Lead-acid battery with polymer membrane

Abstract

The present invention discloses a lead-acid battery with a polymer membrane, which belongs to the field of battery technology. The battery includes a tank body, a cover body and single cells stacked longitudinally in the tank body. The width-to-thickness ratio of the single cells is 8 to 20, and the cells are sealed by a flexible polymer composite film package. A voltage regulating plate that can adjust the cell group voltage is provided in the stacking direction of the single cells. The single cells include stacked positive plates, negative plates and separators. When in use, the positive plates, negative plates and separators are horizontal. The flexible packaging adopts a polymer film, which has high barrier properties, excellent mechanical strength, strong acid and temperature resistance and good pressure resistance. The present invention significantly improves the utilization rate of active materials and reduces the reaction heat through ultra-thin cell design, flexible packaging and pressurized formation process, thereby improving the battery specific energy, cycle life and consistency, and is suitable for modular combination applications.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, in particular to a lead-acid battery with a polymer membrane. Background Art

[0002] Currently, lead-acid batteries on the market typically feature six interconnected cells, each rigidly connected to the rest of the battery. This utilizes an internal formation process, making it difficult to ensure consistent cell formation during production. This simultaneous formation of all six cells results in uneven temperatures within the cells. High-temperature areas are prone to lead dendrite growth, increasing the battery's internal resistance, impacting the transfer rate of active materials and leading to poor initial performance. Severe dendrite formation can cause the battery to short-circuit. Furthermore, current lead-acid batteries often use rigid materials such as virgin ABS or primary or secondary recycled ABS for their outer casings. While these materials offer strong mechanical strength and can provide assembly pressure for the cluster, they also suffer from issues such as inability to compress the outer casing, difficulty inserting the cluster into the casing, decreased cluster pressure, and low specific energy, all of which impact overall battery performance. Aluminum-plastic film packaging technology for lithium batteries offers advantages such as lightweight, ultra-high energy density, dimensional flexibility, and high safety, offering a potential solution to the shortcomings of traditional lead-acid batteries. However, this technology suffers from issues such as insufficient pressure resistance, acid corrosion resistance, and insufficient mechanical strength, making it unsuitable for direct application to lead-acid batteries.

[0003] In order to improve battery consistency, including the consistency of process and finished battery, the best way is to form single-cell battery cells and make them into independent battery cells. The battery cells are then selected based on discharge performance to have good capacity consistency. One of the challenges currently facing single-cell batteries is the technical contradiction between the rigid packaging and flexible deformation of lead-acid batteries. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-energy lead-acid battery, which balances the technical contradiction between rigid packaging and flexible deformation of lead-acid batteries through flexible packaging, thereby improving the capacity and cycle life of single cells.

[0005] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0006] A lead-acid battery with a polymer membrane comprises a tank body with an open end and a cover body matched with the tank body. Single cells are arranged in the tank body. The single cells are stacked longitudinally and electrically connected. The single cells are sealed by flexible packaging.

[0007] The aspect ratio of the single cell is 8 to 20. Increasing the aspect ratio of the cell can make the heat dissipation of the cell easier and reduce the risk of dendrite formation, thereby improving the utilization rate of active materials and reducing the reaction heat, and ultimately achieving the purpose of increasing the capacity and cycle life of the single cell. Preferably, the structural configuration with an aspect ratio ≥ 8 increases the ratio of the effective reaction area of ​​the electrode plate to the geometric projected area. Preferably, the electrode plate can present a multi-level folding configuration in a single cell with an aspect ratio ≥ 8, so that the actual reaction surface area per unit volume of the electrode plate is increased. By limiting the thickness of the electrode plates to cells with an aspect ratio of ≥8, the thickness of the electrode plates can be reduced in the case of single cells or single batteries of the same volume, thereby increasing the number of electrode plates that can be folded and stacked in the single cells or batteries. The adjacent surfaces of the electrode plates in the stacked state all participate in the electrochemical reaction, which can increase the overall surface area of ​​the electrode plates in the single cell or battery participating in the electrochemical reaction, that is, increase the actual surface area of ​​the electrode plates, and ultimately achieve a reduction in the degree of polarization of the battery composed of cells with this aspect ratio during the charge and discharge process, increase the battery's high current charging and high current discharging capabilities, reduce the internal resistance and charge transfer resistance during the charge and discharge process, and reduce the battery's heat generation. The aspect ratio value of the single cell can be specifically selected from one of the following specific values ​​or a range between any two of them: 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0008] The individual cells include a pole group connected to a pole group packaging head. The pole group and the pole group packaging head are encapsulated in a packaging bag to form a flexible package. The packaging bag is a polymer film with a thickness of 0.8mm or less. The flexible packaging forms a single, sealed cell, allowing for pressurized formation. The pressurized environment accelerates the deep penetration of sulfuric acid into the plate active material, improving the contact efficiency between the lead paste and the electrolyte. Simultaneously, the two sides of the ultra-thin cell are in contact with water (with only a film layer in between). The use of a flexible polymer composite film with a thickness of no more than 0.8mm as the packaging structure addresses the poor heat dissipation performance of traditional rigid-cased batteries. The polymer film's acid and heat resistance and insulation properties ensure the cell's reliability in harsh environments while also achieving excellent thermal conductivity. The flexible, ultra-thin cell design facilitates internal heat transfer to external cooling water, maintaining an internal temperature below 40°C, reducing the risk of dendrite formation and improving the transfer rate of active materials.

[0009] The water vapor permeability of the polymer film is 0.2-2.5g / m 2 / 24h. The polymer membrane is a composite polyimide / polytetrafluoroethylene film. Combined with the superhydrophobicity and chemical resistance of polytetrafluoroethylene, it further resists the penetration of acidic media and exhibits excellent resistance to strong acid corrosion. Combining the high strength of polyimide with the flexibility of polytetrafluoroethylene, it is suitable for flexible film substrates. In addition to resistance to sulfuric acid corrosion, it also possesses high mechanical strength, wear resistance, and flame retardancy, extending the service life of lead-acid batteries and increasing battery safety.

[0010] The single battery cells are 2V single battery cells, and the single battery cells can be combined into a battery module in a series or parallel manner.

