode subassembly's expansion range to improve the condition of battery monomer inflation deformation, effectively promoted above-mentioned battery monomer's safety in utilization.

In some embodiments of the present application, the number of the circumference of the restraining band around the outer circumferential side of the electrode assembly is 1 to 5 weeks.

By adopting the technical scheme, the binding force of the binding belt on the electrode assembly is effectively ensured, so that the expansion amplitude of the electrode assembly is effectively reduced.

In some embodiments of the present application, the elastic tie down is an expanding glue tie down.

Through adopting above-mentioned technical scheme, the restriction piece is glued in the inflation can effectively cushion electrode subassembly produced bulging force at the charge-discharge in-process, has effectively reduced electrode subassembly's expansion range to improve the condition of battery monomer inflation deformation, effectively promoted above-mentioned battery monomer's safety in utilization.

In some embodiments of the present application, the electrode assembly includes a separator and a pole piece, the separator has a tail section, and the tail section is wound on the outer periphery side of the pole piece so that the tail section covers the outer periphery side of the pole piece.

Through adopting above-mentioned technical scheme, can realize tying electrode subassembly, effectively reduce electrode subassembly's expansion amplitude to improve the condition of battery monomer inflation deformation, effectively promoted above-mentioned battery monomer's safety in utilization.

In some embodiments of the present application, the number of the circumference of the ending section around the outer circumference side of the pole piece is 1 to 5.

Through adopting above-mentioned technical scheme, effectively guaranteed the binding power of diaphragm to the pole piece, reduced electrode subassembly's expansion range more effectively to further improve the condition of battery monomer inflation deformation, promoted above-mentioned battery monomer's safety in utilization more effectively.

In some embodiments of the present application, the case and the electrode assembly each have a regular prismatic structure.

Through adopting above-mentioned technical scheme, can make electrode subassembly can utilize the inner space of casing more fully to the free energy of battery has further been promoted.

In some embodiments of the present application, the electrode assembly includes a pole piece having a first winding start end and a first winding end, the first winding start end and/or the first winding end being located on an angular bisector of an angle of the case.

By adopting the technical scheme, the situation that the corresponding part of the electrode assembly is extruded by the first winding starting end and/or the first winding tail end of the pole piece due to the fact that the side wall of the shell extrudes the first winding starting end and/or the first winding tail end of the pole piece after the electrode assembly expands can be effectively avoided, and therefore the electrode assembly is prevented from being damaged due to local stress, and the service life of a battery cell is effectively prolonged.

In some embodiments of the present application, the electrode assembly includes a separator having a second winding start end and a second winding end, and the second winding start end and/or the second winding end are located on an angular bisector of an angle of the case.

By adopting the technical scheme, the phenomenon that the corresponding part of the electrode assembly is extruded by the second winding starting end and/or the second winding tail end of the diaphragm due to the fact that the second winding starting end and/or the second winding tail end of the diaphragm are/is extruded by the side wall of the shell after the electrode assembly expands can be effectively avoided, so that the electrode assembly is prevented from being damaged due to local stress, and the service life of the battery cell is effectively prolonged.

In some embodiments of the present application, the corners of the electrode assembly are rounded.

By adopting the technical scheme, a gap is formed between the edge of the electrode assembly and the edge of the shell, so that the situation that the shell extrudes the first winding starting end and/or the first winding tail end of the pole piece or extrudes the second winding starting end and/or the second winding tail end of the diaphragm after the electrode assembly expands is more effectively avoided, the electrode assembly is more effectively prevented from being damaged due to local stress, and the service life of a battery cell is further prolonged.

In some embodiments of the present application, the electrode assembly includes a pole piece having a first winding start end and a first winding end, and a separator having a second winding start end and a second winding end, the first winding start end and the first winding end corresponding one-to-one to adjacent two sidewalls of the case in a direction around a winding axis of the electrode assembly, the second winding start end and the second winding end corresponding one-to-one to adjacent two sidewalls of the case.

By adopting the technical scheme, the number of the pole piece layers and the number of the diaphragm layers corresponding to each outer side face of the electrode assembly are the same, on one hand, the electrode assembly can more fully utilize the inner space of the shell, and thus the energy of a battery monomer is further improved; on the other hand, when the electrode assembly is pressed against the case after expansion, the pressing force applied to the electrode assembly is uniform in a direction around the winding axis of the electrode assembly, thereby ensuring uniform force applied to the inside of the electrode assembly.

In some embodiments of the present application, the electrode assembly includes a pole piece having a first winding start end and a first winding end, and a separator having a second winding start end and a second winding end, the first winding start end and the first winding end being located on a bisector of the same corner of the case in a direction around a winding axis of the electrode assembly, the second winding start end and the second winding end being located on a bisector of the same corner of the case.

