Multi-tab battery

Abstract

The utility model relates to the technical field of batteries, and particularly discloses a multi-tab battery, which comprises positive pole pieces, negative pole pieces, diaphragms arranged among the pole pieces, a flexible packaging bag used for sleeving the pole pieces and electrolyte, the battery comprises at least three groups of tabs, the plurality of groups of tabs at least comprise a group of positive tabs and a group of negative tabs, and the positive pole pieces and the negative pole pieces are arranged on the flexible packaging bag. The positive pole lug is connected with the positive pole piece, the negative pole lug is connected with the negative pole piece, only one group of pole lugs is arranged on the same side of any pole piece, and only one group of pole lugs is arranged on the same side of the pole piece group after the positive pole piece and the negative pole piece are stacked to form the pole piece group. The multi-tab battery has the beneficial effects that by adjusting the arrangement positions of the tabs, the tabs connected to the same pole piece in the multi-tab battery do not conflict, and each tab can adopt a style with a larger size, so that the overall size of the sectional area of the battery tab is improved, and the overall size of the sectional area of the battery tab is reduced. And therefore, the whole battery has lower resistance.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a multi-tab battery. Background Technology

[0002] In a multi-tab battery, more than one tab is arranged on the electrode. This structure can effectively reduce the length and impedance of the current path by increasing the number of tabs, thereby reducing the internal resistance of the entire battery and bringing less energy loss and higher efficiency to the battery. In addition, the multi-tab design can make the current more evenly distributed on the electrode, reducing the possibility of hot spots, thus protecting the battery from damage caused by local overheating.

[0003] However, in existing multi-tab battery designs, conflicts between multiple sets of tabs can easily occur, thus limiting the cross-sectional area of ​​each set of tabs. This limitation restricts the beneficial effects of the multi-tab battery structure on reducing internal resistance and other aspects. Utility Model Content

[0004] This invention provides a multi-tab battery. By adjusting the arrangement of the tabs on the battery, each set of tabs can have a larger cross-sectional area, thereby further reducing the overall internal resistance of the battery.

[0005] This utility model is achieved through the following technical solution:

[0006] A multi-tab battery includes a positive electrode, a negative electrode, a separator disposed between the electrodes, a flexible packaging bag for housing the electrodes, and an electrolyte filled in the flexible packaging bag. The battery includes at least three sets of tabs, and at least one set of positive tabs and one set of negative tabs are included in the plurality of sets of tabs. The positive tabs are connected to the positive electrode and the negative tabs are connected to the negative electrode. Only one set of tabs is provided on the same side of any electrode, and after the positive electrode and the negative electrode are stacked to form an electrode group, only one set of tabs is provided on the same side of the electrode group.

[0007] As a further improvement of this utility model, the ratio of the width of the electrode tab to the length of the side edge of the electrode sheet is (0.75~0.85):1.

[0008] As a further improvement of this utility model, the length of the electrode tab is 35~45 mm.

[0009] As a further improvement of this utility model, the electrode tab is welded to the electrode sheet, and the ratio between the length of the weld and the width of the electrode tab is (0.95~1):1.

[0010] As a further improvement of this utility model, the width of the solder mark is 13~18 mm.

[0011] As a further improvement of this utility model, the side length of the positive electrode sheet is 400~550 mm.

[0012] As a further improvement of this utility model, the side length of the negative electrode sheet is 455~555mm, and the side length of the negative electrode sheet is greater than or equal to the side length of the positive electrode sheet.

[0013] As a further improvement of this utility model, the thickness of the positive electrode sheet is 170~180 μm, and the thickness of the negative electrode sheet is 130~140 μm.

[0014] As a further improvement of this utility model, the diaphragm includes a diaphragm sleeve that is fitted over the negative electrode sheet.

[0015] As a further improvement of this utility model, the battery also includes an air bag, which is disposed on the side of the flexible packaging bag away from the tab.

[0016] The beneficial effect of this utility model is that by adjusting the position of the tabs, that is, limiting the arrangement of only one set of tabs on the same side of a single electrode, the tabs connected to the same electrode in a multi-tab battery will not conflict. Therefore, the tabs used can be of a larger size, which can increase the overall size of the battery tab cross-sectional area, thereby enabling the battery to have a lower overall resistance.

[0017] Meanwhile, the larger and wider tabs that can be set on one side of the electrode can distribute the current more evenly, reduce the heat generation of the tabs themselves, and help maintain the battery in a more stable operating temperature range. Similarly, it can avoid local overload or material damage caused by current concentration in a small area. Both of these beneficial effects can improve the overall lifespan of the battery. Attached Figure Description

[0018] The accompanying drawings are provided below to illustrate the preferred embodiments of this utility model, in order to aid in understanding the purpose and advantages of this utility model, wherein:

[0019] Figure 1 This is a schematic diagram of the positive electrode structure;

[0020] Figure 2 This is a schematic diagram of the negative electrode structure;

[0021] Figure 3 This is a schematic diagram of the structure after the negative electrode sheet is encased in the diaphragm bag.

