CN216413218U

CN216413218U - Battery cell, battery pack, power consumption device, and ultrasonic welding device

Info

Publication number: CN216413218U
Application number: CN202122616652.6U
Authority: CN
Inventors: 缪伟振; 张敏; 伍永彬; 林蹬华; 程兴
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2022-04-29
Anticipated expiration: 2031-10-28

Abstract

The application discloses battery monomer, group battery, power consumption device and ultrasonic welding device relates to the battery field for improve the free manufacturing performance of battery. The battery unit comprises a pole ear and an adapter sheet. The tab has a first side and a second side, the first side including a first area and a second area; the second region comprises a transition part and at least two inner concave parts; the transition is located between the fillet and the first region. The adapter plate is fixedly connected with the second side of the pole lug. According to the technical scheme, the phenomenon that the tab cracks at the edge of the welding seal is reduced, namely the possibility that the cracking phenomenon occurs at the edge of the welding seal is improved, and the processing quality of the single battery is improved; in addition, in the process of welding by adopting the ultrasonic welding device, the possibility of cracking at the edge of the welding seal can be improved without other auxiliary components, which is a great improvement on the processing quality and process of the single battery, and the performance of the single battery is greatly improved.

Description

Battery cell, battery pack, power consumption device, and ultrasonic welding device

Technical Field

The application relates to the field of batteries, in particular to a battery monomer, a battery pack, an electric device and an ultrasonic welding device.

Background

New energy technology is developed rapidly day by day, and the application field of new energy technology is more and more extensive. The battery technology is an important factor for measuring the development of new energy technology.

In the processing process of the single battery, the pole ear and the adapter sheet of the single battery need to be welded and fixed together. During the welding process of the pole lug and the adapter plate, the pole lug is easy to weld through.

SUMMERY OF THE UTILITY MODEL

The application provides a battery monomer, group battery, power consumption device and ultrasonic welding device for improve the free manufacturing performance of battery.

The embodiment of the application provides a battery monomer, which comprises a pole lug and an adapter sheet; the tab has a first side and a second side, the first side including a first area and a second area; the second region comprises a transition portion and at least two inner concave portions; the transition portion is located between the inner recess and the first region; the adapter plate is fixedly connected with the second side of the pole lug.

According to the technical scheme, the phenomenon that the tab cracks at the edge of the welding seal due to welding is reduced, namely the possibility that the cracking phenomenon occurs at the edge of the welding seal is improved, and the processing quality of the single battery is improved; in addition, in the process of welding by adopting the ultrasonic welding device, the possibility of cracking at the edge of the welding seal can be improved without other auxiliary components, which is a great improvement on the processing quality and process of the single battery, and the performance of the single battery is greatly improved.

In some embodiments, the transition is configured in a stepped manner, the transition being fixedly connected to the first region. With such a configuration, the deformation amount of the edge of the second region of the tab, that is, the region where the transition portion is located, is required to be small, the extension amount of the extension region is small, and the region where the transition portion and the inner recessed portion are located is not broken by the excessive stretching.

In some embodiments, the transition is configured to be tapered in thickness, the transition smoothly transitioning with the first region. With this configuration, there is no abrupt height difference between the transition and the first region. If the transition part is of gradually changing thickness, the transition part and the first area are smoothly transited, and a highly abrupt area is hardly existed between the transition part and the first area. Therefore, the transition part of the tab extends more uniformly, and the phenomenon of fracture caused by over-stretching is less likely to occur.

In some embodiments, the transition portion comprises an inner groove having a circumferential dimension that is less than a circumferential dimension of the inner groove of the second region. According to the technical scheme, the requirement on the deformation of the edge of the second region of the tab, namely the region where the inner groove is located is small, the extension amount of the extension region is small, and the transition part cannot be broken due to over-stretching.

In some embodiments, the transition portion has inner grooves having a lower arrangement density than the inner grooves of the second region. According to the technical scheme, the requirement on the deformation of the edge of the second region of the tab, namely the region where the transition part is located is small, the extension amount of the extension region is small, and the region where the transition part and the inner concave part are located cannot be broken due to over-stretching.

In some embodiments, the cross-sectional shape of the inner recess and/or the transition portion is configured to take one of the following shapes: circular, rectangular, trapezoidal. According to the technical scheme, the inner concave part and the transition part of the same battery monomer adopt the structural form, so that the welding mark cracking phenomenon in the welding process of the battery monomer can be obviously reduced without greatly changing the existing ultrasonic welding device, and the quality of the battery monomer is improved.

In some embodiments, the cross-sectional shape of the fillet is rectangular; and, along the depth direction of the inner recess, the circumferential dimension of the inner recess is reduced; and/or the transition portion comprises an inner groove, and the cross section of the inner groove is rectangular; and a circumferential dimension of the inner groove decreases in a depth direction of the inner groove. Above-mentioned technical scheme, the circumference size of concave part opening part is big, the circumference size of concave part bottom is little. The structure can reduce the deformation amount of the area where the concave part is positioned in the welding process, reduce the phenomenon of pole ear cracking and improve the quality of a battery monomer. The circumferential size of the opening of the inner groove is large, and the circumferential size of the bottom of the inner groove is small. The structure can reduce the deformation amount of the area where the inner groove is located in the welding process, reduce the phenomenon of pole ear cracking and improve the quality of the battery monomer.

