CN219457944U - Current collector and battery - Google Patents

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a current collector and a battery, wherein the current collector comprises: the current collecting disc is made of rigid conductive materials and is used for connecting the lugs of the battery cells; and the pin is made of conductive materials, a first end of the pin is electrically connected with the current collecting disc, a second end of the pin is used for being electrically connected with the inner wall of the battery shell, and at least part of area between the first end and the second end of the pin is made of flexible materials. The current collecting disc is connected with the battery shell through the flexible pins, and the flexible pins have good deformation capability in the process of rolling groove sealing of the battery shell, so that bending angles can be avoided from being formed at bending positions, further compression of bending areas on electrodes is avoided, active substances coated on the electrodes are prevented from being damaged, and phenomena of cracking, falling and the like of welding marks at welding positions of the current collecting disc and the shell are avoided.

Description

Current collector and battery

Technical Field

The utility model belongs to the technical field of batteries, and particularly relates to a current collector and a battery.

Background

The coiled battery is also called as a coiled core battery and comprises a cylindrical metal shell and a coiled electric core accommodated in the metal shell, wherein the negative electrode of the electric core is provided with spirally distributed lugs, and the lugs are electrically connected with the metal shell of the battery through a negative electrode switching piece. The negative electrode switching sheet is connected with the steel shell in a penetrating welding mode, and then is mechanically blocked and sealed through a rolling groove to form a final cell seal; because the negative electrode transfer sheet material adopts nickel plating copper sheet (thickness is about 1 ~ 2 mm), will lead to the transfer piece to bend when the roll groove, after the overcurrent demand of electric core became big, the transfer piece needs to thicken, can lead to bending department to form the bent angle, and the bent angle can be impressed inside the battery and cause the active material damage of coating on the electrode to can lead to the welding of transfer piece and casing welding department to take place fracture and transfer piece and casing separation even owing to bending stress when bending, thereby lead to electric core reliability to reduce.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present utility model is to provide a current collector and a battery, which can reduce the compression of a battery sealing structure on a negative electrode of a battery cell, improve the reliability of electrical connection, and improve the assembly quality and reliability of the battery cell.

To achieve the above and other related objects, the present utility model provides a current collector for electrical connection between a battery case and an electrode of a battery cell, the current collector comprising:

a current collecting plate made of rigid conductive material for connecting the tabs of the electrodes;

and the pin is made of conductive materials, a first end of the pin is electrically connected with the current collecting disc, a second end of the pin is used for being electrically connected with the inner wall of the battery shell, and at least part of area between the first end and the second end of the pin is made of flexible materials.

In an alternative embodiment of the utility model, the pins comprise a plurality of layers of metal foil stacked on top of each other.

In an alternative embodiment of the present utility model, the pins are arranged at intervals along the circumference of the current collecting plate.

In an alternative embodiment of the present utility model, the total thickness of the metal foil of each layer of the pins is greater than or equal to the thickness of the current collecting plate.

In an alternative embodiment of the present utility model, the number of pins is 2-8, and the width is 4-10 mm.

To achieve the above and other related objects, the present utility model also provides a battery comprising:

a battery case made of a conductive material;

the battery cell comprises an electrode assembly formed by winding, wherein both ends of the electrode assembly are respectively provided with a positive electrode lug and a negative electrode lug, and the electrode assembly is accommodated in the battery shell;

and the current collector is electrically connected with the positive electrode tab or the negative electrode tab.

In an alternative embodiment of the present utility model, a ring of annular concave parts recessed inwards is formed at one end of the battery shell, which is close to the negative electrode of the battery cell, and the second ends of the pins are connected to the inner sides of the annular concave parts.

In an alternative embodiment of the utility model, at least a partial area of the pin, which is made of the flexible material, is clamped between the annular recess and the negative electrode of the cell after bending.

In an alternative embodiment of the present utility model, the second end of the pin is connected to a side of the annular recess away from the battery cell.

In an alternative embodiment of the utility model, the first end of the pin is connected with the current collecting disc and/or the second end of the pin is connected with the battery shell in a welding mode.

In an alternative embodiment of the present utility model, the pins are disposed at intervals along the circumferential direction of the current collecting plate, the pins comprise a plurality of layers of copper foils stacked on each other, and the number n of pins is configured to: n=ceil (I/8/D), where I is the preset overcurrent demand, 8 is the empirical constant, D is the pin width, and D is the weld width.

