A lead-acid battery with thin plates

Abstract

The present invention belongs to the technical field of lead-acid power batteries and provides a lead-acid storage battery with thin plates. The present invention includes at least two single cells provided with plates and a battery container for loading the single cells, and is characterized in that the outer shell of the single cell includes a flexible material, and the flexible material is a polymer film of at least two layers; the single cell is provided with plates inside, and the interior of the single cell contains electrolyte, and the horizontal diffusion distance of the electrolyte solute of the single cell is greater than the vertical convection distance. The purpose of the present invention is to reduce the density difference of the electrolyte in different areas of the battery, give full play to the energy of the active substances in various parts of the plate, and improve the energy utilization rate of the chemical energy inside the battery; increase the internal pressure of the single cell, reduce the distance between the plates, reduce the internal resistance of the battery, and improve the output efficiency of the battery; increase the specific energy of the single cell, control the weight of the single cell, and improve the endurance of electric vehicles with the same weight.

Description

Technical Field

[0001] The invention relates to the technical field of lead-acid power batteries and provides a lead-acid battery with thin polar plates. Background Art

[0002] Lead-acid batteries are widely used in the electric bicycle industry, accounting for over 90% of the market share, dominating the electric bicycle power battery market with an absolute advantage. The new mandatory national standard, "Safety Technical Specifications for Electric Bicycles" (GB17761-2024), was officially released on December 31, 2024, and will be implemented on September 1, 2025. The vehicle weight limit for lead-acid battery electric vehicles has been adjusted from 55kg to 63kg. In traditional electric bicycle lead-acid batteries, the plates and separators are placed vertically. Due to gravity, the acid within the plates and separators stratifies, with the upper layer having a lower density and the lower layer having a higher density. This creates an imbalance in the electrolyte, preventing the active material from fully utilizing its energy. This results in higher utilization rates in the upper portion of the plate and lower utilization rates in the lower portion, creating a potential difference between the upper and lower portions of the plate. The current national standard for electric bicycles uses weight as a key metric, making it crucial to maximize the efficiency and energy of the limited active material. The inventors believe that there is significant room for improvement in the existing technology. The goal is to address the relationship between battery weight and capacity, avoiding the aforementioned potential differences caused by density differences within current standards, while also reducing the internal resistance of the plates and increasing the specific energy per unit alloy and active material utilization. Summary of the Invention

[0003] The purpose of this invention is to reduce the concentration differences of the electrolyte in different areas of the battery under current standards, fully utilize the energy of the active materials in each part of the plate, and improve the energy utilization rate of the battery's internal chemical energy. Secondly, it increases the internal pressure of the single cell, reduces the distance between the plates, reduces the battery's internal resistance, and improves the battery's output efficiency. It also increases the specific energy of the single cell, controls the weight of the single cell, and controls the overall weight of the lead-acid battery electric vehicle, thereby improving the endurance of the electric vehicle at the same weight.

[0004] A lead-acid battery with thin plates comprises at least two single cells provided with plates and a battery container for loading the single cells. The shell of the single cells comprises a flexible material, which is a polymer film of at least two layers. The aspect ratio of the single cells is B / δ, where 8≤B / δ<20. The single cells are provided with plates, which include positive plates. Preferably, the alloy content of the positive plates is 0.569-0.853 g / ml. The single cells contain an electrolyte, the horizontal diffusion distance of the electrolyte in the single cells is greater than the vertical convection distance, the electrolyte contains sulfuric acid, and the density difference of the sulfuric acid at various positions on the plates is less than 0.002 g / ml. The method of containing electrolyte inside the single cell and arranging the single cell horizontally greatly reduces the thickness of the single cell. The polymer membrane can prevent the solute in the electrolyte contained in the single cell from settling downward, that is, avoid significant stratification of the electrolyte inside the single cell and avoid the specific gravity difference of the electrolyte inside the single cell being greater than 0.02. Therefore, the potential of each part of the plate is consistent, eliminating the internal self-discharge caused by the inconsistent potential of each part of the conventional battery; the consistent sulfuric acid density inside the single cell also improves the utilization rate of active materials in each part of the plate, thereby The battery capacity and specific energy are increased; the aspect ratio of the single cell is B / δ, 8≤B / δ<20, and the temperature rise rate of the single cell with an aspect ratio of B / δ≥10 in the present application is reduced by 67% to 83% compared with the traditional structure; the equilibrium temperature is reduced by 8°C-12°C; so that the heat dissipation performance and material transfer rate of the single cell in this state are better than those of other single cells with aspect ratios of the same capacity. By optimizing the overall size of the single cell, the heat dissipation area is increased and the thickness of the single cell is reduced without changing the weight of the single cell, thereby achieving rapid heat dissipation of the single cell.

[0005] Preferably, the lead-acid battery with thin plates further comprises a lead plate, which is located at the top of the single cell group. The single cell comprises a pole arranged at the top of the single cell. The pole of each single cell is connected to the positive and negative poles of the lead-acid battery with thin plates by a lead plate circuit. The poles of the pole groups of traditional lead-acid power batteries are connected in series by welding, which reduces the fixing cost of the pole groups and the connection cost of the lead poles, while ensuring reliable connection between the pole groups. However, the present application uses single cells to complete the packaging of the pole groups, avoiding the problem of needing to fix the pole groups and the problem of reliable connection between the pole groups. The poles of each pole group can be connected in series through wires between the lead plates, reducing the risk of pole oxidation or plate active material falling off due to high-temperature welding. At the same time, since the lead plate connection poles are simpler and more detachable than welding, it is convenient for inspecting, maintaining and replacing single cells. The cells are screened and grouped according to their electrical properties. The electrical properties, such as output voltage, pressure, etc., maintain the consistency of the cells in the single cell group, significantly improving the cycle life and reliability of the battery.

[0006] Preferably, the outer shell of the single cell battery also includes a pole group head, which is provided with a through fitting hole, and a removable sealing cap is provided on one side of the fitting hole. After the pole passes through the fitting hole, it fits with the sealing cap, and the fitting gap between the sealing cap and the pole is filled with sealing material. The polymer film and the pole group head can fix the pole, and the single cell battery forms a closed container.

[0007] Preferably, the pole group head is provided with a pressure regulating valve, and the valve opening pressure range of the pressure regulating valve is 10kPa to 35kPa. If the internal positive pressure of the single battery cell is less than 10KPa, the pole group is frequently depressurized, and the oxygen and water vapor in the reaction of the primary battery of the pole group are depressurized and carry away the concentrated sulfuric acid, which reduces the service life of the battery; if the internal positive pressure of the single battery cell of the present application is greater than 35KPa, the flexible material shell of the single battery, and the sealed package formed outside the plate and electrolyte are easy to burst. The internal pressure of the single battery cell is adjusted within a range by the pressure regulating valve to keep the internal pressure of the single battery cell within an appropriate range. In addition, appropriately increasing the internal pressure of the single battery cell can inhibit the sulfation of the plate, delay the capacity decay, and at the same time enhance the wettability of the electrolyte to the plate and reduce the concentration gradient.

