CN218414789U - Battery cell, battery and power consumption device - Google Patents

Abstract

The application provides a battery monomer, a battery and an electric device, wherein the battery monomer comprises a shell, an electrode component and at least one current collecting piece; the shell is provided with an electrode leading-out structure; an electrode assembly is accommodated in the case, the electrode assembly including a cylindrical electrode body and tabs led out from the electrode body; and at least one current collector for electrically connecting the electrode lead-out structure with the tab. The application provides a battery monomer can improve the free ability of overflowing of battery, and then improves the free security performance of battery.

Description

Battery cell, battery and power consumption device

Technical Field

The present application relates to the field of battery technology, and more particularly, to a battery cell, a battery, and an electric device.

Background

Batteries are widely used in electronic devices such as mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, and the like. The battery monomer can comprise a cadmium-nickel battery monomer, a hydrogen-nickel battery monomer, a lithium ion battery monomer, a secondary alkaline zinc-manganese battery monomer and the like.

In the development of the battery cell technology, in addition to improving the service performance of the battery cell, how to improve the safety performance of the battery cell is a considerable problem. Improving the safety performance of the battery cell has a significant impact on energy conservation. Therefore, how to improve the safety performance of the battery cell is a technical problem of continuous improvement in the battery cell technology.

SUMMERY OF THE UTILITY MODEL

The application provides a battery monomer, battery and power consumption device can improve the free security performance of battery.

In a first aspect, embodiments of the present application provide a battery cell including a case, an electrode assembly, and at least one current collector; a housing provided with an electrode lead-out structure; an electrode assembly received in the case, the electrode assembly including a cylindrical electrode body and tabs drawn from the electrode body; and at least one current collecting piece for electrically connecting the electrode lead-out structure with the tab.

The single battery provided by the embodiment of the application can improve the overcurrent capacity of the single battery by arranging the current collecting piece and arranging the lug to be electrically connected with the electrode leading-out structure through the current collecting piece, and is favorable for improving the safety performance of the single battery.

In some embodiments, the electrode assembly includes two pole pieces of opposite polarity, each having an active material region and an inactive material region, wound to form an electrode body, and a separator wound to form a tab in a compressed state. So, be favorable to improving the compactness of utmost point ear, reduce the possibility that laser passed utmost point ear scald the isolator, improve the structural integrity of isolator, and then improve the free security performance of battery.

In some embodiments, the total length of the pole piece in the winding direction is l, the maximum dimension of the electrode body in the radial direction is d0, the thickness of the current collector is σ, and the minimum dimension of the tab protruding out of the separator before being compressed in the thickness direction of the current collector is a, a is more than or equal to 1150 σ d0/l. So set up, be favorable to guaranteeing that utmost point ear satisfies certain scope at the distance of compression back protrusion separator to guarantee the compactness after the compression of utmost point ear. So, carrying out the welded in-process to utmost point ear, reducing because the distance undersize of utmost point ear and separator causes the welding light to see through the risk that utmost point ear scalded the separator like laser, reduces simultaneously because the compactness of utmost point ear is lower and cause utmost point ear to take place deformation and the risk of damaging in the course of the work, can further improve the free security performance of battery.

In some embodiments, the minimum dimension of the tab protruding out of the separator in compression along the thickness of the current collector is h, the thickness of the current collector is σ, and h ≧ 1.5. So, carry out the welded in-process at utmost point ear, be favorable to reducing because utmost point ear is apart from the distance undersize of separator, causes the heat that produces among the welding process, see through the risk that utmost point ear scalded the separator like laser, so be favorable to improving the free security performance of battery.

In some embodiments, the minimum distance between the current collecting piece and the separating piece in the thickness direction of the current collecting piece is h, and h is more than or equal to 0.1mm and less than or equal to 1.5mm. So, carry out the welded in-process to mass flow piece and utmost point ear, reduce the welding light, pass the risk that utmost point ear scalded the separator like laser, can reduce simultaneously because of the too big risk that causes battery monomer along the oversize of the thickness direction of mass flow piece of the interval of mass flow piece and separator, so be favorable to improving battery monomer's energy density.

In some embodiments, 0.3mm ≦ h ≦ 1mm. So, be favorable to further reducing the risk that the in-process of mass flow piece welding scalded the separator to further be favorable to the promotion of the free energy density of battery.

In some embodiments, the diameter of the electrode body is d0, the current collector is disk-shaped and has a diameter d1,1 ≦ d0/d1 ≦ 1.3. Therefore, when the electrode assembly is placed in the shell, the risk of dislocation caused by the fact that the pole piece of the outer ring cannot be effectively supported is reduced.

In some embodiments, 1.05 ≦ d0/d1 ≦ 1.1. So, further, reduce the risk of pole piece dislocation.

In some embodiments, the current collector has a dimension d1, 18mm ≦ d1 ≦ 60mm in a radial direction of the electrode body. So, be favorable to rationally setting up battery monomer's size as required to guarantee that battery monomer has sufficient energy density.

In some embodiments, the two electrode leading-out structures comprise a first electrode leading-out structure and a second electrode leading-out structure, and the two tabs comprise a first tab and a second tab which are led out from two ends of the electrode main body respectively and have opposite polarities; the at least one current collecting piece comprises a first current collecting piece, and the first current collecting piece is used for electrically connecting the first electrode leading-out structure with the first tab; and/or at least one of the current collectors includes a second current collector for electrically connecting the second electrode lead-out structure with the second electrode tab.

In some embodiments, the first electrode lead structure is secured to the housing, the first electrode lead structure having a base positioned within the housing and abutting the first current collector. The first current collecting piece is electrically connected with the first electrode leading-out structure through the base, and the connection stability of the first current collecting piece and the first electrode leading-out structure is improved.

In some embodiments, the base is disposed coaxially with the first current collector. The welding connection of the base and the flow collecting piece is convenient to realize. In addition, when the electrode assembly is placed in a shell, the acting force of the base on the first current collecting piece is symmetrically distributed as much as possible relative to the winding center of the electrode assembly, and the risk of dislocation of two adjacent circles of pole pieces is reduced.

In some embodiments, the size of the first current collecting piece is d2, the size of the base is d3, and 1 ≦ d2/d3 ≦ 1.7 in the radial direction of the electrode body. The risk that the single weight of increase battery because of the oversize of base is reduced to be favorable to realizing the free lightweight of battery, can also reduce because of the size undersize of base and at the in-process of income shell, the base produces stress concentration to first mass flow piece and leads to the risk that first mass flow piece warp, and then reduces the risk that the pole piece of two adjacent circles of electrode subassembly takes place the dislocation along thickness direction, can reduce the risk that the extension area of negative pole piece produces the dislocation along thickness direction for positive pole piece simultaneously.

In some embodiments, 1.2 ≦ d2/d3 ≦ 1.5. The risk that the weight of the single battery is increased due to the fact that the size of the base is too large is further reduced, the weight of the single battery is reduced, the risk that the first current collecting piece deforms due to the fact that the base generates stress concentration on the first current collecting piece in the process of entering the shell due to the fact that the size of the base is too small is further reduced, the risk that the pole pieces of two adjacent circles of the electrode assembly are staggered in the thickness direction is further reduced, and meanwhile the risk that the protruding area of the negative pole piece is staggered in the thickness direction relative to the positive pole piece can be reduced.