Through adopting above-mentioned technical scheme, in the direction of the axis is rolled up around electrode subassembly, electrode subassembly thickness everywhere is the same, not only can fully utilize the inner space of casing to further promoted the free energy of battery, the extrusion force that electrode subassembly received is more even moreover, thereby effectively guarantees that electrode subassembly's inside atress is even.

In order to achieve the above object, an embodiment of the present application further provides a battery, which includes the battery cell described in any of the above embodiments.

Since the battery adopts the single battery described in any of the above embodiments, the battery at least has the beneficial effects of the above embodiments, and details are not repeated herein.

In order to achieve the above object, an electric device is further provided in an embodiment of the present application, and includes the above battery.

Since the battery according to any of the above embodiments is adopted in the electric device, at least the beneficial effects of the above embodiments are achieved, and no further description is given here.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

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

fig. 2 is a schematic structural diagram of a battery provided in an embodiment of the present application;

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

fig. 4 is a schematic structural diagram of a battery cell according to another embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a battery cell according to another embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of a battery cell according to yet another embodiment of the present disclosure.

Wherein, in the figures, the respective reference numerals:

1000. a vehicle;

100. a battery;

10. a box body; 11. an accommodating space;

20. a battery cell; 21. a housing; 211. an angular bisector plane; 22. an electrode assembly; 221. pole pieces; 2211. a first winding start end; 2212. a first winding end; 222. a diaphragm; 2221. a second winding start end; 2222. a second winding end; 23. a resilient tie;

200. a controller;

300. a motor.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

Furthermore, the terms "first", "second", "third", "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", "third", "fourth" may explicitly or implicitly include one or more of the features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

The single battery cell refers to a minimum electric energy storage unit comprising a pole piece, a diaphragm and a shell, wherein the pole piece and the diaphragm are manufactured into an electrode assembly by adopting a winding process or a stacking process, and the winding process is simple and easy to realize, so that the winding process is more widely applied compared with the stacking process. At present, a battery cell having a prismatic structure is gradually appeared on the market, and a case of the battery cell has a prismatic structure, and an electrode assembly is accommodated in the case.

The inventors of the present application have noticed that since the case of the battery cell has a prismatic structure, after the electrode assembly is mounted in the case, there is much space between the inner circumferential side of the case and the outer circumferential side of the electrode assembly, in other words, the inner space of the case is not fully utilized, so that the energy of the battery cell having the prismatic structure is to be increased.

In order to improve the energy of the battery monomer with the prismatic structure, the inventor of the application designs the battery monomer through deep research, the shell and the electrode assembly of the battery monomer are both in the prismatic structure, and the outer side faces of the electrode assembly and the inner side faces of the shell are arranged right opposite to each other and in parallel. Therefore, the electrode assembly can utilize the inner space of the shell to the maximum extent according to the actual application requirement, so that the volume of the electrode assembly is effectively increased, and the energy of the battery cell is effectively improved.

The battery cell disclosed in the embodiment of the present application may be used in various power consumption devices using a battery as a power source or in various energy storage systems using a battery as an energy storage element. The powered device may be, but is not limited to, a cell phone, tablet, laptop, electronic toy, electric tool, battery car, electric car, ship, spacecraft, and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

For convenience of description, the following embodiments take an example in which a power consuming apparatus according to an embodiment of the present application is a vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to an embodiment of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or an extended range automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, and for example, the battery 100 may serve as an operation power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

In some embodiments of the present application, the battery 100 may not only serve as an operating power source of the vehicle 1000, but also serve as a driving power source of the vehicle 1000, instead of or in part instead of fuel or natural gas, to provide driving power for the vehicle 1000.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a battery 100 according to an embodiment of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide the accommodating space 11 for the battery cell 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion and a second portion that cover each other, and the first portion and the second portion together define a receiving space 11 for receiving the battery cell 20. The second part can be a hollow structure with one open end, the first part can be a plate-shaped structure, and the first part covers the open side of the second part, so that the first part and the second part jointly define the accommodating space 11; the first part and the second part can be hollow structures with one side opened, and the opening side of the first part is covered on the opening side of the second part. Of course, the first and second portions forming the housing 10 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In the battery 100, there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the plurality of battery cells 20. The plurality of battery cells 20 may be directly connected in series or in parallel or in series-parallel, and the whole body formed by the plurality of battery cells 20 is accommodated in the case 10. Of course, the battery 100 may also be formed by connecting a plurality of battery cells 20 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and accommodating the whole in the case 10. The battery 100 may also include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a battery cell 20 according to an embodiment of the present disclosure. The battery cell 20 includes a case 21 and an electrode assembly 22, and the electrode assembly 22 is accommodated in the case 21.