In some embodiments, the indentations are arranged in rows. According to the single battery obtained by the technical scheme, the deformation of the area where the inner concave part is located is balanced, the quality of the single battery is improved, and the probability of defective products in the processing and manufacturing process of the single battery is reduced.

According to the technical scheme, the phenomenon that the tab cracks at the edge of the welding seal due to welding is reduced, namely the possibility that the cracking phenomenon occurs at the edge of the welding seal is improved, and the processing quality of the single battery is improved; in addition, in the process of welding by adopting the ultrasonic welding device, the possibility of cracking at the edge of the welding seal can be improved without other auxiliary components, the processing quality and the process of the single battery are obviously improved, and the performance of the single battery is greatly improved.

The embodiment of the application also provides a battery pack which comprises the battery monomer provided by any technical scheme of the application. The battery pack provided by the technical scheme also has the technical effects introduced above due to the battery cells provided by the technical scheme.

The embodiment of the application also provides an electric device using the battery pack, which comprises the battery pack provided by any technical scheme of the application. The electric device provided by the technical scheme also has the technical effects introduced above due to the battery pack provided by the technical scheme.

The embodiment of the application also provides an ultrasonic welding device, which comprises a main body and a welding head; the welding head comprises a connecting part and a welding spot, and the connecting part is arranged on the main body; the welding spot is arranged on the main body or the connecting part, and the welding spot is configured to be convex relative to the main body.

The welding spots are the main structure of the ultrasonic welding device and are arranged in rows, and each welding spot correspondingly forms an inner concave part in the welding process. The connecting part corresponds to the transition part, and the shape of the connecting part corresponds to the shape of the transition part. The height difference between the main body and the welding head is smaller due to the existence of the connecting part, and a certain transition exists between the main body and the welding head, so that when an ultrasonic welding device is adopted to weld the lug and the adapter plate of the single battery, the phenomenon that the lug cracks at the edge of a welding mark due to welding can be reduced, namely, the possibility that the cracking phenomenon occurs at the edge of the welding mark is improved, and the processing quality of the single battery is improved; in the process of welding by adopting the ultrasonic welding device, the possibility of cracking of the welding edge of the single battery can be improved without other auxiliary components except the welding head and the supporting seat, the processing quality of the single battery is greatly improved, and the processing technology of the single battery is improved.

In some embodiments, the connection portion is configured to be tapered or stepped in thickness; the welding spot is arranged on the connecting part. Above-mentioned technical scheme is favorable to reducing the welding seal fracture phenomenon in the battery monomer course of working.

In some embodiments, the connecting portion is configured as a protruding portion, the protruding portion is arranged around the circumferential outer side of the welding point, and the circumferential size of the protruding portion is smaller than the circumferential size of the welding point.

According to the technical scheme, the circumferential size of the protruding portion is smaller than that of the welding head, so that when the ultrasonic welding device is adopted, the extension amount of the transition portion of the second area of the corresponding tab is smaller, and the extension amount of the inner concave portion of the second area is larger. With such a structure, the requirement for the deformation amount of the edge of the second region of the tab, that is, the region where the transition portion is located, is small, the extension amount of the extension region is small, and the region where the transition portion and the inner recessed portion are located does not break due to excessive stretching.

In some embodiments, the connecting portion is configured as a protruding portion, the protruding portion is arranged around the circumferential outer side of the welding point, and the arrangement density of the protruding portion is lower than that of the welding point.

According to the technical scheme, the protrusions are distributed sparsely, so that when the ultrasonic welding device is adopted, the extension amount of the transition part of the second area of the corresponding tab is smaller, and the extension amount of the concave part of the second area is larger. With such a structure, the requirement for the deformation amount of the edge of the second region of the tab, that is, the region where the transition portion is located, is small, the extension amount of the extension region is small, and the region where the transition portion and the inner recessed portion are located does not break due to excessive stretching.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic diagram of a welding process for obtaining a battery cell provided in an embodiment of the present application;

fig. 2 is a schematic perspective view of an ultrasonic welding device used for obtaining a battery cell according to an embodiment of the present disclosure;

fig. 3 is a partial schematic structural view of an ultrasonic welding apparatus used to obtain the first and second configurations of the battery cells;

FIG. 4 is a schematic diagram illustrating the distribution of weld points on the horn of the ultrasonic welding apparatus illustrated in FIG. 3;

fig. 5 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

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

fig. 7 is a partial schematic structural view illustrating an ultrasonic welding apparatus used to obtain battery cells of third and fourth configurations;

FIG. 8 is a schematic diagram illustrating the distribution of weld points on the horn of the ultrasonic welding apparatus illustrated in FIG. 7;

fig. 9 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

fig. 10 is a schematic structural diagram of a battery cell according to another embodiment of the present application;

fig. 11 is a partial schematic structural view of an ultrasonic welding apparatus used to obtain battery cells of fifth and sixth configurations;

FIG. 12 is a schematic diagram illustrating the distribution of weld points on the horn of the ultrasonic welding apparatus illustrated in FIG. 11;

fig. 13 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

fig. 14 is a schematic structural diagram of a battery cell according to another embodiment of the present application.