[0008] Preferably, the electrode plates include alternating positive and negative electrode plates, the unit alloy dosage of the positive electrode plates is 2.0g / Ah-2.5g / Ah, the electrode columns include positive electrode columns, and the number of positive electrode plates connected to the positive electrode columns is no more than 3. The positive electrode plates of the present invention are of a compression-expansion type. Compared with the existing positive electrode plates with compressed thickness dimensions, the battery capacity is maintained or even improved on the basis of increasing or maintaining the width dimensions, so that the capacity of a single electrode plate reaches 10Ah, which is twice the 5Ah of the traditional design. After the plate surface dimensions of the positive electrode plates of the present invention are changed, the internal resistance is reduced by 15% to 20%. Reducing the number of plates reduces the number of connection points, improving reliability. As the number of plates is reduced, the internal resistance is further reduced, and the performance of the plates when large currents pass through is improved, thereby achieving the goal of maintaining the battery discharge performance and cycle life while reducing the amount of lead material.

[0009] Preferably, the amount of active material used in the positive plate is 15.5g / Ah-16.5g / Ah. On the basis of maintaining or even enhancing the performance of lead-acid batteries, the use of positive plate alloys and active materials is greatly reduced, achieving the multiple advantages of lightweight, high energy density and long life. This innovation reduces material consumption while enhancing the electrochemical activity of the plate by improving the grid processing technology of the positive plate and the coating process of the active material, thereby increasing the energy density and capacity per unit weight of the battery. At the same time, by changing the pressurization structure and assembly method of the single cell, the stability of the internal pressure of the battery and the smooth installation of the single cell are ensured. In addition, the reduced amount of alloys and active materials also reduces manufacturing costs, so that the battery maintains high power output while enhancing its market competitiveness.

[0010] Preferably, the positive plate includes a positive electrode grid, which is a lead plate with a thickness greater than 12 mm, which is subjected to a roller-pounding process and then a heat treatment, with the roller-pounding process being performed at least 7 times, the heat treatment temperature being 80°C-90°C, and the heat treatment time being 12h-24h. The positive plate includes a positive electrode grid, which is a 15 mm thick lead plate subjected to 7-9 roller-pounding processes. Since the grid has been subjected to multiple roller-pounding processes, the density and strength of the alloy are very high, and the corrosion resistance is strong. A smaller amount of grid alloy can be used to meet the usage requirements during the battery life. The pounded grid is then heat-treated at a high temperature of 80°C-90°C for 12-24 hours. After the grid has been subjected to multiple roller-pounding processes, the thickness of the positive electrode grid reaches 0.3-0.6 mm. The hardness of the grid is improved, which facilitates improving the efficiency and pass rate of the plate coating. The roller-pounding process used in this application can improve the density and strength of the alloy and provide strong corrosion resistance.

[0011] Preferably, the positive plate after heat treatment is surface treated using a corona process, and the actual surface area of ​​the positive plate after corona treatment is greater than the actual surface area of ​​the positive plate before corona treatment. The corona process is as follows: the gas near the lead surface is ionized by a high-voltage electrode, generating active particles such as high-energy electrons, O3, and oxygen free radicals. These particles react with the lead surface in the following ways: oxidation, where Pb reacts with active oxygen to form lead oxide, PbO or Pb3O4, forming a thin oxide layer; surface activation, where high-energy particles bombard the lead surface, breaking molecular bonds and introducing polar groups, increasing surface energy; and cleaning, where corona discharge can remove surface organic pollutants or oxides, improving cleanliness. Because the previous process of roller pounding improves the density of the alloy, the surface finish of the alloy is improved, the surface energy is low, and the bonding strength with the active material of the plate is poor. The corona process, after treating the grid surface, increases the actual surface area and can improve these defects.

[0012] Preferably, the surface of the positive plate after corona treatment is sprayed with a suspension containing an antimony compound with a mass percentage of 1% to 5% at a spraying speed of 10 to 30 meters per minute. The grid sprayed with the antimony compound solution has a strong bond with the active material, improves conductivity, and has a low interface resistance between the active material and the grid. The above-mentioned positive grid surface spraying process can achieve enhanced mechanical strength. Specifically, Sb forms a lead-antimony alloy with lead Pb, such as Pb3Sb, which significantly improves the hardness and deformation resistance of the grid, prevents the active material PbO2 from falling off due to the expansion / contraction of the plate during charging and discharging, and can inhibit dendrite growth. Antimony can hinder the formation of lead dendrites, avoid structural damage to the positive active material and the risk of short circuit, and extend the cycle life.

[0013] In addition, it can realize the conversion of catalytically active substances: antimony acts as a catalyst for the nucleation of PbO2, promoting the uniform distribution of active substances and improving the discharge capacity.

[0014] Preferably, the lead-acid battery is placed in its intended use state and subjected to 20 to 100 cycle tests. The electrolyte contains sulfuric acid, and the density difference of the sulfuric acid at various locations within the individual cells is ≤0.002 g / ml. After prolonged charge and discharge cycles, the specific gravity of the acid at various locations within the individual cells remains similar, resulting in similar potentials at different locations on the plates. This improves the utilization of active material in the middle and lower portions of the plates, thereby increasing battery capacity and achieving higher specific energy.

[0015] A lead-acid battery with thin plates comprises at least two cells each provided with plates and a battery compartment for loading the cells. Adjacent cells are closely attached to form a cell pack, and a pressurizing structure is provided between the ends of the cell pack and the inner wall of the battery compartment. The cells are internally provided with plates, including negative plates, and the alloy content of the negative plates is 0.665 to 0.845 g / ml. The pressurizing structures at both ends of the cell pack, combined with the increased cross-sectional area of ​​the cells, prevent the internal structure of the cells from being damaged by pressure. Furthermore, the pressurizing structures increase the battery pressure within a safe range, improving the gas recombination efficiency. The increased internal pressure promotes the diffusion and recombination reaction of oxygen on the negative plates, reducing it to water, reducing the water loss rate of the battery and extending the battery's maintenance period and service life. The pressurizing structures also inhibit expansion of the positive plates and shedding of active materials within the cells during charge and discharge cycles.

[0016] Preferably, the pressurizing structure includes a pressure regulating plate with at least two thicknesses, the pressure regulating plate is located between the two ends of the single battery pack and the inner wall of the battery slot, and the pressure regulating plate is parallel to the single battery.

[0017] Preferably, the voltage regulating plate is parallel to the electrode, and the area of ​​the voltage regulating plate matches the area of ​​the electrode. The area of ​​the voltage regulating plate matches the area of ​​the electrode to avoid uneven pressure distribution of the pressure structure on the single cell, and the plate will break due to concentrated pressure. The voltage regulating plate and the electrode need to have a high degree of parallelism, and the area of ​​the voltage regulating plate is larger than the single cell, which improves the uniformity of pressure distribution in various parts of the plate and avoids the local generation of bubbles on the plate. The pressure structure uses voltage regulating plates of different thicknesses and sizes, which are installed according to the pressure of the entire group of single cells, compressing the thickness of the single cell group, thereby increasing the internal pressure of the single cell. Compared with the traditional single cell pressurization method, the voltage regulating plate of this application is always located in the battery slot from installation to use, and the structure increases the power The pressure inside the cell can prevent the pressure of the single cell from dropping sharply after the external pressurizing equipment is disconnected. High pressure is needed to put the single cell into the slot to ensure that the single cell has the preset pressure during use. The pressurizing structure in this application has higher reliability. At the same time, the pressure regulating plate in this application can adjust its thickness at any time to ensure that the single cell has the preset pressure during the insertion and use of the single cell. The traditional single cell pressurizing method cannot maintain the pressure of the single cell after the single cell is inserted into the slot, and due to the pressure drop in the subsequent cycle, the plate expansion stress cannot be controlled, resulting in a high scrap rate during battery production and use.