[0011] A lead-acid battery with a polymer membrane comprises a tank body with an open end and a cover body that cooperates with the tank body. The tank body is provided with a single cell, and the single cell includes a pole group, wherein the pole group includes a positive plate, a negative plate, and a separator. The positive and negative plates of the pole group and the separator therebetween are stacked and placed horizontally during use. Since the positive plates, negative plates, and separators are placed horizontally during use, the sulfuric acid within the same separator is at the same horizontal position, forming a stable horizontal diffusion layer, eliminating natural convection caused by gravity, thereby achieving a uniform distribution of electrolyte density. Adjacent separators, separated by the positive and negative plates, form independent electrolyte units, eliminating density differences due to gravity. Therefore, the potential of each part of the plate is consistent, eliminating the internal self-discharge caused by inconsistent potentials in various parts of conventional batteries. The consistent internal acid density also improves the utilization rate of active materials in various parts of the plate, thereby achieving an increase in battery capacity and specific energy.

[0012] After the lead-acid battery has been tested for 100 cycles and then left to stand for 24 hours, the internal acid density deviation of the battery is ≤0.002g / mL. The battery is placed in the test state according to the test method of GB / T22199.1-2017 Valve-regulated Lead-acid Batteries for Electric Powered Vehicles Part 1: Technical Conditions 5.11. After 100 cycles, the battery is fully charged and left to stand for 24 hours. The battery is dissected and the separator is divided into three equal parts: upper (sample a), middle (sample b), and lower (sample c). The acid is squeezed out of three samples and the acid density is measured with a density meter. The internal acid density deviation is ≤0.002g / mL, that is, ρ 最大值 -ρ 最小值 ≤0.002g / mL, while the internal acid density deviation of ordinary lead-acid batteries is 0.04g / mL~0.06g / mL. Reducing the acid density deviation can improve the utilization rate of active materials.

[0013] The individual cells are encapsulated in a polymer film. After immersion in 1.20-1.40 g / mL sulfuric acid for 6-8 days, the change in water vapor transmission rate is less than 10%. The polymer film exhibits excellent acid resistance and exhibits no wrinkling, shrinkage, delamination, or brittleness after immersion in 1.20-1.40 g / mL sulfuric acid for 6-8 days. The polymer film also hinders the longitudinal flow of acid, ensuring uniform acid distribution between the upper and lower layers.

[0014] A lead-acid battery with a polymer membrane comprises a trough body with an opening at one end and a cover body matched with the trough body. A single cell is arranged in the trough body, wherein there are at least two single cells stacked vertically. A voltage regulating plate is provided in the trough body, and the voltage regulating plate adjusts the internal pressure of the single cell by changing the thickness. By setting the voltage regulating plate, the wet-state electrode group pressure of the single cell is greater than 20kPa, and the wet-to-dry ratio is not less than 1:1. The internal assembly pressure of the finished battery is directly controllable and adjustable, that is, a moderate assembly pressure is maintained in the dry state, and the internal group pressure of the finished battery can be flexibly adjusted in the wet state, thereby making the battery conductivity and internal resistance controllable, reducing battery heat generation and loss, and achieving an increase in battery cycle life.

[0015] The voltage regulating plates are located on both sides of the single cell stacking direction.

[0016] The single cell includes an electrode group, which includes a positive electrode plate and a negative electrode plate. The positive and negative electrode plates of the electrode group are stacked so that the positive and negative electrode plates are horizontal during use. The positive, negative, and separators of the present invention are placed horizontally, so that the acids on the same horizontal plane tend to be consistent, which can improve the utilization rate of active materials in the middle and lower parts of the original electrode plates, thereby achieving an increase in battery capacity and specific energy.

[0017] The wet electrode group pressure of the single cell is adjusted to 20 kPa-60 kPa by changing the thickness of the voltage regulating plate.

[0018] The single cell includes a pole group, which is connected to a pole group packaging head. The pole group and the pole group packaging head are covered with a packaging bag to form a flexible package. The packaging bag is a polymer film. The single cell is provided with a pressure maintaining mechanism to maintain an internal pressure of 20kPa-60kPa. The modular battery adopts the structure of a soft pack of battery cells, a separate grid, and this grid consists of a pole group packaging head, a pole group, a packaging bag and a safety valve. The single group of pole groups assembled with the pole group packaging head needs to be placed in a packaging bag. The pole group packaging head has a valve mouth structure for placing a safety valve. The safety valve is a one-way valve, which can not only isolate external gas from entering the battery cell, but also relieve pressure when the internal pressure is too high to keep the internal air pressure stable.

[0019] The electrode group packaging head is equipped with a safety valve, which is a one-way exhaust valve with an opening and closing pressure range of 10kPa to 35kPa. The sealing structure formed by the electrode group packaging head and the safety valve effectively prevents electrolyte leakage and improves battery safety.

[0020] The packaging bag is made of a polymer film with a compressive strength exceeding 1500N. Compressive strength testing of polymer films according to the national standard GB / T 21302-2007 shows that the compressive strength of the polymer film is above 1500N. The tensile strength of the polymer film is 80-200N / 15mm. The packaging bag isolates the electrode group from the external environment, reducing the risk of corrosion and extending the battery life.

[0021] A polymer film for lead-acid batteries comprises at least two film substrates and an adhesive layer, wherein the film substrates comprise at least two of polyethylene terephthalate film, polypropylene film, nylon film, and composite polyimide / polytetrafluoroethylene film. Conventional flexible films are prone to problems during the lead-acid assembly process, such as sulfuric acid or acid mist overflowing onto the outer layer, thereby corroding the outer layer, and sulfuric acid or acid mist penetrating into the adhesive layer, resulting in adhesive layer failure and delamination between the inner and outer layers. Furthermore, conventional curing processes typically employ a single energy field action mode, such as long-term thermal curing or using only ultraviolet light to initiate surface curing, which can easily lead to premature hardening of the surface resin, hindering internal cross-linking and causing insufficient curing of the core layer. In order to enhance the interlayer peel strength of the composite film and improve the long-term reliability of the packaging material under complex working conditions, the present invention provides a polymer film for lead-acid batteries that combines the characteristics of lightweight, high energy density, high strength, and acid resistance, systematically balancing the technical contradictions between rigid packaging and flexible deformation of lead-acid batteries.