Reference numerals:

1. a tab; 2. a patch; 3. a main body; 4. a welding head; 5. a supporting seat; 11. a first side; 12. a second side; 111. a first region; 112. a second region; 113. a polar tab; 112a, a transition portion; 112b, an inner concave portion; 41. a connecting portion; 42. and (7) welding points.

Detailed Description

The technical solution provided by the present application is explained in more detail below with reference to fig. 1 to 14.

The technical means of the present application will be described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Aspects so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature considered to be preferred or advantageous may be combined with one or more other features considered to be preferred or advantageous.

The terms "first", "second", and the like in this application are used for convenience of description only to distinguish different constituent elements having the same name, and do not denote a sequential or primary-secondary relationship. Further, when an element is referred to as being connected to another element, it can be directly connected to the other element or be indirectly connected to the other element with one or more intervening elements interposed therebetween. Hereinafter, like reference numerals denote like elements.

One of the important steps in manufacturing the battery cell is to fixedly connect the pole piece of the battery cell with the adapter sheet. In the related art, an ultrasonic welding device is used to weld the pole piece of the battery cell and the adapter sheet together by means of the protection sheet. In order to reduce the processing and manufacturing cost of the battery monomer and reduce the occurrence of defective products and equipment faults caused by the adoption of the protection sheet, a new technology is to not adopt the protection sheet in the welding process of the pole piece and the adapter piece. The battery protection plate is not adopted, so that the processing and manufacturing cost of the battery can be reduced, the faults of defective products and equipment caused by the adoption of the protection plate are reduced, the deformation of the tab in the welding process is too large, the tab is welded through or is welded to crack, and the rejection rate of the battery monomers is greatly improved. In order to solve this problem, the applicant of the present application has made creative efforts to propose the following solutions. This scheme not only can not adopt the screening glass in the welding process of free utmost point ear of battery and switching piece, reduces owing to adopt the defective products and the equipment trouble that the screening glass caused, can also greatly reduced utmost point ear by the welding, weld the probability of splitting, obviously improve free processingquality of battery and finished product qualification rate.

The embodiment of the application provides an electric device using the battery pack, and the electric device adopts the battery pack provided by the embodiment of the application to provide energy. The electric device can be, but is not limited to, a new energy vehicle, a ship, an intelligent electric cabinet, an aircraft electronic terminal (such as a mobile phone, a tablet computer, a desktop computer and the like), an electric toy, an electric tool, a ship and the like. The battery pack is used as a power supply part to supply required electric energy to various electrical components of the device.

The embodiment of the application also provides a battery pack which comprises the battery monomer provided by any technical scheme of the application.

The battery unit is installed in a case of the battery pack. The battery monomer and the box body are fixedly connected, and are fixed together by glue. In order to fix the battery monomer and the box body stably and reliably, glue can be arranged on the bottom wall of the box body and the side wall of the box body. Further, still keep off the piece through setting up, limit the height of gluing of battery monomer and box lateral wall and the thickness of gluing of box diapire, and then the thickness of gluing of accurate control battery monomer and box lateral wall and battery monomer and box diapire.

The battery pack includes a plurality of battery cells. A plurality of battery cells may be arranged in a plurality of rows along a length direction of the case. Multiple rows of battery cells may also be provided along the width of the battery pack. One or more layers of battery cells may also be provided in the height direction of the battery pack, as desired. The individual cells are electrically connected, such as in parallel, in series, or in series-parallel, to achieve desired electrical performance parameters.

Each battery cell includes a case, an electrode assembly, a positive end cap assembly, and a negative end cap assembly. The housing has a cavity, and both ends of the housing are open. The electrode assembly is mounted in the cavity of the case. The positive terminal cover assembly is arranged at the opening at one end of the shell to close the opening at one end of the shell, and the positive terminal cover assembly is electrically connected with the positive electrode tab of the electrode assembly. The negative end cap assembly is disposed at the other end of the case to close the opening at the other end of the case, and the negative end cap assembly is electrically connected with a negative electrode tab of the electrode assembly.

The electrode assembly is manufactured in a laminated type or a wound type. The laminated electrode assembly is formed by cutting a positive electrode plate, a negative electrode plate and a diaphragm into a size with a specified size, and then laminating the positive electrode plate, the diaphragm and the negative electrode plate into an electrode assembly. The winding electrode assembly is formed by winding a positive electrode plate, a negative electrode plate and a diaphragm. In some embodiments, the battery cell is exemplified by a wound electrode assembly, and the case is also cylindrical. The end cap assemblies are generally circular to match the open shape of the two ends of the housing.

Referring to fig. 1 and 2, a specific implementation of the battery cell is described below. The embodiment of the application provides a battery cell, including utmost point ear 1 and switching piece 2. The tab 1 has a first side 11 and a second side 12, the first side 11 including a first region 111 and a second region 112; the second region 112 includes a transition portion 112a and at least two inner recess portions 112 b; the transition portion 112a is located between the inner recess portion 112b and the first region 111. The adapter plate 2 is fixedly connected with the second side 12 of the tab 1.

