CN217903391U

CN217903391U - Battery with improved battery capacity

Info

Publication number: CN217903391U
Application number: CN202221758675.9U
Authority: CN
Inventors: 廖科军; 张叶; 舒清宇; 邹浒
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2022-11-25
Anticipated expiration: 2032-07-08

Abstract

A battery, comprising: an electric core; the soft lug is electrically connected with the battery cell and extends out of the battery cell; the hard lug is connected with the soft lug and comprises a welding end and a probing end, the welding end is connected with the soft lug, and the thickness of the welding end is smaller than that of the probing end. The utility model discloses divide into probe end and welding end with hard utmost point ear to the thickness that will probe end and welding end sets up to the difference, makes the thickness of welding end be less than the thickness of probing the end, thereby reduces the thickness of soft utmost point ear and hard utmost point ear hookup location, not only can reduce the welding energy, reduces the height of welding the seal bump on utmost point ear, but also can make to roll over occupy on electric core height space after utmost point ear, and then improved the energy density of battery.

Description

Battery with improved battery capacity

Technical Field

The utility model belongs to the technical field of the lithium cell, more specifically says, relates to a battery.

Background

Lithium ion batteries are widely used in electronic devices such as mobile phones, notebook computers, electric tools, and the like. With the progress and development of science and technology, people have higher and higher requirements on electronic equipment, and besides basic requirements such as safety and the like, higher performance requirements such as high multiplying power and quick charging are also provided. The multi-tab structure is one of the ways for realizing high-rate charge and discharge of the battery, the high-rate charge and discharge can be realized by increasing the number of tabs of the battery cell, and the temperature cannot rise too fast under the high-rate use condition, so that the application of the battery with the multi-tab structure is more and more common.

One of the differences between the manufacturing processes of the battery with the multi-tab structure and the battery with the conventional single-tab structure is that the soft tab and the hard tab of the battery cell are required to be welded together, welding spot protective glue is pasted at the welding spot position after welding, and then the hard tab is folded for packaging. In order to ensure the welding firmness between the hard tab and the soft tab and have enough overcurrent sectional area, a relatively thick hard tab is often used. However, when the thickness of the hard tab is thick, the hard tab can occupy more height space of the battery cell after being folded. On the other hand, the hard tab is thick, so that the required welding energy is large, the welding mark on the hard tab is deep, the size of the folded tab is increased, the height space of a battery cell is occupied, and the energy density of the battery is influenced finally. In addition, still be provided with the insulating cement on the hard utmost point ear, at present in the lithium ion battery production technology of many utmost point ears structure, the necking zone of insulating cement easily takes place the insulating cement excessive phenomenon when carrying out the plastic-aluminum membrane encapsulation, leads to utmost point ear and insulating cement necking zone's PP (polypropylene) to keep the rate lower, can form tiny electrolyte passageway after electrolyte soaks, causes the electrolyte weeping, influences electric core security performance.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a can improve energy density's battery.

In order to achieve the above object, the present invention adopts the following technical solutions:

a battery, comprising: an electric core; the soft lug is electrically connected with the battery cell and extends out of the battery cell; the hard lug is connected with the soft lug and comprises a welding end and a probing end, the welding end is connected with the soft lug, and the thickness of the welding end is smaller than that of the probing end.

According to the above technical scheme, the utility model discloses divide into probe end and welding end with hard utmost point ear to the thickness that will probe end and welding end sets up to the difference, makes the thickness of welding end be less than the thickness of probing the end, thereby reduces the thickness of soft utmost point ear and hard utmost point ear hookup location, not only can reduce the welding energy, reduces the height of welding the seal bump on the utmost point ear, but also can make to roll over and take on electric core height space behind the utmost point ear, and then improved the energy density of battery.

Further, the ratio of the thickness of the welding end to the thickness of the probing end is greater than 0.3 and less than 1.

Furthermore, the number of the soft tabs is more than one.

Furthermore, the device also comprises insulating glue, wherein the insulating glue is pasted on the front surface and the back surface of the joint of the detection end and the welding end.

Further, the insulating glue is provided with a necking section, and the thickness of the necking section is larger than that of other positions of the insulating glue.

