CN111370639A

CN111370639A - Battery core, manufacturing method thereof and battery

Info

Publication number: CN111370639A
Application number: CN202010459071.3A
Authority: CN
Inventors: 张锐; 蒋合林
Original assignee: Beijing Xiaomi Mobile Software Co Ltd
Current assignee: Beijing Xiaomi Mobile Software Co Ltd
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2020-07-03
Anticipated expiration: 2040-05-27
Also published as: CN111370639B

Abstract

The disclosure provides a battery cell, a manufacturing method thereof and a battery. The battery cell comprises: electrode slice and at least one utmost point ear. The electrode sheet includes: a current collector and an active layer. The current collector includes: the active layer is arranged on at least one of the first surface and the second surface. The tab comprises a first connecting end and a second connecting end, wherein the first connecting end is arranged along the current conduction direction, the second connecting end is opposite to the first connecting end, and the tail end face of the first connecting end is connected with the first end face in a welding mode. The battery core and the battery have high energy density.

Description

Battery core, manufacturing method thereof and battery

Technical Field

The disclosure relates to the technical field of batteries, and in particular relates to a battery cell, a manufacturing method of the battery cell and a battery.

Background

With the development of electronic devices, batteries with higher energy density are favored. The energy density of the battery is affected not only by the battery material but also by the packaging structure of the battery cell. For example, the battery cell includes: electrode slice and utmost point ear. The surface of the electrode plate comprises an active area and a welding area, wherein an active layer is formed on the active area, and the welding area is connected with the electrode lug in a welding mode. Since the welding region is connected to the tab and the welding region is not provided with an active layer, which affects the energy density of the cell, it is particularly important to provide a cell structure or a method for manufacturing a cell, which can improve the energy density.

Disclosure of Invention

The present disclosure provides an improved cell, a method of manufacturing the same, and a battery.

One aspect of the present disclosure provides a battery cell, comprising: an electrode sheet and at least one tab;

the electrode sheet includes: a current collector and an active layer;

the current collector includes: the active layer is arranged on at least one of the first surface and the second surface;

the tab comprises a first connecting end and a second connecting end, the first connecting end is arranged along the current conduction direction, the second connecting end is opposite to the first connecting end, and the tail end face of the first connecting end is connected with the first end face in a welding mode.

Optionally, the battery cell further includes an insulating protective colloid, and the insulating protective colloid surrounds the welding connection between the first connection end and the first end face.

Optionally, the battery cell further comprises a protective shell, the protective shell is packaged outside the electrode plate, and the second connection end of the tab extends out of the protective shell;

the tab comprises a bendable body, the tail end face of the bendable body is connected with the first end face, and the protective shell and the bendable body are bent in the same direction.

Optionally, the bendable body comprises a metal wire, and one end of the metal wire is connected with the first end face.

Optionally, the number of the metal wires is multiple, and the multiple metal wires are separately arranged.

Optionally, the metal wire includes first linkage segment and second linkage segment, the one end of second linkage segment with the one end of first linkage segment is connected, the other end of second linkage segment with first terminal surface is connected, the radial dimension of first linkage segment is greater than the thickness of the mass flow body, the second linkage segment with the radial dimension of the tip that the mass flow body is connected is less than or equal to the thickness of the mass flow body.

Optionally, the radial dimension of the first connecting section ranges from 10 μm to 20 μm, and the thickness of the current collector ranges from 6 μm to 9 μm.

Another aspect of the present disclosure provides a method of manufacturing a battery cell for a battery cell, the battery cell comprising: an electrode sheet and at least one tab; the electrode sheet includes: a current collector and an active layer; the current collector includes: the active layer is arranged on at least one of the first surface and the second surface; the lug comprises a first connecting end and a second connecting end, wherein the first connecting end is arranged along the current conduction direction, the second connecting end is opposite to the first connecting end, and the tail end face of the first connecting end is connected with the first end face in a welding mode; the manufacturing method comprises the following steps:

drawing the first connection end of the tab to the first end face of the current collector;

and welding and connecting the tail end face of the first connecting end with the first end face.