The tab 1 includes at least one layer of tab 113, specifically one or more layers. Each pole tab 113 is sheet-like. Hereinafter, the example in which the tab 1 includes the multi-layer tab piece 113 will be described. Initially, the respective layers of tab pieces 113 are separated from each other without being fixedly connected to each other during the manufacturing process of the battery cell. The pole ear 1 and the adapter plate 2 are also separated and not fixedly connected. In the manufacturing process of the single battery, the support seat is adopted to support the adapter sheet 2, then the multi-layer pole lug sheets 113 are mutually overlapped and attached, and the pole lug sheet 113 closest to the adapter sheet 2 is attached to the adapter sheet 2. And then, the welding head 4 is adopted to abut against the outer side of the pole lug 1 of the multi-layer pole lug sheet 113 farthest from the adapter sheet 2. Starting the welding head 4, and mutually melting and fixing the multi-layer tab sheets 113; the tab piece 113 closest to the interposer 2 is welded and fixed to the interposer 2.

In the above welding process, the side of the tab piece 113 closest to the welding head 4 is the first side 11 of the tab 1, and the tab piece 113 located on the first side 11 has the largest deformation amount in the welding process. The side of the tab 113 farthest from the welding head 4 is the second side 12 of the tab 1, and the tab 113 farthest from the welding head 4 has the smallest deformation.

The first side 11 of the tab 1 has a first region 111 and a second region 112, and as shown in fig. 1 to 2, the first region 111 is a region where the tab 1 is not deformed during welding. The second region 112 is a region where the tab 1 is in contact with the welding head 4 during welding. The second region 112 is deformed during the welding process in such a way that it is recessed in the direction of the support seat.

Referring to fig. 3 to 6, fig. 3 illustrates a partial structure diagram of a welding head 4 used in a process of welding a tab 1 and an adapter sheet 2, and fig. 4 illustrates a distribution diagram of a connecting portion 41 and a welding point 42 on the welding head 4. Fig. 5 illustrates a schematic structural diagram of a single-side tab formed by using the welding head 4 provided in fig. 3 and 4, and fig. 6 illustrates a schematic structural diagram of a single-side tab formed by using the welding head 4 provided in fig. 3 and 4. The shape of the second region 112 of the battery cell corresponds to the shape of the soldering tip 4. In the position where the horn 4 assumes a convex shape, after welding, an inward recess 112b is correspondingly formed in the tab 1.

The difference between fig. 5 and 6 is that the tab 1 of the battery cell protrudes from one side or both sides of the battery cell. In the embodiment illustrated in fig. 5, the tab 1 of the battery cell protrudes from one side. In the process of manufacturing the battery monomer, two ultrasonic welding devices can be adopted to respectively weld and fix the two tabs 1 and the corresponding adapter plates 2; or an ultrasonic welding device can be adopted to sequentially complete the welding and fixing of the two tabs 1 and the corresponding adapter plates 2. The battery cell shown in fig. 6 has tabs 1 extending from both sides of the battery cell in the axial direction, i.e., one tab 1 is provided on each side of the battery cell in the axial direction. Similarly, in the process of manufacturing the single battery, two ultrasonic welding devices can be adopted to respectively weld and fix the two tabs 1 and the corresponding adapter pieces 2; or an ultrasonic welding device can be adopted to sequentially complete the welding and fixing of the two tabs 1 and the corresponding adapter plates 2.

The battery cell shown in fig. 5 and 6 can be obtained by using the ultrasonic welding apparatus shown in fig. 3 and 4. To more clearly illustrate the structure of the battery cell, the structure of the ultrasonic welding apparatus will be described. Referring to fig. 3 and 4, the welding head 4 comprises a body 3 and a welding head 4. The soldering tip 4 comprises a connection 41 and a soldering point 42. The connecting part 41 is mounted on the main body 3; the weld 42 is provided on the body 3 or the connection portion 41, and the weld 42 is formed to be convex with respect to the body 3. The connection portion 41 is configured to be stepped. Since the welding head 4 is attached to the tab 1 during welding, the structure of the ultrasonic welding apparatus corresponds to that of the battery cell. The transition portion 112a makes a height difference between the inner concave portions 112b of the first and

second regions

111 and 112 relatively small, and there is a certain transition therebetween.

Therefore, the phenomenon that the edge of the welding seal of the tab 1 cracks due to welding can be reduced, namely the possibility that the edge of the welding seal cracks is improved, and the processing quality of the single battery is improved; in addition, in the process of welding by adopting the ultrasonic welding device, the possibility of cracking at the edge of the weld mark can be improved without other auxiliary components, which is a great improvement on the processing quality and process of the single battery.

Various implementations of the transition portion 112a are described in detail below.

Referring to fig. 3-6, in some embodiments, the transition portion 112a is configured to be stepped, and the transition portion 112a is fixedly connected with the first region 111.