[0018] Preferably, the unit alloy dosage of the negative plate is 1.3g / Ah to 1.7g / Ah, and the number of negative plates in a single cell is ≤4. In the power lead-acid batteries currently on the market, the grid alloy and active material dosage of the negative plate are relatively high. Taking a typical 6-DMF-20Ah battery as an example, the negative plate alloy dosage is 2.0g / Ah to 2.8g / Ah, and the active material dosage is 11.6g / Ah to 13.6g / Ah. In comparison, the present application optimizes the negative plate to reduce the negative plate alloy dosage to 1.3g / Ah to 1.7g / Ah, a reduction of 39% to 50%, and the negative plate active material dosage to 7.5g / Ah to 9.0g / Ah, a reduction of 30% to 40%. The above improvements reduce material usage and usage costs, achieve improvements in lightweighting, cost control, and energy density of power lead-acid batteries, and provide more efficient energy solutions for applications such as electric vehicles and energy storage systems.

[0019] Preferably, the negative plate includes a negative grid, which is a lead plate with a thickness greater than 12 mm, which is subjected to a roller-pounding process and then a heat treatment, with the roller-pounding process being performed at least 7 times, the heat treatment temperature being 80°C to 90°C, and the heat treatment time being 12h to 24h. The positive plate includes a positive grid, which is a 15 mm thick lead plate subjected to 7 to 9 roller-rolling processes. Since the grid has been subjected to multiple roller-rolling processes, the density and strength of the alloy are very high, and the corrosion resistance is strong. A smaller amount of grid alloy can be used to meet the usage requirements during the battery life. The pounded grid is then heat-treated at a high temperature of 80°C to 90°C for 12 to 24 hours. After the grid has been subjected to multiple roller-rolling processes, the thickness of the negative grid reaches 0.3 to 0.4 mm. The hardness of the grid is increased, which facilitates improving the efficiency and pass rate of the plate coating. The roller-rolling process used in this application can improve the density and strength of the alloy and provide strong corrosion resistance.

[0020] Preferably, the negative electrode plate after heat treatment is surface treated by corona treatment, and the actual surface area of ​​the negative electrode plate after corona treatment is greater than the actual surface area of ​​the negative electrode plate before corona treatment.

[0021] Preferably, the surface of the negative electrode plate after corona treatment is sprayed with a graphene solution having a mass percentage of 0.1% to 0.4% at a spraying speed of 10 to 30 m / min, and dried at 90° C. to 120° C.

[0022] The present invention solves the problems of different concentrations of electrolyte in different areas of the battery, which leads to insufficient energy utilization of active materials in various parts of the plate; low internal pressure of single cells, large plate spacing and large internal resistance of the battery, and has the following beneficial effects: single cells can be disassembled, which is conducive to the inspection, maintenance and replacement of single cells, maintains the consistency of single cells in the single battery pack, and significantly improves the cycle life and reliability of the battery; while maintaining or improving the performance of power lead-acid batteries, the amount of positive plate alloy and active material is significantly reduced, achieving the comprehensive advantages of lightweight, high energy density and long life; the voltage regulating plate can adjust its thickness at any time to ensure that the single cell has a preset pressure during the insertion and use of the single cell, thereby improving the success rate and service life of the battery during production and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1This is a schematic structural diagram of a lead-acid battery with thin plates according to Example 1;

[0025] Figure 2 This is a schematic diagram of the connection structure between the electrode column and the negative plate in Example 1;

[0026] Figure 3 This is a schematic structural diagram of a single cell of Example 1 equipped with a sealing cap;

[0027] Figure 4 This is a structural schematic diagram of a single cell in Example 1 with the sealing cap removed;

[0028] Figure 5 This is a schematic diagram of the structure of the interconnected pole group heads of Example 1;

[0029] Figure 6 This is a schematic structural diagram of a single battery pack according to the second embodiment;

[0030] Figure 7 Schematic diagram of the structure of the pole and the positive plate of the second embodiment;

[0031] Figure 8 is a side view schematic diagram of a single cell of the present invention;

[0032] Figure 9 A schematic diagram of battery dissection sampling according to the present invention;

[0033] Figure 10 This is a metallographic image of the negative electrode plate in Example 2 without roller rolling treatment;

[0034] Figure 11 This is a metallographic diagram of the negative electrode plate after 7 to 9 roll-rolling processes in Example 2;

[0035] Figure 12 This is an SEM image of the negative grid in Example 2 without graphene spraying treatment;

[0036] Figure 13 This is an SEM image of the negative grid in Example 2 after graphene spraying treatment;

[0037] Figure 14 This is a SEM image of the positive electrode plate in Example 1 without corona treatment;

[0038] Figure 15 This is an SEM image of the positive electrode plate after the corona treatment process in Example 1;

[0039] Figure 16 The following is a graph showing the difference in formation temperature between cells with three width-to-thickness ratios.

[0040] Figure 17 The internal resistance test results of Example 2 and a traditional lead-acid battery are shown;

[0041] Figure 18 for Figure 17 A local enlarged view within the range of 0.0030-0.0060 on the horizontal axis;

[0042] Figure 19 for Figure 17 A local enlarged view within the range of 0.010-0.030 on the horizontal axis;

[0043] Figure 20 The results of the cycle test of Example 2 and a traditional lead-acid battery are shown.

[0044] Legend: 1 voltage regulating plate; 2 lead plate; 3 single cell; 31 pole; 32 pressure regulating valve; 33 sealing cap; 34 buckle; 35 plate; 351 negative plate; 352 positive plate; 4 upper part of single cell; 5 middle part of single cell; 6 lower part of single cell; 7 battery slot; 8 glass fiber. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0046] Example 1

[0047] like Figure 1 As shown, a lead-acid battery with thin plates includes at least two single cells 3 each provided with plates and a battery container 7 for loading the single cells 3. The housing of the single cells 3 includes a flexible material, wherein the flexible material is at least a two-layer polymer film. The single cells 3 have an aspect ratio of B / δ, where 8 ≤ B / δ < 20. The single cells 3 are internally provided with plates, each including a positive plate 351. The alloy content of the positive plate 351 is 0.56 to 0.86 g / ml. The single cells 3 are internally provided with an electrolyte containing sulfuric acid as a solute. The density difference of the sulfuric acid at each position on the plate 35 is less than 0.002 g / ml. The electrolyte is contained in the single cell 3 and the single cell 3 is arranged horizontally, which greatly reduces the thickness of the single cell 3. The polymer membrane can prevent the solute in the electrolyte contained in the single cell 3 from settling downward, that is, it can prevent the significant stratification of the electrolyte in the single cell 3 and prevent the difference in sulfuric acid density of each part of the electrolyte in the single cell 3 from being greater than 0.002. According to the test method of Article 5.11 of GB / T22199.1-2017 Valve-regulated Lead-acid Batteries for Electric Powered Vehicles Part 1: Technical Conditions Standard, after 100 cycle tests, the battery is fully charged and left to stand for 24 hours, and then the battery is dissected. Figure 9As shown, the separator is divided into three equal parts: the upper part 4 of the single cell, the middle part 5 of the single cell, and the lower part 6 of the single cell. Three samples of acid are squeezed out and the acid density is measured with a density meter. The internal acid density deviation is less than or equal to 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 0.04~0.06g / ml. Reducing the acid density deviation can improve the utilization rate of active materials.