The case 21 is a component for providing an internal environment of the battery cell 20, wherein the internal environment may be used to house the electrode assembly 22, the electrolyte, and other components. The housing 21 may be a separate component, and an opening may be formed in the housing 21, and an end cap may be disposed at the opening to form an internal environment of the battery cell 20. In other embodiments, the housing 21 and the end cap may be integrally disposed, and specifically, the housing 21 and the end cap may form a common connecting surface before other components are inserted into the housing, and when it is necessary to enclose the inside of the housing 21, the end cap covers the housing 21. Alternatively, the material of the housing 21 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and is not limited in particular.

The end cap (not shown) refers to a member that covers the opening of the case 21 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end caps may be adapted to the shape of the housing 21 to fit the housing 21, i.e. the end caps have a polygonal configuration. The end cap may be provided with functional components such as electrode terminals. The electrode terminals may be used to electrically connect with the electrode assembly 22 for outputting or inputting electric power of the battery cell 20. In some embodiments, a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value may be further disposed on the end cap. Alternatively, the end cap may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap is not easily deformed when being extruded and collided, and thus the single battery 20 may have a higher structural strength and the safety performance may be improved. Of course, the material of the end cap includes various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and is not limited herein. In some embodiments, insulation may also be provided on the inside of the end caps, which may be used to isolate the electrical connection components within the housing 21 from the end caps to reduce the risk of short circuits. Alternatively, the insulator may be plastic, rubber, or the like.

The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. The electrode assembly 22 is mainly formed by laminating and winding a pole piece 221 and a separator 222. Specifically, the electrode sheet 221 is divided into a positive electrode sheet and a negative electrode sheet, the separator 222 is divided into a first separator and a second separator, and the first separator, the negative electrode sheet, the second separator and the positive electrode sheet are stacked and wound to form the electrode assembly 22. The portions of the positive and negative electrode tabs having the active material constitute the body portions of the electrode assembly 22, and the portions of the positive and negative electrode tabs having no active material each constitute a tab. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charge and discharge of the battery cell 20, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop. The first diaphragm is used for insulating and separating the negative plate from the shell 21, and the second diaphragm is used for insulating and separating the positive plate from the negative plate.

Referring to fig. 3, the case 21 and the electrode assembly 22 are both in a prism structure, the electrode assembly 22 is accommodated in the case 21, and the outer sides of the electrode assembly 22 are opposite to and parallel to the inner sides of the case 21.

The prism refers to a geometric body in which the top surface and the bottom surface are parallel to each other, each side surface is quadrilateral, and the common edges of every two adjacent side surfaces are parallel to each other. The prism structure includes, but is not limited to, a triangular prism structure, a quadrangular prism structure, a pentagonal prism structure, and a hexagonal prism structure. In the present embodiment, as shown in fig. 3, the housing 21 has a hexagonal prism structure.

The fact that the outer sides of electrode assembly 22 are opposite to and parallel to the inner sides of case 21 means that the number of the outer sides of electrode assembly 22 is the same as the number of the inner sides of case 21, each outer side of electrode assembly 22 is opposite to and parallel to one inner side of case 21, the outer sides of electrode assembly 22 and the corresponding inner sides of case 21 are spaced from each other, so that a gap is formed between electrode assembly 22 and case 21, and the size of the gap can be set according to practical application requirements, so that the gap can serve as an expansion buffer space between electrode assembly 22 and case 21 when electrode assembly 22 expands.

The battery cell 20 that this application embodiment provided is through all setting up casing 21 and electrode assembly 22 to prismatic structure to make each lateral surface of electrode assembly 22 just to and parallel arrangement one by one with each medial surface of casing 21, so, electrode assembly 22 can utilize the inner space of casing 21 according to actual application needs furthest, thereby has effectively increased electrode assembly 22's volume, has effectively promoted battery cell 20's energy.

In addition, by setting the housing 21 to be a prism structure, when a plurality of battery cells 20 with the prism structure are accommodated in the box 10 and arranged to form the battery 100 in a group, the side walls of two adjacent battery cells 20 can be attached or attached in parallel, so that the gap between two adjacent battery cells 20 is small, and the energy density of the battery 100 is effectively improved.

In some embodiments of the present application, referring to fig. 5 and fig. 6, the battery cell 20 further includes an elastic binding member 23, and the elastic binding member 23 is wrapped around the outer circumference of the electrode assembly 22.

The elastic binder 23 is a member that is elastically deformed by an external force and serves to restrict the form of the electrode assembly 22. Optionally, the material of the elastic binding member 23 includes, but is not limited to, acrylic adhesive, silicone pressure sensitive adhesive, rubber pressure sensitive adhesive, expansion glue binding member, etc., and is not limited herein.

The outer peripheral side of the electrode assembly 22 refers to a portion of the electrode assembly 22 that is wound around itself around the axis and faces the inner peripheral wall of the case 21.