Optionally, the drawing the first connection end of the tab to the first end face of the current collector includes:

fixing the electrode plate between an adsorption plate and a top plate, and exposing the first end face between the adsorption plate and the top plate;

the first connection end is pulled to the first end face by a ceramic riving knife.

Optionally, the welding the terminal end surface of the first connection end to the first end surface includes:

melting the tail end of the first connecting end into a molten mass, wherein the radial dimension of the molten mass is smaller than the thickness of the current collector;

and under the action of ultrasonic waves, controlling the ceramic cleaver to pull the molten mass of the first connecting end to be welded and connected with the first end face.

Optionally, after the welding connection of the terminal end face of the first connection end with the first end face, the manufacturing method further includes:

dispensing glue around the welding joint of the first connecting end and the first end face to form an insulating protective colloid.

Another aspect of the present disclosure provides a battery including the battery cell of any one of the above-mentioned.

The technical scheme provided by the disclosure at least has the following beneficial effects:

because the first connecting end of the tab is connected with the first end face of the current collector, the area of the active layer arranged on the first face and the second face is not influenced, the active layer can completely cover the first face or the second face, and the improvement of the energy density of the battery core and the battery is facilitated. And, need not paste the protection adhesive tape at the first face and the second face of mass flow body, this space that avoids the protection adhesive tape to occupy the thickness direction of electric core does benefit to the energy density who improves electric core and battery.

Drawings

Fig. 1 is a schematic view illustrating connection between electrode sheets and tabs according to an exemplary embodiment;

fig. 2 is a partial structural cross-sectional view of a cell according to an exemplary embodiment;

fig. 3 is a schematic diagram illustrating a partial structure of a cell according to an exemplary embodiment of the present disclosure;

fig. 4 is a schematic diagram illustrating a partial structure of a cell according to an exemplary embodiment of the present disclosure;

fig. 5 illustrates a partial structural cross-sectional view of a cell shown in accordance with an exemplary embodiment of the present disclosure;

FIG. 6 is a schematic view illustrating the connection of a metal lead to a current collector according to an exemplary embodiment of the present disclosure;

fig. 7 is a schematic view illustrating the connection of a metal lead to a current collector according to an exemplary embodiment of the present disclosure;

fig. 8 is a flow chart illustrating a method of manufacturing a cell according to an exemplary embodiment of the present disclosure;

fig. 9 is a flow chart illustrating a method of manufacturing a cell according to an exemplary embodiment of the present disclosure;

fig. 10 is a schematic diagram illustrating a manufacturing process of a battery cell according to an exemplary embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in the description and claims does not indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. Unless otherwise indicated, the word "comprise" or "comprises", and the like, means that the element or item listed before "comprises" or "comprising" covers the element or item listed after "comprises" or "comprising" and its equivalents, and does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

As used in this disclosure and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

Fig. 1 is a schematic diagram illustrating a partial structure of a battery cell according to an exemplary embodiment, and fig. 2 is a cross-sectional view illustrating a partial structure of a battery cell according to an exemplary embodiment. In some embodiments, referring to fig. 1 and 2 in combination, a cell includes: electrode sheet 110, tab 120 and aluminum plastic film 130. The electrode sheet 110 includes a current collector 111 and an active layer 112. The current collector 111 includes a first face and a second face opposite to the first face. The first side includes an active region provided with an active layer 112 and a welding region connected with a tab 120. Since the active layer 112 is not disposed in the welding area, the coating area of the active layer 112 is reduced, which is not beneficial to increasing the energy density of the cell.

The aluminum-plastic film 130 is encapsulated outside the electrode sheet 110, and part of the tab 120 extends out of the aluminum-plastic film 130. By sticking the protective gummed paper 140 on the welding position of the current collector 111 and the tab 120, the welding projection is prevented from piercing the aluminum plastic film 130. However, the protective adhesive tape 140 occupies the space in the thickness direction (i.e., the x-axis direction) of the battery cell, which is not favorable for increasing the energy density of the battery cell.