[0048] The polymer film comprises at least two layers of film substrates. According to the national standard GB / T21302-2007, under specified conditions, the compressive strength of the polymer film for lead-acid batteries is above 1500N, including the above. The tensile strength of the polymer film for lead-acid batteries is 80-200N / 15mm. The water vapor permeability of the polymer film for lead-acid batteries is 0.2-2.5g / (m 2 ·24h).

[0049] Preparation of the polymer film: The upper surface of a polyethylene terephthalate film was corona treated and then coated with a pH-responsive adhesive to form a first adhesive layer, resulting in a polyethylene terephthalate adhesive composite film. The lower surface of a polypropylene film was corona treated and laminated with the polyethylene terephthalate adhesive composite film. The film was then rapidly cooled using water-cooled rollers and heat-sealed on three sides to form a straight-cut seal with a width of 4 mm, resulting in a polymer film. The first adhesive layer had a thickness of 20 μm. The light-heat gradient synergistic curing process included UV and infrared curing, with UV curing for 10 seconds followed by infrared curing for 35 seconds. Infrared curing was initiated within 0.3 seconds of the completion of UV curing. During the three-side heat sealing, the hot knife temperature was 170°C, the pressure was 0.7 MPa, and the holding time was 3.0 seconds.

[0050] like Figure 4 As shown, the ratio of the width-to-thickness ratio of the single cell is B / δ, 8≤B / δ<20, and 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. In this application, the ratio of the width-to-thickness ratio of single cells B / δ=12.25 and B / δ=8 is compared with a single cell with a traditional width-to-thickness ratio of B / δ=2.4 through experiments to explore the effect of the width-to-thickness ratio on the temperature rise of a single electrode group during the formation process.

[0051] The experimental steps are as follows:

[0052] Step 1: Fill three battery cells with different aspect ratios with acid using an acid filling machine at 25°C. The acid density is 1.26g / ml and the amount of acid filled is 290g. The three battery cells are: battery cells with aspect ratio = 12.25, battery cells with aspect ratio = 8 and battery cells with aspect ratio = 2.4. Fill 12 battery cells of each type with acid.

[0053] Step 2: After the acid filling of each cell is completed, place it in the same forming water bath and set the water bath temperature to 25°C;

[0054] Step 3: Use the Nissan EYENCE paperless recorder to record the temperature (°C) of the battery cell during the formation process. Install two temperature probe monitoring lines on each of the three battery cells with different width-to-thickness ratios. The probes are attached to the center of the side surface of the battery cell to ensure the monitored temperature is accurate.

[0055] Step 4: All three battery cells adopt the "modular 85h" formation process charging and discharging program. While starting the charging and discharging program, turn on the paperless recorder to record the temperature data.

[0056] After the three types of cells are formed, the temperature data of the formation process is retrieved and plotted. The temperature difference curve is shown in the attached figure. Figure 7 shown.

[0057] According to the attached Figure 16 It can be seen that: the larger the modular width-to-thickness ratio, the lower the maximum temperature of the formation process; when the traditional single cell has a width-to-thickness ratio of 2.4, the maximum temperature of the formation process is 52.3°C; when the single cell has a width-to-thickness ratio of 8 in the present application, the maximum temperature of the formation process is 45.1°C; when the single cell has a width-to-thickness ratio of 12.25 in the present application, the maximum temperature of the formation process is only 38.2°C.

[0058] The above experimental results show that when the width-to-thickness ratio of the battery cell is larger, the battery cell will be relatively thinner, so that the water bath can more effectively remove the heat generated by charging and discharging of the battery cell during the formation process; under appropriate width and thickness conditions, the larger the width-to-thickness ratio of the battery cell, the lower the internal temperature of the battery cell during the formation process.

[0059] The aspect ratio of the single cell of the present application is B / δ, 8≤B / δ<20. The temperature rise rate of the single cell of the present application is reduced by 67% to 83% compared with the traditional structure; the equilibrium temperature is reduced by 8°C-12°C; so that the heat dissipation performance and material transfer rate of the single cell in this state are better than those of other single cells with the same aspect ratio of capacity. By optimizing the overall size design of the single cell, the heat dissipation area is increased and the thickness of the single cell is reduced without changing the weight of the single cell, thereby achieving rapid heat dissipation of the single cell.

[0060] like Figure 1As shown, the thin-plate lead-acid battery further includes a lead plate 2, which is located at the top of the cell pack. The cell 3 includes a terminal 31 disposed at the top of the cell. The terminal of each cell is connected to the positive and negative electrodes of the thin-plate lead-acid battery by a circuit connected by the lead plate 2. Conventional lead-acid power battery terminals are connected in series by welding, reducing the cost of fixing the plates 35 and the cost of connecting the lead terminals, while ensuring a reliable connection between the plates. However, the present application uses cells to package the plates, avoiding the need to fix the plates 35 and the problem of reliable connection between the plates 35. The terminals 31 of each cell can be connected in series via wires between the lead plates, reducing the risk of oxidation of the terminals 31 or loss of active material from the plates due to high-temperature welding. Furthermore, since the lead plate 2 connecting the terminals 31 is simpler and more removable than welding, it facilitates the inspection, maintenance, and replacement of individual cells 3, maintaining the consistency of the electrical properties of the cells 3 within the cell pack, such as capacity, internal resistance, and output voltage, significantly improving the battery's cycle life and reliability.

[0061] like Figure 5 As shown, the single cells 3 also include pole group headers, which are used to connect the single cells 3 to form a single cell group 3. The width of the pole group header matches the width of the battery slot. The pole group header is used to connect the single cells 3 to form a single cell group 3 fixed inside the battery slot. Compared with traditional welding connections, the pole group header facilitates the removal, inspection, maintenance, and replacement of individual single cells 3, maintains the consistency of the single cells 3 within the single cell group 3, and significantly improves the cycle life and reliability of the battery. In this embodiment, buckles 34 are designed on both sides of the pole group header to facilitate the rapid fixation and disassembly and separation of multiple pole groups, improve assembly efficiency, and replace abnormal single cells 3 when necessary.

[0062] like Figure 3 and Figure 4 As shown, the pole group head is provided with a through fitting hole, and a detachable sealing cap 33 is provided on one side of the fitting hole. The pole 31 fits with the sealing cap after passing through the fitting hole. The fitting gap between the sealing cap 33 and the pole 31 is filled with sealing material. The polymer film and the pole group head can fix the pole, and the single battery 3 forms a closed container.

