Soft package cylindrical battery and manufacturing method thereof

Abstract

The invention discloses a flexibly-packaged cylindrical battery and a manufacturing method thereof. The flexibly-packaged cylindrical battery comprises a cylindrical roll core and a cylindrical flexibly-packaged shell for packaging the roll core, the cylindrical roll core comprises a first end part and a second end part which are oppositely arranged; the first end part is respectively connected with a positive pole lug and a negative pole lug, and the positive pole lug and the negative pole lug respectively extend outwards from the first end part and penetrate out of the soft package shell; or, the second end part is respectively connected with a positive pole lug and a negative pole lug, and the positive pole lug and the negative pole lug respectively extend outwards from the second end part and penetrate out of the soft package shell. Compared with the prior art, the positive and negative tabs are led out from the same end of the roll core, so that the packaging process of the battery can be simplified, the production efficiency is improved, and the production cost is reduced; meanwhile, as the tab leading-out space only needs to be reserved at one end of the roll core, the utilization rate of the internal space of the battery is improved, and the volume energy density of the battery is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of secondary batteries, and in particular relates to a soft-package cylindrical battery and a manufacturing method thereof. Background Art

[0002] With the booming development of portable electronic devices and new energy vehicle industries, the market demand for high-performance batteries is becoming increasingly urgent. Among the many types of batteries, soft-pack cylindrical batteries have become one of the mainstream choices in the field of consumer electronics and power batteries due to their excellent energy density, cycle stability and safety performance.

[0003] The traditional soft-pack cylindrical battery structure usually uses a cylindrical soft-pack shell (mainly aluminum-plastic film) to encapsulate a cylindrical wound battery cell. Figure 1 As shown, in order to effectively lead out the electrodes and facilitate subsequent packaging and connection, the prior art generally adopts a structural design in which the positive electrode tab 3' and the negative electrode tab 4' are led out at both ends of the winding core 1'. Although this design of leading out the tabs at both ends meets the basic use requirements of the battery to a certain extent, there are still many problems that need to be solved in practical applications.

[0004] The primary issue is the challenge of production efficiency and cost. The design of the two-end tabs requires packaging on both sides of the battery cell, which not only complicates the packaging process, but also significantly reduces production efficiency. The packaging equipment needs to be configured with more stations and perform more operation steps, which leads to higher production costs and longer production cycles. In addition, the packaging method at both ends will also increase the overall volume and weight of the battery, which is contrary to the current development trend of electronic products pursuing miniaturization and lightweight.

[0005] Secondly, the design of the tabs at both ends has an adverse effect on the energy density of the battery. Since space needs to be reserved at both ends of the winding core for the tabs to be led out and insulated, this directly leads to a reduction in the internal space utilization of the battery, which in turn affects the volume energy density of the battery. In the context of the current market demand for high-energy-density batteries, how to improve the internal space utilization of the battery has become a key factor in improving battery performance.

[0006] In view of this, it is necessary to provide a new technical solution to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a soft-pack cylindrical battery to address the deficiencies of the prior art, which can effectively improve the production efficiency of the battery, reduce the production cost, and at the same time increase the energy density of the battery.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A soft-pack cylindrical battery comprises a cylindrical winding core and a cylindrical soft-pack shell encapsulating the winding core; the cylindrical winding core comprises a first end and a second end disposed oppositely;

[0010] The first end is connected to a positive electrode tab and a negative electrode tab, respectively, and the positive electrode tab and the negative electrode tab extend outward from the first end and pass through the soft package shell; or, the second end is connected to a positive electrode tab and a negative electrode tab, respectively, and the positive electrode tab and the negative electrode tab extend outward from the second end and pass through the soft package shell.

[0011] The present invention can simplify the battery packaging process, improve production efficiency and reduce production costs by leading out the positive and negative tabs at the same end of the winding core; at the same time, since only the tab lead-out space needs to be reserved at one end of the winding core, the internal space utilization of the battery is improved, thereby improving the volume energy density of the battery.

[0012] Preferably, the positive electrode tab and the negative electrode tab both include a first tab and a second tab connected to the first tab; the first tab is arranged along a first direction, the second tab is arranged along a second direction, and the first direction intersects with the second direction.

