Bipolar battery tab parallel sealing method

Abstract

The invention discloses a bipolar battery tab parallel sealing method, which is characterized in that a bipolar plate group and a battery jar are designed into a vertical structure, a comb tooth structure with a hollow middle part is designed, comb teeth in the comb tooth structure are in one-to-one correspondence with the bipolar plate group tabs, after the plate group enters the jar, the comb teeth are fixed with the tabs through a sealant, and after the sealant is cured, the comb teeth are fixed with the tabs through the sealant. And injecting a conductive adhesive from the middle hollow part until the tabs are completely submerged, and then injecting a sealant to a proper height to complete sealing of the tabs of the bipolar plate group. The conductive adhesive adopts high-silver-content epoxy resin adhesive and sealant to control viscosity and fluidity. The method solves the problems of conductive reliability and sealing integrity of parallel connection of bipolar battery tabs, is suitable for various batteries such as plumbic acid batteries, lithium / sodium / potassium ion batteries and the like, and improves the battery performance and the production efficiency.

Description

Technical Field

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

[0002] In traditional chemical battery technology, the internal terminals of a single cell are usually electrically connected through a busbar, and the cells are connected in series by cross-bridge welding or through-wall welding. This connection method has the following significant drawbacks: (1) High material consumption. The busbar and cross-bridge connection structure requires a large amount of lead, which increases the raw material cost and environmental burden of the battery. According to statistics, the lead consumption of the connection components of a conventional 12V lead-acid battery accounts for 15%-20% of the total lead consumption; (2) Limited conductivity. When discharging with a large current, the contact resistance between the busbar and the welding point can easily cause local heating, affecting the battery life. Experimental data show that when the discharge current exceeds 5C, the temperature rise of the connection part can reach 30-50℃, accelerating the corrosion and aging of the lead alloy; the high structural complexity and multi-level connection structure increase the difficulty of the production process. In particular, the through-wall welding technology requires extremely high welding precision. The welding defect rate is usually 0.5%-1%, resulting in increased production costs.

[0003] In recent years, researchers have developed a bipolar battery that eliminates the need for a busbar. This utilizes bipolar plates with pre-connected positive and negative tabs to connect the cells in series, eliminating the need for inter-cell bridges. This is expected to reduce lead consumption by 20%-30%, aligning with the trend toward green manufacturing. This shortens the current conduction path, reduces internal resistance, and significantly improves high-current discharge performance. Tests have shown that the 5C discharge capacity of bipolar batteries is 10%-15% higher than that of conventional batteries.

[0004] However, this innovative structure brings new technical difficulties. The tabs of the bipolar plates need to pass through the cell partition wall 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 wall, which can easily lead to leakage of sulfuric acid electrolyte and cause battery short circuit. Due to the lack of the current equalization effect of the busbar, when there is a consistency deviation in the plate manufacturing, the abnormal current of the lagging plate will be directly transmitted to the normal plate of the adjacent cell, forming a "lagging current transfer effect". The traditional horizontal slot structure generates assembly pressure in the vertical direction, which makes capping difficult. Bubbles and shrinkage holes are easily generated during the curing process of the sealant, affecting the reliability of the seal.

[0005] Currently, bipolar battery tab sealing primarily utilizes the following methods. The technical solution in patent document CN202411945613.2 directly fills the gap between the tab and the partition wall with epoxy resin glue, but fails to address the compatibility issues between the conductive connection and the seal. When the conductive glue 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] Patent document CN201811209549.6 achieves parallel connection of tabs by welding thin lead sheets. However, the welding process can easily cause local overheating of the tabs (temperatures can reach 300-400°C), destroying the structure of the active material of the plate. In addition, the mechanical strength of the welding points is insufficient, and they are prone to breakage under vibration conditions.

