A bipolar battery tab parallel sealing method

Abstract

The application discloses a bipolar battery tab parallel sealing method, and designs a bipolar pole group and a battery tank as a vertical structure, designs a middle hollow comb structure, the combs in the comb structure correspond to the bipolar pole group tabs one by one, after the pole group enters the tank, the combs are fixed with the tabs through sealing glue, after the sealing glue solidifies, conductive glue is injected from the middle hollow part to completely immerse the tabs, and then sealing glue is injected to a proper height to complete sealing of the bipolar pole group tabs. The conductive glue adopts high-silver-content epoxy resin glue, and the sealing glue controls viscosity and fluidity. The application solves the problems of conductive reliability and sealing integrity of the bipolar battery tabs in parallel, is suitable for various batteries such as lead-acid, lithium / sodium / potassium ion, and improves battery performance and production efficiency.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, specifically to a method for parallel sealing of tabs in bipolar batteries. Through a unique comb-tooth structure design and layered injection sealing process, it solves the problem of electrical connection and sealing between individual bipolar battery cells, thereby improving battery reliability and production efficiency. Background Technology

[0002] In traditional chemical battery technology, the electrode groups and tabs inside a single cell are usually electrically connected through a busbar, while the cells are connected in series by bridge welding or through-wall welding. This connection method has the following significant drawbacks: (1) High material consumption: The busbar and bridge connection structure require a large amount of lead, which increases the raw material cost of the battery and the environmental burden. According to statistics, the lead consumption of the connection parts of a conventional 12V lead-acid battery accounts for 15%-20% of the total lead consumption; (2) Limited conductivity: During high current discharge, the contact resistance between the busbar and the welding point is prone to local heating, which affects the battery life. Experimental data shows that when the discharge current exceeds 5C, the temperature rise of the connection part can reach 30-50℃, which accelerates the corrosion and aging of lead alloys; High structural complexity: The multi-level connection structure increases the difficulty of the production process, especially the through-wall welding technology, which has extremely high requirements for welding precision. The welding defect rate is usually 0.5%-1%, which leads to an increase in production costs.

[0003] In recent years, a bipolar battery that does not require a busbar has been developed. It utilizes pre-connected bipolar plates with positive and negative tabs to achieve series connection between individual cells, eliminating the bridge connection between cells. This is expected to reduce lead consumption by 20%-30%, aligning with green manufacturing trends. It also shortens the current conduction path, reduces internal resistance, and significantly improves high-current discharge performance. Tests show that the 5C discharge capacity of the bipolar battery is 10%-15% higher than that of conventional batteries.

[0004] However, this innovative structure brings new technical challenges. The tabs of the bipolar plates need to pass through the cell partition to achieve electrical connection. Traditional sealing processes (such as hot melt adhesive sealing) are difficult to form a reliable seal at the complex interface between the tabs and the partition, which can easily lead to leakage of sulfuric acid electrolyte and cause battery short circuits. Due to the lack of current equalization effect of the busbar, when there are consistency deviations in the manufacturing of the plates, the abnormal current of the lagging plates will be directly transmitted to the normal plates of adjacent cells, forming a "lagging current transmission effect". The assembly pressure generated in the vertical direction by the traditional horizontal insertion structure makes capping difficult, and air bubbles and shrinkage cavities are easily generated during the curing process of the sealant, affecting the reliability of the seal.

[0005] Currently, the sealing of the tabs in bipolar batteries mainly employs the following method: the technical solution in patent document CN202411945613.2 directly fills the gap between the tab and the partition with epoxy resin adhesive, which does not solve the compatibility problem between conductive connection and sealing. When the conductive adhesive comes into direct contact with the electrolyte, metal ions (such as lead and copper) dissolve, leading to electrolyte contamination and increased battery self-discharge.

[0006] In patent document CN201811209549.6, parallel connection of electrode tabs is achieved by welding thin lead sheets. However, the welding process is prone to local overheating of the electrode tabs (temperature can reach 300-400℃), which damages the active material structure of the electrode plate. In addition, the mechanical strength of the welding point is insufficient and it is prone to breakage under vibration.

[0007] Patent document CN202410727805.X employs a method of squeezing sealing strips to make them adhere to each other and fit into the shell and cover. The sealing effect is improved by pressing down the components and sealing membrane, avoiding the need for filler. However, the compatibility issue between conductive connections and sealing remains unresolved. When the conductive adhesive comes into direct contact with the electrolyte, metal ions (such as lead and copper) dissolve, leading to electrolyte contamination and increased battery self-discharge.