Based on the above defects, embodiments of the present disclosure provide a battery cell, a manufacturing method thereof, and a battery, which are described in detail below with reference to the accompanying drawings:

some embodiments of the present disclosure provide for a battery for use in an electronic device, including but not limited to: the intelligent mobile phone comprises a mobile phone, a tablet computer, an iPad, a digital broadcast terminal, a messaging device, a game console, a medical device, a fitness device, a personal digital assistant, an intelligent wearable device, an intelligent television, a sweeping robot, an intelligent sound box and the like.

In some embodiments, the battery includes a liquid lithium ion battery and a solid lithium ion battery. The battery comprises an electric core and a battery protection board, the electric core is connected with the battery protection board, the battery protection board is connected with a mainboard of the electronic equipment, and the mainboard of the electronic equipment is connected with a charging interface. The charging current input to the electric core and the power supply current output by the electric core are adjusted through the battery protection board.

Fig. 3 is a schematic diagram illustrating a partial structure of a battery cell according to an exemplary embodiment of the present disclosure. Referring to fig. 3, the cell includes: an electrode tab 210 and at least one tab 220. The electrode tabs 210 include a positive electrode tab and a negative electrode tab, at least one tab 220 is connected to the positive electrode tab, and at least one tab 220 is connected to the negative electrode tab.

The electrode sheet 210 includes: a current collector 211 and an active layer 212. The current collector 211 is a metal layer such as a copper foil and an aluminum foil. Illustratively, the active layer 212 includes a lithium cobaltate material, in which case the electrode sheet 210 may be a positive electrode sheet. Illustratively, the active layer 212 includes a graphite material, in which case the electrode tab 210 may be a negative electrode tab.

The current collector 211 includes: a first side 201, a second side 202 opposite to the first side 201, and a first end side 203 connecting the first side 201 and the second side 202, and an active layer 212 is provided on at least one of the first side 201 and the second side 202. Note that the first end surface 203 is not provided with the active layer 212.

The tab 220 includes a first connection end 221 arranged along the current conducting direction and a second connection end 222 opposite to the first connection end 221, and a terminal end surface of the first connection end 221 is welded to the first end surface 203. That is, the tab 220 is not connected to the first side 201 or the second side 202 of the current collector 211, which does not affect the area of the active layer 212 disposed on the first side 201 and the second side 202. In addition, the second connection end 222 of the tab 220 may be connected with a battery protection plate.

Based on the above, since the first connection end 221 of the tab 220 is connected with the first end face 203 of the current collector 211, the area of the active layer 212 disposed on the first face 201 and the second face 202 is not affected, and the active layer 212 can completely cover the first face 201 or the second face 202, which is beneficial to improving the energy density of the battery cell and the battery. Moreover, protective adhesive tapes do not need to be pasted on the first surface 201 and the second surface 202 of the current collector 211, so that the protective adhesive tapes are prevented from occupying the space in the thickness direction (x-axis direction) of the battery core, and the improvement of the energy density of the battery core and the battery is facilitated.

In addition, it also saves the cost of using protective gummed paper. The tab 220 can be welded at any position of the first end surface 203 of the current collector 211 to meet the design of different overcurrent currents, so that the design flexibility is increased.

For example, the first end surface 203 of the current collector 211 may be provided with a groove, and the first connection end 221 of the tab 220 is welded in the groove, which is beneficial to increase the connection force between the current collector 211 and the tab 220.

Fig. 4 is a schematic diagram illustrating a partial structure of a battery cell according to an exemplary embodiment of the present disclosure. In some embodiments, referring to fig. 4, the battery cell further includes an insulating protective colloid 230, and the insulating protective colloid 230 surrounds the welding connection between the first connection end 221 and the first end face 203. That is, the insulating protective colloid 230 covers the welding connection between the first connection end 221 and the first end surface 203. In this way, the insulating protective colloid 230 protects the joint between the tab 220 and the current collector 211, which not only increases the connection force between the tab 220 and the current collector 211, but also fills the gap at the welded joint to prevent the welding protrusion from piercing the protective shell or other parts.