With reference to the structure of the welding head 4 illustrated in fig. 3 and 4, at its edges a step is provided which allows a transition zone between the body 3 and the weld 42. Due to the presence of the step, the amount of deformation occurring in the region of the tab 1 corresponding to the step during welding of the tab 1 of the battery cell is determined by the height of the step. Referring to fig. 5 and 6, the battery cell obtained by using the welding head 4 illustrated in fig. 3 and 4 also has a step on the tab 1. The step is a transition part 112a of the tab 1 of the battery cell. Due to the existence of the transition part 112a, the height difference between the first region 111 and the inner concave part 112b of the second region 112 of the tab 1 does not reach at one time in the process of welding the tab 1, but changes from the first region 111 of the tab 1 to the region where the transition part 112a is located, and then reaches the depth where the inner concave part 112b of the second region 112 is located from the region where the transition part 112a is located.

With such a structure, the edge of the second region 112 of the tab 1, that is, the region where the transition portion 112a is located, is required to have a small deformation amount, the extension amount of the extension region is small, and the regions where the transition portion 112a and the inner concave portion 112b are located are not broken by excessive stretching.

In another similar configuration, in other embodiments, the transition portion 112a is configured to be tapered, and the transition portion 112a smoothly transitions with the first region 111.

In the battery cell of fig. 5 and 6 described above, the edge of the second region 112 is the transition portion 112a, and the transition portion 112a is a step that is depressed with respect to the first region 111. With this structure, there is no abrupt height difference between the transition portion 112a and the first region 111. If the transition portion 112a is formed with a gradually changing thickness, the transition portion 112a smoothly transitions with the first region 111, and there is almost no highly abrupt region between the transition portion 112a and the first region 111.

This makes the transition portion 112a of the tab 1 more uniformly extended, and is less likely to be broken due to excessive stretching.

Referring to fig. 7-10, in other embodiments, the transition portion 112a has an inner recess having a circumferential dimension that is less than a circumferential dimension of the inner recess 112b of the second region 112.

Referring to fig. 7 and 8, fig. 7 illustrates a partial structural view of an ultrasonic welding apparatus used to obtain battery cells of the third and fourth structures, and fig. 8 illustrates a distribution view of a connection portion 41 and a welding point 42 on a welding head 4 of the ultrasonic welding apparatus illustrated in fig. 7.

The difference between fig. 9 and 10 is that the tab 1 of the battery cell protrudes from one side or both sides of the battery cell. In the embodiment illustrated in fig. 9, the tab 1 of the battery cell protrudes from one side. In the process of manufacturing the battery monomer, two ultrasonic welding devices can be adopted to respectively weld and fix the two tabs 1 and the corresponding adapter plates 2; or an ultrasonic welding device can be adopted to sequentially complete the welding and fixing of the two tabs 1 and the corresponding adapter plates 2. The battery cell shown in fig. 10 has tabs 1 extending from both sides of the battery cell in the axial direction, i.e., the tabs 1 are provided on each side of the battery cell in the axial direction. Similarly, in the process of manufacturing the single battery, two ultrasonic welding devices can be adopted to respectively weld and fix the two tabs 1 and the corresponding adapter pieces 2; or an ultrasonic welding device can be adopted to sequentially complete the welding and fixing of the two tabs 1 and the corresponding adapter plates 2.

Referring to fig. 9 and 10, the battery cell obtained by using the welding head 4 illustrated in fig. 7 and 8 has the transition portion 112a of the tab 1 having an inner groove. The inner grooves and the inner concave portions 112b are recessed in the same direction toward the side where the interposer 2 is located. The inner groove and the inner recess 112b are different in that: the circumferential dimension of the inner groove is smaller than the circumferential dimension of the inner recess 112b of the second region 112. Taking the inner groove 112b with a hemispherical or spherical crown shape as an example, the inner groove 112b has a small radius and the inner groove 112b has a large radius; the depth of the inner groove is shallow and the depth of the inner recess 112b is large. Due to the existence of the inner grooves, the height difference between the inner grooves 112b of the first region 111 and the second region 112 of the tab 1 does not reach at one time in the process of welding the tab 1, but changes from the first region 111 of the tab 1 to the region where the inner grooves of the transition portion 112a are located, and then changes from the region where the inner grooves are located to the depth where the inner grooves 112b of the second region 112 are located.

With such a configuration, the edge of the second region 112 of the tab 1, i.e., the region where the inner groove is located, is required to have a small deformation amount, the extension amount of the extension region is small, and the transition portion 112a is not broken by excessive stretching.

Referring to fig. 11-14, in some embodiments, the transition portion 112a has inner grooves arranged at a lower density than the inner grooves 112b of the second region 112.

Fig. 11 illustrates a partial structural view of an ultrasonic welding device used for obtaining battery cells of fifth and sixth configurations, fig. 12 illustrates a distribution view of welding points 42 on a welding head 4 of the ultrasonic welding device illustrated in fig. 11, fig. 13 is a structural view of battery cells provided in some embodiments of the present application, and fig. 14 is a structural view of battery cells provided in other embodiments of the present application.