In some embodiments, the housing includes a body having an opening and an end cap for covering the opening, the second current collector is positioned between the end cap and the second pole ear, the second pole ear is electrically connected to the body through the second current collector, and the second electrode lead structure is part of the body. Thus, the second electrode lead-out structure can be electrically connected with the tab.

In some embodiments, the end cap has an annular boss protruding towards the electrode body, the second current collector abuts against the annular boss, the inner diameter of the annular boss is d4 along the radial direction of the electrode body, the size of the second current collector is d5, and d5/d4 is larger than or equal to 1.15mm. When the electrode assembly is placed into the shell, the stability of the second current collecting piece is favorably improved, and the risk of deformation and arching of the second current collecting piece caused by pressing the end cover is reduced, so that the risk of a gap between the second current collecting piece and the end cover is favorably reduced, and the risk of axial dislocation of the electrode main body in a region close to the outer ring due to pressing is favorably reduced, and the risk of axial dislocation of the extending region of the negative electrode pole piece relative to the positive electrode pole piece is favorably reduced.

In some embodiments, d5/d4 is ≧ 1.2mm. The stability of the second current collecting piece is further improved, the risk that the second current collecting piece deforms and arches due to the fact that the end cover is pressed downwards is reduced, and therefore the risk that a gap exists between the second current collecting piece and the end cover is reduced, the risk that the electrode main body is axially dislocated due to pressing in an area close to the outer ring is reduced, and the risk that the extending area of the negative electrode pole piece is axially dislocated relative to the positive electrode pole piece is reduced.

In some embodiments, the end cap is provided with a pressure relief mechanism, the pressure relief mechanism is spaced apart from a second current collector, the second current collector supports the electrode assembly, the thickness of the second current collector is sigma, the Young modulus of the second current collector is E, and sigma E is larger than or equal to 27000MPa. Therefore, the risk that the second current collecting piece deforms is reduced, the risk that the pressure relief mechanism is damaged to influence the bursting pressure of the pressure relief mechanism is reduced, and the work safety of the battery is improved.

In some embodiments, σ E ≧ 40000MPa. Therefore, the bending resistance of the second current collecting piece is further improved, the risk that the second current collecting piece deforms is reduced, the risk that the explosion pressure of the pressure relief mechanism is influenced due to damage of the pressure relief mechanism is further reduced, and the working safety of the single battery is further improved.

In a second aspect, embodiments of the present application provide a battery, including a battery cell as in any of the embodiments of the first aspect.

According to the battery provided by the embodiment of the application, since the battery cell provided by any one of the above embodiments is adopted, the same technical effects are achieved, and details are not repeated herein.

In a third aspect, an embodiment of the present application provides an electric device, including a battery as in the embodiment of the second aspect, where the battery is used to provide electric energy.

According to the power consumption device provided by the embodiment of the application, the battery provided by the embodiment of the application is adopted, so that the same technical effects are achieved, and the details are not repeated.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and it is obvious for a person skilled in the art to obtain other drawings based on the drawings without any creative effort.

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

fig. 2 is an exploded view of a battery according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a battery module in a battery provided in an embodiment of the present application;

fig. 4 is an exploded view of a battery cell according to some embodiments of the present disclosure;

fig. 5 is a schematic cross-sectional view illustrating an electrode assembly in a battery cell according to an embodiment of the present disclosure;

fig. 6 is a schematic front view of a battery cell according to an embodiment of the present disclosure;

FIG. 7 isbase:Sub>A schematic cross-sectional view taken along A-A of FIG. 6;

FIG. 8 is an enlarged view of a portion of FIG. 7 at B;

fig. 9 is a partial enlarged view at C in fig. 7.

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

Description of the reference numerals:

1. a vehicle; 1a, a motor; 1b, a controller;

10. a battery; 11. a first tank portion; 12. a second tank portion;

20. a battery module;

30. a battery cell;

31. a housing; 311. a housing; 311a, an opening; 311b, an electrode lead-out hole; 3111. a bottom wall; 312. an end cap; 3121. an annular boss;

32. an electrode assembly; 321. an electrode main body; 322. a tab; 3221. a first tab; 3222. a second tab; 323. pole pieces; 323a, an extension area; 3231. a first pole piece; 3232. a second pole piece; 324. a spacer;

33. an electrode lead-out structure; 331. a first electrode lead-out structure; 3311. a base; 332. a second electrode lead-out structure;

34. a current collector; 341. a first current collecting member; 342. a second current collecting member; 35. a pressure relief mechanism;

x, thickness direction; y, winding direction.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

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

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "attached" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as the case may be.

The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, C and/or D, which may mean: c exists alone, C and D exist simultaneously, and D exists alone. In addition, the character "/" in this application generally indicates that the former and latter related objects are in an "or" relationship.

In the embodiments of the present application, like reference numerals denote like parts, and a detailed description of the same parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only exemplary and should not constitute any limitation to the present application.

The appearances of "a plurality" in this application are intended to mean more than two (including two).

In this application, the battery cell may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, and the embodiment of the present application is not limited thereto. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application. The battery cells are generally divided into three types in an encapsulation manner: the cylindrical battery monomer, the square battery monomer and the soft package battery monomer are also not limited in the embodiment of the application.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The box can avoid liquid or other foreign matters to influence the charging or discharging of battery monomer.

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive pole piece, a negative pole piece and a separator. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece comprises a positive current collector and a positive active substance layer, and the positive active substance layer is coated on the surface of the positive current collector; the positive electrode current collector comprises a positive electrode current collecting portion and a positive electrode convex portion protruding out of the positive electrode current collecting portion, the positive electrode current collecting portion is coated with a positive electrode active substance layer, at least part of the positive electrode convex portion is not coated with the positive electrode active substance layer, and the positive electrode convex portion serves as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece comprises a negative pole current collector and a negative pole active substance layer, and the negative pole active substance layer is coated on the surface of the negative pole current collector; the negative current collector comprises a negative current collecting part and a negative convex part protruding out of the negative current collecting part, the negative current collecting part is coated with a negative active material layer, at least part of the negative convex part is not coated with the negative active material layer, and the negative convex part is used as a negative electrode tab. The material of the negative electrode current collector may be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, the number of the positive electrode tabs is multiple and the positive electrode tabs are stacked together, and the number of the negative electrode tabs is multiple and the negative electrode tabs are stacked together. The material of the spacer may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The inventor finds that the single safety performance of the battery is low, and then carries out systematic analysis and research on the structure and the working process of the single battery, and finds that the lug in the single battery is directly connected with the electrode leading-out structure without being connected through an intermediate connecting piece, and the current generated in the pole piece is directly transmitted to the electrode leading-out structure.

Based on the above problems discovered by the inventor, the inventor improves the structure of the battery cell, and the technical solution described in the embodiments of the present application is applicable to the battery cell, the battery including the battery cell, and the electric device using the battery.

A battery cell provided according to an embodiment of the present application includes a case, an electrode assembly, and at least one current collector. The shell is provided with an electrode leading-out structure, the electrode assembly is contained in the shell and comprises a cylindrical electrode main body and a lug led out from the electrode main body, and the current collecting piece is used for electrically connecting the electrode leading-out structure with the lug.