The utility model has the technical effects that: the current collecting disc is connected with the battery shell through the flexible pins, and the flexible pins have good deformation capability in the process of rolling groove sealing of the battery shell, so that bending angles can be avoided from being formed at bending positions, further, compression of bending areas on electrodes is avoided, active substances coated on the electrodes are prevented from being damaged, and phenomena of cracking, falling and the like of welding marks at welding positions of the current collecting disc and the shell are avoided.

Drawings

FIG. 1 is a schematic view of a prior art wound battery negative electrode tab weld;

FIG. 2 is a schematic view of a negative electrode roll groove structure of a conventional wound battery;

fig. 3 is a schematic diagram of a current collector assembly prior to welding provided by an embodiment of the present utility model;

fig. 4 is a schematic view of a sealing structure of a wound battery according to an embodiment of the present utility model;

FIG. 5 is an enlarged schematic view of part of I of FIG. 4;

fig. 6 is a schematic view of a sealing structure of a wound battery according to another embodiment of the present utility model;

fig. 7 is a front view of a current collector provided by an embodiment of the present utility model;

fig. 8 is a cross-sectional view of a current collector provided by an embodiment of the present utility model;

fig. 9 is a schematic perspective view of a pin according to an embodiment of the present utility model;

reference numerals: 1. an existing negative electrode switching piece; 10. a battery case; 11. an annular recessed portion; 20. a battery cell; 21. a negative electrode tab; 30. a collecting tray; 31. pins; 311. a metal foil; 40. a negative end cap.

Detailed Description

Other advantages and effects of the present utility model will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present utility model with reference to specific examples. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict.

It should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present utility model by way of illustration, and only the components related to the present utility model are shown in the illustrations, not according to the number, shape and size of the components in actual implementation, and the form, number and proportion of each component in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

Referring to fig. 1 and 2, the conventional anode switching piece 1 is an integral plate, after the edge of the plate is bent along the inner wall of the battery shell 10, the plate is connected with the battery shell 10 through penetration welding, as shown in fig. 1, after the welding of the anode switching piece is completed, a circle of annular groove is pressed out by a rolling groove device in a region of the battery shell 10 close to the anode, in the process, the bending region of the anode switching piece continues to be bent inwards along with the deformation path of the annular groove and is finally attached to the top surface of the anode switching piece, when the thickness of the anode switching piece is larger, bending angles are formed between the bending region and the anode switching piece, and the bending angles can generate larger compression on the anode tab 21 of the battery core 20, so that active materials coated on the electrode are damaged, and when the bending stress can cause the welding of the switching piece and the welding part of the battery shell to generate cracking even the switching piece and the battery shell to be separated.

Referring to fig. 3-9, the present utility model improves the structure of the existing negative electrode adapter 1, designs a new current collector and a battery, the current collector is connected with the battery case 10 through a flexible material, and the flexible connection structure can avoid the condition that bending angles are formed at bending positions to damage an anode coating region in the process of sealing a battery rolling groove, so that the reliability of the battery core 20 can be effectively improved.

Referring to fig. 3 to 5, the embodiment of the present utility model provides a wound battery including a battery case 10, a battery cell 20, a current collector and a negative electrode end cap 40, and the wound battery of the present embodiment should include necessary positive electrode tabs, positive electrode posts, etc. in addition to the above-mentioned improved parts of the present utility model, and this part of the features is not essential to the protection of the present utility model, and will not be repeated.

Referring to fig. 3 and 4, the battery case 10 is made of a conductive material, such as a steel case or an aluminum case, and the specific material of the battery case 10 may be selected according to the electrochemical reaction type of the battery, for example, when the battery case 10 is used as a negative electrode, a steel case is used, and when the battery case 10 is used as a positive electrode, an aluminum case is used, and in a specific embodiment, the battery case 10 may be a cylindrical structure, for example, at least one end of which is formed with an opening to facilitate the loading of the battery cell 20 into the battery case 10, and after the loading of the battery cell 20 into the battery case 10, the battery case 10 needs to be sealed, and at this time, an annular recess 11 needs to be rolled in a region of the battery case 10 close to the negative electrode to compress the current collector.

Referring to fig. 3 and 4, in a specific embodiment, the battery core 20 is a wound battery core, and includes an electrode assembly, the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator separating the positive electrode sheet from the negative electrode sheet, the positive electrode sheet, the separator, and the negative electrode sheet are wound to form the electrode assembly, the positive electrode sheet includes a coating region coated with a positive electrode active material and an end portion not coated with an active material, the negative electrode sheet includes a coating region coated with a negative electrode active material and an end portion not coated with an active material, and after winding, uncoated regions of the positive electrode and the negative electrode are respectively located at two ends of the electrode assembly to serve as a positive electrode tab and a negative electrode tab 21 of the battery.