Through changing utmost point ear insulating cement's shape, the thickness that makes the necking down section of insulating cement is greater than the thickness of insulating cement other positions to can improve the cross-section reduction phenomenon of necking down section after the insulating cement pastes on utmost point ear, improve hard utmost point ear strap and insulating cement necking down district's PP and keep rate, reduce the bulging problem because utmost point ear position department banding weeping causes in the lithium cell production process, and then promote the security performance of battery.

Furthermore, the thickness of the single-layer insulating glue is 0.1-0.6 mm, and the thickness of the double-layer insulating glue is 0.2-1.2 mm.

Further, welding spot protective glue is arranged on the front surface and the back surface of the joint of the welding end and the soft pole lug, and at least the area between the bottom of the insulating glue and the top of the battery cell is covered by the welding spot protective glue.

Further, the ratio of the thicknesses of the double-layer insulating glue and the single-layer insulating glue is larger than 1 and smaller than 3.

Further, the insulating glue is provided with two necking sections which are arranged at intervals, and the two necking sections are respectively positioned on two sides of the hard tab in the width direction of the hard tab.

Further, the insulating glue is provided with a necking section, and the length of the necking section is larger than the width of the hard tab.

Drawings

In order to illustrate the embodiments of the present invention more clearly, the drawings that are needed in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained by those skilled in the art without inventive effort.

Fig. 1 is a schematic structural diagram of a battery according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a hard tab according to an embodiment of the present invention;

fig. 3 is a side view of a battery according to an embodiment of the present invention;

fig. 4a to 4e are flow charts of welding a hard tab and a soft tab according to an embodiment of the present invention;

fig. 5 is a partially enlarged schematic view of the welding position of the soft tab and the hard tab of the embodiment of the present invention;

fig. 6 is a schematic view of a connection structure between a cell tab and a first bus bar in a second cell unit according to an embodiment of the present invention;

fig. 7 is a schematic view of the tab prepared for application of an insulating adhesive to the front and back sides of the tab;

fig. 8 is a schematic cross-sectional view of the tab after applying insulating glue to the front and back sides of the tab;

fig. 9 is a schematic view of an insulation paste according to an embodiment of the present invention;

fig. 10 is a schematic view of an insulation paste attached to a tab according to an embodiment of the present invention;

fig. 11 is a schematic view of another embodiment of the insulating paste of the present invention;

fig. 12 is a schematic cross-sectional view illustrating an insulation paste applied to a tab according to another embodiment of the present invention;

fig. 13 is a schematic diagram of arranging a welding spot protective adhesive at the joint of the soft tab and the hard tab.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings, wherein for convenience of illustration, the drawings showing the structure of the device are not to scale and are partially enlarged, and the drawings are only examples, which should not limit the scope of the invention. It should be noted that the drawings are in simplified form and are not to precise scale, which is only used for the purpose of facilitating and clearly assisting in the description of the embodiments of the present invention. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated; the terms "front," "back," "bottom," "upper," "lower," and the like refer to an orientation or positional relationship relative to an orientation or positional relationship shown in the drawings, which is for convenience and simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

As shown in fig. 1, fig. 2 and fig. 3, the battery of the present embodiment includes a battery cell 1, a soft tab 2 and a hard tab 3, where the soft tab 2 is electrically connected to the battery cell 1 and extends out of the battery cell 1 from the top of the battery cell 1. The battery with the multi-lug structure is provided with a plurality of soft lugs 2, and the soft lugs 2 are connected with the hard lugs 3 in a welding mode after being laminated together for prewelding. The utility model discloses a hard utmost point ear 3 has welding end 3-1 and a probe end 3-2, and wherein, welding end 3-1 links to each other with soft utmost point ear 2, and probe end 3-2 is hard utmost point ear 3's the one end of keeping away from soft utmost point ear 2. The hard pole lug 3 is provided with an insulating glue 4, the insulating glue 4 is attached to the front surface and the back surface of the joint of the detection end 3-2 and the welding end 3-1, and the front surface and the back surface of the hard pole lug 3 refer to two opposite surfaces of the hard pole lug in the thickness direction.

The thickness of the welding end 3-1 of the hard tab 3 of the utility model is smaller than that of the probing end 3-2, and the space occupied by the folded hard tab 3 can be reduced by reducing the thickness of the welding end of the hard tab; moreover, after the thickness of the welding end 3-1 is reduced, the energy during welding between the hard lug 3 and the soft lug 2 can be reduced, and the height of the welding salient point on the hard lug 3 is correspondingly reduced, so that the space occupied by the hard lug 3 can be reduced when the hard lug 3 is folded, and the energy density of the battery is improved.

