Functional current collector for preparing cylindrical battery cell and cylindrical battery cell
By designing a functional current collector with continuously unequally spaced tabs and indirect transfer welding, the problems of difficult welding folding, high risk and complex process were solved, achieving more efficient and stable preparation of cylindrical cells, and improving yield and battery performance.
Patent Information
- Application Number
- CN202423079499.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-12-13
AI Technical Summary
In the existing technology, functional current collectors have problems such as difficulty in folding and flattening the welding position, high welding risk, increased cost, complex process and low yield when preparing cylindrical cells.
Design a functional current collector with continuously spaced, unequally spaced tabs that are wound into a cylindrical shape from the inner end to the outer end. The tabs overlap on the cylindrical shape to form a tab assembly, and are welded by indirect transfer. The tabs are square or triangular and are welded to the foil and current collector plate after winding.
It enables more convenient and efficient cell fabrication, reduces poor soldering, improves yield, reduces battery energy density, and increases battery stability and power collection efficiency.
Smart Images
Figure CN223665630U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field, concretely relates to a kind of functional current collector for preparing cylindrical battery and cylindrical battery. BACKGROUND
[0002] Functional current collector (multilayer current collector) is the current collector with high molecular film as middle layer and metal layer on both sides, which is gradually widely used due to many advantages.
[0003] The electrode pole piece prepared by using functional current collector (multilayer current collector) needs to be connected to traditional foil, then be wound and folded tab, and be assembled into battery. At present, the following problems still exist in this process:
[0004] (1) the welding position of functional current collector is not easy to fold and rub flat when being connected and welded;
[0005] (2) the continuous connection and welding process is adopted at present, the cost is increased, and the welding risk is higher;
[0006] (3) the existing process is complex, and the qualified rate is low. INVENTION CONTENTS
[0007] The utility model aims at providing a kind of functional current collector for preparing cylindrical battery and cylindrical battery, which can be more convenient and efficient to make cylindrical battery.
[0008] The technical scheme provided by the utility model is:
[0009] A kind of functional current collector for preparing cylindrical battery, the functional current collector is equipped with continuous unequal-distance interval tab;One end of the functional current collector is inner end, the other end is outer end, the functional current collector can be wound into cylinder from inner end to outer end;The continuous unequal-distance interval of tab on the functional current collector is set as, from the inner end of functional current collector to the outer end of functional current collector, the interval between adjacent tabs on the functional current collector gradually increases;After the functional current collector is wound into cylinder, the positions of multiple tabs on the cylinder overlap, forming several tab groups.
[0010] To optimize the above technical scheme, the specific measures taken also include:
[0011] The functional current collector is rectangular, and the tab is arranged at the long side of the rectangle.
[0012] After the functional current collector is wound into cylinder, the positions of multiple tabs on the cylinder overlap, including at least one of the following: multiple positive tabs overlap, forming several positive tab groups;Multiple negative tabs overlap, forming several negative tab groups.
[0013] Further, the tab is connected to the foil by adapter welding.
[0014] Further, the functional current collector wound to form a column shape is welded to the current collector disc.
[0015] The tab is a square tab or a triangular tab with one side connected to the functional current collector.
[0016] The columnar cross section of the functional current collector wound to form a column shape is circular, polygonal or special-shaped, and is used to prepare a cylindrical battery cell, a polygonal column battery cell or a special-shaped column battery cell.
[0017] The number of the positive tab groups is 2-10, and each group has 3-10 tabs; the number of the negative tab groups is 2-10, and each group has 3-10 tabs.
[0018] As a preferred scheme, the number of the positive tab groups is 3-5, and each group has 5-6 tabs; the number of the negative tab groups is 3-5, and each group has 5-6 tabs.
[0019] The utility model discloses still protect a kind of columnar battery cell, by the functional current collector winding described above, and the end of column shape contains several tab groups, and each tab group is overlapped by several tabs.
[0020] Compared with the prior art, the utility model has the beneficial effects that:
[0021] The utility model discloses more convenient, more efficient functional current collector is applied to columnar battery cell;Through the scheme of the utility model, the columnar battery cell prepared can be more flat at both ends, reduce false welding, and improve yield.
[0022] The functional current collector of the utility model is changed from the original continuous adapter welding to indirect adapter welding, and after adapter welding, full-tab battery process can be directly carried out, which is more convenient and has higher preparation efficiency.
[0023] Compared with the traditional cylindrical battery current collector, the functional current collector of the utility model has larger tab contact area, fewer tab quantity, can reduce battery energy density while ensuring current collection effect, and the tab stack is a regular structure, so that the structure after welding is more stable and the current collection effect is more excellent.
[0024] Compared with the traditional battery cell, the columnar battery cell of the utility model has performance advantages. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 The utility model discloses the structure diagram of functional current collector.
[0026] Figure 2 The utility model discloses the structure diagram of functional current collector connecting foil.
[0027] Figure 3 Figure 1 is a schematic diagram of a function current collector winding into a cylindrical-shaped battery core.