[0007] Patent document CN202410727805.X uses a method of extruding sealing strips to fit the strips together and to the housing and lid. This method improves the sealing effect by pressing down the components and sealing film, avoiding the need for filler injection. However, the compatibility issue between the conductive connection and the seal 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] In response to the above problems, there is an urgent need to develop a bipolar battery tab processing technology that combines electrical connection reliability and sealing integrity. Summary of the Invention

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

[0010] In order to achieve the above-mentioned object, the present application provides a method for sealing bipolar battery tabs in parallel, which is characterized by comprising the following steps:

[0011] a) The bipolar pole group and the battery tank are designed as a vertical structure, the partition wall between the monomers is thickened, and comb teeth are provided on the upper part of the partition wall, and the comb teeth include inner partition wall comb teeth and outer partition wall comb teeth;

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

[0013] c) After the bipolar pole group is placed in the slot, the tabs are snapped into the comb teeth, and the directly connected tabs of the pole group are connected to each other through the sunken space. The tabs are sealed by the comb tooth structure, and conductive glue is injected into the internal partition wall conductive glue groove. After the conductive glue is cured, it is installed in the hollow partition wall bridge block;

[0014] d) Inject epoxy resin sealant into the inner partition wall sealant groove and the outer partition wall sealant groove until the bottom of the bridging block is submerged to complete the sealing of the tab and the partition wall.

[0015] Furthermore, the conductive adhesive can be connected in parallel with metal sheets. Since the purpose of parallel connection is to improve charging performance, it does not require a large current to pass, so only a small metal sheet can be used. This metal sheet is buried in the sealant and will not come into contact with the acid. It can be made of lead strips, copper sheets, or other metals.

[0016] Furthermore, the comb teeth are provided with an oblique chamfer at the entrance, and the chamfer width is 0.5-1mm, so that the pole group and pole ear positions can be smoothly inserted into the comb teeth even if there is a slight deviation; slots are provided on both sides of the partition wall corresponding to the comb teeth, and the partition wall bridging block is installed along the slot, and the fitting clearance between the slot and the bridging block is ≤0.1mm.

[0017] Furthermore, the viscosity of the epoxy resin glue is 5000-8000mPa·s, and the fluidity is 3-5cm / min. This parameter is optimized in the medium viscosity range, so that the glue can fully penetrate the tiny gap between the tab and the comb teeth by capillary action to achieve complete infiltration and sealing of the interface, and can also avoid the glue overflowing along the bevel chamfer of the comb teeth due to too low viscosity. Specifically, this viscosity range ensures that the glue maintains a stable laminar state under the action of the injection pressure, evenly fills the fitting gap between the tab and the comb teeth, and prevents overflow pollution caused by excessive flow. The fluidity index is specifically designed so that the glue can only diffuse directionally inside the sealant groove under the balance of gravity and surface tension, which not only meets the gap filling requirements of complex structures, but also forms a uniform and continuous sealing layer, ensuring the sealing integrity and reliability between the tab and the partition wall from the process parameter level.

[0018] Furthermore, the height of the tab slot is flush with the tab, and the width of the slot is 0.1 to 0.3 mm larger than the thickness of the tab. The slot height is consistent with the tab height, so that the tab is completely embedded in the comb groove in the vertical direction, avoiding the tab from being suspended or exposed due to height deviation, and ensuring that the conductive glue groove and the sealing glue groove fully cover the tab. This design eliminates the problem of tab tilting or misalignment in the traditional horizontal slot structure, and provides a stable interface foundation for the subsequent glue injection process. The slot width is 0.1 to 0.3 mm larger than the tab thickness, which allows for manufacturing deviations in the thickness direction of the tab and forms a micron-level gap suitable for glue penetration. This gap guides the conductive glue / sealant to evenly fill the interface through capillary action, avoiding the inability of glue to penetrate due to excessive tightness, or glue loss or sealing layer defects caused by excessive looseness.

[0019] Furthermore, the electrode group has a positive terminal, a negative terminal and a series part, the series part is a bipolar plate with positive and negative plate ears directly connected, and the bipolar plates in the series part are alternately stacked in the form of positive plates superimposed on negative plates, and along the longitudinal direction; the positive terminal has a number of independent unipolar positive plates, the positive plates are stacked longitudinally, and the negative plate of the bipolar plate is stacked between two adjacent unipolar positive plates; the negative terminal has a number of independent unipolar negative plates, the negative plates are stacked longitudinally, and the positive plate of the bipolar plate is stacked between two adjacent unipolar negative plates; a sheet separator is provided between adjacent positive plates 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 of ≥10 -4 S / cm. Silver is one of the most conductive metals. A silver content of 60%-70% gives the conductive adhesive an extremely high conductivity (≥10 -4 S / cm), significantly reducing contact resistance at the parallel connection of tabs, minimizing energy loss and localized heating during high-current discharge. Given that bipolar battery tabs must penetrate partitions for series connection, the conductive adhesive connection eliminates the need for additional busbars or bridge structures. Combined with the comb and bridge block design, it achieves efficient conductivity and reliable sealing in 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 thermal expansion coefficient matches that of the battery slot.