[0008] To address the aforementioned issues, there is an urgent need to develop a bipolar battery tab treatment technology that combines reliable electrical connections with robust sealing. Summary of the Invention

[0009] This invention aims to provide a method for sealing the parallel tabs of bipolar batteries based on a comb-tooth structure. By using a vertical structural design, a layered glue injection sealing process, and a functional partition structure, it solves the problems of reliability and sealing integrity of the parallel tabs of bipolar batteries, while improving production efficiency and battery performance.

[0010] To achieve the above objectives, this application provides a method for sealing bipolar battery tabs in parallel, characterized by comprising the following steps:

[0011] a) The bipolar electrode group and battery compartment are designed as a vertical structure, the partition walls between the individual cells are thickened, and comb teeth are provided on the upper part of the partition walls. The comb teeth include internal partition wall comb teeth and external partition wall comb teeth.

[0012] b) The comb teeth of the internal partition wall are hollowed out in the middle and have a three-layer structure. The middle layer forms the conductive adhesive groove of the internal partition wall. The two sides of the middle layer are hollowed out to form two rows of sealing adhesive grooves of the internal partition wall. The comb teeth of the outer partition wall are hollowed out only in the middle to form the sealing adhesive groove of the outer partition wall.

[0013] c) After the bipolar electrode group is inserted into the groove, the electrode tabs are inserted into the comb teeth. The direct connection electrode tabs of the electrode group realize the cross-bridge connection between the individual units through the sunken space. The electrode tabs are sealed by the comb tooth structure. Conductive adhesive is injected into the conductive adhesive groove of the internal partition wall. After the conductive adhesive is cured, it is installed into the hollow partition wall bridging block.

[0014] d) Inject epoxy resin sealant into the inner and outer partition wall sealant grooves until the bottom of the bridging block is submerged, thus completing the sealing between the electrode lug and the partition wall.

[0015] Furthermore, the conductive adhesive in the middle can also be connected in parallel using metal sheets. Since the parallel connection is only to improve charging performance, a large current is not required; only small metal sheets are needed. This metal sheet is embedded in the sealant and will not come into contact with the acid. It can be a lead strip, copper sheet, or other metals.

[0016] Furthermore, the comb tooth inlet is provided with a chamfered opening, the chamfer width is 0.5-1mm, so that even if the position of the electrode group tabs is slightly deviated, they can be smoothly inserted into the comb teeth; the partition wall on both sides corresponding to the comb teeth is provided with a slot, the partition wall bridging block is installed along the slot, and the fit gap between the slot and the bridging block is ≤0.1mm.

[0017] Furthermore, the epoxy resin adhesive has a viscosity of 5000-8000 mPa·s and a flowability of 3-5 cm / min. This parameter, optimized within a medium viscosity range, ensures that the adhesive can fully penetrate the minute gaps between the tabs and comb teeth through capillary action, achieving complete wetting and sealing of the interface, while preventing overflow along the beveled edges of the comb teeth due to excessively low viscosity. Specifically, this viscosity range ensures that the adhesive maintains a stable laminar flow state under injection pressure, uniformly filling the mating gaps between the tabs and comb teeth, while preventing excessive flow and spillage contamination. The flowability index is specifically designed so that the adhesive diffuses directionally only within the sealing groove under the balance of gravity and surface tension, meeting the gap-filling requirements of complex structures and forming a uniform and continuous sealing layer. This ensures the integrity and reliability of the seal between the tabs and the partition wall from a process parameter perspective.

[0018] Furthermore, the height of the tab groove is flush with the tab, and the groove width is 0.1–0.3 mm wider than the tab thickness. The groove height matches the tab height, ensuring the tab is fully embedded vertically into the comb groove, preventing the tab from being suspended or exposed due to height discrepancies, and ensuring complete coverage of the tab by the conductive adhesive groove and the sealing adhesive groove. This design eliminates the tab tilting or misalignment problems found in traditional horizontal groove structures, providing a stable interface foundation for subsequent adhesive application. The groove width, 0.1–0.3 mm wider than the tab thickness, allows for manufacturing deviations in the thickness direction while creating a micron-level gap suitable for adhesive penetration. This gap guides the conductive adhesive / sealant to uniformly fill the interface through capillary action, preventing adhesive penetration due to excessive tightness or loss of adhesive or defects in the sealing layer due to excessive looseness.