The battery monomer that this application embodiment provided through setting up the mass flow piece to through mass flow piece electricity connection utmost point ear and electrode extraction structure, can improve battery monomer's ability of overflowing effectively, with the individual stored energy of improvement battery. Meanwhile, the current collector is electrically connected with the lug and the electrode leading-out structure, so that the stability of current flowing through the electrode leading-out structure is improved, the damage to the electrode leading-out structure in the working process of the single battery is reduced, the working reliability of the electrode leading-out structure is improved, and the safety performance of the single battery is improved.

The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like; spacecraft include aircraft, rockets, space shuttles, and spacecraft, among others; electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not specifically limit the above power utilization device.

For convenience of explanation, the following embodiments will be described with an electric device as an example of a vehicle.

As shown in fig. 1, a battery 10 is provided inside a vehicle 1. The battery 10 may be disposed at the bottom or the head or the tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, and for example, the battery 10 may serve as an operation power source of the vehicle 1.

The vehicle 1 may further include a controller 1b and a motor 1a. The controller 1b is used to control the battery 10 to supply power to the motor 1a, for example, for operation power demand at the time of starting, navigation, and traveling of the vehicle 1.

In some embodiments of the present application, the battery 10 may be used not only as an operating power source of the vehicle 1, but also as a driving power source of the vehicle 1, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1.

Referring to fig. 2, the battery 10 includes battery cells (not shown in fig. 2). The battery 10 may also include a case for housing the battery cells.

The box is used for holding battery monomer, and the box can be various structural style. In some embodiments, the tank may comprise a first tank portion 11 and a second tank portion 12. The first tank portion 11 and the second tank portion 12 are mutually covered. The first case portion 11 and the second case portion 12 together define a receiving space for receiving the battery cells. The second box portion 12 may be a hollow structure with one open end, the first box portion 11 is a plate-shaped structure, and the first box portion 11 covers the open side of the second box portion 12 to form a box body with an accommodating space; the first tank portion 11 and the second tank portion 12 may be both hollow structures with one side open. The open side of the first casing portion 11 covers the open side of the second casing portion 12 to form a casing having an accommodation space. Of course, the first tank portion 11 and the second tank portion 12 may be various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In order to improve the sealing performance of the connected first box portion 11 and second box portion 12, a sealing member, such as a sealant or a sealing ring, may be disposed between the first box portion 11 and the second box portion 12.

Assuming that the first box portion 11 covers the second box portion 12, the first box portion 11 may also be referred to as an upper box cover, and the second box portion 12 may also be referred to as a lower box body.

In the battery 10, one or more battery cells may be provided. If the number of the battery units is multiple, the multiple battery units can be connected in series or in parallel or in series-parallel. The series-parallel connection means that a plurality of battery monomers are connected in series and in parallel. The plurality of battery cells may be directly connected in series or in parallel or in series-parallel, and then the whole body formed by the plurality of battery cells is accommodated in the case, or the plurality of battery cells may be connected in series or in parallel or in series-parallel to form the battery module 20. The plurality of battery modules 20 are connected in series or in parallel or in series-parallel to form a whole, and are accommodated in the case.

In some embodiments, as shown in fig. 3, fig. 3 is a schematic structural view of the battery module 20 shown in fig. 2. In the battery module 20, there are a plurality of battery cells 30. The plurality of battery cells 30 are connected in series, in parallel, or in series-parallel to form the battery module 20. The plurality of battery modules 20 are connected in series or in parallel or in series-parallel to form a whole, and are accommodated in the case.

In some embodiments, the plurality of battery cells 30 in the battery module 20 may be electrically connected to each other by a bus member, so as to realize parallel connection, series connection or parallel connection of the plurality of battery cells 30 in the battery module 20.

Fig. 4 is an exploded view of the battery cell 30 shown in fig. 3, and fig. 5 is a schematic cross-sectional view of the electrode assembly 32 in the battery cell 30 according to the embodiment of the present disclosure; fig. 6 is a front view of a battery cell 30 according to another embodiment of the present application; FIG. 7 showsbase:Sub>A cross-sectional view along A-A of FIG. 6; FIG. 8 shows a partial enlarged view at B in FIG. 7; fig. 9 shows a partial enlarged view at C in fig. 7.

As shown in fig. 4, the battery cell 30 provided in the embodiment of the present application includes a case 31, an electrode assembly 32, and a current collector 34. The case 31 is provided with an electrode lead-out structure 33, and the electrode assembly 32 is accommodated in the case 31. The electrode assembly 32 includes an electrode body 321 and tabs 322 drawn from the electrode body 321, and the current collector 34 serves to electrically connect the electrode drawing structure 33 with the tabs 322.

As shown in fig. 5, the electrode assembly 32 may optionally include a first pole piece 3231, a second pole piece 3232, and a separator 324, the separator 324 serving to separate the first pole piece 3231 from the second pole piece 3232. The first and second pole pieces 3231 and 3232 have opposite polarities, that is, one of the first and second pole pieces 3231 and 3232 is a positive pole piece, and the other of the first and second pole pieces 3231 and 3232 is a negative pole piece.

The first pole piece 3231, the second pole piece 3232 and the separator 324 are all in a strip structure, and the first pole piece 3231, the second pole piece 3232 and the separator 324 are wound into a whole and form a winding structure. The winding structure may be a cylindrical structure.

It is understood that the electrode body 321 has a cylindrical shape, and may not necessarily have an absolute cylindrical shape, and may have a structure similar to a cylindrical shape with a certain deviation from the cylindrical shape.

As shown in fig. 4 to 6, optionally, the electrode assembly 32 includes an electrode main body 321 and a tab 322 when viewed from the external shape of the electrode assembly 32, the tab 322 may include a first tab 3221 and a second tab 3222, and the first tab 3221 and the second tab 3222 protrude from the electrode main body 321. The first tab 3221 is the portion of the first pole piece 3231 that is not coated with an active material layer, and the second tab 3222 is the portion of the second pole piece 3232 that is not coated with an active material layer. The first tab 3221 and the second tab 3222 are used to draw current from the electrode body 321.

Alternatively, the first tab 3221 and the second tab 3222 may extend from the same side of the electrode body 321, or may extend from opposite sides of the electrode body 321.

Alternatively, the first and second tabs 3221 and 3222 may be respectively disposed at opposite sides of the electrode main body 321, in other words, the first and second tabs 3221 and 3222 are respectively disposed at opposite ends of the electrode assembly 32.

Optionally, the first tab 3221 is wound around the central axis of the electrode assembly 32 in a plurality of turns, and the first tab 3221 includes a plurality of tab layers. After winding, the first tab 3221 is substantially cylindrical, and a gap is left between two adjacent tab layers. The first tab 3221 may be processed in the embodiment of the application to reduce a gap between tab layers, so that the first tab 3221 is conveniently connected with other conductive structures. For example, the present embodiment may perform a kneading treatment on the first tab 3221 to gather and bring together the end regions of the first tab 3221 away from the electrode main body 321; the flattening process forms a dense end surface at the end of the first tab 3221 away from the electrode body 321, which reduces the gap between the tab layers and facilitates the connection of the first tab 3221 with the current collector 34. Alternatively, the embodiment of the application can also fill a conductive material between two adjacent circle pole layers to reduce a gap between the tab layers.