[0013] The present invention cleverly solves the problem that it is difficult to meet the packaging requirements of the soft-package shell when the positive and negative pole ears are led out from the same end of the winding core by setting the first pole ear and the second pole ear extending in different directions. Among them, the first pole ear is connected to the battery pole piece and extends in the axial direction of the battery, which can achieve effective connection with the cylindrical winding core pole piece; the second pole ear is connected to the first pole ear and extends in the radial direction of the battery, which can be conveniently packaged with the soft-package shell; this innovative pole ear structure design not only ensures the reliable connection between the pole ear and the winding core, but also meets the packaging requirements of the pole ear and the soft-package shell, and achieves the purpose of leading the positive and negative pole ears from the same end of the winding core.

[0014] Preferably, the angle between the first direction and the second direction is α, wherein 75°≤α≤105°.

[0015] Preferably, the first pole lug and the second pole lug are both aluminum pole lugs, copper pole lugs, nickel pole lugs or alloy pole lugs.

[0016] Preferably, the first pole lug and the second pole lug are both of a sheet structure or a columnar structure. Among them, the pole lug of the sheet structure can provide a larger connection area and reduce the contact resistance; while the pole lug of the columnar structure can reduce the volume of the pole lug and improve the volume energy density of the battery. In addition, the appropriate pole lug shape and size can be selected according to actual needs, and different pole lug shapes can adapt to different processing requirements, including manufacturing processing and PACK processing.

[0017] Preferably, one end of the first pole ear is connected to the second pole ear, and the other end of the first pole ear is used to connect to the positive electrode sheet or the negative electrode sheet of the winding core; the outer end of the second pole ear is used to connect to an external electrical device.

[0018] Preferably, the second pole tab is provided with a pole tab glue for connecting to the soft-package shell package; and / or, the connection between the first pole tab and the second pole tab is provided with a pole tab glue for connecting to the soft-package shell package.

[0019] Preferably, the first pole lug and the second pole lug are an integrally formed structure or a separate structure.

[0020] Preferably, a connecting portion is provided on the top of the first pole lug, and the first pole lug is embedded in the connecting portion and connected to the second pole lug.

[0021] Preferably, the positive electrode tab and the negative electrode tab each further include a connecting terminal, one end of the connecting terminal is connected to the first electrode tab, and the other end of the connecting terminal is connected to the second electrode tab.

[0022] In addition, the present invention also provides a method for manufacturing the above-mentioned soft-package cylindrical battery, comprising the following steps:

[0023] 1) Connecting the first electrode tab of the positive electrode tab to the positive electrode plate, and connecting the first electrode tab of the negative electrode tab to the negative electrode plate;

[0024] 2) The positive electrode sheet, the separator and the negative electrode sheet are stacked and wound in sequence to form a cylindrical winding core;

[0025] 3) Leading the positive electrode tab and the negative electrode tab out from the same end of the winding core, respectively, and making the second tab of the positive electrode tab and the second tab of the negative electrode tab be on the same plane;

[0026] 4) Using a soft package shell to package the core, wherein the positive electrode tab and the negative electrode tab are respectively connected to the edge sealing of the soft package shell through the tab glue.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects: the present invention sets the positive and negative pole tabs at the same end of the cylindrical winding core and leads them out, which can effectively simplify the packaging process of the battery, improve the packaging efficiency, and reduce the production cost; at the same time, the design of leading the pole tabs at the same end of the winding core can improve the internal space utilization of the battery, thereby improving the energy density of the battery; in addition, leading the pole tabs at the same end of the winding core can reduce the use of packaging materials, reduce the overall weight of the battery, and help to lighten the battery. Therefore, the present invention can effectively improve the production efficiency of the battery, reduce the production cost, and at the same time improve the energy density of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of an existing soft-pack cylindrical battery with positive and negative tabs at both ends;

[0029] Figure 2 It is a schematic structural diagram of the soft-pack cylindrical battery of the present invention.