[0022] Furthermore, the hollowing rate of 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 glue and the groove wall is ≥95% during glue injection.

[0023] Furthermore, the cell walls need to be thickened due to the comb-tooth design. To reduce the weight of the cell shell, the thickened 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 is designed to be wider than that of the plate tab of a conventional battery, so as to reduce the ohmic resistance of the tab as much as possible and prevent the tab from overheating during high current discharge and destroying the sealing effect of the sealant.

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

[0026] a) The bipolar pole group and battery trough 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 pole lug of the pole group, so that the bipolar pole lug passes through the sunken part and the unipolar pole lugs on both sides extend upward;

[0027] b) After the bipolar pole group is placed in the slot, the comb-tooth partition wall bridge block, which is pre-sticked with epoxy resin glue on the comb teeth, is clamped from top to bottom into the pole ear on the partition wall. The comb teeth of the comb-tooth partition wall bridge block correspond one-to-one with the bipolar pole group pole ears. The comb-tooth partition wall bridge block is hollowed out in the middle to form a three-layer sealing structure. The gaps between the comb teeth and the pole ears on both sides are bonded with epoxy resin sealant to form two layers of outer sealing, and the hollowed-out part in the middle is formed with conductive glue to form a conductive sealing layer;

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

[0029] Furthermore, a bevel chamfer is provided at the entrance of the comb teeth, and the chamfer width is 0.5-1mm; a slot is provided on both sides of the corresponding sunken partition wall, and the partition wall bridging block is installed along the slot, and the fitting clearance between the slot and the bridging block is ≤0.1mm; the viscosity of the epoxy resin glue is 5000-8000mPa·s, and the fluidity is 3-5cm / min, so that the glue will not overflow from the gap between the tab and the comb teeth.

[0030] Furthermore, the bipolar pole group has a positive terminal, a negative terminal and a series part, the series part is a bipolar pole plate in which the positive and negative pole plate ears are directly connected, and the bipolar pole plates in the series part are alternately stacked in the manner of positive pole plates superimposed on negative pole plates, and along the longitudinal direction; the positive terminal has a number of independent unipolar positive pole plates, the positive pole plates are stacked longitudinally, and the negative pole plate of the bipolar pole plate is stacked between two adjacent unipolar positive pole plates; the negative terminal has a number of independent unipolar negative pole plates, the negative pole plates are stacked longitudinally, and the positive pole plate of the bipolar pole plate is stacked between two adjacent unipolar negative pole plates; a sheet separator is arranged between adjacent positive plates and negative plates; the unipolar pole ears on both sides of the bipolar pole group extend horizontally or along the longitudinal direction.

[0031] Furthermore, a groove is provided in the middle of the partition wall, which can make the tab seal more reliable, and the provision of the groove extends the acid creeping path, making it less likely for the acid between the monomers to penetrate each other, further improving the safety and sealing of the battery.

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

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

[0034] The present invention changes the conventional horizontal slotting of bipolar batteries into a vertical slotting through a comb-tooth structure design. In addition, 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 glue, and the two sides are epoxy resin sealants. The conductive glue of the middle layer will not directly contact the sulfuric acid liquid in the internal electrode group of the battery. This structural design not only solves the difficulty of sealing caused by the vertical assembly pressure during horizontal slotting, but also makes the tab sealing of the bipolar battery simple and reliable, and at the same time solves the problem of parallel tabs inside the bipolar battery.