Optionally, the second pole ear 3222 is wrapped multiple times around a central axis of the electrode assembly 32, with the second pole ear 3222 including multiple turns of the tab layer. Illustratively, the second pole ear 3222 is also treated with a flattening treatment to reduce the gap between the tab layers of the second pole ear 3222.

It will be appreciated that the electrode lead-out structure 33 serves to electrically connect with other cells 30 via the bus bars to achieve series or parallel connection of different cells 30.

As shown in fig. 7 to 9, the electrode lead-out structure 33 may be a part of the housing 31, or may be a structure provided separately from the housing 31. For example, the electrode lead-out structure 33 may be a part of the case 311, and the electrical connection with the tab 322 and the current collector 34 is achieved through the case 311. Alternatively, an electrode lead-out hole 311b may be provided at one end of the case 311, and the electrode lead-out structure 33 may be electrically connected to the current collector 34 through the electrode lead-out hole 311b.

Alternatively, the battery cell 30 may include two electrode lead-out structures 33, one of which is a positive electrode lead-out structure and the other of which is a negative electrode lead-out structure, the positive electrode lead-out structure is connected to a positive electrode tab through a current collector 34, and the negative electrode lead-out structure is connected to a negative electrode tab through a current collector 34.

Alternatively, the electrode lead-out structure 33 may be formed separately from the housing 31 and then mounted on the housing 31. Alternatively, the electrode lead-out structure 33 may be provided as a part of the housing 31.

Alternatively, one electrode lead-out hole 311b may be provided at each of opposite ends of the case 31, or two electrode lead-out holes 311b may be provided at the same end of the case 31, and the two electrode lead-out structures 33 may be provided in the two electrode lead-out holes 311b, respectively, and the electrode lead-out structures 33 may be provided to be insulated from the case 31. In this embodiment, the housing 31 may not be charged during the operation of the battery cell 30.

Alternatively, one electrode lead-out hole 311b may be provided at one end of the case 31, and one electrode lead-out structure 33 may be provided to be mounted to the electrode lead-out hole 311b, while the other electrode lead-out structure 33 is provided as a part of the case 31 and electrically connected to the tab 322 of the electrode assembly 32 through the case 31. In this embodiment, the housing 31 can serve as an output electrode of the battery cell 30 during the operation of the battery cell 30, and therefore, the housing 31 can be used for transmitting electric energy.

Alternatively, the case 31 may include a case 311 and an end cap 312, the case 311 may have a hollow structure with at least one side opening 311a, and the end cap 312 covers the opening 311a of the case 311 and forms a sealing connection to form a sealed space for accommodating the electrode assembly 32 and the electrolyte.

Alternatively, the housing 311 and the end cap 312 may be formed separately and then connected together by welding, riveting, bonding, or the like.

Alternatively, the housing 311 may have an opening 311a at one end, and an end cover 312 is disposed to cover the opening 311a, in this case, two electrode lead-out holes 311b may be disposed on the end cover 312 and the bottom wall 3111 of the housing 311 opposite to the end cover 312, respectively, and the two electrode lead-out structures 33 may be disposed in the electrode lead-out holes 311b, respectively. Alternatively, an electrode lead-out hole 311b is provided in one of the end cover 312 and the bottom wall 3111 of the case 311 opposite to the end cover 312, and is electrically connected to the current collector 34 through the other to electrically connect the case 31 and the tab 322. Illustratively, an end cap 312 may be provided to electrically connect with the current collector 34, and an electrode lead-out hole 311b may be provided on the bottom wall 3111, and a separate electrode lead-out structure 33 may be provided to be mounted to the battery 10 lead-out hole. Of course, the end cap 312 and the bottom wall 3111 may be provided with the electrode lead-out holes 311b, and the electrode lead-out structures 33 may be attached to the two electrode lead-out holes 311b, respectively.

Alternatively, the opposite ends of the housing 311 may have openings 311a, and two end caps 312 may be disposed to cover the two openings 311a. And one of the end caps 312 is provided with an electrode lead-out hole 311b, and the other end cap 312 is electrically connected to a tab 322 through a current collector 34. Alternatively, both end caps 312 are provided with electrode lead-out holes 311b, and the two electrode lead-out structures 33 are respectively provided in the two electrode lead-out holes 311b.

Illustratively, the bottom wall 3111 of the case 311 opposite to the end cap 312 may be provided with an electrode lead-out hole 311b, one of the electrode lead-out structures 33 is disposed in the electrode lead-out hole 311b and is insulated from the bottom wall 3111, and the electrode lead-out structure 33 is connected with a tab 322 at one end of the electrode assembly 32 through a current collecting member 34. And the tab 322, which is provided at the other end of the electrode assembly 32 and the end cap 312, is connected through the current collector 34, and the bottom wall 3111 is electrically connected to the end cap 312 through the other portion of the case 311, in which case the bottom wall 3111 may be provided as the electrode lead-out structure 33, or the end cap 312 may be provided as the electrode lead-out structure 33.

When assembling the battery cell 30, the electrode assembly 32 is first placed in the case 311, the end cap 312 is then covered on the opening 311a of the case 311, and the electrolyte is then injected into the case 311 through the electrolyte injection port on the end cap 312.

The shape of the case 311 may be determined according to the specific shape of the electrode assembly 32. For example, if the electrode assembly 32 is a cylindrical structure, it can be selected as the cylindrical case 311; if the electrode assembly 32 has a rectangular parallelepiped structure, a rectangular parallelepiped case 311 may be used. Alternatively, both the electrode assembly 32 and the case 311 are cylindrical; correspondingly, the housing 311 is cylindrical, and the end cap 312 is a circular plate-shaped structure.

In some embodiments, the housing 31 may also be used to contain an electrolyte, such as an electrolyte. The housing 31 may take a variety of configurations.

The material of the housing 311 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiment of the present invention is not limited thereto.

The electrode assembly 32 accommodated in the case 311 may be one or more. In fig. 4, there is one electrode assembly 32 accommodated in the case 311.

Alternatively, one cell 30 may include one current collector 34, or may include two current collectors 34, and in an embodiment where the cell 30 includes one current collector 34, the current collector 34 connects one tab 322 and one electrode lead-out structure 33, and the other tab 322 and the other electrode lead-out structure 33 may be directly connected.

The single battery 30 provided by the embodiment of the application can improve the overcurrent capacity of the single battery 30 by arranging the current collecting piece 34 and arranging the tab 322 to be electrically connected with the electrode leading-out structure 33 through the current collecting piece 34, so that the safety performance of the single battery 30 is improved.

In some embodiments, the electrode assembly 32 includes two pole pieces 323 and separators 324 of opposite polarity, each pole piece 323 having an active material region and an inactive material region, the two active material regions and separators 324 being wound to form the electrode body 321, the inactive material regions being wound to form the tabs 322, the tabs 322 being in a compressed state.

Specifically, after the pole piece 323 and the separator 324 are wound to form the tab 322, the tab includes a plurality of tab layers, and two adjacent tab layers are arranged at intervals. In order to electrically connect the tab 322 with the current collecting member 34, the tab 322 needs to be formed into a compact structure, and for this purpose, the tab layers can be compressed through a rubbing process, and the tab layers are arranged more tightly, which facilitates the welding process of the tab 322 with the current collecting member 34. After the tab 322 is welded, the single battery 30 may be subjected to an axial upsetting process to further compress the tab layer and improve the compactness of the tab 322.