Illustratively, the insulating protective colloid 230 may be formed by a shadow-less glue (UV glue).

Fig. 5 illustrates a partial structural cross-sectional view of a cell illustrated in accordance with an exemplary embodiment of the present disclosure. In some embodiments, referring to fig. 5, the battery cell further includes a protective casing 240, the protective casing 240 is encapsulated outside the electrode plate 210, and the second connection end 222 of the tab 220 extends out of the protective casing 240. Illustratively, the protective case 240 includes an aluminum plastic film. In the related art, the top of the protective casing 240 (i.e., the area of the protective casing 240 opposite to the tab 220) needs to be bonded by a glue layer to form an encapsulation area, for example, the size of the encapsulation area along the length direction of the battery cell (i.e., the y-axis direction) is 2.5 mm. Because the tab 220 is made of hard metal, the packaging area cannot be bent, which is not beneficial to improving the energy density of the battery cell. To solve this problem, in some embodiments, with continued reference to fig. 5, the tab 220 includes a bendable body, a distal end surface of the bendable body is connected to the first end surface 203, and a portion of the protective case 240 opposite to the bendable body and the bendable body are bent in the same direction. In other words, the encapsulation region of the protective case 240 is bent together with the bendable body of the tab 220. In this way, the size of the encapsulation area of the protective shell 240 and the length direction (i.e., the y-axis direction) of the battery cell occupied by the tab 220 is reduced, which is beneficial to improving the energy density of the battery cell.

Fig. 6 is a schematic diagram illustrating the connection of a metal lead 223 to a current collector 211 according to an exemplary embodiment of the present disclosure. In some embodiments, referring to fig. 6, the bendable body includes a metal wire 223, and one end of the metal wire 223 is connected to the first end face 203. Because the radial dimension of the metal wire 223 is smaller than that of the common tab 220, the metal wire 223 is matched with the first end surface 203 of the current collector 211 conveniently, and the metal wire 223 has good electric conductivity.

Illustratively, the metal wire 223 includes at least one of a copper wire, an aluminum wire, and other composite metal wires 223.

In some embodiments, with continued reference to fig. 6, the number of metal wires 223 is plural, and the plural metal wires 223 are separately arranged. Illustratively, the plurality of metal wires 223 are uniformly arranged, and one end of each metal wire 223 is connected with the first end surface 203 of the current collector 211, and the other end may be connected to the battery protection plate. Like this, through a plurality of metal wire 223 mating reaction, not only can play the effect of dispersed current, do benefit to and reduce the heat production volume, but also do benefit to and charge for electric core with great electric current.

Fig. 7 is a schematic diagram illustrating the connection of a metal lead 223 to a current collector 211 according to an exemplary embodiment of the present disclosure. In some embodiments, referring to fig. 7, the metal wire 223 includes a first connection section 224 and a second connection section 225, one end of the second connection section 225 is connected with one end of the first connection section 224, the other end of the second connection section 225 is connected with the first end surface 203, a radial dimension of the first connection section 224 is greater than a thickness of the current collector 211, and a radial dimension of an end of the second connection section 225 connected with the current collector 211 is less than or equal to the thickness of the current collector 211. In this way, a larger current can be conducted conveniently through the first connection section 224, and the second connection section 225 is connected with the current collector 211 in a matching manner instead of being connected with the active layer 212, so that the second connection section 225 is firmly connected with the current collector 211. It should be noted that "radial" means: a direction perpendicular to the axial direction of the tab 220.

In some embodiments, the radial dimension of the first connecting section 224 is in a range of 10 μm to 20 μm, such as 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm, and the like, and the thickness of the current collector 211 is in a range of 6 μm to 9 μm, such as 6 μm, 7 μm, 8 μm, or 9 μm, and the like. The tab 220 is not a tab piece of the related art and is sized to facilitate the welded connection of the tab 220 to the first end surface 203 of the current collector 211.