[0019] Furthermore, the electrode group has a positive terminal, a negative terminal, and a series connection section. The series connection section consists of bipolar plates with positive and negative plates directly connected by tabs. The bipolar plates in the series connection section are alternately stacked in a longitudinal direction, with positive plates superimposed on negative plates. The positive terminal has several independent unipolar positive plates, which are stacked longitudinally, and a bipolar negative plate is stacked between two adjacent unipolar positive plates. The negative terminal has several independent unipolar negative plates, which are stacked longitudinally, and a bipolar positive plate is stacked between two adjacent unipolar negative plates. A sheet-like partition is provided between adjacent positive and negative plates.

[0020] Furthermore, the conductive adhesive is a silver-containing epoxy resin adhesive with a silver content of 60%-70% and a conductivity ≥10. -4 S / cm. Silver is one of the metals with the best electrical conductivity; a silver content of 60%-70% gives the conductive adhesive extremely high conductivity (≥10). -4 The conductive adhesive (S / cm) significantly reduces the contact resistance at the parallel connection of the tabs, thereby reducing energy loss and localized heat generation during high-current discharge. Addressing the characteristic of bipolar batteries where the tabs need to penetrate walls for series connection, the conductive adhesive connection eliminates the need for additional busbars or bridge structures. Combined with the comb-tooth and bridging block design, it achieves efficient conductivity and reliable sealing within a compact space, providing key technical support for the miniaturization and high-energy-density design of bipolar batteries.

[0021] Furthermore, the bridging block is made of acid-resistant engineering plastic, and its coefficient of thermal expansion matches that of the battery compartment.

[0022] Furthermore, the hollow area around the partition wall bridging block is ≥30%, the height of the hollow structure matches the depth of the sealant groove, and the contact area between the adhesive and the groove wall is ≥95% during adhesive injection.

[0023] Furthermore, the individual partition walls need to be thickened due to the comb-tooth design. To reduce the weight of the battery casing, the thickened partition walls need to be hollowed out from the bottom. This hollowing out not only reduces weight but also increases the heat dissipation effect inside the battery.

[0024] Furthermore, the tab width design should be wider than that of conventional battery plates to minimize the ohmic resistance of the tab and prevent the temperature of the tab from becoming too high during high current discharge, which could damage the sealing effect of the sealant.

[0025] On the other hand, the present invention also provides a method for sealing the parallel connection of bipolar battery tabs, characterized by comprising the following steps:

[0026] a) The bipolar electrode group and battery compartment are designed as a vertical structure, and the partition wall between the internal cells is thickened and sunken. The sunken height corresponds to the height of the electrode group's tabs, so that the bipolar tabs pass through the sunken part and the unipolar tabs on both sides extend upward.

[0027] b) After the bipolar electrode group is inserted into the groove, the comb tooth partition wall bridging block, which has been pre-coated with epoxy resin on the comb tooth part, is inserted into the electrode tab on the partition wall from top to bottom. The comb teeth of the comb tooth partition wall bridging block correspond one-to-one with the electrode tab of the bipolar electrode group. The comb tooth partition wall bridging block forms a three-layer sealing structure through the hollow part in the middle. The gap between the comb teeth and the electrode tab on both sides is bonded with epoxy resin sealant to form two outer layers of seal. The hollow part in the middle forms a conductive sealing layer with conductive adhesive.

[0028] c) The comb teeth are pre-coated with epoxy resin to fill the gap between the comb teeth and the tabs. After the epoxy resin has cured, conductive adhesive is injected from the hollow part in the middle of the comb tooth partition bridging block until the tabs are completely submerged. After the conductive adhesive has cured, epoxy resin sealant is injected to a suitable height to complete the sealing of the bipolar electrode group tabs.

[0029] Furthermore, the comb tooth inlet is provided with a chamfered edge, the chamfer width being 0.5-1mm; corresponding grooves are provided on both sides of the recessed partition wall, and the partition wall bridging block is inserted along the groove, the fitting gap between the groove and the bridging block being ≤0.1mm; the epoxy resin adhesive has a viscosity of 5000-8000mPa·s and a flowability of 3-5cm / min, so that the adhesive will not overflow from the gap between the tab and the comb tooth.