Alternatively, the pole piece 323 and the separator 324 are wound to form a cylindrical shape, and are not necessarily absolutely cylindrical, and may be approximately cylindrical.

It should be noted that, no matter what state the tab 322 is, for example, a state of the tab 322 before starting to compress, such as a state of the tab 322 being completely flattened, or a state of the tab 322 during the compression process, or a state of the tab 322 after completing the compression, or a state of the tab 322 being compressed and then being flattened, belong to different states of the battery cell 30 in the description of the present application, and thus are within the protection scope of the battery cell 30 in the present application.

The compactness of the compressed tab 322 is improved to a certain extent, so that the tab 322 is conveniently welded with the current collecting piece 34 or the tab 322 is welded with the electrode leading-out structure 33. The connection reliability of the tab 322 and the current collecting piece 34 or the connection reliability of the tab 322 and the electrode leading-out structure 33 is improved, meanwhile, the compactness of the compressed tab 322 is improved, the possibility that laser penetrates through the tab 322 to scald the isolating piece 324 is reduced in the process of welding the tab 322 and the current collecting piece 34 or the tab 322 and the electrode leading-out structure 33, the structural integrity of the isolating piece 324 is improved, and the safety performance of the battery monomer 30 is further improved.

The inventor further studies and finds that the battery cell 30 is usually connected with the current collector 34 and the tab 322 by welding during the manufacturing process, however, during the welding process of the current collector 34 and the tab 322, since the tab 322 is closer to the separator 344 along the thickness direction X of the current collector 34, the separator 344 may be burnt, and the safety performance of the battery cell 30 is reduced.

In some embodiments, the total length of the pole piece 323 in the winding direction Y is l, the maximum dimension of the electrode body 321 in the radial direction is d0, the thickness of the current collector 34 is σ, and the minimum dimension of the tab 322 before being compressed in the thickness direction X of the current collector 34 is a, a ≧ 1150 σ X d0/l.

The total length of the pole piece 323 in the winding direction Y may be the length of the pole piece 323 before winding, or may be the length of the pole piece 323 after winding and then unwinding.

Here, the diameter of the electrode body 321 may be a maximum size of the electrode body 321 in a cross section perpendicular to the axial direction of the electrode body 321, passing through the winding center.

The minimum dimension of the protruding separator 324 before the tab 322 is compressed may be the minimum dimension of the tab 322 protruding the separator 324 after the tab 322 is wound to form a cylindrical shape and before the tab 323 is compressed. It will be appreciated that the size of the tab 322 protruding out of the separator 324 before compression can be determined by flattening the compressed tab 322 and measuring the size of the tab 322 protruding out of the separator 324 after flattening.

The thickness direction X of the current collector 34 may be the axial direction of the electrode assembly 32. The thickness of the current collector 34 does not have to be completely equal throughout the thickness direction X of the current collector 34, and therefore, the thickness σ of the current collector 34 may be the maximum dimension of the current collector 34 in the axial direction of the electrode assembly 32, or the thickness σ of the current collector 34 may be the average thickness of the current collector 34 throughout the axial direction of the electrode assembly 32.

The minimum dimension a of the tab 322 protruding out of the separator 324 before being compressed is set to satisfy: a ≧ 1150 σ × d0/l, i.e., the minimum dimension a of the tab 322 protruding out of the separator 324 before being compressed is set to be greater than a certain value after the length l of the pole piece 323 in the winding direction Y, the thickness σ of the current collector 34, and the diameter d0 of the electrode assembly 32 are determined.

Alternatively, it may be provided that only the minimum dimension a of the positive electrode tab projecting separator 324 satisfies the above-mentioned relationship, or that only the minimum dimension a of the negative electrode tab projecting separator 324 satisfies the above-mentioned relationship, or that both the minimum dimensions a of the positive electrode tab and the negative electrode tab projecting separator 324 satisfy the above-mentioned relationship.

It will be appreciated that with a given compaction density, the greater the size of the tab 322 prior to compression of the protruding spacer 324, and the greater the size of the protruding spacer 324 after compression. On the premise that the size of the protruding spacer 324 is fixed after the compression of the tab 322, the larger the size of the protruding spacer 324 is before the compression of the tab 322, the larger the compaction density of the tab 322 is, i.e., the more dense the tab 322 is.

Therefore, setting the minimum dimension a of the tab 322 protruding the separator 324 before compression satisfies the above relationship is advantageous for ensuring that the distance that the tab 322 protrudes the separator 324 after compression satisfies a certain range, and ensuring the compactness of the tab 322 after compression. So, at utmost point ear 322 the in-process of welding, reduce because utmost point ear 322 protrudes separator 324 the size and crosses lowly, cause the welding light to see through utmost point ear 322 and scald the risk of separator 324 like laser, reduce simultaneously because utmost point ear 322's compactness is lower and cause utmost point ear 322 to take place the risk that deformation and damage in the course of the work, can further improve battery monomer 30's security performance.

The effect of the dimension a of the tab 322 before compression on the performance of the battery cell 30 is described below in conjunction with table 1, where σ, d0, l, and a are all in mm.

Table 1 effect of distance a of protruding spacer 324 before compression of tab 322 on safety performance of battery cell 30

Referring to examples 1 to 6 and comparative examples 1 to 5 in table 1, the examples of the present application can reduce the risk of the separator 324 of the battery cell 30 being scalded by setting a ≧ 1150 σ × d0/l, thereby improving the safety performance of the battery cell 30.

In some embodiments, the tab 322 protrudes in compression through the separator 324 by a minimum dimension h in the thickness direction X of the current collector 34, the thickness of the current collector 34 is σ, and h ≧ 1.5 σ.

Alternatively, only the minimum size of the projecting separator 324 in the compressed state of the positive electrode tab may be set to satisfy the above relationship, or only the minimum size of the projecting separator 324 in the compressed state of the negative electrode tab may be set to satisfy the above relationship, or the minimum sizes of the projecting separators 324 in the compressed states of the positive electrode tab and the negative electrode tab may be set to satisfy the above relationship at the same time.

With a constant thickness σ of the current collector 34, the minimum value of the minimum dimension h of the tab 322, which protrudes in the compressed state beyond the separator 324, is 1.5 σ.

In embodiments where the tab 322 is electrically connected to the electrode lead-out structure 33 through the current collector 34, the tab 322 may be pressed out of the minimum dimension of the separator 324 in a compressed state, which may be the minimum distance between the current collector 34 and the separator 324, and thus, the minimum dimension of the tab 322 pressed out of the separator 324 in a compressed state is set to satisfy the above relationship, i.e., the minimum distance between the current collector 34 and the separator 324 is set to satisfy the above relationship.

It can be understood that the minimum dimension h of the tab 322 protruding out of the separator 324 in the compressed state satisfies the above relationship, and in the process of welding the tab 322, the risk that heat generated in the welding process, such as laser, may scald the separator 324 through the tab 322 is reduced, which is beneficial to improving the safety performance of the battery cell 30.