The elastic binding member 23 is wrapped around the outer circumferential side of the electrode assembly 22 means that the elastic binding member 23 surrounds the outer circumferential side of the electrode assembly 22 to define a restriction space in which the electrode assembly 22 is received to bind the electrode assembly 22, thereby defining the morphology of the electrode assembly 22 to some extent.

By adopting the technical scheme, under the elastic action of the elastic binding piece 23, the expansion force generated by the electrode assembly 22 in the charging and discharging process is effectively buffered, so that the expansion amplitude of the electrode assembly 22 is effectively reduced, the condition that the battery monomer 20 expands and deforms due to mutual extrusion of the expanded electrode assembly 22 and the shell 21 is effectively improved, and the use safety of the battery monomer 20 is effectively improved.

In some embodiments of the present application, referring to fig. 5, the elastic binding member 23 is a binding band, and the binding band is wound around the outer circumferential side of the electrode assembly 22.

The material of the binding band includes, but is not limited to, acrylic adhesive, silicone pressure-sensitive adhesive, rubber pressure-sensitive adhesive, etc., and is not limited specifically herein. The width of the binding band (i.e., the dimension of the binding band in the direction of the winding axis of the electrode assembly 22) corresponds to the height of the electrode assembly 22 (i.e., the dimension of the electrode assembly 22 in the direction of the winding axis thereof). Of course, the width of the binding band may be smaller than the height of the electrode assembly 22, and may be slightly larger than the height of the electrode assembly 22.

The binding band is wound around the outer circumferential side of the electrode assembly 22 means that a first end of the binding band is fixed to the outer circumferential side of the electrode assembly 22 and a second end of the binding band moves around the winding axis of the electrode assembly 22 so that both ends of the binding band are closed at least to each other, thereby forming the above-mentioned restriction space.

Through adopting above-mentioned technical scheme, the constraint area can effectively cushion electrode subassembly 22 at the produced bulging force of charge-discharge in-process, has effectively reduced electrode subassembly 22's expansion amplitude to improve the condition of battery monomer 20 inflation deformation, effectively promoted above-mentioned battery monomer 20's safety in utilization.

Alternatively, the number of the circumferential sides of the restraining band around the outer circumferential side of the electrode assembly 22 is 1 to 5 weeks.

The number of the cycles of the binding band around the electrode assembly 22 can be determined according to the actual application requirement, and specifically can be 1 cycle, 3 cycles, 5 cycles, and the like. When the number of the circumferences of the restraining band around the outer circumference of the electrode assembly 22 is 1, the first end and the second end of the restraining band are butted against each other, and when the number of the circumferences of the restraining band around the outer circumference of the electrode assembly 22 is more than 1, the second end of the restraining band moves around the winding axis of the electrode assembly 22 and then moves for a distance after passing the first end of the restraining band, and then is fixed at any band surface position of the restraining band away from the electrode assembly 22.

By adopting the technical scheme, the binding force of the binding belt on the electrode assembly 22 is effectively ensured, so that the expansion amplitude of the electrode assembly 22 is effectively reduced.

In some embodiments of the present application, referring to fig. 6, the elastic restraint 23 is an expanding glue restraint.

The swelling glue tether refers to a member that is made of swelling glue and serves to restrict the form of the electrode assembly 22. Specifically, when assembling the battery cell 20, the expansion glue binding member may be disposed on the outer circumferential side of the electrode assembly 22, and then the electrode assembly 22 and the expansion glue binding member may be assembled into the case 21 as a whole; it is also possible to first mount electrode assembly 22 in case 21 and then dispose the expansion glue binder between electrode assembly 22 and case 21. After the assembly operation is completed, an electrolyte is injected into the case 21, and the swelling glue binder is capable of undergoing a chemical reaction upon contact with the electrolyte to gradually swell, so that the swelling glue binder is filled between the outer circumferential side of the electrode assembly 22 and the inner wall of the case 21 to bind the electrode assembly 22, thereby defining the morphology of the electrode assembly 22 to some extent. It is understood that the expanded jelly-roll binder has excellent elasticity after expansion, and can effectively buffer the expansion force generated from the electrode assembly 22 during the charge and discharge processes.

Through adopting above-mentioned technical scheme, the produced bulging force of electrode subassembly 22 in charge-discharge process can effectively be cushioned to the restriction piece of inflation glue, has effectively reduced electrode subassembly 22's expansion amplitude to improve the condition of battery monomer 20 inflation deformation, effectively promoted above-mentioned battery monomer 20's safety in utilization.

In some embodiments of the present application, referring to fig. 3 and 4, the electrode assembly 22 includes a diaphragm 222 and a pole piece 221, the diaphragm 222 has a closing section, and the closing section is disposed around an outer circumference of the pole piece 221 so that the closing section covers the outer circumference of the pole piece 221.

