Soft pack cells and batteries
By setting the welding area of the lithium battery soft-pack battery cell on the top edge of the packaging bag, the problem of the welding area occupying the internal space of the battery cell is solved, and the energy density and battery life are improved.
Patent Information
- Application Number
- CN202420533516.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-19
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-03-19
AI Technical Summary
During the production process of existing lithium battery soft-pack battery cells, the welding area between the metal belt ears and the positive and negative ears occupies the space inside the battery cell, resulting in a decrease in energy density.
By setting the welding area of the positive electrode sheet and the negative electrode sheet with the corresponding metal belt ears on the top edge of the packaging bag, the welding area of the metal belt ears is located on the top edge rather than inside the packaging bag.
The welding area avoids the use of the end space of the battery cell body, so that the inner space of the same size of the packaging bag can be used to install a larger battery cell body, thereby increasing the energy density of the soft-packed battery cell and extending the battery life time.
Smart Images
Figure CN222705776U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a soft-pack battery core and a battery. Background Art
[0002] Nowadays, all countries are vigorously developing green and efficient secondary batteries. As a new type of secondary battery, lithium-ion battery has the advantages of high energy density and power density, high working voltage, light weight, small size, long cycle life, good safety, and green environmental protection. It has broad application prospects in portable appliances, power tools, large energy storage, electric transportation power supply, etc.
[0003] At present, the production process of soft-pack lithium battery cells is as follows: the bare cell is first cut through the positive and negative tabs before packaging, and then the positive and negative tabs are welded to the metal strip tabs respectively, and the tab protective glue is applied to the welding area, and then the tabs are bent so that the welding area is attached to the end face of the bare cell, and finally the aluminum-plastic film is packaged to seal the welding area of the bare cell and the metal strip tabs in the aluminum-plastic film bag. For the soft-pack cells produced in this way, since the welding area of the metal strip tabs and the positive and negative tabs is in the packaging bag, the welding area occupies the space inside the cell, which reduces the energy density of the soft-pack cells. Utility Model Content
[0004] The utility model provides a soft-pack battery core, aiming to improve the energy density of the soft-pack battery core.
[0005] To achieve the above-mentioned purpose, the soft-pack battery cell proposed in the utility model includes a packaging bag, a bare battery cell and two metal strip pole ears, the packaging bag includes a accommodating portion and a top seal, the bare battery cell includes a battery cell body and a positive pole ear and a negative pole ear located at the end of the battery cell body, the positive pole ear is welded to one end of one of the metal strip pole ears, and the negative pole ear is welded to one end of the other metal strip pole ear, the battery cell body is adapted to be installed in the accommodating portion, the metal strip pole ears are fixedly connected to the top seal, and the welding area of the metal strip pole ears is located on the top seal.
[0006] In some embodiments, a side of the welding area away from the receiving portion is flush with an end of the top sealing edge away from the receiving portion.
[0007] In some embodiments, one end of the metal strip tab close to the top seal is sealed in the top seal.
[0008] In some embodiments, the metal strip tab is adhered with tab glue, the tab glue is close to the welding area, and the end of the top seal away from the accommodating portion is provided with an extension section extending along the metal strip tab, and the tab glue is bonded and fixed to the extension section.
[0009] In some embodiments, a region of the top sealing edge facing the welding region is provided with a notch to avoid the welding region.
[0010] In some embodiments, the area of the top sealing edge facing the welding area is a transparent material area.
[0011] In some embodiments, the soft-pack battery cell further includes an insulating adhesive layer adhered and covered on the welding area, at least one folding section is provided between the welding area and an end of the metal strip tab away from the accommodating portion, and the folding section is arranged to overlap with the top sealing edge.
[0012] In some embodiments, the folded section is bonded and fixed to the top sealing edge.
[0013] In some embodiments, the positive electrode tabs are multiple and each of the positive electrode tabs is stacked and distributed, and the negative electrode tabs are multiple and each of the negative electrode tabs is stacked and distributed;
[0014] And / or, the bare battery cell is a laminated battery cell or a wound battery cell.
[0015] The utility model also provides a battery, comprising a shell and the above-mentioned soft-pack battery core, wherein the soft-pack battery core is installed in the shell.