The difference between fig. 13 and 14 is that the tab 1 of the battery cell protrudes from one side or both sides of the battery cell. In the embodiment illustrated in fig. 13, the tab 1 of the battery cell protrudes from one side. In the process of manufacturing the battery monomer, two ultrasonic welding devices can be adopted to respectively weld and fix the two tabs 1 and the corresponding adapter plates 2; or an ultrasonic welding device can be adopted to sequentially complete the welding and fixing of the two tabs 1 and the corresponding adapter plates 2. The battery cell shown in fig. 14 has tabs 1 extending from both axial sides of the battery cell, i.e., one tab 1 is provided on each axial side of the battery cell. Similarly, in the process of manufacturing the single battery, two ultrasonic welding devices can be adopted to respectively weld and fix the two tabs 1 and the corresponding adapter pieces 2; or an ultrasonic welding device can be adopted to sequentially complete the welding and fixing of the two tabs 1 and the corresponding adapter plates 2.

Referring to the structure of the horn 4 illustrated in fig. 11 and 12, at its edge is a connecting portion 41, the connecting portion 41 being configured as a raised portion which is sparsely distributed than the horn 4. These sparsely distributed bosses allow for a transition region between the body 3 and the weld 42. Due to the presence of the protrusions which are sparsely distributed, the amount of deformation occurring in the region of the tab 1 corresponding to the protrusions during welding of the tab 1 of the battery cell is determined by the number of the protrusions. Referring to fig. 13 and 14, the battery cell obtained by using the welding head 4 illustrated in fig. 11 and 12 has an inner groove in the tab 1. The inner groove is the transition part 112a of the tab 1 of the battery cell. Due to the existence of the inner grooves with relatively sparse distribution, the extension amount of the transition portion 112a of the second region 112 of the tab 1 is relatively small, and the extension amount of the inner groove 112b of the second region 112 is relatively large. From the first region 111 to the second region 112, the amount of extension of the entire tab 1 during welding is changed to: the extension of the first region 111 is the smallest, the extension of the transition portion 112a is greater than the extension of the first region 111, and the extension of the concave portion 112b is greater than the extension of the transition portion 112 a. It can be seen that the extension amount of the tab 1 is gradually changed. With such a structure, the edge of the second region 112 of the tab 1, that is, the region where the transition portion 112a is located, is required to have a small deformation amount, the extension amount of the extension region is small, and the regions where the transition portion 112a and the inner concave portion 112b are located are not broken by excessive stretching.

Referring to fig. 1-14, in the various embodiments described above, the cross-sectional shape of the inner recess 112b and/or the transition portion 112a is configured to take on one of the following shapes: circular, rectangular, trapezoidal.

As can be seen from the above description, the structure of the ultrasonic welding apparatus is related to the structure of the battery cell to be formed. The weld 42 corresponds in shape to the concave portion 112b and the connecting portion 41 corresponds in shape to the transition portion 112 a. If the connecting portion 41 and the weld spot 42 of the ultrasonic welding apparatus are configured in a convex circular shape, the shape of the transition portion 112a and the concave portion 112b obtained after welding is a concave circular shape. If the connecting portion 41 and the weld spot 42 of the ultrasonic welding apparatus are configured as a convex rectangle, the shape of the transition portion 112a and the concave portion 112b obtained after welding is a concave rectangle. If the connecting portion 41 and the weld spot 42 of the ultrasonic welding apparatus are formed in a convex trapezoidal shape, the shape of the transition portion 112a and the concave portion 112b obtained after welding is a concave trapezoidal shape. The structures of the respective concave portions 112b may be the same or different. The configuration of the inner grooves of the transition portion 112a may be the same or different.

According to the technical scheme, the inner concave part 112b and the transition part 112a of the same single battery adopt the structural form, so that the welding mark cracking phenomenon in the welding process of the single battery can be obviously reduced without great structural change of the existing ultrasonic welding device, and the manufacturing quality of the single battery is improved.

In some embodiments, the cross-sectional shape of the interior recess 112b is rectangular; also, the circumferential dimension of the inner concave portion 112b decreases along the depth direction of the inner concave portion 112 b. And/or, transition portion 112a includes an inner groove having a rectangular cross-sectional shape; and, along the depth direction of the inner groove, the circumferential dimension of the inner groove is reduced.

The number of the inner concave portions 112b of the second region 112 of the battery cell is plural, and the size and the structure of each inner concave portion 112b may be the same or different. Each concave part 112b adopts the same structure, so that the processing is more convenient, each concave part 112b adopts different structures, the pertinence is stronger, and the targeted reduction of the deformation amount of a certain position of a single battery in actual production is facilitated. In some embodiments, the configuration of each of the interior recesses 112b is the same, and the circumferential dimension of each of the interior recesses 112b is tapered from the open end to the bottom thereof.

Specifically, the circumferential dimension at the opening of the inner recess 112b is large, and the circumferential dimension at the bottom of the inner recess 112b is small. The structure can reduce the deformation amount of the area where the inner concave part 112b is positioned in the welding process, reduce the cracking phenomenon of the pole ear 1 and improve the quality of the battery monomer.