In order to ensure that the occupation of the space of the battery cell is reduced and the overcurrent capacity of the battery cell is also met, optionally, the ratio of the thickness of the welding end 3-1 to the thickness of the probing end 3-2 is 0.3-1, namely: the thickness of the welding end is more than 0.3/the thickness of the detecting end is less than 1.

The welding process of the soft tab and the hard tab of the battery according to the present invention will be described with reference to fig. 4a to 4 e. As shown in fig. 4a, the battery cell 1 has a plurality of soft tabs 2, and the soft tabs 2 extend out of the battery cell 1 and are stacked together; as shown in fig. 4b, after cutting the soft tab 2, pre-welding, and fixing the multiple layers of soft tabs 2 together by pre-welding; as shown in fig. 4c, welding the welding end 3-1 of the hard tab 3 and the soft tab 2 after pre-welding together, wherein ultrasonic welding can be adopted, and after the soft tab 2 and the hard tab 3 are welded together, a welding mark is formed at the welding position of the hard tab 3 and the soft tab 2, as shown in part a in fig. 5; then, the hard tab 3 is folded, as shown in fig. 4 d; as shown in fig. 4e, welding spot protective glue 5 is respectively pasted on the outer side of the welding position between the hard tab 3 and the soft tab 2, the welding spot protective glue 5 is used for covering the welding spot, then the pasted soft tab 2 and hard tab 3 are folded towards the head of the battery cell 1 together, the welding of the soft tab 2 and hard tab 3 is completed, and the schematic diagram after the soft tab 2 and hard tab 3 are folded is shown in fig. 6.

Because the utility model discloses a thickness of the welding end of utmost point ear is wanting for the thickness of other positions of utmost point ear, can reduce welding energy during the welding to reduce the height of welding seal (welding bump), also reduced the thickness of soft utmost point ear and hard utmost point ear welding position department simultaneously, consequently when rolling over utmost point ear, can reduce the occupation of utmost point ear space on electric core direction of height, improved the energy density of battery.

Fig. 7 is a schematic diagram of a hard tab when an insulating adhesive 4 is applied to the hard tab, and fig. 7 shows a cross section of the hard tab, wherein a layer of insulating adhesive 4 is applied to each of the front and back surfaces of the hard tab 3, the front and back surfaces of the hard tab 3 refer to two opposite surfaces of the hard tab in the thickness direction, and the side surfaces of the hard tab are surfaces of the hard tab parallel to the thickness direction. As shown in fig. 8, after the application of the adhesive, the adhesive 4 may be subject to a certain necking phenomenon due to tensile stress, i.e., a necking region a is formed in a contact region of the adhesive 4 and the side surface of the hard tab 3, and the thickness of the necking region a is smaller than that of other positions of the adhesive 4. Due to the existence of the necking area a, the PP retention rate at the necking area a is reduced, so that liquid leakage is easily generated from the hard pole lug after edge sealing, and the safety performance of the battery is influenced. In order to avoid the necking phenomenon of the insulating adhesive 4, as an optional embodiment of the present invention, a new design is made for the structure of the insulating adhesive.

As shown in fig. 9, the insulation paste 4 of this embodiment has a necking section 4-1, where the necking section 4-1 is a portion of the insulation paste 4 corresponding to the position of the necking region a after the insulation paste 4 is attached to the hard tab 3, that is, a portion where a necking phenomenon occurs, that is, a necking section. The necked-down section 4-1 is generally the area near the location where the side of the insulation paste contacts the side of the hard tab 3. The thickness of the necked-down section 4-1 of this embodiment is greater than the thickness of the insulating paste 4 at other positions. As shown in fig. 9, the insulating paste 4 has two necked-down sections 4-1 spaced apart from each other, and the thickness of the necked-down section 4-1 is greater than that of the insulating paste 4 at other positions. As shown in fig. 10, after the hard tab 3 is pasted with a layer of insulating glue 4 on the front and back surfaces, since the thickness of the necking section 4-1 is thicker than the thickness of the other positions of the insulating glue 4, the increased thickness of the necking section 4-1 can compensate the reduction of the cross section at the necking region due to the necking phenomenon, thereby avoiding the situation that the insulating glue is insufficient due to the overflow of the insulating glue when the cross section is reduced at the necking region a.