[0022] The adhesive layer comprises a dynamic borate prepolymer, which is obtained by reacting 1,4-phenylenediboric acid and polyglycerol diglycidyl ether under the catalysis of p-toluenesulfonic acid.

[0023] The adhesive layer includes acid-responsive microcapsules whose shell material comprises polymethyl methacrylate-co-acrylic acid and whose core material comprises pentaerythritol triacrylate. The acid-responsive microcapsules in the adhesive layer remain intact in neutral and alkaline environments, but rupture in acidic media, releasing crosslinking agent components, further enhancing the crosslinking density of the adhesive layer and increasing acid resistance.

[0024] The adhesive layer includes a dual-cure initiator, and the dual-cure initiator includes ethyl 2,4,6-trimethylbenzoylphenylphosphonate and dicumyl peroxide.

[0025] The adhesive layer includes an epoxy-acrylate copolymer. The epoxy-acrylate copolymer provides UV-curable active groups, which work together with the dual-curing initiator to achieve a dual-curing mechanism of "light-curing rapid setting-heat-curing deep cross-linking", which can not only fill the micropores on the surface of the substrate, but also dissipate external stress through dynamic reversible characteristics, avoid interface cracking, and increase compressive resistance. Preferably, the film substrates are composited through light-heat gradient synergistic curing. Preferably, light-heat gradient synergistic curing includes UV curing and infrared curing.

[0026] The preparation of a polymer film for a lead-acid battery includes the following steps: corona-treating the surface of a first film substrate, coating it with a pH-responsive adhesive, forming a first adhesive layer, and obtaining an inner-layer adhesive composite film; corona-treating the surface of a second film substrate, compounding it with the inner-layer adhesive composite film, co-curing it through a light-heat gradient, coating it with a pH-responsive adhesive, forming a second adhesive layer, and obtaining an intermediate-layer adhesive composite film; corona-treating the surface of a third film substrate, compounding it with the intermediate-layer adhesive composite film, and co-curing it through a light-heat gradient; rapidly cooling it using a water-cooled roller; and after cooling, heat-sealing it on three sides to form a straight-cut seal with a width of 3 mm to 5 mm, and spraying a layer of polytetrafluoroethylene coating on the straight-cut seal to obtain a polymer film for a lead-acid battery.

[0027] Specifically, the first film substrate includes a polypropylene film; the second film substrate includes one of an ethylene terephthalate film and a nylon film; the third film substrate includes a composite polyimide / polytetrafluoroethylene film; the thickness of the first adhesive layer is 10-30 μm; the thickness of the second adhesive layer is 10-30 μm.

[0028] Specifically, the UV curing time is 3-15s; the infrared curing time is 5-40s; the rapid cooling rate is 14-16°C / s; the hot knife temperature for three-side heat sealing is 165-175°C, the pressure is 0.6-0.8MPa, and the holding time is 2-4s.

[0029] The present invention adopts a composite structure of at least two film substrates selected from polyethylene terephthalate film, polypropylene film, nylon film and composite polyimide / polytetrafluoroethylene film, adopts a pH-responsive adhesive and optimizes the curing process, so the prepared polymer film has high barrier properties, excellent mechanical strength, strong acid and temperature resistance and good pressure resistance.

[0030] The beneficial effects of the present invention are as follows: the present invention significantly improves the comprehensive performance of lead-acid batteries through innovative design. The ultra-thin flexible single cell structure is adopted, combined with a longitudinal stacking layout, which greatly optimizes the heat dissipation efficiency, effectively inhibits the growth of lead dendrites, reduces internal resistance and reaction heat, thereby extending the cycle life and improving the energy density. The flexible polymer composite film packaging not only ensures acid resistance and mechanical strength, but also gives the cell deformation adaptability, solving the problems of uneven assembly pressure and incompressible shell of traditional hard shell batteries, and introduces pH-responsive adhesives to achieve self-repair function in acidic environment, thereby enhancing the reliability and durability of the package. The horizontally arranged positive and negative plates and separators optimize the uniformity of electrolyte distribution and can improve the utilization rate of active substances. The voltage regulating plate in the stacking direction of the single cell can realize the regulation of the internal assembly pressure of the finished battery. The present invention systematically improves the uniformity of electrical performance, acid distribution and temperature of lead-acid batteries through ultra-thin cell structure, flexible packaging materials, precise pressure control, active material optimization and modular design, and significantly improves the specific energy and cycle life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0032] Figure 1 Schematic diagram of the internal structure of the lead-acid battery of the present invention.

[0033] Figure 2 Schematic diagram of a single cell of the present invention.

[0034] Figure 3 This is a schematic structural diagram of a single cell according to the first embodiment.

[0035] Figure 4 The graph is a graph showing impedance test data of the soft-pack single battery of the present invention and a traditional single battery.

[0036] Figure 5 for Figure 4 The enlarged curve of the area where Z' values ​​are between 0.0030 and 0.0060.

[0037] Figure 6 for Figure 4 The graph shows that the Z' value ranges from 0.0060 to 0.030.

[0038] Figure 7 The following is a curve of the formation temperature difference of battery cells with three width-to-thickness ratios.

[0039] Figure 8 Schematic diagram of the structure of polymer membrane for lead-acid batteries.

[0040] Explanation of the accompanying reference numerals: 1 - tank body; 2 - single cell; 21 - positive electrode plate; 22 - negative electrode plate; 23 - separator; 24 - pole; 3 - connecting plate. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] The following first describes the concepts involved in this application with reference to the accompanying drawings. It should be noted that the following description of each concept is intended only to make the content of this application easier to understand and does not limit the scope of protection of this application. At the same time, the embodiments and features in the embodiments of this application can be combined with each other unless there is a conflict. The following detailed description of this application will be made with reference to the accompanying drawings and in conjunction with the embodiments.