The number of the inner grooves of the second region 112 of the battery cell is multiple, and the size and the structure of each inner groove may be the same or different. Each inner groove adopts the same structure to be convenient for more process, and each inner groove adopts different structures then pertinence is stronger, is favorable to reducing the deformation volume of battery monomer somewhere pertinence according to engineering practice. In some embodiments, each side of each inner recess 112b is provided with a row of inner recesses, each of which is of the same configuration, each inner recess having a gradually changing circumferential dimension from its open end to its base.

The circumferential size of the opening of the inner groove is large, and the circumferential size of the bottom of the inner groove is small. The structure can reduce the deformation amount of the area where the inner groove is located in the welding process, reduce the cracking phenomenon of the tab 1 and improve the quality of the battery monomer.

In some embodiments, the recessed portions 112b located in the second region 112 are arranged in rows.

Referring to fig. 1 to 14, the concave portions 112b of the second region 112 are arranged in rows, such as 2 rows, 3 rows, 4 rows, or even more. Each row includes at least two interior recesses 112 b. The concave portions 112b are arranged in a rectangular shape as a whole. In various embodiments where the transition portion 112a employs inner grooves, one or more rows of inner grooves are provided at each edge of the inner recess 112 b. According to the above description, the inner grooves are arranged in two ways: first, the number of inner grooves of each row is the same as the number of corresponding inner recesses 112b, but the circumferential dimension of each inner groove is smaller than the circumferential dimension of the corresponding inner recess 112b, as shown in fig. 7 to 10. Second, the number of inner grooves in each row is smaller than the number of corresponding inner recesses 112b, but the circumferential dimension of each inner groove is equal to the circumferential dimension of the corresponding inner recess 112b, as shown in fig. 11 to 14.

According to the single battery obtained by the technical scheme, the deformation of the lug 1 of the single battery in the area where the inner concave part 112b is located is relatively balanced, so that the quality of the single battery is improved, and the probability of defective products in the processing and manufacturing process of the single battery is reduced.

It is understood that the above only shows some embodiments of the battery cell, and that the above embodiments may be combined with each other without conflict. For example, the transition portion 112a includes both a step and an inner groove. In combination, the transition portion 112a is stepped and has an inner recess with a circumferential dimension less than that of the inner recess 112 b. In another combination, the transition portion 112a is provided with steps and a smaller number of inner grooves than the inner grooves 112 b. In another combination, the transition portion 112a employs steps and inner grooves that are fewer in number than the inner grooves 112b and have a circumferential dimension that is less than a circumferential dimension of the inner grooves 112 b.

The contents of the ultrasonic welding apparatus will be described below, and the battery cell described above can be obtained by using the ultrasonic welding apparatus described herein.

Referring to fig. 1 to 3, other embodiments of the present invention provide an ultrasonic welding apparatus including a main body 3 and a welding head 4. The welding head 4 comprises a connecting part 41 and a welding spot 42, wherein the connecting part 41 is arranged on the main body 3; the weld 42 is provided on the body 3 or the connection portion 41, and the weld 42 is formed to be convex with respect to the body 3.

The welding spots 42 are the main structure of the ultrasonic welding device, and the welding spots 42 are arranged in rows, and each welding spot 42 correspondingly forms one concave part 112b during the welding process. The connecting portion 41 corresponds to the transition portion 112a, and the shape of the connecting portion 41 corresponds to the shape of the transition portion 112 a.

The connecting part 41 enables the height difference between the main body 3 and the welding head 4 to be smaller, and a certain transition exists between the main body 3 and the welding head 4, so that when an ultrasonic welding device is adopted to weld the lug 1 and the adapter plate 2 of the single battery, the phenomenon that the lug 1 cracks at the edge of a welding mark due to welding can be reduced, namely the possibility that the cracking phenomenon occurs at the edge of the welding mark is improved, and the processing quality of the single battery is improved; in the process of welding by adopting the ultrasonic welding device, the possibility of cracking of the welding edge of the single battery can be improved without other auxiliary components except the welding head 4 and the supporting seat 5, the processing quality of the single battery is greatly improved, and the processing technology of the single battery is improved.

Referring to fig. 1 to 4, in some embodiments, the connection portion 41 is configured to be tapered or stepped in thickness; the solder 42 is disposed on the connection portion 41.

With reference to the configuration of the welding head 4 illustrated in fig. 3 and 4, at its edges there correspond the areas where the connection portions 41 are located. The connecting portion 41 has a wedge-shaped structure with a gradually changing thickness. The wedge-shaped structure enables a transition area to exist between the main body 3 and the welding point 42, and is beneficial to reducing welding mark cracking in the processing process of the single battery. In other embodiments, the connection portion 41 is stepped, that is, a step is provided, and the step enables a transition region to exist between the main body 3 and the welding point 42, which is beneficial to reducing welding crack phenomenon during the processing of the battery cell.

Referring to fig. 7 and 8, in some embodiments, the connection portion 41 is configured as a protrusion that surrounds the circumferential outer side of the spot weld 42, and the circumferential dimension of the protrusion is smaller than the circumferential dimension of the spot weld 42.