[0063] The electrode cluster head is equipped with a pressure regulating valve 32, whose opening pressure range is 10kPa to 35kPa. When the internal positive pressure of the single cell 3 is less than 10kPa, the single cell 3 is frequently depressurized, and the oxygen and water vapor in the primary cell reaction of the single cell 3 are depressurized and carry away the concentrated sulfuric acid, reducing the battery life. When the internal positive pressure of the single cell of the present application exceeds 35kPa, the flexible material shell of the single cell 3, which forms a sealed package around the electrode plate 35 and the electrolyte, is easily broken. The pressure regulating valve regulates the internal pressure of the single cell to keep the internal pressure of the single cell within an appropriate range. In addition, appropriately increasing the internal pressure of the single cell 3 can inhibit electrode plate sulfation, delay capacity decay, enhance the wettability of the electrolyte to the electrode plate, and reduce concentration gradients. The conduction range of the pressure regulating valve in this embodiment includes but is not limited to 10kPa, 22kPa, 23kPa, 24kPa, 25kPa, 26kPa, ... 31kPa, 32kPa, 33kPa, 34kPa, 35kPa.

[0064] The pole plate 35 is connected to the pole 31, and the pole 31 passes through the pole group head. The pole group head includes: a main body made of PP material, whose surface is provided with a raised texture with a depth of 0.5mm to 1mm; a pole 31 contact part made of ABS material; a snap-on structure 34 integrated in the edge, with a spacing of 5mm to 8mm between the snaps 34; an epoxy adhesive sealing layer at the position where the pole 31 passes through, and a bonding layer is provided at the connection interface between the main body and the pole 31 contact part, and the bonding layer includes one of a PH-responsive adhesive and a composite layer formed by injection molding.

[0065] The combination of PP and ABS meets the lightweight design requirements of modular batteries. The main material of the pole group head is PP. PP material is a non-polar material with a low surface energy of only 29mN / m~31mN / m, which makes it difficult to bond with other materials. However, when the pole group head and the polymer film part that contacts it are both made of PP material, under certain temperature conditions, the heat seal bond has a high bonding strength and is reliable. PP material can withstand a pH range of 2 to 12 at 80°C, which is greater than the ABS material used in ordinary lead-acid battery tank covers, which can withstand a pH range of 4 to 10 and has better acid and corrosion resistance. A single-layer or multi-layer texture structure is designed on the contact surface between the pole group head and the polymer film to increase the heat seal contact surface area and enhance the bonding strength between the two.

[0066] The contact area between the terminal block and the terminal 31 is made of ABS. ABS contains polar groups like acrylonitrile, resulting in a higher surface energy. Compared to non-polar plastics like PE and PP, ABS has a higher surface energy of 36 to 42 mN / m, making it more susceptible to physical adsorption or chemical bonding with metals such as lead. PP, on the other hand, is a completely non-polar material with low surface energy and inherently weaker bonding with metals. Therefore, ABS is used for the contact area between the terminal block and the terminal 31. ABS is also stronger than PP, providing better protection for the terminal 31.

[0067] Epoxy adhesive is used to seal the ABS and lead pole 31. The bonding strength and mechanism of epoxy adhesive to ABS and lead are primarily determined by the surface properties of the materials and interfacial interactions. For ABS, epoxy adhesive typically exhibits moderate to high bonding strengths, ranging from 5 MPa to 20 MPa. This is due to hydrogen bonding or dipole interactions between the polar surfaces of ABS containing acrylonitrile and styrene and the epoxy adhesive's polar groups, such as hydroxyl and epoxy groups. However, due to its low surface energy and inert oxide layer, lead exhibits a lower bonding strength, ranging from 2 MPa to 10 MPa. Modification of the epoxy adhesive, such as by adding a toughening agent, is necessary to improve the bonding properties.

[0068] like Figure 2 、 Figure 8 As shown, the electrode plates 35 include alternating positive plates 352 and negative plates 351. The unit alloy dosage of the positive plates 352 is 2.0g / Ah-2.5g / Ah. The electrode posts 31 include positive posts, each of which connects no more than three positive plates. In this embodiment, three positive plates 352 and two negative plates 351 are used, overlapping each other.

[0069] It is worth noting that the plate capacity calculation method: refer to the national standard GB / T22199.1-2017 "Valve-regulated lead-acid batteries for electric power-assisted vehicles" Part 1: Technical conditions, the capacity is 2-hour rate capacity, and the plate capacity = capacity / number of single-cell plates.

[0070] Currently, the power batteries on the market with a capacity of 20Ah use 4 positive plates and 5 negative plates. The positive plate capacity = 20Ah / 4 = 5Ah, and the negative plate capacity = 20Ah / 5 = 4Ah. The battery prepared by using the positive plate of the present invention, such as a battery with a capacity of 20Ah, uses 2 positive plates and 3 negative plates. The positive plate capacity = 20Ah / 2 = 10Ah, and the negative plate capacity = 20Ah / 3 = 6.67Ah.

[0071] The active material dosage of the positive plate 352 is 15.5g / Ah-16.5g / Ah. While maintaining or even enhancing the performance of the lead-acid battery, the use of alloy and active materials in the positive plate 352 is significantly reduced, achieving the multiple advantages of lightweight, high energy density, and long life. This innovation reduces material consumption while enhancing the electrochemical activity of the plate by improving the grid processing technology of the positive plate and the coating process of the active material, thereby increasing the battery's energy density and capacity per unit weight. At the same time, by changing the pressurization structure and assembly method of the single cell, the stability of the battery's internal pressure and the smooth installation of the single cell are ensured. In addition, the reduced amount of alloy and active material also reduces manufacturing costs, allowing the battery to maintain high power output while enhancing its market competitiveness.

[0072] The positive electrode grid is a 15 mm thick lead plate that undergoes a roller-pounding treatment and then a heat treatment. The roller-pounding treatment is repeated seven times at a heat treatment temperature of 85°C for 20 hours. The thickness of the single-piece positive electrode grid subjected to the above treatment in this embodiment includes, but is not limited to, 0.51 mm, 0.52 mm, 0.53 mm, 0.54 mm, 0.55 mm, 0.56 mm, 0.57 mm, 0.58 mm, 0.59 mm, and 0.60 mm.

[0073] like Figure 8 and Figure 9 As shown, the positive electrode plate 352 after the heat treatment is surface treated by a corona process, and the actual surface area of ​​the positive electrode plate 352 after the corona treatment is greater than the actual surface area of ​​the positive electrode plate 352 before the corona treatment.

[0074] 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:

[0075] 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.

[0076] The dimensions and configurations of the electrode plate 35 of the present invention and the conventional electrode plate are analyzed, and the specific data are shown in Table 1: Table 1: Comparison of electrode plate area and thickness

[0077] Plate type Thickness / mm <![CDATA[True surface area of electrode plate / m 2 > This application plate Positive plate 1.7mm 444.8 Traditional plates Positive plate 2.7mm 368.3

[0078] Since the real surface area is contributed by the porous active material, as shown in Table 1, the real surface area of ​​the modular plate is increased by about 20% compared with the real surface area of ​​the traditional plate. Under the same conditions, the exchange current density in the equilibrium state of the battery is increased by 20%.

[0079] The surface of the positive plate after corona treatment is sprayed with a suspension containing an antimony compound with a mass percentage of 3% at a spraying speed of 20 meters per minute. The grid sprayed with the antimony compound solution has a strong bond with the active material, improves conductivity, and has a low interface resistance between the active material and the grid. The above-mentioned positive grid surface spraying process can achieve enhanced mechanical strength. Specifically, Sb and Pb form a lead-antimony alloy, such as Pb3Sb, which significantly improves the hardness and deformation resistance of the grid, prevents the active material PbO2 from falling off due to expansion / contraction of the plate during charging and discharging, and can inhibit dendrite growth. Antimony can hinder the formation of lead dendrites, avoid structural damage to the positive active material and the risk of short circuit, and extend the cycle life. The components of the antimony compound solution are: antimony trioxide and water.