[0043] Example 1

[0044] like Figures 1 to 3 As shown, a lead-acid battery with a polymer membrane comprises a tank body 1 with an opening at one end, and a cover body matched with the tank body 1. A single cell 2 is arranged in the tank body 1. The single cell 2 is stacked longitudinally and electrically connected, and the single cell 2 is sealed by flexible packaging. The width-to-thickness ratio of the single cell 2 is 8 to 20. Preferably, the width-to-thickness ratio of the single cell is 8 to 20, which can be specifically selected from one or any two of the following specific values: 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. The single cell 2 includes a pole group, the pole group is connected to the pole group packaging head, and the pole group and the pole group packaging head are covered with a packaging bag to form a flexible package. The packaging bag is a polymer film, and the thickness of the polymer film is ≤0.8mm. Preferably, the water vapor permeability of the polymer film is 0.2-2.5g / m 2 The single battery cell 2 is a 2V single battery cell, and the single battery cells 2 can be combined into a battery module in a series or parallel manner.

[0045] A lead-acid battery with a polymer membrane includes a tank body 1 with an opening at one end and a cover body that cooperates with the tank body 1. A single cell 2 is arranged in the tank body 1. The single cell 2 includes an electrode group, which includes a positive electrode plate 21, a negative electrode plate 22, and a separator 23. The positive electrode plate 21 and the negative electrode plate 22 of the electrode group and the separator 23 therebetween are stacked and placed horizontally when in use.

[0046] After 100 cycles and 24 hours of rest, the lead-acid battery's internal acid density deviation is ≤0.002 g / mL. The single cell 2 is encapsulated in a polymer film. After immersion in 1.20-1.40 g / mL sulfuric acid for 6-8 days, the change in water vapor transmission rate is less than 10%.

[0047] A lead-acid battery with a polymer membrane comprises a tank body 1 with an open end and a cover body that cooperates with the tank body 1. A single cell 2 is disposed within the tank body 1. The single cells 2 are at least two in number and are connected by a connecting plate 3. The single cells 2 are stacked longitudinally. A voltage regulating plate is disposed within the tank body 1. The voltage regulating plate adjusts the internal pressure of the single cell 2 by varying its thickness. The voltage regulating plates are located on both sides of the stacking direction of the single cells 2. The single cell 2 comprises an electrode group, which includes a positive electrode plate 21 and a negative electrode plate 22. The positive electrode plate 21 and the negative electrode plate 22 of the electrode group are stacked. When in use, the positive electrode plate 21 and the negative electrode plate 22 are both horizontal. By changing the thickness of the voltage regulating plate, the wet electrode group pressure of the single cell 2 is set to 20 kPa-60 kPa, which can be specifically selected as one of the following specific values ​​or a value between any two numerical ranges: 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60. The single cell 2 includes an electrode group, which is connected to an electrode group packaging head. The electrode group and the electrode group packaging head are covered with a packaging bag to form a flexible package. The packaging bag is a polymer film. The single cell 2 is provided with a pressure maintaining mechanism to maintain an internal pressure of 20 kPa-60 kPa. The electrode group packaging head is provided with a safety valve, which is a one-way exhaust valve with an opening and closing pressure range of 10kPa to 35kPa. The packaging bag is made of a polymer film with a compressive strength of more than 1500N.

[0048] Figure 8Shown is a polymer film for lead-acid batteries, comprising at least two film substrates and an adhesive layer. The film substrates comprise at least two of polyethylene terephthalate film, polypropylene film, nylon film, and composite polyimide / polytetrafluoroethylene film. Preferably, the adhesive layer comprises a dynamic borate prepolymer obtained by reacting 1,4-phenylenediboronic acid and polyglycerol diglycidyl ether under the catalysis of p-toluenesulfonic acid. Preferably, the adhesive layer comprises acid-responsive microcapsules, the shell material of which comprises polymethyl methacrylate-co-acrylic acid, and the core material of which comprises pentaerythritol triacrylate. Preferably, the adhesive layer comprises a dual-cure initiator comprising ethyl 2,4,6-trimethylbenzoylphenylphosphonate and dicumyl peroxide. Preferably, the adhesive layer comprises an epoxy-acrylate copolymer.

[0049] Example 2

[0050] The technical principle of Example 1 is further explained:

[0051] The plates in single cells with a width-to-thickness ratio of 8 or greater can exhibit a multi-level folding configuration, increasing the actual reaction surface area per unit volume of the plates. By limiting the thickness of the plates to cells with a width-to-thickness ratio of 8 or greater, the thickness of the plates can be reduced for single cells or batteries of the same volume, thereby increasing the number of plates that can be folded and stacked in a single cell or battery. Adjacent surfaces of stacked plates all participate in the electrochemical reaction, increasing the overall surface area of ​​the plates participating in the electrochemical reaction in a single cell or battery, that is, increasing the actual surface area of ​​the plates. Ultimately, the battery composed of cells with this width-to-thickness ratio can reduce the degree of polarization during the charge and discharge process, increase the battery's high-current charge and high-current discharge capabilities, reduce the internal resistance and charge transfer resistance during the charge and discharge process, and reduce the battery's heat generation.

[0052] The specific principle is as follows: The surface area of ​​the plate that reacts with the electrolyte in the battery is called the true surface area. The larger the plate's true surface area, the smaller the battery's polarization during charge and discharge with the same current. While maintaining a constant battery volume, the larger the plate area and the thinner the thickness (the larger the aspect ratio), the smaller the battery's polarization during charge and discharge, and the greater the battery's high-current charge and discharge capabilities.

[0053] According to the basic principles of electrochemical kinetics, the net current density of the electrode reaction is and overpotential The relationship can be characterized by the Butler-Volmer equation, as follows:

[0054] In the formula, is the net current density of the electrode reaction, is the exchange current density, is the anodic transfer coefficient, is the cathode transfer coefficient, usually + =1, is the Faraday constant, is the gas constant, is the thermodynamic temperature, is the overpotential. This formula, derived theoretically, shows that, at the same overpotential, the net current density of the electrode reaction increases significantly as the exchange current density of the positive and negative active materials increases, while electrode polarization decreases accordingly. A higher exchange current density indicates a higher intrinsic activity of the electrode reaction, enabling faster adjustment of the reaction rate in response to potential changes, resulting in relatively smaller changes in the electrode potential.