The finishing section of the separator 222 refers to a portion of the separator 222 for fixing to the outer circumferential side of the electrode assembly 22 after the winding operation of the electrode assembly 22 is completed.

The outer peripheral side of the pole piece 221 refers to a side portion of a wound body formed by winding the pole piece 221 around the winding axis of the electrode assembly 22, which is farthest from the winding axis of the electrode assembly 22.

The step of wrapping the end section around the outer peripheral side of the pole piece 221 means that the end section is wound for the first time and then continues to be wound until the end section is wound for at least the second time to the winding end position of the pole piece 221, in other words, the end section surrounds the winding body formed by winding the pole piece 221 for at least 1 week, and then is fixed on the outer peripheral side of the electrode assembly 22 to wrap the winding body formed by winding the pole piece 221, so that the binding effect on the winding body formed by winding the pole piece 221 is achieved.

By adopting the technical scheme, the electrode assembly 22 can be bound, the expansion amplitude of the electrode assembly 22 is effectively reduced, the expansion deformation condition of the battery monomer 20 is improved, and the use safety of the battery monomer 20 is effectively improved.

Alternatively, the number of the circumference of the ending section around the outer circumferential side of the pole piece 221 is 1 to 5.

The number of the circumference of the ending section around the outer circumference of the pole piece 221 may be determined according to the actual application requirement, and specifically may be 1 circumference, 3 circumferences, 5 circumferences, and the like.

By adopting the technical scheme, the binding force of the diaphragm 222 on the pole piece 221 is effectively ensured, and the expansion amplitude of the electrode assembly 22 is more effectively reduced, so that the expansion deformation of the battery monomer 20 is further improved, and the use safety of the battery monomer 20 is more effectively improved.

In some embodiments of the present application, the case 21 and the electrode assembly 22 each have a regular prism structure.

Regular prisms refer to regular polygons, which include but are not limited to regular triangles, squares, and hexagons, both of which are the top and bottom surfaces. Since the respective outer sides of the electrode assemblies 22 are disposed opposite to and parallel to the respective inner sides of the case 21, that is, the case 21 and the electrode assemblies 22 have the same regular prism structure, for example, the case 21 and the electrode assemblies 22 each have a regular hexagonal prism structure.

As described above, in general, the outer side of electrode assembly 22 and the inner side of case 21 are spaced apart from each other to form a gap between electrode assembly 22 and case 21, and the gap is set according to practical requirements so that the gap can serve as an expansion buffer space between electrode assembly 22 and case 21 when electrode assembly 22 expands, and after electrode assembly 22 expands, the outer sides of electrode assembly 22 and the inner sides of case 21 can be attached to each other one by one, in other words, electrode assembly 22 can completely fill the inner space of case 21 after electrode assembly 22 expands.

By adopting the above technical solution, the electrode assembly 22 can more fully utilize the inner space of the case 21, thereby further improving the energy of the battery cell 20.

In addition, after the electrode assembly 22 expands, the outer side surfaces of the electrode assembly 22 and the inner side surfaces of the casing 21 are attached one by one, so that the electrode piece 221 interface of the electrode assembly 22 can be improved, and gas generated by side reaction of the electrode assembly 22 can be exhausted out of the electrode assembly 22 under the extrusion action of the casing 21 on the electrode assembly 22, so that the charging and discharging performance of the battery cell 20 is effectively improved.

In some embodiments of the present application, referring to fig. 3, the electrode assembly 22 includes a pole piece 221, the pole piece 221 has a first winding start 2211, and the first winding start 2211 is located on the angular bisector 211 of the corner of the housing 21.

In other embodiments of the present application, pole piece 221 has a first winding end 2212, and first winding end 2212 is located on angular bisector 211 of housing 21.

In still other embodiments of the present application, pole piece 221 has first winding start end 2211 and first winding end 2212, and first winding start end 2211 and first winding end 2212 are both located on angular bisector 211 of housing 21.

First winding start end 2211 of pole piece 221 refers to the end of pole piece 221 that is inside electrode assembly 22, i.e., the end of pole piece 221 that is closest to the winding axis of electrode assembly 22, and first winding end 2212 of pole piece 221 refers to the end that is outside electrode assembly 22, i.e., the end of pole piece 221 that is farthest from the winding axis of electrode assembly 22.

The angular bisector 211 of the corner of the case 21 is a plane that can divide the corner of the case 21 into two equal-angle portions, and since the electrode assembly 22 and the case 21 have the same regular prism structure, the angular bisector 211 of the corner of the case 21 passes through the central axis of the case 21.