The insulation paste 4 of the previous embodiment has two necked-down sections 4-1 arranged at intervals, and the two necked-down sections 4-1 are respectively positioned at both sides of the hard tab 3 in the width direction of the hard tab. As another embodiment, the necked-down section 4-1 of the insulation paste 4 is connected into a whole, that is, as shown in fig. 11, the thickness of the portion between the two necked-down sections 4-1 of the insulation paste 4 is the same as the thickness of the necked-down section 4-1, which is equivalent to connecting the two necked-down sections together, there is only one necked-down section 4-1, and the length L of the necked-down section 4-1 is greater than the width w of the hard tab 3. Glue thick through increasing the necking segment to paste 4 with the insulating glue on hard utmost point ear 3 back, can compensate the cross-section reduction of necking zone a department, the thickness that makes the necking zone keeps unanimous (figure 12) with the thickness of other positions of insulating glue, the PP of effectively having improved hard utmost point ear and insulating glue necking zone keeps the rate, greatly reduce the emergence of the bloated phenomenon that causes because utmost point ear position department banding weeping in the lithium cell production process, and then promote the security performance of battery.

In some embodiments, the thickness of the (single layer) insulating glue may be 0.1-0.6 mm, and the thickness of the double layer insulating glue may be 0.2-1.2 mm. The ratio of the thickness of the double-layer insulating glue to the thickness of the single-layer insulating glue is 1-3, namely the thickness of the double-layer insulating glue is more than 1.0 and less than 3.0. The thickness of the hard tab 3 can be 0.15-0.6 mm.

After the soft tab 2 and the hard tab 3 are welded, a welding mark is generated at the connecting position of the soft tab 2 and the hard tab 3 (welding end 3-1), and a welding spot protective adhesive 5 is attached to the area where the welding mark exists. As shown in fig. 13, the welding spot protective glue 5 is attached to the front and back surfaces of the connection position of the soft tab 2 and the hard tab 3, and the welding spot protective glue 5 covers the welding spot to play an insulating role. The solder joint protection paste 5 at least covers the area between the bottom of the insulation paste 4 and the top of the battery cell 1, and the solder joint protection paste 5 of the embodiment extends from the bottom of the insulation paste 4 to the front and back surfaces of the battery cell 1. The utility model discloses a tip that sets up utmost point ear that the top of electric core is electric core, and the bottom of insulating cement is insulating cement and electric core relative tip.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery, comprising:

an electric core;

the soft lug is electrically connected with the battery cell and extends out of the battery cell;

the hard lug is connected with the soft lug and comprises a welding end and a probing end, the welding end is connected with the soft lug, and the thickness of the welding end is smaller than that of the probing end.

2. The battery of claim 1, wherein: the ratio of the thickness of the welding end to the thickness of the probing end is greater than 0.3 and less than 1.

3. The battery of claim 1, wherein: the number of the soft tabs is more than one.

4. The battery of claim 1, wherein: the detection device also comprises insulating glue, wherein the insulating glue is pasted on the front surface and the back surface of the joint of the detection end and the welding end.

5. The battery of claim 4, wherein: the insulating glue is provided with a necking section, and the thickness of the necking section is larger than that of other positions of the insulating glue.

6. The battery of claim 4, wherein: the thickness of the single-layer insulating glue is 0.1-0.6 mm, and the thickness of the double-layer insulating glue is 0.2-1.2 mm.

7. The battery of claim 4, wherein: welding spot protective glue is arranged on the front surface and the back surface of the joint of the welding end and the soft tab, and at least covers the area between the bottom of the insulating glue and the top of the battery cell.

8. The battery of claim 6, wherein: the ratio of the thickness of the double-layer insulating glue to the thickness of the single-layer insulating glue is larger than 1 and smaller than 3.

9. The battery of claim 5, wherein: the insulation paste is provided with two necking sections which are arranged at intervals, and the two necking sections are respectively positioned on two sides of the hard tab in the width direction of the hard tab.

10. The battery of claim 5, wherein: the insulating glue is provided with a necking section, and the length of the necking section is larger than the width of the hard tab.