[0080] In addition, it can realize the conversion of catalytically active substances: antimony acts as a catalyst for the nucleation of PbO2, promoting the uniform distribution of active substances and improving the discharge capacity.

[0081] The working principle of spraying antimony compound solution on the positive grid surface:

[0082]

[0083] Alloy Strengthening Mechanism: After spraying, antimony reacts with lead to form intermetallic compounds such as Pb3Sb. These compounds, with a cubic lattice structure, are more stable than pure lead, improving corrosion resistance by over 30%. Electrochemical Synergistic Effect: Antimony reduces the overpotential for the PbO2 / PbSO4 conversion, accelerating the reaction kinetics. Surface Modification: The micron-sized antimony layer formed by spraying, approximately 1-5μm thick, fills the grid pores and reduces corrosion caused by electrolyte penetration.

[0084] like Figure 1As shown, the lead-acid battery is positioned as intended for use, with the individual cells 3 positioned horizontally. Following 100 cycles of testing in accordance with test method 5.11 of GB / T 22199.1-2017, Valve-Regulated Lead-Acid Batteries for Electric Powered Vehicles, Part 1: Technical Specifications, the difference in sulfuric acid density at each location within the individual cells is ≤0.002 g / ml. After prolonged charge-discharge cycling, the specific gravity of the acid remains similar at each location within the individual cells, resulting in similar potentials at different locations on the plates. This improves the utilization of active material in the middle and lower portions of the plates, thereby increasing battery capacity and specific energy.

[0085] Thin plate lead-acid batteries are Figure 1 The state shown is placed, as Figure 9 As shown, the individual cells 3 were separated and subjected to 100 cycles of testing according to the test method in Section 5.11 of GB / T 22199.1-2017, Valve-Regulated Lead-Acid Batteries for Electric Powered Vehicles Part 1: Technical Requirements. The acid specific gravity at each location of the individual cells 3 remained similar, resulting in similar potentials at different locations of the individual cells 3. This improved the utilization of active materials in the middle 5 and lower 6 portions of the individual cells, thereby increasing battery capacity and specific energy. The test results are shown in the figure below:

[0086] Table 2: Distribution of active material lead dioxide at different locations in a single cell

[0087] Single battery location Ordinary batteries This application upper part 92.02% 92.65% Central 86.33% 91.98% lower part 81.12% 91.34%

[0088] Table 3: Acid specific gravity at different locations in a single battery (25°C)

[0089] Single battery location Ordinary batteries Balanced modular battery upper part 1.3215 1.3506 Central 1.3429 1.3511 lower part 1.3703 1.3500 Extremely poor 0.0488 0.011

[0090] Example 2

[0091] like Figure 6As shown, a thin-plate lead-acid battery includes at least two cells each equipped with a plate 35 and a battery compartment 7 for loading the cells 3. Adjacent cells are closely attached to each other to form a cell pack, with a pressure structure provided between the ends of the cell pack and the inner wall of the battery compartment. The cells are internally provided with a plate 35, which also includes a negative plate 351. The thickness of the negative plate 351 is 0.35 mm. The thickness of the single-piece negative grid in this embodiment includes, but is not limited to, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.37 mm, 0.38 mm, 0.39 mm, and 0.40 mm. A pressurized structure is provided at both ends of the single cell group. Combined with the increased cross-sectional area of ​​the single cell, the pressurized structure can prevent the internal structure of the single cell from being damaged by pressure. At the same time, the pressurized structure can increase the pressure of the battery within the safety range of the battery and improve the gas recombination efficiency. Increasing the internal pressure can promote the diffusion and recombination reaction of oxygen in the negative plate 351, which is reduced to water, reducing the water loss rate of the battery and extending the maintenance period and service life of the battery. The pressurized structure can suppress the expansion of the positive plate 352 and the shedding of active materials inside the single cell due to the charge and discharge cycle.

[0092] The pressurizing structure includes a voltage regulating plate 1 with at least two thicknesses. The voltage regulating plate 1 is located between the two ends of the single battery pack and the inner wall of the battery slot 7 . The voltage regulating plate 1 is parallel to the single battery 3 .

[0093] The voltage regulating plate 1 is parallel to the electrode 35, and the area of ​​the voltage regulating plate 1 matches the area of ​​the electrode 35. The area of ​​the voltage regulating plate matches the area of ​​the electrode 35 to avoid uneven pressure distribution of the pressure structure on the single cell, and the partial cracking of the electrode 35 where the pressure is concentrated; the voltage regulating plate 1 and the electrode 35 need to have a high degree of parallelism, and the area of ​​the voltage regulating plate is larger than the single cell, so as to improve the uniformity of the pressure distribution of each part of the electrode 35 and avoid the local generation of bubbles on the electrode 35; the pressure structure adopts voltage regulating plates of different thicknesses, which are installed according to the pressure of the entire group of single cells, compressing the thickness of the single cell group, thereby increasing the internal pressure of the single cell. Compared with the traditional single cell pressurization method, the voltage regulating plate of the present application is always located in the battery slot from installation to use, and the structure is Increasing the pressure inside the battery can prevent the pressure of the single cell from dropping drastically after the external pressurizing equipment is disconnected. High pressure is needed to insert the single cell into the slot to ensure that the single cell has a preset pressure during use. The pressurizing structure in the present application has higher reliability. At the same time, the pressure regulating plate in the present application can adjust its thickness at any time to ensure that the single cell 3 has a preset pressure during the insertion and use of the single cell 3. The traditional single cell pressurizing method cannot adjust the pressure of the single cell 3 after the single cell 3 is inserted into the slot, and due to the pressure drop in the subsequent cycle, the expansion stress of the plate 35 cannot be controlled, resulting in a high scrap rate during battery production and use.

[0094] like Figure 7 and Figure 8 As shown, the unit alloy dosage of the negative electrode plate 351 is 1.5 g / Ah, and three negative electrode plates 351 are provided inside the single battery 3 . In the power lead-acid batteries currently on the market, the grid alloy and active material usage of the negative plate 351 are relatively high. Taking a typical 6-DMF-20Ah battery as an example, the negative plate 351 alloy usage is 2.0g / Ah to 2.8g / Ah, and the active material usage is 11.6g / Ah to 13.6g / Ah. In comparison, the present application optimizes the negative plate 351 to reduce the negative plate 351 alloy usage to 1.3g / Ah to 1.7g / Ah, a reduction of 39% to 50%, and the negative plate 351 active material usage is reduced to 7.5g / Ah to 9.0g / Ah, a reduction of 30% to 40%. The above improvements reduce material usage and usage costs, achieve improvements in lightweighting, cost control, and energy density of power lead-acid batteries, and provide more efficient energy solutions for applications such as electric vehicles and energy storage systems.

[0095] like Figure 10 and Figure 11As shown, the negative electrode plate 351 includes a negative electrode grid, which is made of lead plate that has been roller-pounded and then heat-treated. The heat treatment temperature is 80°C-90°C and the heat treatment time is 12h~24h. After the above treatment, the lead plate thickness of the negative electrode grid is 0.3~0.4mm.