It should be noted that the pole piece 221 is divided into the positive pole piece 221 and the negative pole piece 221, and the first winding start end 2211 of the positive pole piece 221 and the first winding start end 2211 of the negative pole piece 221 are arranged in a staggered manner in the direction around the winding axis of the electrode assembly 22, and similarly, the first winding end 2212 of the positive pole piece 221 and the first winding end 2212 of the negative pole piece 221 are arranged in a staggered manner. For example, the first winding start end 2211 and the first winding end 2212 of the positive electrode sheet 221 are both located on the angular bisector 211 of one corner of the case 21, and the first winding start end 2211 and the first winding end 2212 of the negative electrode sheet 221 are both located on the angular bisector 211 of the other corner of the case 21.

Here, the direction around the winding axis of the electrode assembly 22 refers to the X direction shown in fig. 3.

Because pole piece 221 has a certain thickness, first winding start end 2211 of pole piece 221 forms a step structure with a certain height on the inner side wall of electrode assembly 22, and similarly, first winding end 2212 of pole piece 221 also forms a step structure with a certain height on the outer side wall of electrode assembly 22, and simultaneously, because each outer side face of electrode assembly 22 and each inner side face of casing 21 are arranged opposite and parallel one to one, when electrode assembly 22 expands, each outer side face of electrode assembly 22 and each inner side face of casing 21 are attached one to one. If the first winding start end 2211 of the pole piece 221 or the first winding end 2212 of the pole piece 221 is located at a position opposite to any inner side surface of the case 21, the pressing force of the side wall of the case 21 on the electrode assembly 22 may directly act on the first winding end 2212 of the pole piece 221 or be transmitted to the first winding start end 2211 of the pole piece 221 along a straight line through other structures of the electrode assembly 22, and due to the existence of the step structure, a local stress is generated inside the electrode assembly 22, so that the electrode assembly 22 is damaged.

By arranging the first winding start end 2211 and/or the first winding end 2212 on the angular bisector 211 of the corner of the casing 21, it can be effectively avoided that the first winding start end 2211 and/or the first winding end 2212 of the pole piece 221 extrudes the first winding start end 2211 and/or the first winding end 2212 of the pole piece 221 after the electrode assembly 22 expands, so that the corresponding part of the electrode assembly 22 is extruded by the first winding start end 2211 and/or the first winding end 2212 of the pole piece 221, the electrode assembly 22 is prevented from being damaged due to local stress, and the service life of the battery cell 20 is effectively prolonged.

Of course, in practical applications, first winding start end 2211 or first winding end 2212 may be slightly deviated from angular bisector 211 of the corner of housing 21 due to assembly error.

In some embodiments of the present application, referring to fig. 3, the electrode assembly 22 includes a separator 222, and the separator 222 has a second winding start end 2221, and the second winding start end 2221 is located on the angular bisector 211 of the corner of the case 21.

In other embodiments of the present application, the separator 222 has a second winding end 2222, and the second winding end 2222 is located on the angular bisecting plane 211 of the corner of the housing 21.

In still other embodiments of the present application, the separator 222 has a second winding start end 2221 and a second winding end 2222, and both the second winding start end 2221 and the second winding end 2222 are located on the angular bisector 211 of the corner of the housing 21.

Second winding start end 2221 of separator 222 refers to the end of separator 222 that is inside electrode assembly 22, i.e., the end of separator 222 that is closest to the winding axis of electrode assembly 22, and second winding end 2222 of separator 222 refers to the end of separator 222 that is outside electrode assembly 22, i.e., the end of separator 222 that is farthest from the winding axis of electrode assembly 22.

Since the separator 222 has a certain thickness, the second winding start end 2221 of the separator 222 forms a stepped structure having a certain height on the inner side wall of the electrode assembly 22, and similarly, the second winding end 2222 of the separator 222 forms a stepped structure having a certain height on the outer side wall of the electrode assembly 22, and since the respective outer sides of the electrode assembly 22 and the respective inner sides of the case 21 are aligned and parallel one to one, the respective outer sides of the electrode assembly 22 and the respective inner sides of the case 21 are fitted one to one when the electrode assembly 22 is expanded. If the second winding start end 2221 of the separator 222 or the second winding end 2222 of the separator 222 is located opposite to any one of the inner sides of the case 21, the pressing force of the side wall of the case 21 against the electrode assembly 22 may be directly applied to the second winding end 2222 of the separator 222 or may be linearly transmitted to the second winding start end 2221 of the separator 222 through other structures of the electrode assembly 22, and due to the presence of the stepped structure, local stress may be generated inside the electrode assembly 22, thereby damaging the electrode assembly 22.