[0028] Figure 4 Figure 2 is a schematic diagram of a function current collector winding into a square column-shaped battery core with triangular tabs.
[0029] In the figure: 1-function current collector body, 2-positive tab, 3-negative tab, 4-adapter foil material, 5-cylindrical battery core, 6-current collecting disc, 7-tab group. DETAILED DESCRIPTION
[0030] The above content of the utility model will be further described in detail in the form of examples, but this should not be understood as the scope of the above subject matter of the utility model is limited to the following examples, and any technology realized based on the above content of the utility model belongs to the scope of the utility model.
[0031] Unless otherwise specified, the terms used in this application have the commonly understood meanings understood by those skilled in the art. Unless otherwise specified, the values of each parameter mentioned in this application can be measured by various measurement methods commonly used in the art.
[0032] The utility model provides a kind of function current collector for preparing cylindrical battery core, and function current collector is equipped with continuous unequal-distance interval tab;One end of function current collector is inner end, the other end is outer end, and function current collector can be wound into column from inner end to outer end;Continuous unequal-distance interval of tab on function current collector is set as, from function current collector inner end to function current collector outer end, the interval between adjacent tabs on function current collector gradually increases.
[0033] As shown in Figure 1 In the figure, the left end of function current collector body 1 is inner end, and the right end of function current collector body 1 is outer end;After winding into column, multiple tabs are overlapped on the position of column, and form several tab groups 7;In the wound battery core, the tabs in each group need to be neatly stacked at the same folding position.
[0034] In some embodiments, the tab of the present application can be a square tab.
[0035] In some preferred embodiments, the tab of the present application is a triangular tab connected to the function current collector by one side;Because the thickness of tab layer is thick after lamination, such triangular tab can reduce volume and be relatively flat after lamination, avoiding congestion between each tab group, as shown in Figure 4
[0036] The cylindrical cross section formed by winding the functional current collector fluid is circular, polygonal or special-shaped, and is used to prepare cylindrical battery cells, polygonal cylindrical battery cells or special-shaped cylindrical battery cells respectively. Therefore, the scheme of the application can be used to prepare various cylindrical battery cells 5, such as:
[0037] When the cylindrical shape formed by winding the functional current collector fluid is a cylinder, it is used to prepare a cylindrical battery cell, as shown in Figure 3 When the cylindrical shape formed by winding the functional current collector fluid is a square cylinder, it is used to prepare a square cylindrical battery cell, as shown in Figure 4 When the cylindrical shape formed by winding the functional current collector fluid is a special-shaped cylinder, it is used to prepare a special-shaped cylindrical battery cell, and so on.
[0038] In the utility model, the position of the tab on the functional current collector fluid can be set according to the shape and size of the cylindrical battery cell to be prepared, and the required distances of the tabs are calculated in advance, and then the tabs are designed on the functional current collector fluid according to the distances.
[0039] Preferably, the tabs in the utility model can be formed by laser cutting, and the tabs are laser die-cut on the functional current collector fluid according to the above distances.
[0040] The shape of the functional current collector fluid in the utility model can adopt a shape convenient for winding, such as a strip or a rectangle, and the tabs are arranged at the long edges of the strip or the rectangle.
[0041] Before the functional current collector fluid is wound to form a cylinder, the tabs can be connected with the adapter welding foil material 4, as shown in Figure 2 After the functional current collector fluid is wound to form a cylinder and welded with the current collector disc 6, the battery cell is inserted into the shell after the positive and negative current collector discs are welded. The functional current collector fluid in the utility model is changed from the original continuous adapter welding to indirect adapter welding, and the adapter welding can be directly carried out after the full-tab battery process.
[0042] After the functional current collector fluid is wound to form a cylinder, the positions of the multiple tabs on the cylinder overlap, and a plurality of tab groups are obtained. In this way, the prepared battery cell can have relatively flat ends, reduce false welding and improve the yield; the energy density of the battery can also be improved; the rate performance and cycle life of the battery can also be improved.
[0043] The overlapping of the positions of the multiple tabs on the cylinder includes at least one of the following:
[0044] The multiple positive tabs 2 overlap to form a plurality of positive tab groups;
[0045] The multiple negative tabs 3 overlap to form a plurality of negative tab groups.
[0046] In the application of the scheme, the number of positive tab groups can be set to 2-10 groups, and each group has 3-10 tabs; the number of negative tab groups can be set to 2-10 groups, and each group has 3-10 tabs.
[0047] As a preferred scheme, the positive electrode lug groups are 3-5 groups, and each group has 5-6 electrode lugs.
[0048] The utility model discloses further provide cylindrical electric core by the function of the above-mentioned current collector winding, the end of cylindrical contains several lug groups, and each lug group is overlapped by several electrode lugs.
[0049] The present application is through the setting of lug group number and the lug number of each group in-depth research, obtains the product with better performance obviously through a large number of tests, and part test scheme is shown in the following table 1 embodiment and comparative example. The preparation process of comparative example and embodiment is same, and the difference is only lug group number and the lug number of each group.