[0055] The lead-acid battery of the present invention is tested and the internal acid density deviation is ≤0.002g / mL, i.e., ρ 最大值 -ρ 最小值 ≤0.002g / mL, while the internal acid density deviation of ordinary lead-acid batteries is 0.04g / mL~0.06g / mL. The lead-acid battery of the present invention has a higher utilization rate of active substances than ordinary lead-acid batteries. This is because:

[0056] During the charging stage, sulfuric acid is generated on the surface of the positive and negative electrodes, causing the density of sulfuric acid near the plates to increase;

[0057] Oxidation reaction occurs at the positive electrode: PbSO4+2H2O→PbO2+H2SO4+2H + +2e －

[0058] Reduction reaction occurs at the negative electrode: PbSO4+2e － →Pb+SO4 2－

[0059] During the discharge phase, both the positive and negative electrode reactions consume sulfuric acid, causing the sulfuric acid density on the plate surface to decrease;

[0060] Positive electrode reduction: PbO2+H2SO4+2H + +2e － →PbSO4+2H2O

[0061] Negative electrode oxidation: Pb+SO4 2－ →PbSO4+2e －

[0062] In traditional lead-acid batteries, because the positive and negative plates and separators are positioned vertically, high-density acid settles due to gravity during charging, forming a concentrated acid zone at the bottom. During discharge, the resulting low-density electrolyte rises to the top, creating a vertical concentration gradient. This creates a stable "acid-poor top, acid-rich bottom" structure during cycling. This results in: insufficient acid concentration on the upper plate, leading to irreversible lead sulfate deposition; excessive acid concentration on the lower plate, accelerating grid corrosion; and a gradient in active material utilization, with low active material utilization at the bottom. The present invention utilizes an innovative acid-balancing structure, positioning the positive and negative plates to optimize the active material equilibrium. The plates and separators are positioned horizontally, aligning the sulfuric acid within the same separator to form a stable horizontal diffusion layer. This eliminates gravity-induced natural convection and ensures a uniform electrolyte density distribution. Adjacent separators, separated by the positive and negative plates, form independent electrolyte units, eliminating density differences due to gravity.

[0063] Since the acid concentration in each active area of ​​the lead-acid battery plate of the present invention is balanced, according to the Nernst equation

[0064]

[0065] The potential distribution of the electrode plate of the present invention is good and uniform, which can eliminate the self-discharge reaction caused by the potential difference between the upper and lower parts, and at the same time make the grids of each part corrode evenly, avoiding the abnormally rapid corrosion of the lower grid of conventional batteries due to high acid density environment, so as to improve the battery life. is the standard electromotive force, usually between 1.93V and 2.04V, and are the activities of sulfuric acid and water, respectively. The coefficient 0.059 corresponds to the temperature condition of 25°C. n=2 is the number of electrons transferred in the reaction.

[0066] The primary active material in the positive plate 21 is lead dioxide (PbO2), with a theoretical density of approximately 10.0 g / cm³. The primary active material in the negative plate 22 is spongy lead (Pb), with a theoretical density of 11.34 g / cm³, and lead sulfate (PbSO4), with a theoretical density of 6.2 g / cm³. Due to these different densities, the active materials expand during discharge and contract during charge. By adjusting the thickness and pressure of the pressure-regulating plate, the present invention allows for direct control of the internal assembly pressure of the finished battery, ensuring a wet electrode group pressure of 20 kPa to 60 kPa.

[0067] Example 3: The preparation method of the polymer film described in Example 1 is described in detail.

[0068] The preparation of polymer membrane for lead-acid battery comprises the following steps:

[0069] The surface of the first film substrate is corona treated and then coated with a pH-responsive adhesive to form a first adhesive layer to obtain an inner adhesive composite film; the surface of the second film substrate is corona treated and then composited with the inner adhesive composite film, and then cured by light-heat gradient synergistic curing, and then coated with a pH-responsive adhesive to form a second adhesive layer to obtain an intermediate adhesive composite film; the surface of the third film substrate is corona treated and then composited with the intermediate adhesive composite film, and then cured by light-heat gradient synergistic curing; the film substrate is rapidly cooled using a water-cooled roller; after cooling, the film substrate is heat-sealed on three sides to form a straight-cut seal with a width of 3mm to 5mm, and a layer of polytetrafluoroethylene coating is sprayed on the straight-cut seal to obtain a polymer film for lead-acid batteries. Specifically, the first film substrate includes a polypropylene film; the second film substrate includes one of an ethylene terephthalate film and a nylon film; the third film substrate includes a composite polyimide / polytetrafluoroethylene film; the thickness of the first adhesive layer is 10-30μm; the thickness of the second adhesive layer is 10-30μm. Specifically, the UV curing time is 3-15s; the infrared curing time is 5-40s; the rapid cooling rate is 14-16°C / s; the hot knife temperature for three-side heat sealing is 165-175°C, the pressure is 0.6-0.8MPa, and the holding time is 2-4s.

[0070] The present invention also provides a method for preparing acid-responsive microcapsules, comprising:

[0071] Preparation of acid-responsive microcapsules: Methyl methacrylate and acrylic acid are dispersed in ethyl acetate, azobisisobutyronitrile is added, and the mixture is stirred evenly. Under nitrogen protection and at 65-75°C, polymerization is carried out for 1-3 hours to form a copolymer shell layer, and pentaerythritol triacrylate is added and stirred evenly to obtain a core material / shell material mixed solution; Span 85 and Tween 20 are dispersed in deionized water and stirred evenly to obtain an emulsifier solution; the core material / shell material mixed solution is added to the emulsifier solution under stirring conditions of 1500-2500 rpm, and stirring is continued for 20-40 minutes. The mixture is transferred to a well-ventilated environment, and the solvent is evaporated for 5-7 hours at room temperature and stirring conditions of 200-400 rpm. The mixture is centrifuged at 3500-4500 rpm for 5-15 minutes. After washing, the mixture is dried at 35-45°C for 1-3 hours to obtain acid-responsive microcapsules.

[0072] Preferably, the mass ratio of methyl methacrylate to acrylic acid is 31.5-315:9-90.

[0073] Preferably, the mass ratio of methyl methacrylate to ethyl acetate is 31.5-315:94.5-945.

[0074] Preferably, the mass ratio of methyl methacrylate to azobisisobutyronitrile is 31.5-315:0.15-1.5.

[0075] Preferably, the mass ratio of pentaerythritol triacrylate to methyl methacrylate is 120-1200:31.5-315.