By disposing the second winding start end 2221 and/or the second winding end 2222 on the angular bisector 211 of the corner of the case 21, it is effectively avoided that the second winding start end 2221 and/or the second winding end 2222 of the separator 222 presses the corresponding portion of the electrode assembly 22 due to the pressing of the side wall of the case 21 against the second winding start end 2221 and/or the second winding end 2222 of the separator 222 after the expansion of the electrode assembly 22, so that the electrode assembly 22 is prevented from being damaged due to local stress, and the service life of the battery cell 20 is effectively prolonged.

Of course, in practical applications, due to assembly errors, the second winding start end 2221 or the second winding end 2222 may be slightly deviated from the angular bisector 211 of the corner of the housing 21.

In some embodiments of the present application, referring to fig. 4, the corners of electrode assembly 22 are rounded.

Since electrode assembly 22 and case 21 have the same regular prism structure, after electrode assembly 22 is mounted in case 21, not only the respective outer sides of electrode assembly 22 correspond one-to-one to the respective inner sides of case 21, but also the respective corners of electrode assembly 22 correspond one-to-one to the respective corners of case 21. Meanwhile, because the edge of the electrode assembly 22 is in a fillet structure, two opposite sides of the fillet structure will be tangent to two adjacent inner sides of the case 21, in other words, the edge of the electrode assembly 22 and two adjacent inner sides of the case 21 enclose a gap of a certain size, that is, a gap is formed between the edge of the electrode assembly 22 and the edge of the case 21.

By adopting the technical scheme, a gap is formed between the corner of the electrode assembly 22 and the corner of the casing 21, so that the situation that the casing 21 presses the first winding starting end 2211 and/or the first winding tail end 2212 of the pole piece 221 or presses the second winding starting end 2221 and/or the second winding tail end 2222 of the diaphragm 222 after the electrode assembly 22 expands is more effectively avoided, the electrode assembly 22 is more effectively prevented from being damaged due to local stress, and the service life of the battery cell 20 is further prolonged.

In some embodiments of the present application, referring to fig. 3, the electrode assembly 22 includes a pole piece 221 and a separator 222, the pole piece 221 has a first winding start end 2211 and a first winding end 2212, the separator 222 has a second winding start end 2221 and a second winding end 2222, the first winding start end 2211 and the first winding end 2212 correspond to two adjacent side walls of the case 21 one by one, and the second winding start end 2221 and the second winding end 2222 correspond to two adjacent side walls of the case 21 one by one, in a direction around a winding axis of the electrode assembly 22.

The one-to-one correspondence between the first winding start end 2211 and the first winding end 2212 and the two adjacent side walls of the case 21 means that in the process of winding the pole piece 221 around the winding axis of the electrode assembly 22, the pole piece 221 firstly winds through one side wall (hereinafter, referred to as a first side wall) of the case 21 with the first winding start end 2211 as the winding start point, and finally winds through the other side wall (hereinafter, referred to as a second side wall) of the case 21 with the first winding end 2212 as the winding end point, and the first side wall and the second side wall are two adjacent side walls of the case 21.

Similarly, the one-to-one correspondence between the second winding start end 2221 and the second winding end 2222 and the two adjacent side walls of the case 21 means that in the process of winding the separator 222 around the winding axis of the electrode assembly 22, the separator 222 is wound first through one side wall (hereinafter, referred to as a third side wall) of the case 21 with the second winding start end 2221 as the winding start point, is wound last through the other side wall (hereinafter, referred to as a fourth side wall) of the case 21 with the second winding end 2222 as the winding end point, and the third side wall and the fourth side wall are two adjacent side walls of the case 21.

It is understood that the first sidewall and the third sidewall may be the same sidewall, and the second sidewall and the fourth sidewall may be the same sidewall. Of course, in other embodiments, the first sidewall and the third sidewall may be different sidewalls, and similarly, the second sidewall and the fourth sidewall may also be different sidewalls.

By adopting the above technical scheme, the number of layers of the pole pieces 221 and the number of layers of the diaphragm 222 corresponding to each outer side of the electrode assembly 22 are the same, on one hand, the electrode assembly 22 can more fully utilize the inner space of the casing 21, thereby further improving the energy of the battery cell 20; on the other hand, when electrode assembly 22 is pressed against case 21 after expansion, the pressing force applied to electrode assembly 22 is uniform in a direction around the winding axis of electrode assembly 22, thereby ensuring uniform internal stress of electrode assembly 22.

In some embodiments of the present application, referring to fig. 3, electrode assembly 22 comprises a pole piece 221 and a separator 222, wherein pole piece 221 has a first winding start end 2211 and a first winding end 2212, separator 222 has a second winding start end 2221 and a second winding end 2222, and in a direction around a winding axis of electrode assembly 22, first winding start end 2211 and first winding end 2212 are located on a same angular bisector 211 of case 21, and second winding start end 2221 and second winding end 2222 are located on a same angular bisector 211 of case 21.