[0030] Furthermore, the bipolar electrode group has a positive terminal, a negative terminal, and a series connection section. The series connection section consists of bipolar plates with positive and negative electrode tabs directly connected. The bipolar plates in the series connection section are alternately stacked in a manner where positive plates are superimposed on negative plates, along the longitudinal direction. The positive terminal has several independent unipolar positive plates, which are stacked longitudinally, and a bipolar negative plate is superimposed between two adjacent unipolar positive plates. The negative terminal has several independent unipolar negative plates, which are stacked longitudinally, and a bipolar positive plate is superimposed between two adjacent unipolar negative plates. A sheet-like partition is provided between adjacent positive and negative plates. The unipolar electrode tabs on both sides of the bipolar electrode group extend horizontally or longitudinally.

[0031] Furthermore, a groove is provided in the middle of the partition wall. The groove makes the tab sealing more reliable, and the groove extends the acid creep path, making it less likely for acid to penetrate between cells, thereby further improving the safety and sealing of the battery.

[0032] The present invention also provides a battery prepared by any of the methods described above, wherein the battery is one of lead-acid battery, lithium-ion battery, sodium-ion battery, and potassium-ion battery.

[0033] The present invention has the following beneficial effects:

[0034] This invention uses a comb-tooth structure design to change the conventional horizontal insertion method of bipolar batteries to a vertical insertion method. In order to achieve parallel sealing of the tabs of the internal partition wall of the bipolar battery, the sealing of the internal partition wall comb teeth is divided into three layers: the middle layer is conductive adhesive, and the two sides are epoxy resin sealant. The conductive adhesive in the middle layer will not come into direct contact with the sulfuric acid solution of the battery's internal electrode group. This structural design not only solves the difficulty of sealing caused by the vertical assembly pressure when inserting the battery horizontally, but also makes the tab sealing of the bipolar battery simple and reliable, and solves the problem of parallel connection of the internal tabs of the bipolar battery.

[0035] The conductive adhesive uses silver-containing epoxy resin (silver content 60%-70%, conductivity ≥10). -4 S / cm) replaces the traditional welding process, avoiding the risk of overheating damage to the tabs and breakage of the solder joints. It has excellent conductivity and a firm connection. The sealant is an epoxy resin with a viscosity of 5000-8000mPa·s and a flow rate of 3-5cm / min, which ensures that it penetrates the gap between the tabs and the comb teeth without overflowing. After curing, it forms a complete sealing layer, which effectively prevents electrolyte leakage.

[0036] The electrode group uses alternating stacking of bipolar and unipolar plates to eliminate busbar and bridge welding, reduce the consumption of conductive substrate, and conform to the trend of green manufacturing. The wide tab design reduces ohmic resistance, suppresses local overheating during high current discharge (avoiding damage to sealant), and improves high current discharge capacity. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 It is a long-ear monopolar plate;

[0039] Figure 2 It is a bipolar plate;

[0040] Figure 3 It is a bipolar polar group;

[0041] Figure 4 The battery compartment has a comb-like structure.

[0042] Figure 5 This is a top view of the battery compartment with a comb-like structure.

[0043] Figure 6 This is a cross-sectional view of the battery compartment with a comb-like structure.

[0044] Figure 7Isometric view of the pole group after it enters the slot;

[0045] Figure 8 This is a top view of the pole group after it has entered the slot;

[0046] Figure 9 For use as a bridging block for partition walls;

[0047] Figure 10 The state in which the partition wall bridging block is installed;

[0048] Figure 11 This is a cross-sectional view of the battery's interior before it was sealed.

[0049] Figure 12 This is a bipolar polar group with both ends upright;

[0050] Figure 13 A battery compartment without comb teeth, recessed into the partition wall;

[0051] Figure 14 It is a partition wall bridging block with comb teeth;

[0052] Figure 15 A vertical terminal bipolar battery structure with comb-tooth sealing;

[0053] 1-Inner partition wall conductive adhesive groove; 2-Inner partition wall sealing adhesive groove; 3-Outer partition wall sealing adhesive groove. Detailed Implementation

[0054] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0055] (I) Battery compartment structure design

[0056] 1. Vertical structure and partition wall optimization

[0057] The bipolar battery is designed with a vertical insertion structure (unlike the traditional horizontal structure). The thickness of the partition walls between cells is increased to 10-20mm (compared to the conventional 2-3mm), and they are recessed downwards to the tab bridge area, forming a stepped support structure. The upper part of the partition walls adopts a comb-like design (e.g., Figures 4-6 As shown, the comb tooth height is the same as the tab width, and the tooth spacing is determined according to the thickness of the electrode plate and the separator to ensure accurate positioning of the tab.