[0050] The following test is to show the influence of lug group number and the lug number of each group on the performance of the battery, taking the commonly used cylindrical battery as an example, and setting the lug number in each lug group is same (the lug number is shown in the third column of table 1), and the positive lug group number and the negative lug group number of the electric core are same (the lug group number is shown in the second column of table 1).
[0051] But the scheme of the present application is not limited to making the lug number of each lug group same, and can be different lug number, and is not limited to making the positive lug group number and the negative lug group number of the electric core same, and the positive electrode and the negative electrode can be different lug group number.
[0052] Test method:
[0053] Rate performance test method: refers to the ability of battery to output large current in a short time, and the test method mainly has that constant current discharge test battery is discharged to specified terminal voltage, records battery discharge time and output current, and the rate index of battery is obtained by calculation
[0054] Cycle life test method: set a constant current charge-discharge test: by setting constant current value, the battery is charged and discharged, and the working condition of the battery in actual application is simulated.
[0055] Table 1 comparative test results of each embodiment and comparative example
[0056]
[0057] From the test data in the above table, it can be seen that:
[0058] When the lug group number of the electric core is too much, and the lug number of each group is less, such as the case of comparative example 1, the weight energy density of the battery prepared by the electric core prepared by the scheme has better value, but the rate performance is poor.
[0059] When the number of the tab groups of the battery cell is too small, such as the case of the comparative example 4, the weight energy density, the rate performance and the cycle life of the battery prepared by the battery cell using the scheme are poor.
[0060] It is found by the test that when the number of the tab groups and the number of the tabs of the battery cell are in the proper range, the performance of the battery prepared by the battery cell is good in all aspects, including the weight energy density, the rate performance and the cycle life.
[0061] After sufficient test and research, it is found that when the number of the tab groups is 2-10 groups and the number of the tabs in each group is 3-10, the basic performance of the battery is balanced in all aspects; when the number of the tab groups is 3-5 groups and the number of the tabs in each group is 5-6, the performance of the battery is good in all aspects and the comprehensive performance is better; when the positive electrode and the negative electrode both use the scheme, the performance is better.
[0062] The above is only the preferred embodiment of the present application, and does not limit the present application in any form, and any skilled person in the art, without departing from the technical scheme of the present application, according to the technical essence of the present application, any simple modification, equivalent replacement and improvement of the above embodiment, etc. still belongs to the protection scope of the technical scheme of the present application.
Claims
1. A functional current collector for making a cylindrical battery cell, characterized by: The functional current collector has continuous unequal-distance spaced tabs; one end of the functional current collector is an inner end and the other end is an outer end, and the functional current collector can be wound into a column from the inner end to the outer end; the continuous unequal-distance spaced tabs on the functional current collector are arranged such that the interval between adjacent tabs on the functional current collector gradually increases from the inner end to the outer end of the functional current collector; and after the functional current collector is wound into a column, the plurality of tabs can overlap to form a plurality of tab groups.
2. The functional current collector for making a cylindrical electrochemical cell of claim 1, wherein: The functional current collector is rectangular, and the tabs are arranged at the long sides of the rectangle.
3. The functional current collector for making a cylindrical electrochemical cell of claim 1, wherein: After the functional current collector is wound into a column, the plurality of tabs overlap at the position on the column to form a plurality of tab groups, including at least one of the following: a plurality of positive tabs overlap to form a plurality of positive tab groups; and a plurality of negative tabs overlap to form a plurality of negative tab groups.
4. The functional current collector for making a cylindrical electrochemical cell of claim 1, wherein: The tabs are connected to the foil material through adapter welding.
5. The functional current collector for making a cylindrical electrochemical cell of claim 1, wherein: The functional current collector wound into a column is welded to the current collector disc.
6. The functional current collector for making a cylindrical electrochemical cell of claim 1, wherein: The tabs are square tabs or triangular tabs with one side connected to the functional current collector.
7. The functional current collector for making a cylindrical electrochemical cell of claim 1, wherein: The column cross section of the functional current collector wound into a column is circular, polygonal or special-shaped, and is used to prepare a cylindrical battery cell, a polygonal column battery cell or a special-shaped column battery cell.
8. The functional current collector for making a cylindrical electrochemical cell of claim 3, wherein: The number of positive tab groups is 2-10 groups, and each group has 3-10 tabs; and the number of negative tab groups is 2-10 groups, and each group has 3-10 tabs.
9. The functional current collector for making a cylindrical electrochemical cell of claim 8, wherein: The number of positive tab groups is 3-5 groups, and each group has 5-6 tabs; and the number of negative tab groups is 3-5 groups, and each group has 5-6 tabs.
10. A cylindrical cell characterized by: The functional current collector wound into a column according to any one of claims 1-9 has a plurality of tab groups at the end of the column, and each tab group is composed of a plurality of overlapping tabs.