[0076] Preferably, the mass ratio of Span 85 to deionized water is 1.75-17.5:1200-12000.

[0077] Preferably, the mass ratio of Tween 20 to deionized water is 5.25-52.5:1200-12000.

[0078] Preferably, the particle size of the acid-responsive microcapsules is 10-30 μm.

[0079] The present invention also provides a method for preparing a pH-responsive adhesive, comprising:

[0080] Preparation of pH-responsive adhesive: 1,4-phenylenediboric acid and polyglycerol diglycidyl ether are uniformly mixed, p-toluenesulfonic acid is added, and the mixture is reacted at 115-125°C for 1-3 hours to obtain a dynamic borate prepolymer; 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester and diisopropylbenzene peroxide are uniformly mixed to obtain a dual-cure initiator; the dynamic borate prepolymer, acid-responsive microcapsules, epoxy-acrylate copolymer, and dual-cure initiator are mixed, and the mixture is stirred at 90-110 rpm for 1-3 hours to obtain a pH-responsive adhesive.

[0081] Preferably, the mass ratio of 1,4-phenylenediboronic acid to polyglycerol diglycidyl ether is 0.5-5:1-10.

[0082] Preferably, the mass ratio of p-toluenesulfonic acid to 1,4-phenylenediboronic acid is 1.5-15 mg:0.5-5 g.

[0083] Preferably, the mass ratio of ethyl 2,4,6-trimethylbenzoylphenylphosphonate to dicumyl peroxide is 1-10:2.25-22.5.

[0084] Preferably, the mass ratio of the dynamic borate prepolymer to the acid-responsive microcapsules is 15-150:6.75-67.5.

[0085] Preferably, the mass ratio of the dynamic borate prepolymer to the epoxy-acrylate copolymer is 15-150:25-250.

[0086] Preferably, the mass ratio of the dynamic borate prepolymer to the dual-cure initiator is 15-150:3.25-32.5.

[0087] Example 4: Experimental test on the lead-acid battery and polymer membrane described in Example 1.

[0088] Test 1: Study the effect of aspect ratio on the impedance of single cell.

[0089] In order to verify the performance difference between the electrode plate of the present invention and the traditional electrode plate during battery use, the impedance test was carried out on the single battery cell with the modular electrode plate of the present invention and the single battery cell with the traditional electrode plate. In this embodiment, the test was carried out using the 65V20A model electrochemical workstation of the modulabxm manufacturer. The test results are as follows: Figure 4-Figure 6 As shown, Figure 4-Figure 6 The "soft-pack single cell" in the present invention refers to a single cell with modular plates. Figure 4-Figure 6 The term "traditional single cell" refers to a single-cell battery with traditional plates.

[0090] It should be noted that the internal resistance R1 and charge transfer resistance R2 of the battery impedance can be preliminarily determined through the original data. The specific data needs to be calculated after constructing an equivalent circuit. The software used for fitting is Zview.

[0091] Step 1: Fill three batteries with different width-to-thickness ratios with acid using an acid filling machine. The acid density is 1.26g / cm 3 (25℃), the acid filling amount is 290g, the three types of battery cells are: soft-pack single cell with aspect ratio = 12.25, soft-pack single cell with aspect ratio 8 and traditional single cell with aspect ratio 2.4, and 12 cells of each type of single cell are filled with acid;

[0092] Step 2: After each single cell is filled with acid, place it in the same formation water bath, and set the water bath temperature to 25°C;

[0093] Step 3: Use the Nissan EYENCE paperless recorder to record the temperature (°C) of the single cell formation process. Install two temperature probe monitoring lines on each of the three single cells with different aspect ratios. The probes are attached to the center of the side surface of the single cell to ensure the monitored temperature is accurate.

[0094] Step 4: All three types of single cells adopt the "modular 85h" formation process charge and discharge program. While starting the charge and discharge program, turn on the paperless recorder to record the temperature data.

[0095] The above experiments were conducted twice for single cells with a width-to-thickness ratio of 12.25 and 8, respectively, and once for traditional single cells, for a total of five experiments.

[0096] Soft pack single battery: R1 is 3.2016 , R2 is 1.0467 ;

[0097] Traditional single cell battery: R1 is 3.5455 , R2 is 1.2787 .

[0098] Among them: R1 can be Figure 4 Preliminary judgment of the Z' value when -Z'' in the first half is 0;

[0099] Figure 4 In the figure, -Z" is the ordinate, which represents the imaginary part of the impedance, mainly reflecting the reactance component in the test system; Z' is the abscissa, which represents the real part of the impedance, mainly reflecting the resistance component in the test system. Figure 5 、 Figure 6 They are Figure 4 The enlarged curve diagram of the area where Z' value is 0.0030~0.0060 and 0.0060~0.030. Figure 5 It can be obtained that R1 of the soft-pack single battery is 3.2016mΩ, and R1 of the traditional single battery is 3.5455mΩ. The smaller Z' is, the smaller R1 is. Figure 6 The R2 of the soft-pack single cell is 1.0467 mΩ, while the R2 of the traditional single cell is 1.2787 mΩ. The larger the slope, the smaller the R2. By comparison, it can be seen that both R1 and R2 of the modular cell are smaller than those of the traditional lead-acid battery. This indicates that the single cell using the present invention has lower internal resistance and charge transfer resistance, less polarization during the charge and discharge process, greater charge and discharge capacity, and less useless power consumption, thereby achieving the single cell of the present invention having less heat generation and a lower temperature after use.

[0100] Test 2: Study the effect of width-to-thickness ratio on the temperature rise of a single electrode group during the formation process.

[0101] In order to highlight the formation advantage of the single cell with a high aspect ratio of the present invention, the single cell with an aspect ratio ≥ 8 of the present invention is experimentally compared with single cells with other aspect ratio ranges to explore the effect of the modular single cell pole group head aspect ratio on the temperature rise of a single pole group during the formation process.