Referring to fig. 3-5 and 7, the current collector includes a current collecting disc 30 and a pin 31, wherein the current collecting disc 30 is made of a rigid conductive material, such as nickel plated copper sheet, and the current collecting disc 30 is accommodated in the battery case 10 and is attached to the negative electrode tab 21 of the battery cell 20, and in a specific embodiment, the current collecting disc 30 may be fixedly connected to the negative electrode tab 21 by penetration welding, for example.

Referring to fig. 3-5 and 7, the lead 31 is made of a conductive material, a first end of the lead 31 is electrically connected to the current collecting plate 30, a second end of the lead 31 is electrically connected to an inner wall of the battery case 10, and a partial area between at least the first end and the second end of the lead 31 is made of a flexible material, and in a specific embodiment, the lead 31 may be a metal foil 311, such as a copper foil, an aluminum foil, or a flexible high polymer film coated with a conductive layer. It should be understood that, the current collecting disc 30 is connected with the battery case 10 through the flexible pins 31, and the flexible pins 31 have good deformation capability in the process of rolling groove sealing of the battery case 10, so that the bending angle can be avoided, the electrode is prevented from being pressed by a bending area, the active material coated on the electrode is prevented from being damaged, and the phenomena of cracking, falling and the like of welding at the welding position of the current collecting disc and the case are avoided.

Referring to fig. 5, the second end of the pin 31 is connected to the inner side of the annular recess 11, and in one embodiment, at least a portion of the pin 31 is bent and clamped between the annular recess 11 and the negative electrode of the battery cell 20, wherein the portion is made of the flexible material. It will be appreciated that in other embodiments, the second ends of the pins 31 may be attached to the upper side of the annular recess 11, and the welding may be performed from the pin side through the open side of the housing prior to sealing the cover plate, thereby avoiding the battery from rusting during use by damaging the plating on the outside of the housing during penetration welding from the outside of the housing. As shown in fig. 6.

In an alternative embodiment, the first ends of the pins 31 are connected with the current collecting plate 30 and the second ends of the pins 31 are connected with the battery case 10 by welding. It should be appreciated that in other embodiments, the first end of the pin 31 may be connected to the current collecting plate 30 in other manners, such as by screwing or riveting.

In a specific embodiment, the pins 31 are disposed at intervals along the circumferential direction of the current collecting plate 30, the pins include a plurality of layers of copper foils stacked on each other, and the number n of the pins 31 is configured as follows: n=ceil (I/8/D), where I is the preset overcurrent demand, 8 is the empirical constant, D is the pin 31 width, and D is the weld width. For example, when the overcurrent requirement of the battery cell 20 is 150A, the width of the pins 31 of the battery cell 20 is 6mm, and the welding seam is 1mm, then according to the empirical formula, the number of the required pins 31 is 4, and the calculation method is as follows: 150/8/6/1=3.1, 3.1 rounded up to 4; for example, when 200A is needed for overcurrent of the battery cell 20, the width of the pins 31 is 5mm, and the welding seam is 1mm, the number of the pins 31 is 5 according to an empirical formula, and the calculation method is as follows: 200/8/5/1=5. In the practical application process, the number of the pins 31 is generally 2-8, and the width is 4-10 mm; it should be noted that the above empirical constant may be adjusted according to the specific material of the pin, for example, when the material of the pin is aluminum, the empirical constant may be 5.

Referring to fig. 8 and 9, in a preferred embodiment, the lead 31 includes multiple layers of metal foils 311 stacked on each other, it should be understood that the metal foils 311 can achieve free bending of the lead 31, but the single-layer metal film has a smaller through-flow cross section, so that the present utility model stacks the multiple layers of metal foils 311 on each other to form the lead 31, which not only achieves flexible bending of the lead 31, but also can meet the requirement of overcurrent.

In a preferred embodiment, the total thickness of the metal foil 311 of each layer of the lead 31 is greater than or equal to the thickness of the current collecting plate 30, so as to ensure that the overcurrent capacity of the lead is equivalent to that of the current collecting plate, and avoid that the lead generates excessive heat when passing a large current due to the weak overcurrent capacity of the lead, so that the thermal runaway of the battery is caused; for example, in a specific embodiment, the thickness of each metal foil 311 is 4.5-100 μm, preferably 100 μm, and the number of layers of the metal foil 311 depends on the total thickness of the current collecting plate 30 of the battery cell 20, for example, the total thickness of the current collecting plate 30 is 1mm, and at least 10 metal foils 311 should be disposed when each metal foil 311 is 100 μm thick.