[0030] Figure 3 It is a schematic diagram of the structure of conventional tabs leading out from the same end of a cylindrical winding core;

[0031] Figure 4 It is a schematic diagram of the structure of the positive electrode tab and the negative electrode tab of the present invention being led out from the same end of a cylindrical winding core;

[0032] Figure 5 A schematic diagram of the structure of a positive electrode tab or a negative electrode tab according to an embodiment of the present invention;

[0033] Figure 6 A schematic diagram of the structure of a positive electrode tab or a negative electrode tab according to another embodiment of the present invention;

[0034] Figure 7 A schematic diagram of the structure of a positive electrode tab or a negative electrode tab according to another embodiment of the present invention;

[0035] Figure 8 It is a schematic structural diagram of a positive electrode tab or a negative electrode tab according to another embodiment of the present invention.

[0036] In the figure: 1, winding core; 2, soft package shell; 21, edge sealing; 3, positive electrode tab; 4, negative electrode tab; 5, tab glue; 100, first tab; 200, second tab; 300, connecting part; 400, connecting terminal; 1', winding core; 3', positive electrode tab; 4', negative electrode tab. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In the description of this application, unless otherwise clearly specified and limited, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; the term "plurality" refers to two or more; unless otherwise specified or explained, the terms "connected", "fixed", etc. should be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] Please refer to the attached Figure 2 According to the first aspect of the present application, the present application provides a soft-package cylindrical battery, comprising a cylindrical winding core 1 and an electrolyte, and a cylindrical soft-package shell 2 encapsulating the winding core 1 and the electrolyte; the cylindrical winding core 1 comprises a first end and a second end disposed oppositely;

[0040] The first end is respectively connected to the positive electrode tab 3 and the negative electrode tab 4, which extend outward from the first end and pass through the soft package shell 2; or, the second end is respectively connected to the positive electrode tab 3 and the negative electrode tab 4, which extend outward from the second end and pass through the soft package shell 2.

[0041] Among them, the present invention can simplify the battery packaging process, improve production efficiency and reduce production costs by leading out the positive and negative tabs at the same end of the winding core 1; at the same time, since only one end of the winding core 1 needs to reserve a space for leading out the tabs, the internal space utilization of the battery is improved, thereby improving the volume energy density of the battery.

[0042] like Figure 3 As shown, the conventional positive electrode tab 3' or negative electrode tab 4' is a straight sheet structure. Since the winding core 1' is a cylindrical structure, the positive electrode tab 3' and the negative electrode tab 4' welded with the electrode sheet are two parallel sheets after being led out, and it is impossible to lead them out side by side on the same plane, resulting in the inability to effectively package with the soft package shell 2. Because the packaging process of the soft package shell 2 usually requires that the positive and negative tabs are led out on the same plane, so as to facilitate the alignment of the packaging equipment and the packaging process.

[0043] Therefore, in order to meet both welding and packaging requirements, the present application also makes the following improvements to the existing conventional straight-shaped tabs.

[0044] like Figures 4 to 8 As shown, in one embodiment according to the present application, the positive electrode tab 3 and the negative electrode tab 4 both include a first tab 100 and a second tab 200 connected to the first tab 100; the first tab 100 is arranged along a first direction, the second tab 200 is arranged along a second direction, and the first direction intersects with the second direction.

[0045] Among them, the present invention cleverly solves the problem that it is difficult to meet the packaging requirements of the soft-package shell 2 when the positive and negative pole tabs are led out from the same end of the winding core 1 by setting the first pole tab 100 and the second pole tab 200 extending in different directions. Among them, the first pole tab 100 is connected to the battery pole piece and extends in the axial direction of the battery, which can achieve effective connection with the pole piece of the cylindrical winding core 1; the second pole tab 200 is connected to the first pole tab 100 and extends in the radial direction of the battery, which can be conveniently packaged with the soft-package shell 2; this innovative pole tab structure design not only ensures the reliable connection between the pole tab and the winding core 1, but also meets the packaging requirements of the pole tab and the soft-package shell 2, and achieves the purpose of leading the positive and negative pole tabs from the same end of the winding core 1.