[0102] Three types of cells with different width-to-thickness ratios were selected for comparison: a soft-packed single cell with a width-to-thickness ratio of 12.25, a soft-packed single cell with a width-to-thickness ratio of 8, and a traditional single cell with a width-to-thickness ratio of 2.4. After the three single cells were formed, the temperature data of the formation process was retrieved and plotted. The temperature difference curve is shown in the figure below. Figure 7 As shown. Figure 7 It can be seen that the larger the width-to-thickness ratio of the single cell, the lower the maximum temperature of the formation process; when the width-to-thickness ratio of the soft-pack single cell is 12.25, the maximum temperature of the formation process is only 38.2°C; when the width-to-thickness ratio of the soft-pack single cell is 8, the maximum temperature of the formation process is 45.1°C; the width-to-thickness ratio of the traditional single cell is 2.4, and the maximum temperature of the formation process is 52.3°C.

[0103] The above experimental results show that when the width-to-thickness ratio of the single cell is larger, the single cell will be relatively thinner, so that the water bath can more effectively remove the heat generated by the charging and discharging of the single cell during the formation process; under appropriate width and thickness conditions, the larger the width-to-thickness ratio of the single cell, the lower the internal temperature of the single cell during the formation process.

[0104] Test 3:

[0105] Acid density distribution test of lead-acid batteries.

[0106] The battery was placed in a used state for testing. According to the test method in Article 5.11 of GB / T22199.1-2017, Valve-Regulated Lead-Acid Batteries for Electric Powered Vehicles Part 1: Technical Conditions, after 100 cycles of testing, the battery was fully charged and left to rest for 24 hours. The battery was then dissected and the separator was divided into three equal parts: upper (sample a), middle (sample b), and lower (sample c). The acid was squeezed out of three samples and the acid density was measured using a density meter. The test results are as follows:

[0107] Table 1 Acid density distribution

[0108]

[0109] The lead-acid battery of the present invention is tested and the internal acid density deviation is ≤0.002g / mL, i.e., ρ 最大值 -ρ 最小值 ≤0.002g / mL, while the internal acid density deviation of ordinary lead-acid batteries is 0.04g / mL~0.06g / mL. The lead-acid battery of the present invention has improved active material utilization compared with ordinary lead-acid batteries.

[0110] Test 4: Voltage resistance test of polymer membrane for lead-acid batteries.

[0111] Test sample: polymer membrane for lead-acid battery prepared in each example.

[0112] Test method: According to the national standard GB / T 21302-2007, under the specified conditions, the test is carried out using a polymer membrane for lead-acid batteries.

[0113] The compressive strength of the polymer film used in lead-acid batteries is above 1500N.

[0114] The polymer membrane for lead-acid batteries prepared by the present invention uses dynamic interface bonding of pH-responsive adhesives, ultraviolet-infrared collaborative curing technology and multi-layer composite structure design, so that the adhesive layer can adapt to the deformation of the substrate during the heat sealing process, reduce interface defects, and significantly improve the compressive strength of the polymer membrane for lead-acid batteries.

[0115] Test 5: Tensile strength test of polymer membrane for lead-acid batteries.

[0116] Test sample: polymer membrane for lead-acid battery prepared in each example.

[0117] Test method: Cut dumbbell-shaped specimens from polymer film of lead-acid batteries and use an electronic universal testing machine with a clamp spacing of 50 mm and a tensile speed of 50 mm / min. Record the maximum force when the specimen breaks and calculate the elongation at break.

[0118] The tensile strength of the polymer film for lead-acid batteries is 80-200N / 15mm.

[0119] The longitudinal tensile strength of the polymer film for lead-acid batteries is 110-200N / 15mm.

[0120] The transverse tensile strength of the polymer film for lead-acid batteries is 80-180N / 15mm.

[0121] The polymer film for lead-acid batteries prepared by the present invention combines the high strength of various film substrates with the high toughness of polypropylene and has excellent mechanical properties.

[0122] Test 6: Water vapor transmission rate test of polymer membrane for lead-acid batteries.

[0123] Test sample: polymer membrane for lead-acid battery prepared in each example.

[0124] Test method: Pour 30mL of deionized water into a moisture permeable cup with an inner diameter of 70mm. Seal the cup mouth of the sample, weigh the initial mass m0 of the polymer membrane for lead-acid batteries, and place it in a constant temperature and humidity chamber. After 24 hours, take it out and weigh the mass m1. The moisture permeable area is S. Calculate the water vapor transmission rate according to the formula WVT=(m1-m0) / (S×24h).

[0125] The water vapor permeability of polymer membranes for lead-acid batteries is 0.2-2.5g / m 2 / 24h.

[0126] The polymer membrane for lead-acid batteries prepared by the present invention forms a high-barrier structure through process optimization and material synergy, while the adhesive fills the interface micropores to further block the water vapor permeation path.

[0127] Test 7: Acid resistance test of polymer membrane for lead-acid batteries.

[0128] Test sample: polymer membrane for lead-acid battery prepared in each example.

[0129] Test method: Take the polymer film for lead-acid batteries, measure the initial water vapor transmission rate F0, cut it into 50mm×50mm after drying, and completely immerse it in 1.35g / mL sulfuric acid solution at 25℃. After soaking for 7 days, take it out, rinse it with deionized water 3 times, dry it at room temperature for 24 hours, and measure the final water vapor transmission rate F0. t, according to the formula ∆F=(F t -F0) / F0×100%, and calculate the change rate of water vapor transmission rate.

[0130] The polymer membrane for lead-acid batteries prepared by the present invention maintains an intact appearance after being soaked in sulfuric acid, without wrinkling, shrinkage, delamination or brittleness, and the water vapor permeability change rate is less than 10%, indicating that the dynamic 1,4-phenylenediboronate bond in the pH-responsive adhesive remains stable in an acidic environment, and the acid-responsive microcapsules in the adhesive layer are not broken, thereby ensuring the interfacial bonding strength between the adhesive layer and the substrate. At the same time, the effect of the multiple membranes shows that the inorganic layer can physically isolate the corrosive medium and enhance the acid resistance. The composite membrane solves the durability problem of a single material in a strong acid environment through material complementarity and process optimization, thereby meeting the long-term corrosion resistance requirements of lead-acid batteries.

[0131] It should be noted that the terms used in this application are only for describing specific embodiments and are not intended to limit the scope of this application. As shown in the specification of this application, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular and may also include the plural. The terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method or device comprising a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of further restrictions, the elements defined by the sentence "comprise a..." do not exclude the presence of other identical elements in the process, method or device comprising the elements.