[0096] like Figure 14 and 15 As shown, the negative electrode plate 351 after heat treatment is surface treated by corona process, and the actual surface area of ​​the negative electrode plate 351 after corona treatment is greater than the actual surface area of ​​the negative electrode plate 351 before corona treatment.

[0097] The dimensions and configurations of the negative plates of the present invention and conventional plates are analyzed, and the specific data are shown in Table 4: Table 4: Comparison of plate area and thickness

[0098] Plate type Thickness / mm <![CDATA[True surface area of the electrode plate / m 2 > Modular plates Negative plate 1.0 444.8 Traditional plates Negative plate 1.8 368.3

[0099] According to the basic principles of electrochemical kinetics, since the real surface area is contributed by porous active materials, as shown in Table 4, the real surface area of ​​the modular plate is increased by about 20% compared with the real surface area of ​​the traditional plate. Under the same conditions, the exchange current density in the equilibrium state of the battery is increased by 20%.

[0100] like Figure 12 and Figure 13 As shown, a 0.2% graphene solution by mass is sprayed onto the surface of the corona-treated negative plate 351 at a spray speed of 20 m / min and then dried at 100°C. The graphene solution consists of graphene nanosheets and water. The graphene coating on the surface of the plate 35 produces the following effects: a physical barrier effect: the graphene coating acts as a dense barrier, reducing direct contact between the electrolyte and lead, inhibiting the irreversible deposition of lead sulfate; and an electrochemical synergy: the graphene's conductive network promotes rapid electron transport, accelerating the reduction reaction of PbSO4 to Pb, as shown in the following reaction equation:

[0101]

[0102] Porous structure enhancement: The specific surface area of ​​graphene (2630m 2 / g) can provide more reaction sites and enhance electrolyte wetting and ion transport.

[0103] The main function of this reaction is to inhibit sulfation: the graphene coating prevents PbSO₄ crystals from forming large aggregates on the negative electrode surface, maintaining them in a small particle state. This makes it easier to dissolve back into active Pb during charging, significantly extending cycle life. Enhanced conductivity: Graphene's high conductivity and electron mobility of up to 15,000 cm₂ / (V⋅s) reduce the negative electrode's internal resistance, improve charge and discharge efficiency, and particularly enhance fast charging capabilities. Graphene's porous network structure supports the active material (sponge lead), preventing it from falling off during charge and discharge, thereby improving mechanical strength and cycle stability.

[0104] The pressure structure includes a voltage regulating plate 1 with at least two thicknesses. The voltage regulating plate 1 is located between the two ends of the single battery group 3 and the inner wall of the battery tank. The voltage regulating plate 1 is parallel to the single battery 3. The pressurizing structure adopts pressure regulating plates 1 of different thicknesses, which are installed according to the pressure conditions of the entire group of single cells 3, compressing the thickness of the single cell 3 group, thereby increasing the internal pressure of the single cell 3. Compared with the traditional single cell 3 pressurizing method, the pressure regulating plate 1 of this application is always located in the battery slot from installation to use. The structural type increases the pressure inside the battery, which can prevent the pressure of the single cell 3 from dropping sharply after the external pressurizing equipment is disconnected. High pressure is required to insert the single cell 3 into the slot to ensure that the single cell 3 has a preset pressure during use. The pressurizing structure in this application has higher reliability. At the same time, the pressure regulating plate 1 in this application can adjust its thickness at any time to ensure that the single cell 3 has a preset pressure during the insertion and use of the single cell 3. The traditional single cell 3 pressurizing method cannot maintain the pressure of the single cell 3 after the single cell 3 is inserted into the slot, and due to the pressure drop in the subsequent cycle, the expansion stress of the plate 35 cannot be controlled, resulting in a high scrap rate during battery production and use. In this embodiment, the thickness of the voltage regulating plate 1 can be adjusted in the range of 1.0 mm to 5.0 mm, which can be one of the following specific values ​​or a range between any two of them: 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm. The voltage regulating plate is used to make the electrode group pressure of the single battery 3 in the wet state 20 kPa-60 kPa, which can be specifically selected from one of the following specific values ​​or a range between any two of them: 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.

[0105] Specifically, when assembling a 24V battery, 12 battery cells are stacked up, and 1 voltage regulator plate is added on both sides, with each voltage regulator plate being 3mm thick. When assembling a 12V battery, 6 battery cells are stacked up, and 1 voltage regulator plate is added on both sides, with each voltage regulator plate being 2mm thick.

[0106] like Figure 17-19 As shown, 6 single cells 3 are used to assemble a 12V lead-acid battery with a voltage regulating mechanism, and the internal resistance of the battery is tested. At the same time, the internal resistance of a traditional 12V lead-acid battery is tested, and the obtained impedance data are fitted. It should be noted that Figure 18 、 Figure 19 Yes Figure 17 Local magnification.

[0107] Impedance data was measured using a 65V20A electrochemical workstation from modulabxm. To interpret the impedance graph, the battery impedance R1 and R2 can be preliminarily determined from the raw data. R1 represents the internal resistance, and R2 represents the charge transfer resistance. Specific data requires constructing an equivalent circuit and then fitting and calculating it using the Zview software. Here, -Z'' represents the imaginary part of the impedance, primarily reflecting the reactance component of the test system; Z' represents the real part of the impedance, primarily reflecting the resistance component of the test system.

[0108] R1 can be Figure 18 The Z' value when -Z'' is 0 is initially judged. The smaller Z' is, the smaller R1 is, and R2 can be Figure 19 The slope of the initial judgment is that the larger the slope, the smaller R2. In the figure, the soft-pack single battery, that is, the single battery of the present application: R1 is 3.2016, R2 is 1.0467; the traditional single battery: R1 is 3.5455, R2 is 1.2787.

[0109] By comparison, both R1 and R2 modular cells are smaller than traditional lead-acid batteries. This indicates that the cells of the present invention have lower internal resistance and charge transfer resistance, less polarization during the charge and discharge process, greater charge and discharge capacity, and less wasted power consumption, thereby achieving lower heat generation and a lower temperature after use in the single cell of the present invention.

[0110] Six single cells were used to assemble a 12V lead-acid battery equipped with a voltage regulator. The battery was subjected to a cycle test 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. Figure 20As shown, the pre-pressure equalizing modular battery is the lead-acid battery with a voltage regulating mechanism in this application. After 550 cycles, the discharge capacity remains 16.10Ah, while the traditional lead-acid battery has a discharge capacity of only 16.20Ah after 400 cycles. In addition, the cycle platform of the pre-pressure equalizing modular battery is higher, which shows that the lead-acid battery with a voltage regulating mechanism in this application has better cycle performance.

[0111] Multiple ultrafine glass fibers 8 are cross-linked into a sheet-like structure, ensuring good contact between the separator and the electrode plates. The glass fibers 8 are elastic, maintaining a certain pressure on the electrode plates while absorbing electrolyte. Because the separator is composed of glass fibers 8, excessive pressure can cause them to break and lose their elasticity. Therefore, appropriate pressure ensures that the separator 23 maintains pressure on the electrode plates when wet, reducing the risk of increased internal resistance and even active material shedding caused by active material expansion, thus preventing premature failure.