[0046] In one embodiment of the present application, the angle between the first direction and the second direction is α, wherein 75°≤α≤105°, and more preferably, the first direction is perpendicular to the second direction. The tab structure can be further optimized to reduce the space occupied by the tab and improve the internal space utilization of the battery. In addition, the vertically arranged tab structure also facilitates standardized and automated production and improves production efficiency.

[0047] In one embodiment of the present application, the first pole tab 100 and the second pole tab 200 are both aluminum pole tabs, copper pole tabs, nickel pole tabs or alloy pole tabs. The pole tabs can be guaranteed to have good electrical conductivity and mechanical strength to meet the requirements of large current charging and discharging and long cycle use of the battery; these materials also have good weldability and processing performance, which is convenient for reliable connection with the battery pole piece and the soft package shell 2.

[0048] In one embodiment of the present application, the first pole tab 100 and the second pole tab 200 are both of a sheet structure or a columnar structure. Among them, the pole tab of the sheet structure can provide a larger connection area and reduce the contact resistance; while the pole tab of the columnar structure can reduce the volume of the pole tab and improve the volume energy density of the battery. In addition, the appropriate pole tab shape and size can be selected according to actual needs, and different pole tab shapes can adapt to different processing requirements, including manufacturing processing and PACK processing.

[0049] In one embodiment of the present application, one end of the first pole tab 100 is connected to the second pole tab 200, and the other end of the first pole tab 100 is used to connect to the positive electrode sheet or the negative electrode sheet of the winding core 1; the outer end of the second pole tab 200 is used to connect to an external electrical device. Among them, by connecting one end of the first pole tab 100 to the second pole tab 200 and the other end to the positive electrode sheet or the negative electrode sheet of the winding core 1, a reliable connection between the pole tab and the winding core 1 can be achieved; by connecting the outer end of the second pole tab 200 to an external electrical device, the external electrical connection of the battery can be conveniently achieved.

[0050] In one embodiment of the present application, the second pole tab 200 is provided with a pole tab glue 5 for encapsulating and connecting with the soft-package shell 2; and / or, the connection between the first pole tab 100 and the second pole tab 200 is provided with a pole tab glue 5 for encapsulating and connecting with the soft-package shell 2. The sealing and reliability of the pole tab and the soft-package shell 2 can be improved; the pole tab glue 5 can fill the gap between the pole tab and the soft-package shell 2 to prevent electrolyte leakage and external water vapor from entering, thereby improving the safety and service life of the battery.

[0051] In one embodiment of the present application, the first pole tab 100 and the second pole tab 200 are an integrally formed structure or a split structure. The integrally formed pole tab structure can be formed by processes such as stamping, hot pressing, forging, casting or 3D printing; the integrally formed pole tab structure can simplify the production process and improve production efficiency. The split structure can be connected by welding and other methods, and the production process is more flexible, but additional assembly steps are required.

[0052] In one embodiment of the present application, a connection portion 300 is provided on the top of the first pole tab 100, and the first pole tab 100 is embedded in the connection port of the connection portion 300 and connected to the second pole tab 200. This can not only improve the reliability and stability of the pole tab connection, but also increase the connection area between the pole tabs and reduce the contact resistance. In order not to affect the packaging, the connection portion 300 is preferably thinner under the premise of meeting the connection reliability.

[0053] In one embodiment of the present application, the positive pole tab 3 and the negative pole tab 4 also include a connection terminal 400, one end of the connection terminal 400 is connected to the first pole tab 100, and the other end of the connection terminal 400 is connected to the second pole tab 200. Introducing the connection terminal 400 as a connection medium between the first pole tab 100 and the second pole tab 200 can further improve the flexibility and adaptability of the pole tab structure. Among them, the connection terminal 400 can be made of different materials and shapes, and optimized according to actual needs. It can not only achieve reliable connection between the pole tabs, but also have conductive properties. Among them, the connection terminal 400 can be a separate connection component, or it can be an integrally formed structure with the first pole tab 100 and the second pole tab 200.