The first winding start end 2211 and the first winding end 2212 are located on the angular bisector 211 of the same corner of the housing 21, which means that the pole piece 221 uses the first winding start end 2211 as a winding start point and the first winding end 2212 as a winding end point, and the winding start point and the winding end point of the pole piece 221 are both located on the angular bisector 211 of the same corner of the housing 21, in other words, the projection is performed in a direction toward the central axis of the housing 21 along the angular bisector 211, and the obtained projection of the first winding start end 2211 and the projection of the first winding end 2212 of the pole piece 221 are mutually overlapped.

Similarly, the fact that the second winding start end 2221 and the second winding end 2222 are located on the angular bisector plane 211 of the same corner of the housing 21 means that the winding start point and the winding end point of the separator 222 are both located on the angular bisector plane 211 of the same corner of the housing 21 with the second winding start end 2221 as the winding start point and the second winding end 2222 as the winding end point, in other words, the projection is performed in the direction toward the central axis of the housing 21 along the angular bisector plane 211, and the obtained projection of the second winding start end 2221 and the projection of the second winding end 2222 of the separator 222 are overlapped with each other.

By adopting the technical scheme, the thicknesses of all parts of the electrode assembly 22 are the same in the direction of the winding axis of the electrode assembly 22, so that the inner space of the shell 21 can be fully utilized, the energy of the battery cell 20 is further improved, the extrusion force applied to the electrode assembly 22 is more uniform, and the uniform stress applied to the inner part of the electrode assembly 22 is effectively ensured.

Of course, in practical applications, due to assembly errors, first winding start end 2211 or first winding end 2212 may be slightly deviated from angular bisector 211 of the corner of housing 21; similarly, the second winding start 2221 or the second winding end 2222 may be slightly offset from the angular bisector 211 of the corner of the housing 21.

The present application is intended to cover various modifications, equivalent arrangements, and adaptations of the present application without departing from the spirit and scope of the present application.

Claims (15)

1. A battery cell, comprising: the battery monomer includes casing and electrode subassembly, the casing with electrode subassembly all is prismatic structure, electrode subassembly hold in the casing, each lateral surface of electrode subassembly with each medial surface one by one just to and parallel arrangement of casing.

2. The battery cell of claim 1, wherein: the battery unit further comprises an elastic binding piece which is wrapped on the outer periphery side of the electrode assembly.

3. The battery cell of claim 2, wherein: the elastic binding piece is a binding belt, and the binding belt is wound on the outer peripheral side of the electrode assembly.

4. The battery cell of claim 3, wherein: the number of the circumferences of the binding band around the outer circumference of the electrode assembly is 1 to 5.

5. The battery cell of claim 2, wherein: the elastic binding piece is an expansion glue binding piece.

6. The battery cell of claim 1, wherein: the electrode assembly comprises a diaphragm and a pole piece, wherein the diaphragm is provided with a tail end section, and the tail end section is wound on the outer peripheral side of the pole piece so that the tail end section covers the outer peripheral side of the pole piece.

7. The battery cell of claim 6, wherein: the number of the peripheries of the ending sections surrounding the outer periphery of the pole piece is 1-5 weeks.

8. The battery cell of claim 1, wherein: the case and the electrode assembly each have a regular prism structure.

9. The battery cell of claim 8, wherein: the electrode assembly comprises a pole piece, wherein the pole piece is provided with a first winding starting end and a first winding tail end, and the first winding starting end and/or the first winding tail end are/is positioned on an angular bisector of an edge angle of the shell.

10. The battery cell of claim 8, wherein: the electrode assembly includes a separator having a second winding start end and a second winding end, the second winding start end and/or the second winding end being located on an angular bisector of an edge of the case.

11. The battery cell of claim 9 or 10, wherein: the edges and corners of the electrode assembly are in a fillet structure.

12. The battery cell of claim 8, wherein: the electrode assembly includes a pole piece having a first winding start end and a first winding end, and a separator having a second winding start end and a second winding end, the first winding start end and the first winding end corresponding to two adjacent sidewalls of the case one to one in a direction around a winding axis of the electrode assembly, and the second winding start end and the second winding end corresponding to two adjacent sidewalls of the case one to one.

13. The battery cell of claim 8, wherein: the electrode assembly comprises a pole piece and a diaphragm, wherein the pole piece is provided with a first winding starting end and a first winding tail end, the diaphragm is provided with a second winding starting end and a second winding tail end, in the direction of the winding axis of the electrode assembly, the first winding starting end and the first winding tail end are positioned on the angular bisector of the same corner of the shell, and the second winding starting end and the second winding tail end are positioned on the angular bisector of the same corner of the shell.

14. A battery, characterized by: the battery comprises a cell as defined in any one of claims 1 to 13.

15. An electric device, characterized in that: the powered device comprises the battery of claim 14.

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