[0035] Conductive adhesive uses silver-containing epoxy resin glue (silver content 60%-70%, conductivity ≥10 -4 S / cm), replacing the traditional welding process, avoiding the risk of overheating damage to the tabs and solder joint breakage, with excellent conductivity and firm connection. The sealant uses epoxy resin glue with a viscosity of 5000-8000mPa·s and a fluidity of 3-5cm / min to ensure that it penetrates the gap between the tabs and the comb teeth without overflowing. After curing, it forms a complete sealing layer, effectively preventing electrolyte leakage;

[0036] The electrode group uses bipolar plates and unipolar plates stacked alternately to eliminate bus and bridge welding, reduce the consumption of conductive substrate, and comply with the trend of green manufacturing; the tab width is designed with a wide tab mode to reduce ohmic resistance, inhibit local overheating during high current discharge (to avoid damage to the sealant), and improve high current discharge capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0039] Figure 2 It is a bipolar plate;

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

[0041] Figure 4 A battery slot with a comb-tooth structure;

[0042] Figure 5 A top view of the comb-tooth structure battery slot;

[0043] Figure 6 A cross-sectional view of a battery slot with a comb-tooth structure;

[0044] Figure 7This is an isometric view of the pole group after it is slotted;

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

[0046] Figure 9 Bridging blocks for partition walls;

[0047] Figure 10 The state of having partition wall bridging blocks installed;

[0048] Figure 11 This is a cross-sectional view of the battery before capping;

[0049] Figure 12 It is a bipolar pole group with upright pole ears at both ends;

[0050] Figure 13 A battery slot without comb teeth is sunken into the partition wall;

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

[0052] Figure 15 It is a vertical terminal bipolar battery structure with comb seal;

[0053] 1-Internal partition wall conductive adhesive groove; 2-Internal partition wall sealing adhesive groove; 3-External partition wall sealing adhesive groove. DETAILED DESCRIPTION

[0054] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0055] (1) Battery slot structure design

[0056] 1. Vertical structure and partition wall optimization

[0057] The bipolar battery is designed as a vertical slot structure (different from the traditional horizontal type), the thickness of the partition wall between the cells is increased to 10-20mm (conventional 2-3mm), and it sinks down to the bridge of the tab to form a stepped support structure. The upper part of the partition wall adopts a comb-tooth design (such as Figure 4-6 The height of the comb teeth is the same as the width of the tab, and the spacing between the teeth is determined according to the thickness of the plate and separator to ensure accurate positioning of the tab.

[0058] 2. Comb-teeth layered functional design

[0059] Internal partition wall (not external): The middle of the comb teeth is hollowed out to form an internal partition wall conductive glue groove 1 with a width of 4-6mm, and two rows of internal partition wall sealing glue grooves 2 are opened on each side to form a three-layer isolation structure of "conductive glue-sealant-conductive glue" (such as Figure 6A 2-3mm deep notch is provided 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 sealant groove 3 with a width of 6-8 mm, eliminating the need for conductive glue and simplifying the outer sealing process.

[0061] 3. Functional detail design

[0062] Bevel chamfer: A bevel is set at the entrance of the comb teeth, with a chamfer width of 0.5-1mm, allowing a deviation range of ±0.8mm for the tab position to improve the assembly tolerance.

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

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

[0065] (2) Electrode group assembly and injection process

[0066] 1. Pole group composition

[0067] Bipolar pole group (see Figure 3 ) by bipolar plates (see Figure 2 ) and long tab plates (see Figure 1 ) is composed of alternating laminated plates. The electrode group has a positive terminal, a negative terminal, and a series section. The series section is a bipolar plate with positive and negative plate tabs directly connected. The bipolar plates in the series section are alternately stacked in the form of positive plates stacked on negative plates, and along the longitudinal direction; the positive terminal has several independent unipolar positive plates, which are stacked longitudinally, and the negative plate of the bipolar plate is stacked between two adjacent unipolar positive plates; the negative terminal has several independent unipolar negative plates, which are stacked longitudinally, and the positive plate of the bipolar plate is stacked between two adjacent unipolar negative plates; a sheet separator is provided between adjacent positive and negative plates. The tab width is designed to be 20-30mm (conventionally 16-20mm) to reduce ohmic resistance and improve high current discharge capability.

[0068] 2. Assembly process

[0069] Pre-pressing and positioning: The electrode group is pre-pressed in the mold, and the pressure is controlled at 0.2-0.3MPa. Then the electrode group is installed into the battery slot from the top. After the electrode group is installed in the battery slot, the electrode ear is just stuck in the comb teeth to ensure that the electrode ear is aligned with the comb teeth. Figure 7 、 Figure 8 It is the state after the extreme group enters the slot.