[0054] According to the second aspect of the present application, the present invention also provides a method for manufacturing the above-mentioned soft-pack cylindrical battery, comprising the following steps:

[0055] 1) Connecting the first electrode tab 100 of the positive electrode tab 3 to the positive electrode plate, and connecting the first electrode tab 100 of the negative electrode tab 4 to the negative electrode plate;

[0056] 2) stacking the positive electrode sheet, the separator and the negative electrode sheet in sequence and winding them to form a cylindrical winding core 1;

[0057] 3) Leading the positive electrode tab 3 and the negative electrode tab 4 out from the same end of the winding core 1, respectively, and making the second tab 200 of the positive electrode tab 3 and the second tab 200 of the negative electrode tab 4 on the same plane;

[0058] 4) The core 1 is packaged with a soft-package shell 2 to obtain the soft-package cylindrical battery; wherein the positive electrode tab 3 and the negative electrode tab 4 are respectively connected to the sealing edge 21 of the soft-package shell 2 through the tab glue 5.

[0059] Among them, the manufacturing method of the soft-pack cylindrical battery provided by the present invention can efficiently realize the production and manufacturing of the soft-pack cylindrical battery of the present invention through the process of connecting the pole ear and the pole piece, winding and stacking, leading the pole ear out at the same end and packaging.

[0060] It should be noted that the contents not described in detail in this specification belong to the prior art known to professional and technical personnel in the field and will not be repeated here.

[0061] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A soft-pack cylindrical battery, characterized in that: It comprises a cylindrical winding core and a cylindrical soft package shell encapsulating the winding core; the cylindrical winding core comprises a first end and a second end which are arranged opposite to each other; The first end is connected to a positive electrode tab and a negative electrode tab, respectively, and the positive electrode tab and the negative electrode tab extend outward from the first end and pass through the soft package shell; or, the second end is connected to a positive electrode tab and a negative electrode tab, respectively, and the positive electrode tab and the negative electrode tab extend outward from the second end and pass through the soft package shell.

2. The soft-pack cylindrical battery according to claim 1, characterized in that: The positive electrode tab and the negative electrode tab both include a first tab and a second tab connected to the first tab; the first tab is arranged along a first direction, the second tab is arranged along a second direction, and the first direction intersects with the second direction.

3. The soft-pack cylindrical battery according to claim 2, characterized in that: The angle between the first direction and the second direction is α, wherein 75°≤α≤105°.

4. The soft-pack cylindrical battery according to claim 2, characterized in that: The first pole ear and the second pole ear are both aluminum pole ears, copper pole ears, nickel pole ears or alloy pole ears; the first pole ear and the second pole ear are both sheet-like structures or columnar structures.

5. The soft-pack cylindrical battery according to claim 2, characterized in that: One end of the first pole tab is connected to the second pole tab, and the other end of the first pole tab is used to be connected to the positive electrode sheet or the negative electrode sheet of the winding core.

6. The soft-pack cylindrical battery according to claim 2, characterized in that: The second pole tab is provided with a pole tab glue for connecting with the soft-package shell package; and / or, the connection between the first pole tab and the second pole tab is provided with a pole tab glue for connecting with the soft-package shell package.

7. The soft-pack cylindrical battery according to claim 2, characterized in that: The first pole tab and the second pole tab are an integrally formed structure or a separate structure.

8. The soft-pack cylindrical battery according to claim 2, characterized in that: A connecting portion is disposed on the top of the first pole tab, and the first pole tab is embedded in the connecting portion and connected to the second pole tab.

9. The soft-pack cylindrical battery according to claim 2, characterized in that: It also includes a connecting terminal, one end of which is connected to the first electrode tab, and the other end of which is connected to the second electrode tab.

10. A method for manufacturing a soft-package cylindrical battery according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) Connecting the first electrode tab of the positive electrode tab to the positive electrode plate, and connecting the first electrode tab of the negative electrode tab to the negative electrode plate; 2) The positive electrode sheet, the separator and the negative electrode sheet are stacked and wound in sequence to form a cylindrical winding core; 3) Leading the positive electrode tab and the negative electrode tab out from the same end of the winding core, respectively, and making the second tab of the positive electrode tab and the second tab of the negative electrode tab be on the same plane; 4) Using a soft package shell to package the core, wherein the positive electrode tab and the negative electrode tab are respectively connected to the edge sealing of the soft package shell through the tab glue.

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