The effect of the minimum spacing h of the tabs 322 protruding through the separator 324 in a compressed state on the performance of the battery cell 30 is described below in conjunction with table 2, where h and σ are in mm.

Table 2 effect of minimum spacing h of tab 322 protruding through separator 324 in compression on performance of cell 30

Referring to examples 1 to 6 and comparative examples 1 to 6 in table 2, the battery cell 30 provided in the example of the present application can reduce the risk of the separator 324 of the battery cell 30 being burned by setting h ≧ 1.5 ∑, thereby improving the safety performance of the battery cell 30.

In some embodiments, the minimum spacing of the current collectors 34 from the spacers 324 in the thickness direction X of the current collectors 34 is h,0.1mm ≦ h ≦ 1.5mm.

Alternatively, the minimum distance between the current collector 34 corresponding to the positive electrode tab and the separator 324 may be set to satisfy the above relationship, or the minimum distance between the current collector 34 connected to the negative electrode tab and the separator 324 may be set to satisfy the above relationship, or the minimum distances between the current collector 34 connected to the positive electrode tab and the current collector 34 connected to the negative electrode tab and the separator 324 may be set to satisfy the above relationship.

Alternatively, the minimum spacing h of the current collector 34 from the separator 324 may be 0.1mm, 0.2mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or the like.

It will be appreciated that the spacing between the current collector 34 and the separator 324 may be the distance that the tab 322 projects from the separator 324, and thus, setting the minimum spacing h between the current collector 34 and the separator 324 satisfies the above relationship, i.e., setting the distance that the tab 322 projects from the separator 324 within the above numerical range.

The minimum distance h between the collector 34 and the separator 324 satisfies: h is more than or equal to 0.1mm and less than or equal to 1.5mm, a certain distance between the current collecting piece 34 and the isolating piece 324 can be ensured, so that the risk of welding light, such as laser penetrating through the tab 322 to scald the isolating piece 324, is reduced in the process of welding the current collecting piece 34 and the tab 322. In addition, on the premise that the separator 324 is not damaged in the process of welding the current collecting piece 34 and the tab 322, the upper limit is set to the value h, so that the risk that the dimension of the battery cell 30 in the thickness direction X of the current collecting piece 34 is too large due to too large distance between the current collecting piece 34 and the separator 324 is reduced, and the improvement of the energy density of the battery cell 30 is facilitated.

In some embodiments, 0.3mm ≦ h ≦ 1mm.

Alternatively, h may be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, or the like.

The minimum distance h between the current collector 34 and the separator 324 is further set to satisfy: h is more than or equal to 0.3mm and less than or equal to 1mm, so that the risk of scalding the separator 324 in the welding process of the current collecting piece 34 is further reduced, and the energy density of the single battery 30 is further improved.

In some embodiments, the diameter of the electrode body 321 is d0, the current collector 34 is disk-shaped and has a diameter d1,1 ≦ d0/d1 ≦ 1.3.

Alternatively, d0/d1 may be 1, 1.1, 1.15, 1.2, 1.25, 1.3, or the like.

Alternatively, the diameter of the electrode body 321 may be a direction passing through the geometric center of the electrode body 321 and perpendicular to the axial direction of the electrode body 321.

The diameter d0 of the electrode main body 321 and the diameter of the current collector 34 are set to be d1, which satisfies the above relationship, that is, the diameter of the electrode main body 321 is greater than or equal to the diameter of the current collector 34, so that the risk of metal particles caused by scraping with the shell 31 in the shell entering process due to the overlarge diameter of the current collector 34 can be reduced. In addition, d0/d1 is set to be less than or equal to 1.3, that is, a lower limit value is set for the diameter of the current collecting piece 34, so as to reduce the risk that the partial area of the end part where the electrode assembly 32 is matched with the current collecting piece 34 due to the excessively small diameter of the current collecting piece 34, for example, the pole piece 323 at the outer ring of the electrode assembly 32 is not effectively supported, and the pole piece 323 at two adjacent rings is dislocated when entering the shell.

It can be understood that, in the charging process of the battery cell 30, in order to ensure that the active ions coming out of the positive electrode plate can be completely received by the negative electrode plate, so as to reduce the risk of lithium precipitation of the battery cell 30, the two ends of the negative electrode plate along the winding direction Y are both arranged to extend out of the positive electrode plate by a certain distance. That is, in the circumferential direction of the electrode assembly 32, as shown in fig. 5, the negative electrode tab has a certain protruding region 323a with respect to the positive electrode tab. By setting the diameter of the current collector 34 to have a lower limit value, it is also beneficial to ensure that the current collector 34 provides effective support for the protruding region 323a, and the risk of the protruding region 323a of the negative electrode plate moving relative to other regions when the electrode assembly 32 is housed is reduced, which may cause damage to the protruding region 323a of the negative electrode plate.

In some embodiments, 1.05 ≦ d0/d1 ≦ 1.1.

Alternatively, d0/d1 may be 1.05, 1.06, 1.08, 1.09, 1.1, etc.

D0/d1 is more than or equal to 1.05 and less than or equal to 1.1, so that the risk of metal particles caused by scraping of the outer shell 31 in the shell entering process of the current collector 34 is further reduced. Meanwhile, the risk that the pole pieces 323 at the outer ring of the electrode assembly 32 are dislocated in the casing entering process due to the fact that the pole pieces 323 at the outer ring are not effectively supported is reduced. In addition, the risk of damage to the protruding region 323a of the negative electrode tab during the insertion of the electrode assembly 32 into the case can be further reduced.

In some embodiments, the current collector 34 has a dimension d1, 18mm ≦ d1 ≦ 60mm in the radial direction of the electrode body 321.

It is understood that there are a plurality of directions in the radial direction of the electrode body 321, and the dimension d1 of the current collector 34 may be arranged in any one radial direction of the electrode body 321 to satisfy the above relationship.

Alternatively, d1 may be 18mm, 20mm, 25mm, 30mm, 35mm, 40mm, 44mm, 45mm, 50mm, 55mm, 60mm, or the like.

The size of the current collector 34 in the radial direction of the electrode body 321 satisfies the above relationship, which is beneficial to reasonably setting the size of the battery cell 30 according to the requirement to ensure that the battery cell 30 has sufficient volume energy density.

In some embodiments, the two electrode lead-out structures 33 include a first electrode lead-out structure 331 and a second electrode lead-out structure 332, and the two tabs 322 include a first tab 3221 and a second tab 3222 of opposite polarities respectively led out from both ends of the electrode main body 321.

One of the first and second electrode lead-out structures 331 and 332 is electrically connected to the first tab 3221, and the other is electrically connected to the second tab 3222.

In some embodiments, the at least one current collector 34 includes a first current collector 341, and the first current collector 341 is used to electrically connect the first electrode lead out structure 331 with the first tab 3221.

Specifically, both ends of the first current collecting member 341 in the thickness direction X are respectively abutted against the first electrode lead-out structure 331 and the first tab 3221, and may be welded or merely separably contacted to transfer electric energy.

In some embodiments, the at least one current collector 34 includes a second current collector 342, and the second current collector 342 is used to electrically connect the second electrode lead structure 332 with the second electrode tab 3222.