[0022] Figure 4This is a schematic diagram of the structure of the positive and negative electrode plates after they are packaged in a flexible packaging bag.

[0023] Among them, the electrode includes two types: positive electrode and negative electrode. Therefore, the side length of the electrode is used to describe the side length of the positive electrode or the negative electrode. Similarly, the tab includes positive tab and negative tab. The width and length of the tab are also used to describe the width and length of the positive tab or the negative tab, respectively. Therefore, the above structures may be referred to by the same mark in different positions in the attached drawings. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0025] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0026] The electrodes currently used are typically rectangular in structure; therefore, the electrodes listed in this embodiment are also rectangular in structure, and the multi-tab batteries listed are three-tab batteries. In this embodiment, the positive electrode 1 of all batteries has the following composition ratio: lithium iron phosphate: conductive carbon black: polyvinylidene fluoride (PVDF) = 96.2: 2.0: 1.8; the negative electrode 2 has the following composition ratio: artificial graphite: conductive carbon black: carboxymethyl cellulose (CMC): styrene-butadiene rubber (SBR) = 96: 1: 1.2: 1.8; the positive electrode tab 5-1 is made of aluminum; and the negative electrode tab 5-2 is made of copper plated with nickel.

[0027] Example 1:

[0028] This embodiment provides a three-tab battery, wherein a set of positive tabs 5-1 are arranged on the positive electrode plate 1, and two sets of negative tabs 5-2 are arranged on the negative electrode plate 2. Figure 1 Taking the display angle as an example, the positive electrode tab 5-1 on the positive electrode plate 1 is located on its right side; Figure 2 Taking the display angle as an example, the two sets of negative electrode tabs 5-2 on the negative electrode plate 2 are respectively set on its upper and lower sides. Therefore, when the positive electrode plate 1 and the negative electrode plate 2 are stacked to form an electrode group, as shown in the figure... Figure 4 Taking the display angle as an example, the three sets of electrodes 5 are respectively arranged on the upper, lower and right sides of the electrode group, and the three sets of electrodes 5 do not interfere with each other.

[0029] In this embodiment, the side length W2 of the positive electrode 1 is 500 mm, and the thickness of the positive electrode 1 is 174 μm; the side length W2 of the negative electrode 2 is 505 mm, and the thickness of the negative electrode 2 is 136 μm. In this structure, the size of the negative electrode 2 is larger than that of the positive electrode 1. This ensures that during battery use, all lithium ions extracted from the positive electrode 1 have sufficient space and active sites to embed into the negative electrode 2. This reduces the possibility of lithium ions failing to embed in time due to the negative electrode being "fully loaded," thereby effectively preventing lithium deposition on the negative electrode surface, i.e., lithium plating.

[0030] Based on the aforementioned electrode dimensions and structure, in this embodiment, the ratio of the width W1 of the positive electrode tab 5-1 to the side length W2 of the positive electrode sheet 1 is 0.8:1, meaning the width W1 of the positive electrode tab 5-1 is 400 mm, and the length L of the positive electrode tab 5-1 is 40 mm. Similarly, the ratio of the width W1 of the negative electrode tab 5-2 to the side length W2 of the negative electrode sheet 2 is 0.79:1, meaning the width W1 of the negative electrode tab 5-2 is 400 mm, and the length L of the negative electrode tab 5-2 is 40 mm. This size allows the tab 5 to have a large cross-sectional area, but its size is not excessively large, thus avoiding difficulties in battery assembly and compatibility.

[0031] Based on the aforementioned electrode and tab 5 dimensions, the ratio of the solder mark length to the tab 5 width W1 is 0.95:1, meaning the solder mark length is 380 mm and the width is 15 mm. Appropriate solder mark dimensions ensure a good mechanical connection between the electrode and tab 5, maintaining the stability and durability of the battery's internal structure. Solder mark dimensions that are too large or too small can lead to poor connection strength, making tab 5 more susceptible to breakage or detachment when the battery is subjected to vibration or impact.

[0032] Preferably, in this embodiment, such as Figure 3 As shown, the diaphragm is formed by a diaphragm sleeve 4 that is fitted over the negative electrode plate 2. The diaphragm sleeve 4 structure can better prevent direct contact between the positive and negative electrodes, thereby effectively avoiding the occurrence of internal short circuits.

[0033] Preferably, the battery further includes an air bag 301, which is disposed on the side of the flexible packaging bag 3 away from the tab 5, so as to... Figure 4 Taking the display angle as an example, the air bag 301 is set on the left side of the soft packaging bag 3 and away from the seat position of the electrode 5, so as to avoid the occurrence of conflict between the air bag 301 and the electrode 5 during the steps of venting and secondary sealing after formation, which would make the operation difficult.