The connection portion 41 is a projection, and the structures of the projections may be the same or different. In the embodiment illustrated in fig. 7 and 8, the structure of each convex portion is taken as an example. As introduced above, the welding heads 4 are arranged in a rectangular shape. One or more rows of projections may be provided on each side of the periphery of the horn 4.

In the above technical solution, the circumferential dimension of the protruding portion is smaller than the circumferential dimension of the welding head 4, so that when the ultrasonic welding apparatus is used, the extension amount of the transition portion 112a of the second region 112 of the corresponding tab 1 is relatively small, and the extension amount of the inner concave portion 112b of the second region 112 is relatively large. With such a structure, the deformation of the edge of the second region 112 of the tab 1, i.e., the region where the transition portion 112a is located, is required to be small, the extension amount of the extension region is small, and the regions where the transition portion 112a and the inner concave portion 112b are located are not broken by excessive stretching.

In some embodiments, the connecting portion 41 is configured as a protruding portion, the protruding portion is disposed around the circumferential outer side of the welding spots 42, and the arrangement density of the protruding portion is lower than that of the welding spots 42.

The connection portion 41 is a projection, and the structures of the projections may be the same or different. In the embodiment illustrated in fig. 11 and 12, the structure of each of the protrusions is the same as an example. As introduced above, the welding heads 4 are arranged in a rectangular shape. One or more rows of projections may be provided on each side of the periphery of the horn 4. The number of projections is less than the number of welding heads 4 to which they correspond. One for each two or more welding heads 4. As shown in fig. 11 and 12, there are 10 horn 4 in each row and 5 lobes in each row. Each vertical column has 2 welding heads 4 and each vertical column also has 2 protrusions, although only one protrusion may be provided.

The configuration and dimensions of each boss are the same as the configuration and dimensions of each horn 4, which facilitates manufacturing to form the bosses.

In the above technical solution, the protrusions are distributed sparsely, so that when the ultrasonic welding apparatus is used, the extension amount of the transition portion 112a of the second region 112 of the corresponding tab 1 is relatively small, and the extension amount of the inner recess portion 112b of the second region 112 is relatively large. With such a structure, the deformation of the edge of the second region 112 of the tab 1, i.e., the region where the transition portion 112a is located, is required to be small, the extension amount of the extension region is small, and the regions where the transition portion 112a and the inner concave portion 112b are located are not broken by excessive stretching.

In the description of the present application, it is to be understood that the terms "central," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present disclosure.

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

1. A battery cell, comprising:

a tab (1) having a first side (11) and a second side (12); the first side (11) comprises a first region (111) and a second region (112); the second region (112) comprises a transition portion (112a) and at least two inner recess portions (112 b); the transition (112a) is located between the inner recess (112b) and the first region (111); and

and the adapter plate (2) is fixedly connected with the second side (12) of the tab (1).

2. The battery cell according to claim 1, characterized in that the transition (112a) is designed in a stepped manner, the transition (112a) being fixedly connected to the first region (111).

3. The battery cell according to claim 1, characterized in that the transition (112a) is configured to be of a gradual thickness, the transition (112a) smoothly transitioning with the first region (111).

4. The battery cell according to claim 1, characterized in that the transition portion (112a) comprises an inner groove having a circumferential dimension smaller than a circumferential dimension of an inner groove (112b) of the second region (112).

5. The battery cell according to claim 1, wherein the transition portion (112a) has inner grooves having a lower arrangement density than inner grooves (112b) of the second region (112).

6. The battery cell according to claim 4 or 5, characterized in that the cross-sectional shape of the inner groove of the inner recess (112b) and/or the transition (112a) is configured to take one of the following shapes: circular, rectangular, trapezoidal.

7. The battery cell according to claim 6, wherein the cross-sectional shape of the concave portion (112b) is rectangular; and, along the depth direction of the inner concave portion (112b), the circumferential dimension of the inner concave portion (112b) is reduced; and/or, the transition portion (112a) comprises an inner groove having a rectangular cross-sectional shape; and a circumferential dimension of the inner groove decreases in a depth direction of the inner groove.

8. The battery cell according to any one of claims 1 to 5, wherein the recessed portions (112b) are arranged in a row.

9. A battery pack comprising a battery cell according to any one of claims 1 to 8.

10. An electric device using the battery pack, characterized by comprising the battery pack according to claim 9.

11. An ultrasonic welding apparatus, comprising:

a main body (3); and

a welding head (4) comprising a connecting portion (41) and a welding spot (42), the connecting portion (41) being mounted to the body (3); the weld (42) is arranged on the main body (3) or the connecting part (41), and the weld (42) is convex relative to the main body (3).

12. The ultrasonic welding device according to claim 11, characterized in that the connection portion (41) is configured to be tapered or stepped in thickness; the welding spot (42) is arranged on the connecting part (41).

13. The ultrasonic welding device according to claim 11, characterized in that the connection portion (41) is configured as a projection which is provided around the circumferential outside of the weld spot (42) and has a circumferential dimension which is smaller than the circumferential dimension of the weld spot (42).

14. The ultrasonic welding device according to claim 11, characterized in that the connecting portion (41) is configured as a raised portion which is provided around a circumferential outer side of the welding spots (42) and has an arrangement density lower than that of the welding spots (42).