Specifically, both end surfaces of the second current collecting member 342 in the thickness direction X are respectively abutted against the second electrode lead-out structure 332 and the second electrode tab 3222, and may be welded or merely detachably contacted to transfer electric energy.

In some alternative embodiments, the first electrode lead structure 331 is fixed to the housing 31, the first electrode lead structure 331 has a base 3311, and the base 3311 is located inside the housing 31 and abuts against the first current collector 341.

That is, in the present embodiment, the first electrode lead-out structure 331 is a structure separately provided on the housing 31, and specifically, the housing 31 may be provided with an electrode lead-out hole 311b, and at least a portion of the base 3311 of the first electrode lead-out structure 331 is extended into the electrode lead-out hole 311b, and the first electrode lead-out structure 331 and the housing 31 are provided to be insulated from each other.

Alternatively, the first electrode lead-out structure 331 may be fixed to the housing 31 by riveting, clipping, or bonding.

Alternatively, the base 3311 of the first electrode lead structure 331 abuts against the first current collecting member 341, and then the base 3311 and the first current collecting member 341 may be fixedly connected together by welding or the like, or the base 3311 and the first current collecting member 341 may be detachably connected together in contact, so as to electrically connect the first current collecting member 341 and the first electrode lead structure 331.

Alternatively, the second electrode lead-out structure 332 and the first electrode lead-out structure 331 may have the same structure and be electrically connected to the second electrode tab 3222 through the second current collector 342, and in this case, the housing 31 may not be charged during the operation of the battery cell 30.

Alternatively, the second electrode lead-out structure 332 may be further provided differently from the first electrode lead-out structure 331, and the second electrode lead-out structure 332 may be provided as a part of the case 311, for example.

The first electrode leading-out structure 331 is fixed on the housing 31, the first electrode leading-out structure 331 is provided with a base 3311 which is located in the housing 31 and abuts against the first current collecting piece 341, and the first current collecting piece 341 is electrically connected with the first electrode leading-out structure 331 through the abutment of the base 3311 and the first current collecting piece 341 and the base 3311, so that the connection stability of the first electrode leading-out structure and the first current collecting piece 341 is improved.

Alternatively, the first current collector 341 and the base 3311 may be coaxially disposed, or the first current collector 341 and the base 3311 may be non-coaxially disposed, and may be selected according to the requirement.

In some embodiments, the base 3311 is disposed coaxially with the first current collector 341.

It will be appreciated that the provision of the base 3311 coaxially with the first current collector 341 facilitates a welded connection of the base 3311 to the current collector 34. In addition, when the electrode assembly is placed in the shell, the force of the base 3311 on the first current collector 341 is distributed symmetrically as much as possible relative to the winding center of the electrode assembly 32, and the risk of dislocation between two adjacent circles of the pole pieces 323 is reduced.

In some embodiments, the first current collector 341 has a dimension d2 and the base 3311 has a dimension d3 along the radial direction of the electrode body 321, and 1. Ltoreq. D2/d 3. Ltoreq.1.7.

Alternatively, d2/d3 may be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, or the like.

Alternatively, since the first current collecting member 341 may have a circular plate shape or a square plate shape, the base 3311 may have a circular plate shape or a square plate shape. In the embodiment where the first current collector 341 is disc-shaped and the base 3311 is also disc-shaped, d1 is the diameter of the first current collector 341 and d3 is the diameter of the base 3311.

Since the electrode body 321 has a plurality of radial directions, in the embodiment in which the first current collector 341 and the base 3311 have a non-cylindrical shape, the size d1 of the first current collector 341 is different from each other and the size d3 of the base 3311 is different from each other in different directions. Accordingly, the dimension d1 of the first current collector 341 and the dimension d3 of the base 3311 may be the dimensions of the first current collector 341 and the base 3311 in either same direction.

It can be understood that d1/d3 is set to be 1 ≤ d1/d3 ≤ 1.7, that is, the size of the first current collecting member 341 is set to be larger than the size of the base 3311, and the size of the base 3311 has a lower limit value on the premise that the size of the first current collecting member 341 is fixed, so that the risk of increasing the weight of the battery cell 30 due to an excessively large size of the base 3311 is reduced to facilitate the weight reduction of the battery cell 30, and the risk of deformation of the first current collecting member 341 due to stress concentration of the base 3311 on the first current collecting member 341 during the insertion into the case due to an excessively small size of the base 3311 is also reduced, thereby reducing the risk of misalignment of the electrode pieces 323 of two adjacent turns of the electrode assembly 32 in the thickness direction X, and simultaneously reducing the risk of misalignment of the extension region 323a of the negative electrode piece relative to the positive electrode piece in the thickness direction X.

In some embodiments, 1.2 ≦ d2/d3 ≦ 1.5.

Alternatively, d2/d3 may be 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, or the like.

With such an arrangement, the risk of increasing the weight of the single battery 30 due to the oversize of the base 3311 is further reduced, so as to facilitate the light weight of the single battery 30, and at the same time, the risk of deformation of the first current collecting member 341 due to stress concentration generated by the base 3311 on the first current collecting member 341 in the process of entering the case due to the undersize of the base 3311 is further reduced, so that the risk of dislocation of the adjacent two circles of the pole pieces 323 of the electrode assembly 32 along the thickness direction X is reduced, and meanwhile, the risk of dislocation of the extending region 323a of the negative pole piece along the thickness direction X relative to the positive pole piece can be reduced.

In some embodiments, the housing 31 includes a housing 311 and an end cap 312, the housing 311 has an opening 311a, the end cap 312 is used for covering the opening 311a, the second current collector 342 is located between the end cap 312 and the second pole ear 3222, the second pole ear 3222 is electrically connected to the housing 311 through the second current collector 342, and the second electrode lead-out structure 332 is a part of the housing 311.

Alternatively, the electrical connection with the second electrode ear 3222 may be achieved through the end cap 312, and the second electrode lead-out structure 332 may be a part of the end cap 312, that is, the end cap 312 of the different battery cells 30 is connected through the bus bar, so as to achieve the electrical connection of the different battery cells 30; alternatively, the second electrode lead-out structure 332 may be provided as a portion of the bottom wall 3111 of the housing 31 opposite to the end cap 312, i.e., a bus bar connecting the bottom walls 3111 of the different battery cells 30 to achieve electrical connection of the different battery cells 30.

Alternatively, the second electrode lead-out structure 332 may be provided in connection with a negative electrode tab, or the second electrode lead-out structure 332 may be provided in connection with a positive electrode tab.

For example, the second electrode lead structure 332 may be connected to a negative electrode tab, so that the case 311 is at a low potential state during operation of the battery cell 30, and the case 311 at the low potential is not easily corroded by the electrolyte and the like.

Alternatively, the end cap 312 may be entirely planar and a portion of the end cap 312 may be disposed to be electrically connected to the second current collector 342, or the end cap 312 may be disposed to have a protruding structure to electrically connect the end cap 312 to the second current collector 342.

In some embodiments, the end cap 312 has an annular boss 3121 protruding toward the electrode body 321, the second current collecting part 342 abuts on the annular boss 3121, the inner diameter of the annular boss 3121 is d4, the size of the second current collecting part 342 is d5, and d5/d4 is greater than or equal to 1.15mm along the radial direction of the electrode body 321.

Alternatively, d5/d4 may be 1.15, 1.2, 1.25, etc.