[0034] Example 2:

[0035] The difference between this embodiment and embodiment 1 is that, in this embodiment, with the same viewing angle as in embodiment 1, the two sets of positive electrode tabs 5-1 on the positive electrode plate 1 are respectively arranged on its upper and lower sides; the negative electrode tabs 5-2 on the negative electrode plate 2 are arranged on its right side.

[0036] Example 3:

[0037] The difference between this embodiment and Embodiment 1 is that, in this embodiment, with the same viewing angle as in Embodiment 1, the two sets of positive electrode tabs 5-1 on the positive electrode plate 1 are arranged on its upper and right sides; the negative electrode tabs 5-2 on the negative electrode plate 2 are arranged on its lower side.

[0038] Example 4:

[0039] The difference between this embodiment and embodiment 1 is that, in this embodiment, with the same viewing angle as in embodiment 1, the two sets of positive electrode tabs 5-1 on the positive electrode plate 1 are arranged on its upper and right sides; the negative electrode tabs 5-2 on the negative electrode plate 2 are respectively arranged on its lower side.

[0040] Comparative Example 1:

[0041] The difference between this comparative example and Example 1 is that, in this comparative example, two sets of positive electrode tabs 5-1 are provided on the same side of the positive electrode 1, and one set of negative electrode tabs 5-2 are provided on the negative electrode 2. After forming the electrode group, all three sets of tabs 5 are placed on the same side of the electrode group.

[0042] Battery performance testing:

[0043] In this embodiment, the internal resistance of the battery and the degree of temperature rise of the tab 5 after use were tested in Examples 1-4 and Comparative Example 1.

[0044] The battery internal resistance was measured using an internal resistance meter, with a test frequency set to 1000 Hz. The temperature rise of tab 5 after use was primarily measured and statistically analyzed at a 1C charge / discharge rate, focusing on the maximum temperature rise of tab 5.

[0045] The battery-related performance test results of Examples 1-4 and Comparative Example 1 are shown in Table 1.

[0046] Table 1 Summary of battery performance test results for Examples 1-4 and Comparative Example 1

[0047] serial number Internal resistance (mΩ) Maximum temperature rise at 1°C (°C) Example 1 1.02 5 Example 2 1.05 5.2 Example 3 1.1 5.5 Example 4 1.08 5.3 Comparative Example 1 1.5 9

[0048] As can be seen from the results in Table 1, with the tab 5 arrangement in the embodiment, the overall resistance of the battery is reduced, resulting in lower energy loss and higher charge / discharge efficiency. It can also be seen that the maximum 1C temperature rise of the tab 5 in the embodiment is significantly lower than that in the comparative example. This results in less thermal stress generated by the tab 5 in the embodiment, which could cause material expansion and contraction, thus extending the overall battery life.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A multi-pole ear battery comprising a positive electrode sheet (1), a negative electrode sheet (2), a separator disposed between the electrode sheets, a soft packaging bag (3) for wrapping the electrode sheets, and an electrolyte filled in the soft packaging bag (3), characterized in that, The battery comprises at least three groups of the tab (5), wherein at least one group of the positive tab (5-1) and one group of the negative tab (5-2) are included in the groups of the tab (5), the positive tab (5-1) is connected with the positive tab sheet (1), the negative tab (5-2) is connected with the negative tab sheet (2), wherein only one group of the tab (5) is arranged on the same side of any tab sheet, and only one group of the tab (5) is arranged on the same side of the tab sheet group after the positive tab sheet (1) and the negative tab sheet (2) are stacked to form the tab sheet group.

2. The multi-pole cell of claim 1, wherein, The ratio of the width (W1) of the tab (5) to the side length (W2) of the tab sheet is (0.75-0.85):

1.

3. The multi-pole cell of claim 1, wherein, The length (L) of the tab (5) is 35-45 mm.

4. The multi-pole cell of claim 1, wherein, The ratio of the length of the welding mark to the width (W1) of the tab (5) is (0.95-1):

1.

5. The multi-pole cell of claim 4, wherein, The width of the welding mark is 13-18 mm.

6. The multi-pole cell of claim 1, wherein, The side length (W2) of the positive tab sheet (1) is 400-550 mm.

7. The multi-pole cell of claim 6, wherein, The side length (W2) of the negative tab sheet (2) is 455-555 mm, and the side length (W2) of the negative tab sheet (2) is greater than or equal to the side length (W2) of the positive tab sheet (1).

8. The multi-pole cell of claim 1, wherein, The thickness of the positive tab sheet (1) is 170-180 μm, and the thickness of the negative tab sheet (2) is 130-140 μm.

9. The multi-pole cell of claim 1, wherein, The diaphragm comprises a diaphragm sleeve bag (4) sleeved outside the negative tab sheet (2).

10. The multi-pole cell of claim 1, wherein, The battery further comprises a gas bag (301) arranged on the side of the soft packaging bag (3) away from the tab (5).

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