[0058] 2. Layered comb tooth design

[0059] Internal partition (non-outer): The comb teeth are hollowed out in the middle to form an internal partition conductive adhesive groove 1 with a width of 4-6mm. Two rows of internal partition sealing adhesive grooves 2 are opened on each side, forming a three-layer isolation structure of "conductive adhesive-sealant-conductive adhesive" (e.g., Figure 6(As shown in the cross-sectional view). A 2-3mm deep injection notch is made at the top of the sealant groove to facilitate glue injection.

[0060] Outer partition wall: Only the middle part is hollowed out to form a 6-8mm wide sealing groove 3, which eliminates the need for conductive adhesive and simplifies the outer sealing process.

[0061] 3. Functional details design

[0062] Beveled edge: A bevel is set at the entrance of the comb teeth, with a bevel width of 0.5-1mm, allowing a deviation range of ±0.8mm in the position of the tab, thereby improving the assembly error tolerance.

[0063] Card slots and bridging blocks: Card slots are provided on both sides of the comb teeth to match the hollow partition bridging blocks (such as...). Figure 9 As shown, the hollow area around the bridging block is ≥30% to ensure that the glue is in full contact with the tank wall during injection.

[0064] Hollowed-out bottom: The bottom of the partition wall can be hollowed out, which can reduce weight by 15%-20% and increase the heat dissipation area.

[0065] (II) Assembly and Glue Application Process of the Extreme Group

[0066] 1. Polar group composition

[0067] Bipolar polar groups (see) Figure 3 ) Consists of bipolar plates (see Figure 2 ) and long electrode plate (see Figure 1 The electrode group consists of alternating stacked plates, with a positive terminal, a negative terminal, and a series connection section. The series connection section comprises bipolar plates where the positive and negative plates are directly connected by tabs. These bipolar plates are alternately stacked, with positive plates superimposed on negative plates, along the longitudinal direction. The positive terminal has several independent unipolar positive plates, stacked longitudinally, with a bipolar negative plate superimposed between adjacent unipolar positive plates. The negative terminal has several independent unipolar negative plates, stacked longitudinally, with a bipolar positive plate superimposed between adjacent unipolar negative plates. Sheet-like separators are placed between adjacent positive and negative plates. The tab width is designed to be 20-30mm (typically 16-20mm) to reduce ohmic resistance and improve high-current discharge capability.

[0068] 2. Assembly process

[0069] Pre-compression positioning: The electrode group is pre-compressed in the mold with a pressure controlled at 0.2-0.3 MPa. Then, the electrode group is installed into the battery slot from the top. After the electrode group is installed into the battery slot, the tabs fit precisely into the comb teeth, ensuring that the tabs and comb teeth are aligned. Figure 7 , Figure 8 This is the state after the polar group enters the tank.

[0070] Conductive adhesive injection: Use a dispensing machine with an accuracy of ±0.1mm to inject conductive adhesive (such as silver-containing epoxy resin adhesive with conductivity ≥10) into the conductive adhesive tank. -4 S / cm).

[0071] Bridging block installation: After curing, insert the bridging block, precisely positioning it along the slot to avoid misalignment, such as... Figure 9 As shown.

[0072] Sealant filling: Use epoxy resin with a viscosity of 5000-8000 mPa·s. Inject the resin from the center of the bridging block at a pressure of 0.1-0.2 MPa until the resin submerges the bottom of the bridging block by 2-3 mm, ensuring a gap filling rate of ≥99%, thus completing the sealing of the electrode lugs and partition walls. Figure 10 This is the state after the bridging block is installed. Figure 11 This is a cross-sectional view of the battery's interior before it was sealed.

[0073] After the sealant has cured, the battery can be assembled by sealing, welding the outer busbar, welding the terminals, and sealing the side cover.

[0074] Figures 12-15 In another specific embodiment of the present invention, the comb teeth are designed in the opposite direction, the partition wall has no comb teeth, the comb teeth are designed at the bottom of the partition wall bridging block, and the comb teeth are inserted into the electrode tab from the top.

[0075] The battery sealing process involves designing the bipolar electrode group and battery case as a vertical structure, thickening and lowering the partition walls between the internal cells, with the lowering height corresponding to the height of the electrode group's tabs, allowing the bipolar tabs to pass through the lowered part, while the unipolar tabs on both sides extend upwards.