[0016] The technical solution of the soft-pack battery cell of the utility model is to arrange the welding areas of the positive electrode sheet and the negative electrode sheet with the corresponding metal strip ears on the top sealing edge of the packaging bag respectively, so that the welding areas of the two metal strip ears are no longer squeezed in the space inside the packaging bag (i.e., in the accommodating portion), and the internal space of the packaging bag is only used to accommodate the battery body. Compared with the prior art in which the welding area is arranged inside the packaging bag close to the end of the bare battery cell, the solution of the soft-pack battery cell in this embodiment avoids the occupation of the end space of the battery body by the welding area, so that the size of the battery body can be made larger for the same size of the internal space of the packaging bag, thereby effectively improving the energy density of the soft-pack battery cell, so that the capacity of the manufactured battery is larger and the battery life is longer. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the structure of a soft-pack battery cell in one embodiment of the utility model;
[0018] Figure 2 This is a schematic diagram of the structure of a bare battery cell in one embodiment of the utility model;
[0019] Figure 3 It is a schematic diagram of the structure in which a bare battery cell is welded with a metal tab in one embodiment of the utility model;
[0020] Figure 4 for Figure 1 A schematic diagram of the structure of the top edge seal in the embodiment;
[0021] Figure 5 It is a schematic diagram of the structure of the soft-pack battery in the second embodiment of the utility model;
[0022] Figure 6 It is a schematic diagram of the three-dimensional structure of the soft-pack battery cell in the third embodiment of the utility model;
[0023] Figure 7 It is a side view of the soft-pack battery cell in the third embodiment of the utility model. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0026] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.
[0027] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.
[0028] The utility model provides a soft-package battery core, which is used for making batteries, such as mobile phone batteries.
[0029] See also Figures 1 to 3In this embodiment, the soft-pack battery cell includes a packaging bag 10, a bare battery cell 20 and two metal strip tabs 30. The packaging bag 10 includes a housing 11 and a top sealing edge 12. The bare battery cell 20 includes a battery cell body 21 and a positive tab 22 and a negative tab 23 located at the end of the battery cell body 21. The positive tab 22 and the negative tab 23 are located at the same end and are staggered. The positive tab 22 is welded to one end of one of the metal strip tabs 30, and the negative tab 23 is welded to one end of the other metal strip tab 30. The welding of the metal strip tab 30 with the positive tab 22 and / or the negative tab 23 can be completed by laser welding, and of course other welding methods can also be adopted. In this embodiment, the battery cell body 21 is adapted to be installed in the accommodating portion 11, that is, the space in the accommodating portion 11 is adapted to the shape and size of the battery cell body 21, the packaging bag 10 is tightly wrapped around the battery cell body 21, and the positive electrode ear 22 and the negative electrode ear 23 are located at the top sealing edge 12 and are respectively welded to the corresponding metal strip electrode ears 30; the metal strip electrode ears 30 are fixedly connected to the top sealing edge 12, and the welding area S of the metal strip electrode ears 30 is located on the top sealing edge 12, that is, the welding area S between any metal strip electrode ears 30 and the corresponding electrode ears (positive electrode ears 22 or negative electrode ears 23) is not in the accommodating portion 11.
[0030] The packaging bag 10 may be an aluminum-plastic film bag or a bag made of other materials; the bare battery cell 20 may be a laminated battery cell or a wound battery cell.
[0031] The technical solution of the soft-pack battery cell of the present embodiment is to arrange the welding areas S of the positive electrode sheet and the negative electrode sheet with the corresponding metal strip tabs 30 on the top sealing edge 12 of the packaging bag 10, so that the welding areas S of the two metal strip tabs 30 are no longer squeezed in the space inside the packaging bag 10 (i.e., in the accommodating portion 11), and the internal space of the packaging bag 10 is only used to accommodate the battery body 21. Compared with the prior art in which the welding area S is arranged close to the end of the bare battery cell 20 inside the packaging bag 10, the solution of the soft-pack battery cell of the present embodiment avoids the occupation of the end space of the battery body 21 by the welding area S, so that the size of the battery body 21 can be made larger for the internal space of the packaging bag 10 of the same size, thereby effectively improving the energy density of the soft-pack battery cell, so that the capacity of the manufactured battery is larger and the battery life is longer.
[0032] See also Figure 5In some embodiments, the side of the welding area S away from the accommodating portion 11 is flush with the end of the top sealing edge 12 away from the accommodating portion 11, that is, the top sealing edge 12 just covers the welding area S. In this way, the width of the top sealing edge 12 can be minimized under the premise of ensuring the normal packaging function of the packaging bag 10, so that the size of the soft-pack battery cell is smaller, which is more conducive to its use in making smaller batteries. The width of the top sealing edge 12 is determined by the width of the welding area S. When there is a need to further reduce the size of the soft-pack battery cell, a better welding method can be selected to further reduce the required width of the welding area S under the premise of ensuring welding stability, thereby further reducing the width of the top sealing edge 12 and reducing the size of the soft-pack battery cell.