Fig. 8 is a flowchart illustrating a method for manufacturing a battery cell according to an exemplary embodiment of the present disclosure. Some embodiments of the present disclosure provide a method for manufacturing a battery cell, the battery cell including: an electrode tab 210 and at least one tab 220; the electrode sheet 210 includes: a current collector 211 and an active layer 212; the current collector 211 includes: a first side 201, a second side 202 opposite to the first side 201, and a first end 203 connecting the first side 201 and the second side 202, an active layer 212 being provided on at least one of the first side 201 and the second side 202; the tab 220 includes a first connection end 221 and a second connection end 222 opposite to the first connection end 221, which are arranged along the current conducting direction, and a terminal end surface of the first connection end 221 is welded to the first end surface 203. Referring to fig. 8, the manufacturing method includes:

step 81, the first connection end 221 of the tab 220 is pulled to the first end face 203 of the current collector 211.

And 82, welding and connecting the tail end surface of the first connecting end 221 with the first end surface 203.

In some embodiments, the method of manufacturing a cell further comprises:

the electrode tab 210 is encapsulated by the protective case 240, so that the second connection end 222 of the tab 220 extends out of the protective case 240.

According to the method for manufacturing the battery cell, the first connection end 221 of the tab 220 is pulled to the first end face 203 of the current collector 211, so that the end face of the first connection end 221 is welded to the first end face 203. Since the first connection end 221 of the tab 220 is connected with the first end face 203 of the current collector 211, the area of the active layer 212 arranged on the first face 201 and the second face 202 is not affected, and the active layer 212 can completely cover the first face 201 or the second face 202, which is beneficial to improving the energy density of the battery cell and the battery. Moreover, protective adhesive tapes do not need to be pasted on the first surface 201 and the second surface 202 of the current collector 211, so that the protective adhesive tapes are prevented from occupying the space in the thickness direction of the battery cell, and the improvement of the energy density of the battery cell is facilitated. The manufacturing method is simple, and the tab 220 can be welded at any position of the first end surface 203 of the current collector 211 so as to meet the design of different overcurrent currents.

Fig. 9 is a flowchart illustrating a method for manufacturing a battery cell according to an exemplary embodiment of the present disclosure. Fig. 10 is a schematic diagram illustrating a manufacturing process of a battery cell according to an exemplary embodiment of the present disclosure. Some embodiments of the present disclosure also provide a method for manufacturing a battery cell, which is combined with fig. 9 and fig. 10, and the method includes:

step 91 fixes the electrode sheet 210 between the suction plate 320 and the top plate 330, and exposes the first end surface 203 between the suction plate 320 and the top plate 330.

After step 91, step 92 may be performed.

Step 92, cleaning the first end face 203 and the first connection end 221.

Illustratively, the first end surface 203 of the current collector 211 is cleaned with a dust collection brush 310 to remove dust from the first end surface 203 of the current collector 211. Illustratively, the first connection end 221 of the tab 220 is subjected to a scrubbing process to remove contaminants from the first connection end 221 of the tab 220. In this way, a firm welding between the first end face 203 of the current collector 211 and the first connection end 221 of the tab 220 is facilitated.

Step 93, the first connection end 221 is pulled to the first end face 203 by the ceramic riving knife 340.

Illustratively, the position of the ceramic riving knife 340 can be adjusted by the control device such that the ceramic riving knife 340 pulls the first connection end 221 to the first end face 203 and the first connection end 221 is opposite to the first end face 203.

Illustratively, the ceramic riving knife 340 pulls the tab 220 opposite to the first end surface 203 of the current collector 211, and the extension direction of the tab 220 is perpendicular to the first end surface 203. In this way, accurate welding connection of the first connection end 221 of the tab 220 and the first end surface 203 of the current collector 211 is facilitated.

Step 94, melting the end of the first connection end 221 into a molten mass, wherein the radial dimension of the molten mass is smaller than the thickness of the current collector 211.