[0076] Design a comb-tooth partition wall bridging block with comb teeth at the bottom and a hollow center. Each comb tooth corresponds to a bipolar electrode group tab. After the electrode group is inserted into the groove, the comb-tooth partition wall bridging block, pre-applied with adhesive to the comb teeth, is inserted from top to bottom into the partition wall tabs. The pre-applied adhesive fills the gap between the comb teeth and the tabs. After the adhesive cures, conductive adhesive is injected through the hollow center until the tabs are completely submerged. Then, sealant is injected to the appropriate height to seal the bipolar electrode group tabs. The comb-tooth partition wall bridging block is constructed through the hollow center. This design forms a three-layer sealed structure. The gaps between the comb teeth on both sides and the tabs are bonded with epoxy resin sealant to form two outer layers of sealant, while the hollowed-out middle section forms a conductive sealant layer. For bipolar electrode groups, the unipolar tabs on both sides can extend horizontally. In this case, the partitions at both ends of the battery compartment should also be designed as recessed structures, similar to the internal partitions. The tabs on both sides are also sealed by a bridging block in the partition with comb teeth. Since the two ends will eventually be connected via a busbar, there is no need to inject conductive sealant in the middle of the partitions at both ends. This structure allows for the production of batteries with side-mounted front terminals, facilitating battery pack connection.

[0077] The assembly process is very simple, and the conductive adhesive in the middle will automatically and fully bond with the tabs, avoiding the common problem of poor soldering. The comb-tooth structure with three layers of adhesive sealing is very strong and reliable, effectively solving the problem of parallel sealing of the tabs in bipolar batteries.

[0078] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for sealing bipolar battery tabs in parallel, characterized in that, Includes the following steps: a) The bipolar electrode group and battery compartment are designed as a vertical structure, and the partition wall between the internal cells is thickened and sunken. The sunken height corresponds to the height of the electrode tabs of the electrode group, so that the bipolar electrode tabs pass through the sunken part and the unipolar electrode tabs on both sides extend upward. b) After the bipolar electrode group is inserted into the groove, the comb tooth partition wall bridging block, which has been pre-coated with epoxy resin on the comb tooth part, is inserted into the electrode tab on the partition wall from top to bottom. The comb teeth of the comb tooth partition wall bridging block correspond one-to-one with the electrode tab of the bipolar electrode group. The comb tooth partition wall bridging block forms a three-layer sealing structure through the hollow part in the middle. The gap between the comb teeth and the electrode tab on both sides is bonded with epoxy resin sealant to form two outer layers of seal. The hollow part in the middle forms a conductive sealing layer with conductive adhesive. c) The comb teeth are pre-coated with epoxy resin to fill the gap between the comb teeth and the tabs. After the epoxy resin has cured, conductive adhesive is injected from the hollow part in the middle of the comb tooth partition bridging block until the tabs are completely submerged. After the conductive adhesive has cured, epoxy resin sealant is injected to a suitable height to complete the sealing of the bipolar electrode group tabs.

2. The method according to claim 1, characterized in that, The comb tooth inlet is provided with a chamfered opening, the chamfer width being 0.5-1mm; corresponding grooves are provided on both sides of the recessed partition wall, and the partition wall bridging block is installed along the groove, the fitting gap between the groove and the bridging block being ≤0.1mm; the epoxy resin adhesive has a viscosity of 5000-8000 mPa·s and a flowability of 3-5 cm / min, so that the adhesive will not overflow from the gap between the tab and the comb tooth.

3. The method according to claim 1, characterized in that, The bipolar electrode group has a positive terminal, a negative terminal, and a series connection section. The series connection section consists of bipolar plates with positive and negative electrode tabs directly connected. The bipolar plates in the series connection section are alternately stacked in a longitudinal direction, with positive plates superimposed on negative plates. The positive terminal has several independent unipolar positive plates, which are stacked longitudinally, and a bipolar negative plate is superimposed between two adjacent unipolar positive plates. The negative terminal has several independent unipolar negative plates, which are stacked longitudinally, and a bipolar positive plate is superimposed between two adjacent unipolar negative plates. A sheet-like partition is provided between adjacent positive and negative plates. The unipolar electrode tabs on both sides of the bipolar electrode group extend horizontally or longitudinally.

4. The method according to claim 1, characterized in that, The partition wall also has a groove in the middle.

5. A battery prepared by the method according to any one of claims 1-4, wherein the battery is one of lead-acid battery, lithium-ion battery, sodium-ion battery, and potassium-ion battery.

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