[0033] In some embodiments, one end of the metal strip tab 30 close to the top sealing edge 12 is sealed in the top sealing edge 12, that is, the one end of the metal strip tab 30 close to the top sealing edge 12 is located between the upper and lower material films (such as aluminum-plastic films) of the top sealing edge 12 and are bonded together.
[0034] See also Figure 3 and Figure 5 In some embodiments, a tab glue 31 is attached to the metal tab 30, and the tab glue 31 is close to the welding area S. An extension section 122 extending along the metal tab 30 is provided at one end of the top sealing edge 12 away from the accommodating portion 11. The tab glue 31 is bonded and fixed to the extension section 122. When the packaging bag 10 is packaged, the tab glue 31 melts and fuses with the adhesive layer of the extension section 122. The extension section 122 can be formed by directly sealing the top sealing edge 12 to the end of the extension section 122 (i.e., the end away from the accommodating portion 11) when the packaging bag 10 is packaged. After the packaging is completed, the top sealing edge 12 on both sides of the metal tab 30 is cut (such as laser cutting) to be flush with the end of the welding area S away from the accommodating portion 11; the extension section 122 can also be formed by correspondingly setting a molding part of the extension section 122 on the packaging mold of the packaging bag 10. After the packaging is completed, the top sealing edge 12 with the extension section 122 is directly obtained. In this embodiment, by adding the tab glue 31 and bonding it to the extension section 122, the fixation between the metal strip tab 30 and the top sealing edge 12 is made more firm and reliable, thereby ensuring the stability of the tab of the soft-pack battery cell.
[0035] See also Figure 1 , Figure 4 and Figure 5In some embodiments, a notch 121 is provided in the area of the top sealing edge 12 facing the welding area S to avoid the welding area S, that is, the welding area S is not covered by the film on the side of the top sealing edge 12 facing it, so that the welding area S is clearly exposed. The notch 121 can be formed by not packaging the welding area S during packaging, so that the top sealing edge 12 structure obtained after packaging has the notch 121, or, after the packaging is completed, the notch 121 is cut out at the position of the top sealing edge 12 facing the welding area S. In the present embodiment, by providing the notch 121 on the top sealing edge 12 to avoid the welding area S, the position of the welding area S can be clearly known, so that after the packaging bag 10 is packaged, it is convenient to accurately cut the top sealing edge 12 to be flush with the end of the welding area S away from the accommodating portion 11, so as to avoid excessive cutting of the top sealing edge 12 causing packaging failure, or too little cutting of the top sealing edge 12 causing the size of the soft-pack battery cell to be not minimized.
[0036] In some embodiments, the area opposite to the top sealing edge 12 and the welding area S is a transparent material area; it can be understood that when the packaging bag 10 is packaged, a transparent material is used for packaging at the position corresponding to the welding area S, so that there is no need to cut the top sealing edge 12 for the welding area S after packaging, and the position of the welding area S can be clearly known. Further, after the packaging bag 10 is packaged, the top sealing edge 12 can be accurately cut to be flush with the end of the welding area S away from the accommodating portion 11.
[0037] See also Figure 6 and Figure 7 In some embodiments, the soft-pack battery cell further includes a layer of insulating glue 40 pasted and covered on the welding area S, and at least one folding section 32 is provided between the welding area S and the end of the metal strip pole ear 30 away from the accommodating portion 11 (a reciprocating fold, i.e., a folding section 32 is taken as an example in the figure), and the folding section 32 is arranged to overlap with the top sealing edge 12. In this embodiment, by providing a folding section 32 on the metal strip pole ear 30, the folding section 32 overlaps with the top sealing edge 12, so that the length of the soft-pack battery cell extending from the metal strip pole ear 30 is effectively shortened to a certain extent, so that the length of the metal strip pole ear 30 extending is not too long, so that the soft-pack battery cell can better meet the production requirements of the battery. By pasting 40 layers of insulating glue on the welding area S, the short circuit between the welding point of the welding area S and the folding section 32 is avoided, thereby ensuring the safety of the operation of the soft-pack battery cell.