Illustratively, the striking rod 350 is provided at the outlet of the ceramic riving knife 340, and the striking rod 350 is actuated to melt the distal end surface of the first connection end 221 of the tab 220 into a melt.

Illustratively, the outlet size of the ceramic riving knife 340 is smaller than the thickness of the current collector 211, such that the radial size of the outgoing melt is smaller than the thickness of the current collector 211.

And step 95, controlling the ceramic cleaver 340 to pull the molten mass of the first connecting end 221 to be welded and connected with the first end surface 203 under the action of ultrasonic waves.

In this way, the first connection end 221 of the tab 220 is welded to the first end surface 203 of the current collector 211 by the ceramic riving knife 340 and the ultrasonic wave.

And step 96, controlling the ceramic riving knife 340 to move to a set position back to the current collector 211, controlling the wire clamp 360 to clamp the tab 220, and cutting the tab 220 by using the wire cutting knife 370.

Step 97, dispensing around the welding connection between the first connection end 221 and the first end face 203 to form an insulating protective colloid 230.

Illustratively, UV glue is dispensed around the welded connection of the first connection end 221 of the tab 220 and the first end face 203 of the current collector 211 by a glue gun 380 and exposed to ultraviolet light to form the UV glue into the insulating protective glue 230.

The manufacturing method of the battery cell provided by the embodiment of the disclosure is not only simple, but also can weld the tab 220 at any position of the first end surface 203 of the current collector 211 so as to meet the design of different overcurrent currents. And the prepared battery core and the prepared battery have higher energy density, so that the cruising ability of the electronic equipment is improved, and the user experience is improved.

For the method embodiments, since they substantially correspond to the apparatus embodiments, reference may be made to the apparatus embodiments for relevant portions of the description. The method embodiment and the device embodiment are complementary.

The above embodiments of the present disclosure may be complementary to each other without conflict.

The above description is only exemplary of the present disclosure and should not be taken as limiting the disclosure, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.

Claims

1. A battery cell, comprising: an electrode sheet and at least one tab;

the electrode sheet includes: a current collector and an active layer;

2. The battery cell of claim 1, further comprising an insulating protective gel surrounding the welded connection of the first connection end and the first end face.

3. The battery cell of claim 1, further comprising a protective casing, wherein the protective casing is encapsulated outside the electrode sheet, and the second connection end of the tab extends out of the protective casing;

4. The electrical core of claim 3, wherein the bendable body comprises a metal wire, and one end of the metal wire is connected to the first end face.

5. The battery cell of claim 4, wherein the number of the metal wires is multiple, and the multiple metal wires are separately arranged.

6. The battery cell of claim 4, wherein the metal wire comprises a first connection section and a second connection section, one end of the second connection section is connected with one end of the first connection section, the other end of the second connection section is connected with the first end face, a radial dimension of the first connection section is greater than a thickness of the current collector, and a radial dimension of an end portion of the second connection section connected with the current collector is less than or equal to the thickness of the current collector.

7. The cell of claim 6, wherein the first connection segment has a radial dimension in a range from 10 μm to 20 μm, and the current collector has a thickness in a range from 6 μm to 9 μm.

8. A method of manufacturing a battery cell, the method being used for a battery cell, the battery cell comprising: an electrode sheet and at least one tab; the electrode sheet includes: a current collector and an active layer; the current collector includes: the active layer is arranged on at least one of the first surface and the second surface; the lug comprises a first connecting end and a second connecting end, wherein the first connecting end is arranged along the current conduction direction, the second connecting end is opposite to the first connecting end, and the tail end face of the first connecting end is connected with the first end face in a welding mode; the manufacturing method comprises the following steps:

9. The method of manufacturing of claim 8, wherein said drawing the first connection end of the tab to the first end face of the current collector comprises:

10. The manufacturing method according to claim 8, wherein the weld-connecting the distal end surface of the first connection end with the first end surface includes:

11. The manufacturing method according to claim 8, wherein after the solder-connecting the distal end face of the first connection end with the first end face, the manufacturing method further comprises:

12. A battery comprising the cell of any one of claims 1-7.