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

[0071] Bridge block installation: After curing, install the bridge block and position it accurately along the slot to avoid misalignment, such as Figure 9 shown.

[0072] Sealant filling: Use epoxy resin glue with a viscosity of 5000-8000mPa·s, inject glue from the middle of the bridge block, with a pressure of 0.1-0.2MPa, until the glue submerges 2-3mm from the bottom of the bridge block, ensuring that the gap filling rate is ≥99%, and complete the sealing of the tab and partition wall. Figure 10 This is the state after the bridge block is loaded. Figure 11 This is a cross-sectional view of the battery before the cover is sealed.

[0073] After the sealing glue is cured, the cover can be sealed, the outer busbar can be welded, the terminals can be welded, and the side cover can be sealed to complete the assembly of the entire battery.

[0074] Figure 12-15 This is another specific embodiment of the present invention, in which 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 bridge block, and the comb teeth are clamped into the pole ear from the top.

[0075] The battery sealing process is to design the bipolar pole group and battery container into a vertical structure, and the partition wall between the internal cells is thickened and sunken. The sunken height corresponds to the height of the pole group's tabs, so that the bipolar tabs pass through the sunken part and the unipolar tabs on both sides extend upward.

[0076] A comb-tooth partition wall bridge block with comb teeth at the bottom and hollowed-out middle is designed. The comb teeth correspond to the bipolar pole group tabs one by one. After the pole group is put into the slot, the comb-tooth partition wall bridge block with glue pre-applied on the comb teeth will be inserted into the partition wall tabs from top to bottom. The comb teeth pre-applied with glue will fill the gap between the comb teeth and the tabs. After the glue solidifies, the conductive glue is injected from the hollowed-out middle part to completely submerge the tabs, and then the sealing glue is injected to a suitable height to complete the sealing of the bipolar pole group tabs. The comb-tooth partition wall bridge block is hollowed-out in the middle. , forming a three-layer sealing structure. The gaps between the comb teeth and the tabs on both sides are bonded with epoxy resin sealant to form two outer seals, and the hollowed-out area in the middle is sealed with conductive glue to form a conductive sealing layer. The bipolar pole group can also extend the unipolar tabs on both sides horizontally. In this case, the partition walls at both ends of the battery slot should also be designed as a sunken structure like the internal partition walls. The tabs on both sides are also sealed by the partition wall bridge blocks with comb teeth. Since the two ends will eventually be connected by a busbar, there is no need to inject conductive glue in the middle of the partition walls at both ends. This structure can produce a battery with side-front terminals, with the terminals on the side for easy connection of the battery pack.

[0077] The assembly process is very simple, and the conductive glue in the middle will automatically bond fully with the tabs, and conventional cold solder joints will not occur. The structure of comb teeth plus three layers of glue sealing is very strong and reliable, effectively solving the problem of parallel sealing of tabs in bipolar batteries.

[0078] The embodiments described above are some, but not all, of the embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

Claims

1. A method for sealing bipolar battery tabs in parallel, characterized in that: The following steps are involved: a) The bipolar pole group and the battery tank are designed as a vertical structure, the partition wall between the monomers is thickened, and comb teeth are provided on the upper part of the partition wall, and the comb teeth include inner partition wall comb teeth and outer partition wall comb teeth; b) The middle of the internal partition wall comb teeth are hollowed out to form a three-layer structure, with the middle layer forming the internal partition wall conductive glue groove, and both sides of the middle layer are hollowed out to form two rows of internal partition wall sealing glue grooves. The outer partition wall comb teeth are hollowed out only in the middle to form the outer partition wall sealing glue groove; c) After the bipolar pole group is placed in the slot, the tabs are snapped into the comb teeth. The directly connected tabs of the pole group are connected by bridges between the monomers through the sunken space. The tabs are sealed by the comb tooth structure. Conductive glue is injected into the internal partition wall conductive glue groove. After the conductive glue is cured, it is installed in the hollow partition wall bridge block; d) Inject epoxy resin sealant into the inner partition wall sealant groove and the outer partition wall sealant groove until the bottom of the bridging block is submerged to complete the sealing of the tab and the partition wall.