[0038] In some embodiments, the folded section 32 can be bonded and fixed to the top sealing edge 12 (such as by glue or tape) to prevent the folded section 32 from loosening, ensure the stability of the position of the metal strip tab 30, and further ensure the stability of the battery made of soft-pack cells.
[0039] In some embodiments, there are multiple positive pole ears 22 and each positive pole ear 22 is stacked and distributed, and there are multiple negative pole ears 23 and each negative pole ear 23 is stacked and distributed, that is, each positive pole ear 22 overlaps in the thickness direction of the battery cell body 21, and each negative pole ear 23 also overlaps in the thickness direction of the battery cell body 21, that is, the bare battery cell 20 is a multi-pole ear structure; wherein each positive pole ear 22 is welded to one end of one of the metal strip pole ears 30, and each negative pole ear 23 is welded to one end of another metal strip pole ear 30. The bare battery cell 20 with a multi-pole ear structure has each positive ear 22 and each negative ear 23 stacked to a certain thickness. If the welding area S between the positive and negative ears 23 and the metal strip ears 30 is set in the packaging bag 10 according to the prior art, the end space of the battery cell body 21 will be occupied more and more space will be wasted. Therefore, the soft-pack battery cell of this embodiment sets the welding area S between the positive and negative ears 23 and the metal strip ears 30 on the top sealing edge 12, which saves more end space in the packaging bag 10 and can improve the energy density of the soft-pack battery to a greater extent.
[0040] It should be noted that the above-mentioned embodiments of the soft-pack battery cell of the utility model can be arbitrarily combined or combined to form a new embodiment when there is no contradiction or conflict between them.
[0041] The utility model also proposes a battery, comprising a shell and the above-mentioned soft-pack battery cell, wherein the soft-pack battery cell is installed in the shell. The specific structure of the soft-pack battery cell refers to the above-mentioned embodiment. Since the battery adopts all the technical solutions of all the embodiments of the above-mentioned soft-pack battery cells, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.
[0042] The above description is only a partial or preferred embodiment of the present invention. Neither the text nor the drawings can limit the scope of protection of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect application in other related technical fields are included in the scope of protection of the present invention.
Claims
1. A soft-pack battery cell, comprising a packaging bag, a bare battery cell and two metal tabs, wherein the packaging bag comprises a containing portion and a top sealing edge, the bare battery cell comprises a battery cell body and a positive tab and a negative tab located at the end of the battery cell body, the positive tab is welded to one end of one of the metal tabs, and the negative tab is welded to one end of the other of the metal tabs, characterized in that: The battery cell body is adapted to be installed in the accommodating portion, the metal strip tab is fixedly connected to the top sealing edge, and the welding area of the metal strip tab is located on the top sealing edge.
2. The soft-pack battery cell according to claim 1, characterized in that: A side of the welding area away from the accommodating portion is flush with an end of the top sealing edge away from the accommodating portion.
3. The soft-pack battery cell according to claim 2, characterized in that: One end of the metal strip tab close to the top sealing edge is sealed in the top sealing edge.
4. The soft-pack battery cell according to claim 3, characterized in that: The metal strip pole lug is pasted with pole lug glue, the pole lug glue is close to the welding area, and the end of the top seal away from the accommodating portion is provided with an extension section extending along the metal strip pole lug, and the pole lug glue is bonded and fixed to the extension section.
5. The soft-pack battery cell according to claim 3, characterized in that: A notch is provided in the area of the top sealing edge facing the welding area to avoid the welding area.
6. The soft-pack battery cell according to claim 3, characterized in that: The area of the top sealing edge facing the welding area is a transparent material area.
7. The soft-pack battery cell according to claim 1, characterized in that: The soft-pack battery cell also includes an insulating adhesive layer pasted and covered on the welding area, and at least one folding section is provided between the welding area and an end of the metal strip tab away from the accommodating portion, and the folding section is overlapped with the top sealing edge.
8. The soft-pack battery cell according to claim 7, characterized in that: The folded section is bonded and fixed to the top sealing edge.
9. The soft-pack battery cell according to any one of claims 1 to 8, characterized in that: There are a plurality of positive electrode tabs and each of the positive electrode tabs is stacked and distributed; there are a plurality of negative electrode tabs and each of the negative electrode tabs is stacked and distributed; And / or, the bare battery cell is a laminated battery cell or a wound battery cell.
10. A battery, characterized in that: The invention comprises a shell and the soft-pack battery cell according to any one of claims 1 to 9, wherein the soft-pack battery cell is installed in the shell.