[0112] The present invention solves the problems of different concentrations of electrolyte in different areas of the battery, which leads to insufficient energy utilization of active materials in various parts of the electrode plate 35; low internal pressure of the single cell 3, large spacing between the electrode plates 35, and large internal resistance of the battery, and has the following beneficial effects: the single cell 3 can be disassembled, which is conducive to the inspection, maintenance and replacement of the single cell 3, maintaining the consistency of the single cell 3 in the single cell 3 group, and significantly improving the cycle life and reliability of the battery; while maintaining or improving the performance of the power lead-acid battery, the amount of positive plate 352 alloy and active material is significantly reduced, achieving the comprehensive advantages of lightweight, high energy density and long life; the voltage regulating plate 1 can adjust its thickness at any time to ensure that the single cell 3 has a preset pressure during the insertion and use of the single cell 3, thereby improving the success rate and service life of the battery during production and use.

[0113] The above embodiments and / or implementation methods are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any form. 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.

Claims

1. A lead-acid battery with thin plates, comprising at least two single cells (3) provided with plates and a battery container (7) for loading the single cells (3), characterized in that: The shell of the single cell (3) comprises a flexible material, wherein the flexible material is a polymer film of at least two layers; a plate (35) is provided inside the single cell (3); an electrolyte is contained inside the single cell (3); and a horizontal diffusion distance of the electrolyte solute in the single cell is greater than a vertical convection distance; The electrode plate (35) includes a positive electrode plate (352) and a negative electrode plate (351) that are alternately arranged. The unit grid alloy dosage of the positive electrode plate is 2.0 g / Ah to 2.5 g / Ah. The lead-acid battery also includes an active material. The active material dosage of the positive electrode plate (352) is 15.5 g / Ah to 16.5 g / Ah. The capacity of a single positive electrode plate is 10 Ah. The positive electrode plate (352) includes a positive electrode grid, the positive electrode grid is made of a lead plate that has been subjected to a rolling process and then to a heat treatment process, the heat treatment temperature is 80°C-90°C, the heat treatment time is 12h-24h, and the thickness of the positive electrode grid after the lead plate treatment is 0.3-0.6mm; the positive electrode plate (352) after the rolling process is surface treated by a corona process, and the actual surface area of ​​the positive electrode plate (352) after the corona treatment is greater than the actual surface area of ​​the positive electrode plate (352) before the corona treatment; the surface of the positive electrode plate (352) before the active material is coated is sprayed with a suspension containing an antimony compound with a mass percentage of 1%-5% at a spraying speed of 10m / min-30m / min; The rolling process is to roll the lead plate with a thickness greater than 12 mm at least 7 times, and the thickness of the lead plate reaches 0.3 to 0.6 mm after multiple rolling processes.

2. A lead-acid battery with thin plates according to claim 1, characterized in that: The electrode plate comprises a positive electrode plate, and the alloy dosage of the positive electrode plate (352) is 0.56-0.86 g / ml; the width-to-thickness ratio of the single cell (3) is B / δ, and 8≤B / δ<20.

3. A lead-acid battery with thin plates according to claim 1 or 2, characterized in that: The electrolyte contains sulfuric acid, and the density difference of the sulfuric acid at various positions of the electrode plate is ≤0.002 g / ml.

4. A lead-acid battery with thin plates according to claim 3, characterized in that: The lead-acid battery with thin plates further comprises a lead plate (2), the lead plate (2) being located at the top of the group of single cells (3), the single cells (3) comprising poles (31) arranged at the top of the single cells (3), the poles (31) of each single cell (3) being connected to the positive and negative poles of the lead-acid battery with thin plates by means of a lead plate (2); the housing of the single cells further comprises a pole group head, the pole group head being provided with a through-fitting hole, a detachable sealing cap (33) being provided on one side of the fitting hole, the poles (31) fitting with the sealing cap (33) after passing through the fitting hole, the fitting gap between the sealing cap (33) and the poles (31) being filled with sealing material, the polymer film and the pole group head being able to fix the poles (31), and the single cells (3) forming a closed container; the pole group head being provided with a pressure regulating valve (32), the valve opening pressure range of the pressure regulating valve (32) being 10 kPa to 35 kPa.

5. A lead-acid battery with thin plates according to claim 4, characterized in that: The pole column comprises a positive pole column, and the number of positive plates (352) connected to the positive pole column is no more than 3.

6. A lead-acid battery with thin plates according to claim 1, characterized in that: The lead-acid battery is placed according to the usage state and subjected to 20 to 100 cycle tests. The density difference of sulfuric acid at each position of the single battery (3) is ≤0.002 g / ml.

7. A lead-acid battery with thin plates, comprising at least two single cells (3) provided with plates and a battery container (7) for loading the single cells (3), characterized in that: Adjacent single cells (3) are closely attached to each other to form a single cell group, and a pressure structure is provided between the two ends of the single cell group and the inner wall of the battery container (7); a plate (35) is provided inside the single cell (3); the plate (35) includes a positive plate (352) and a negative plate (351) arranged alternately, the unit grid alloy dosage of the positive plate is 2.0g / Ah to 2.5g / Ah, the active material dosage of the positive plate (352) is 15.5g / Ah to 16.5g / Ah, and the capacity of a single positive plate is 10Ah; The positive plate (352) includes a positive plate grid, the positive plate grid is a lead plate that has been subjected to a rolling process and then to a heat treatment process, the heat treatment temperature is 80°C-90°C, the heat treatment time is 12h-24h, and the thickness of the positive plate grid after the lead plate treatment is 0.3-0.6mm; the positive plate (352) after the rolling process is surface treated by a corona process, and the actual surface area of ​​the positive plate (352) after the corona treatment is greater than the actual surface area of ​​the positive plate (352) before the corona treatment; the lead-acid battery also includes an active material, and the surface of the positive plate (352) before the active material is coated is sprayed with a suspension containing an antimony compound with a mass percentage of 1%-5% at a spraying speed of 10 m / min-30 m / min; The rolling process is to roll the lead plate with a thickness greater than 12 mm at least 7 times, and the thickness of the lead plate reaches 0.3 to 0.6 mm after multiple rolling processes.

8. A lead-acid battery with thin plates according to claim 7, characterized in that: The pressurizing structure comprises a voltage regulating plate (1) having at least two thicknesses, the voltage regulating plate (1) being located between the two ends of the single battery (3) group and the inner wall of the battery slot (7), the voltage regulating plate (1) being parallel to the single battery (3), the voltage regulating plate (1) being parallel to the electrode plate (35), and the area of ​​the voltage regulating plate (1) being matched with the area of ​​the electrode plate (35).

9. A lead-acid battery with thin plates according to claim 8, characterized in that: The negative electrode plate (351) includes a negative electrode grid, which is made of a lead plate that has been subjected to a rolling process and then to a heat treatment process, wherein the heat treatment temperature is 80°C-90°C and the heat treatment time is 12h-24h; the thickness of the negative electrode grid after the lead plate treatment is 0.3-0.4mm; the negative electrode plate (351) after the heat treatment is surface treated by a corona process, and the actual surface area of ​​the negative electrode plate (351) after the corona treatment is greater than the actual surface area of ​​the negative electrode plate before the corona treatment; the surface of the negative electrode plate (351) after the corona treatment is sprayed with a graphene solution having a mass percentage of 0.1%-0.4% at a spraying speed of 10m-30m / min, and is dried at 90°C-120°C.

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