That is, on the premise that the inner diameter of the annular boss 3121 is fixed, the size of the second current collecting part 342 in the radial direction of the electrode body 321 has a lower limit value, when the electrode assembly 32 is housed, the stability of the second current collecting part 342 is favorably improved, and the risk of deformation and arching of the second current collecting part 342 due to the downward pressing of the end cover 312 is reduced, so that the risk of a gap between the second current collecting part 342 and the end cover 312 is favorably reduced, and the risk of axial misalignment of the region of the electrode body 321 close to the outer ring due to the pressing is favorably reduced, and the risk of axial misalignment of the protruding region 323a of the negative electrode plate with respect to the positive electrode plate is favorably reduced.

In some embodiments, d5/d4 ≧ 1.2mm

Alternatively, d5/d4 may be 1.2, 1.21, 1.22, 1.25, 1.3, etc.

With such an arrangement, when the electrode assembly 32 is housed, the stability of the second current collecting piece 342 is further improved, the risk of the second current collecting piece 342 being deformed and arched due to the fact that the end cover 312 is pressed downwards is reduced, the risk of a gap existing between the second current collecting piece 342 and the end cover 312 is reduced, meanwhile, the risk of axial dislocation of the region, close to the outer ring, of the electrode main body 321 due to pressing is reduced, and the risk of axial dislocation of the extending region 323a of the negative electrode plate relative to the positive electrode plate is reduced.

In some embodiments, the end cap 312 is provided with the pressure relief mechanism 35, the pressure relief mechanism 35 is spaced apart from the second current collector 342, the second current collector 342 supports the electrode assembly 32, the thickness of the second current collector 342 is σ, the young's modulus of the second current collector 342 is E, and σ ≧ 27000mpa.

Because the second current collecting piece 342 needs to support the electrode assembly 32, in order to reduce the risk that the pressure relief mechanism 35 is crushed due to the deformation of the second current collecting piece 342 and further the explosion pressure of the pressure relief mechanism 35 is reduced, the second current collecting piece 342 needs to have certain bending resistance, therefore, the setting of σ E is larger than or equal to 27000mpa mm, which is beneficial to reducing the risk that the second current collecting piece 342 is deformed, and further the risk that the normal operation of the pressure relief mechanism 35 is influenced due to the damage of the pressure relief mechanism is reduced, so that the safety performance of the battery cell 30 is improved.

In some embodiments, σ E ≧ 40000MPa.

So set up, be favorable to further improving the anti bending ability of second class of current piece 342, reduce second class of current piece 342 and produce the risk of deformation to further reduce pressure relief mechanism 35 damage and influence its normal operating risk, so, can further improve battery monomer 30's security performance.

The battery 10 provided according to the embodiment of the present application includes the battery cell 30 provided in any one of the above embodiments.

The battery 10 provided in the embodiment of the present application has the same technical effect due to the use of the single battery cell 30 provided in any one of the above embodiments, and details are not repeated here.

The power utilization device provided according to the embodiment of the present application includes the battery 10 provided in the above embodiment, and the battery 10 is used for providing electric energy.

The power consumption device provided by the embodiment of the present application has the same technical effect due to the battery 10 provided by the above embodiment, and details are not described herein again.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be equivalently replaced, but the modifications or the replacements do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (21)

1. A battery cell, comprising:

a housing provided with an electrode lead-out structure;

an electrode assembly received in the case, the electrode assembly including a cylindrical electrode main body and tabs led out from the electrode main body; and

and the current collecting piece is used for electrically connecting the electrode leading-out structure with the electrode lug.

2. The battery cell of claim 1, wherein the electrode assembly comprises two pole pieces of opposite polarity and a separator, each pole piece having an active material region and an inactive material region, the two active material regions and the separator being wound to form the electrode body, the inactive material region being wound to form the tab, the tab being in a compressed state.

3. The battery cell as recited in claim 2, wherein the total length of the pole piece in the winding direction is l, the maximum dimension of the electrode body in the radial direction is d0, the thickness of the current collector is σ, and the minimum dimension of the tab protruding out of the separator before being compressed in the thickness direction of the current collector is a, a ≧ 1150 σ d0/l.

4. The cell defined in claim 2, wherein the tabs protrude through the separator in compression by a minimum dimension h in the thickness direction of the current collector, the thickness of the current collector is σ, and h is greater than or equal to 1.5 σ.

5. The battery cell as recited in claim 2, wherein the minimum distance between the current collector and the separator in the thickness direction of the current collector is h, and h is 0.1mm or less and 1.5mm or less.

6. The battery cell of claim 5, wherein 0.3mm ≦ h ≦ 1mm.

7. The battery cell of claim 1, wherein the electrode body has a diameter d0, the current collector is disk-shaped and has a diameter d1,1 ≦ d0/d1 ≦ 1.3.

8. The battery cell of claim 7, wherein 1.05. Ltoreq. D0/d 1. Ltoreq.1.1.

9. The battery cell as recited in claim 1, wherein the current collector has a dimension d1, 18mm ≦ d1 ≦ 60mm in a radial direction of the electrode body.

10. The battery cell according to any one of claims 1 to 9, wherein the two electrode lead-out structures comprise a first electrode lead-out structure and a second electrode lead-out structure, and the two tabs comprise a first tab and a second tab with opposite polarities, which are led out from two ends of the electrode main body respectively;

at least one of the current collectors includes a first current collector for electrically connecting the first electrode lead out structure with the first tab; and/or

At least one of the current collectors includes a second current collector for electrically connecting the second electrode lead structure with the second electrode tab.

11. The battery cell as recited in claim 10 wherein the first electrode lead structure is secured to the housing, the first electrode lead structure having a seat within the housing and abutting the first current collector.

12. The battery cell as recited in claim 11 wherein the base is disposed coaxially with the first current collector.

13. The battery cell as recited in claim 11, wherein the first current collector has a size d2 and the base has a size d3, and 1 ≦ d2/d3 ≦ 1.7 in a radial direction of the electrode body.

14. The battery cell of claim 13, wherein 1.2 ≦ d2/d3 ≦ 1.5.

15. The cell defined in claim 10, wherein the housing includes a shell having an opening and an end cap configured to cover the opening, the second current collector is positioned between the end cap and the second pole ear, the second pole ear is electrically connected to the shell via the second current collector, and the second electrode lead structure is part of the shell.

16. The battery cell as recited in claim 15, wherein the end cap has an annular boss protruding toward the electrode body, the second current collector abuts against the annular boss, the inner diameter of the annular boss is d4 along the radial direction of the electrode body, the size of the second current collector is d5, and d5/d4 is greater than or equal to 1.15mm.

17. The battery cell of claim 16, wherein d5/d4 is greater than or equal to 1.2mm.

18. The battery cell as recited in claim 15 wherein the end cap is provided with a pressure relief mechanism spaced from the second current collector, the second current collector supporting the electrode assembly, the second current collector having a thickness σ, the second current collector having a young's modulus E, σ E ≧ 27000mpa mm.

19. The battery cell of claim 18, wherein σ ≧ E40000MPa.

20. A battery comprising a cell according to any one of claims 1 to 19.

21. An electrical device comprising a battery as claimed in claim 20 for providing electrical energy.

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