2. The method according to claim 1, characterized in that The internal partition wall comb teeth have a three-layer structure, the middle layer is a conductive adhesive layer, and the two sides are sealing adhesive layers. The comb teeth are provided with a bevel chamfer at the entrance, and the chamfer width is 0.5-1mm; slots are provided on both sides of the partition wall, and the partition wall bridge block is installed along the slot, and the matching clearance between the slot and the bridge block is ≤0.1mm.

3. The method according to claim 1, characterized in that The viscosity of the epoxy resin glue is 5000-8000mPa·s, and the fluidity is 3-5cm / min, so that the glue will not overflow from the gap between the tab and the comb teeth; the conductive glue is a silver-containing epoxy resin glue with a silver content of 60%-70% and a conductivity of ≥10 -4 S / cm.

4. The method according to claim 1, wherein The bipolar pole group has a positive terminal, a negative terminal and a series part. The series part is a bipolar plate in which the positive and negative plate tabs are directly connected. The bipolar plates in the series part are alternately stacked in the form of positive plates stacked on negative plates, and along the longitudinal direction; the positive terminal has a plurality of independent unipolar positive plates, the positive plates are stacked longitudinally, and the negative plate of the bipolar plate is stacked between two adjacent unipolar positive plates; the negative terminal has a plurality of independent unipolar negative plates, the negative plates are stacked longitudinally, and the positive plate of the bipolar plate is stacked between two adjacent unipolar negative plates; a sheet separator is provided between adjacent positive plates and negative plates.

5. A method for sealing bipolar battery tabs in parallel, characterized in that: The following steps are involved: a) The bipolar pole group and battery trough 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 pole lug of the pole group, so that the bipolar pole lug passes through the sunken part and the unipolar pole lugs on both sides extend upward; b) After the bipolar pole group is placed in the slot, the comb-tooth partition wall bridge block, which is pre-sticked with epoxy resin glue on the comb teeth, is clamped from top to bottom into the pole ear on the partition wall. The comb teeth of the comb-tooth partition wall bridge block correspond one-to-one with the bipolar pole group pole ears. The comb-tooth partition wall bridge block is hollowed out in the middle to form a three-layer sealing structure. The gaps between the comb teeth and the pole ears on both sides are bonded with epoxy resin sealant to form two layers of outer sealing, and the hollowed-out part in the middle is formed with conductive glue to form a conductive sealing layer; c) The comb teeth are pre-soaked with epoxy resin glue to fill the gap between the comb teeth and the tabs. After the epoxy resin glue is cured, the conductive glue is injected from the hollow part in the middle of the comb tooth partition wall bridge block until the tabs are completely submerged. After the conductive glue is cured, the epoxy resin sealant is injected to a suitable height to complete the sealing of the bipolar pole group tabs.

6. The method according to claim 5, characterized in that The comb teeth are provided with an oblique chamfer at the entrance, and the chamfer width is 0.5-1mm; slots are provided on both sides of the corresponding sunken partition wall, and the partition wall bridging block is installed along the slot, and the fitting clearance between the slot and the bridging block is ≤0.1mm; the viscosity of the epoxy resin glue is 5000-8000mPa·s, and the fluidity is 3-5cm / min, so that the glue will not overflow from the gap between the tab and the comb teeth.

7. The method according to claim 5, characterized in that The bipolar pole group has a positive terminal, a negative terminal and a series part, the series part is a bipolar pole plate with positive and negative pole plate ears directly connected, and the bipolar pole plates in the series part are alternately stacked in the form of positive plates superimposed on negative plates, and along the longitudinal direction; the positive terminal has a number of independent unipolar positive pole plates, the positive pole plates are stacked longitudinally, and the negative pole plate of the bipolar pole plate is stacked between two adjacent unipolar positive pole plates; the negative terminal has a number of independent unipolar negative pole plates, the negative pole plates are stacked longitudinally, and the positive pole plate of the bipolar pole plate is stacked between two adjacent unipolar negative pole plates; a sheet separator is arranged between adjacent positive plates and negative plates; the unipolar pole ears on both sides of the bipolar pole group extend horizontally or longitudinally.

8. The method according to claim 5, characterized in that A groove is also provided in the middle of the partition wall.

9. A battery prepared according to any one of claims 1 to 8, wherein the battery is a lead-acid battery, a lithium-ion battery, a sodium-ion battery, or a potassium-ion battery.

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