[0132] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0133] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and do not impose any form of limitation on the implementation methods of the technology of the present invention. Any person skilled in the art may make slight changes to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0134] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of this application, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A lead-acid battery with a polymer membrane, comprising a tank body (1) with an opening at one end, a cover body matched with the tank body (1), a single cell (2) being arranged in the tank body (1), and characterized in that: The monomer cells (2) are stacked longitudinally and electrically connected, and the monomer cells (2) are sealed by flexible packaging. The monomer cells (2) include a pole group, and the pole group is connected to a pole group packaging head. The pole group and the pole group packaging head are covered with a packaging bag to form a flexible packaging. The packaging bag is a polymer film, including at least two layers of film substrates and an adhesive layer. The adhesive layer includes a dynamic borate prepolymer, and the dynamic borate prepolymer is obtained by reacting 1,4-phenylenediboric acid and polyglycerol diglycidyl ether under the catalysis of p-toluenesulfonic acid. The adhesive layer also includes acid-responsive microcapsules, the shell material of the acid-responsive microcapsules includes polymethyl methacrylate-co-acrylic acid, and the core material of the acid-responsive microcapsules includes pentaerythritol triacrylate.

2. A lead-acid battery with a polymer membrane according to claim 1, characterized in that: The width-to-thickness ratio of the single battery cell (2) is 8-20, the single battery cell (2) is a 2V single battery cell, and the single battery cells (2) are combined into a battery module in a series or parallel manner.

3. The lead-acid battery with a polymer membrane according to claim 1, characterized in that: The thickness of the polymer film is ≤0.8mm, and the water vapor permeability of the polymer film is 0.2-2.5g / m 2 / 24h.

4. A lead-acid battery with a polymer membrane, comprising a tank body (1) with an opening at one end, a cover body matched with the tank body (1), a single cell (2) being arranged in the tank body (1), and characterized in that: The single cell (2) includes a pole group, wherein the pole group includes a positive plate (21), a negative plate (22), and a separator (23). The positive plate (21) and the negative plate (22) of the pole group and the separator (23) therebetween are stacked and placed horizontally when in use. The single cell (2) is provided with a packaging bag, wherein the packaging bag is a polymer film, comprising at least two layers of film substrates and an adhesive layer. The adhesive layer comprises a dynamic borate prepolymer, wherein the dynamic borate prepolymer is obtained by reacting 1,4-phenylenediboronic acid and polyglycerol diglycidyl ether under the catalysis of p-toluenesulfonic acid. The adhesive layer also comprises acid-responsive microcapsules, wherein the shell material of the acid-responsive microcapsules comprises polymethyl methacrylate-co-acrylic acid, and the core material of the acid-responsive microcapsules comprises pentaerythritol triacrylate.

5. The lead-acid battery with a polymer membrane according to claim 4, characterized in that: After the lead-acid battery has been tested for 100 cycles and then left to stand for 24 hours, the deviation of the acid density inside the battery is ≤0.002g / mL.

6. The lead-acid battery with a polymer membrane according to claim 4, characterized in that: When the polymer membrane is immersed in 1.20-1.40 g / mL sulfuric acid for 6-8 days, the change rate of water vapor transmission rate is less than 10%.

7. A lead-acid battery with a polymer membrane, comprising a tank body (1) with an opening at one end, a cover body matched with the tank body (1), a single cell (2) being arranged in the tank body (1), and characterized in that: There are at least two monomer cells (2), which are stacked longitudinally. A voltage regulating plate is provided in the tank body (1), and the voltage regulating plate adjusts the internal pressure of the monomer cell (2) by changing the thickness. The monomer cell (2) includes a pole group, which is connected to a pole group packaging head. The pole group and the pole group packaging head are covered with a packaging bag to form a flexible package. The packaging bag is a polymer film, which includes at least two layers of film substrates and an adhesive layer. The adhesive layer includes a dynamic borate prepolymer, which is obtained by reacting 1,4-phenylenediboric acid and polyglycerol diglycidyl ether under the catalysis of p-toluenesulfonic acid. The adhesive layer also includes acid-responsive microcapsules, the shell material of the acid-responsive microcapsules includes polymethyl methacrylate-co-acrylic acid, and the core material of the acid-responsive microcapsules includes pentaerythritol triacrylate.

8. The lead-acid battery with a polymer membrane according to claim 7, characterized in that: The voltage regulating plates are located on both sides of the stacking direction of the single battery cell (2), and the wet electrode group pressure of the single battery cell (2) is adjusted to 20 kPa-60 kPa by changing the thickness of the voltage regulating plates; the electrode group comprises a positive electrode plate (21) and a negative electrode plate (22), and the positive electrode plate (21) and the negative electrode plate (22) of the electrode group are stacked, and the positive electrode plate (21) and the negative electrode plate (22) are both horizontal when in use; the compressive strength of the polymer film is above 1500 N; the single battery cell (2) is provided with a pressure maintaining mechanism to maintain an internal pressure of 20 kPa-60 kPa, and a safety valve is provided on the electrode group packaging head, and the safety valve is a one-way exhaust valve, and the opening and closing valve pressure range of the one-way exhaust valve is 10 kPa~35 kPa.

9. A polymer membrane for a lead-acid battery, characterized in that: The invention comprises at least two film substrates and an adhesive layer, wherein the film substrates comprise at least two of polyethylene terephthalate film, polypropylene film, nylon film and composite polyimide / polytetrafluoroethylene film; the adhesive layer comprises a dynamic borate prepolymer obtained by reacting 1,4-phenylenediboric acid and polyglycerol diglycidyl ether under the catalysis of p-toluenesulfonic acid; the adhesive layer also comprises acid-responsive microcapsules, the shell material of the acid-responsive microcapsules comprises polymethyl methacrylate-co-acrylic acid, and the core material of the acid-responsive microcapsules comprises pentaerythritol triacrylate.

10. The polymer membrane for lead-acid batteries according to claim 9, characterized in that: The adhesive layer includes a dual-cure initiator, and the dual-cure initiator includes ethyl 2,4,6-trimethylbenzoylphenylphosphonate and dicumyl peroxide; The adhesive layer includes an epoxy-acrylate copolymer.

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