In summary, the current collecting disc 30 of the present utility model is connected with the battery case 10 through the flexible pins 31, and the flexible pins 31 have good deformation capability in the process of rolling and sealing the battery case 10, so that the formation of a bent angle at the bending position can be avoided, the damage to the anode coating area of the battery cell 20 can be avoided, and the reliability of the battery cell 20 can be effectively improved.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the utility model. One skilled in the relevant art will recognize, however, that an embodiment of the utility model can be practiced without one or more of the specific details, or with other apparatus, systems, components, methods, components, materials, parts, and so forth. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the utility model.

Reference throughout this specification to "one embodiment," "an embodiment," or "a particular embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment, and not necessarily all embodiments, of the present utility model. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present utility model may be combined in any suitable manner with one or more other embodiments. It will be appreciated that other variations and modifications of the embodiments of the utility model described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the utility model.

It will also be appreciated that one or more of the elements shown in the figures may also be implemented in a more separated or integrated manner, or even removed because of inoperability in certain circumstances or provided because it may be useful depending on the particular application.

In addition, any labeled arrows in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise specifically indicated. Furthermore, the term "or" as used herein is generally intended to mean "and/or" unless specified otherwise. Combinations of parts or steps will also be considered as being noted where terminology is foreseen as rendering the ability to separate or combine is unclear.

As used in the description herein and throughout the claims that follow, unless otherwise indicated, "a", "an", and "the" include plural references. Also, as used in the description herein and throughout the claims that follow, unless otherwise indicated, the meaning of "in …" includes "in …" and "on …".

The above description of illustrated embodiments of the utility model, including what is described in the abstract, is not intended to be exhaustive or to limit the utility model to the precise forms disclosed herein. Although specific embodiments of, and examples for, the utility model are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present utility model, as those skilled in the relevant art will recognize and appreciate. As noted, these modifications can be made to the present utility model in light of the foregoing description of illustrated embodiments of the present utility model and are to be included within the spirit and scope of the present utility model.

The systems and methods have been described herein in general terms as being helpful in understanding the details of the present utility model. Furthermore, various specific details have been set forth in order to provide a thorough understanding of embodiments of the utility model. One skilled in the relevant art will recognize, however, that an embodiment of the utility model can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, and/or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the utility model.

Thus, although the utility model has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of the utility model will be employed without a corresponding use of other features without departing from the scope and spirit of the utility model as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present utility model. It is intended that the utility model not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this utility model, but that the utility model will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the utility model should be determined only by the following claims.

Claims (11)

1. A current collector for electrical connection between a battery housing and an electrode of a cell, the current collector comprising:

a current collecting plate made of rigid conductive material for connecting the tabs of the electrodes;

and the pin is made of conductive materials, a first end of the pin is electrically connected with the current collecting disc, a second end of the pin is used for being electrically connected with the inner wall of the battery shell, and at least part of area between the first end and the second end of the pin is made of flexible materials.

2. The current collector of claim 1, wherein the pins comprise a plurality of layers of metal foil stacked on top of each other.

3. The current collector of claim 2, wherein the pins are spaced apart circumferentially of the collector plate.

4. The current collector of claim 2, wherein the total thickness of the metal foil of each layer of the pins is greater than or equal to the thickness of the current collecting tray.

5. The current collector of claim 1, wherein the number of pins is 2-8 and the width is 4-10 mm.

6. A battery, comprising:

a battery case made of a conductive material;

the battery cell comprises an electrode assembly formed by winding, wherein both ends of the electrode assembly are respectively provided with a positive electrode lug and a negative electrode lug, and the electrode assembly is accommodated in the battery shell;

and the current collector according to any one of claims 1 to 5, the current collector being electrically connected to the positive electrode tab or the negative electrode tab.

7. The battery of claim 6, wherein a ring of inwardly recessed annular recess is formed in the battery housing at an end adjacent to the cell cathode, and the second ends of the pins are connected to the inside of the annular recess.

8. The battery of claim 7, wherein at least a portion of the lead is clamped between the annular recess and the negative electrode of the cell after bending, the portion being made of the flexible material.

9. The battery of claim 7, wherein the second end of the pin is connected to a side of the annular recess remote from the cell.

10. The battery of claim 6, wherein the first end of the pin is connected to the current collecting plate and/or the second end of the pin is connected to the battery case by welding.

11. The battery of claim 10, wherein the pins are disposed in plurality at intervals along the circumferential direction of the current collecting plate, the pins comprise a plurality of layers of copper foil stacked on each other, and the number n of pins is configured to: n=ceil (I/8/D), where I is the preset overcurrent demand, 8 is the empirical constant, D is the pin width, and D is the weld width.