A negative plate for a lead-acid battery

Abstract

The present invention discloses a negative plate for a lead-acid battery, which relates to the technical field of batteries. The amount of negative plate alloy used is 1.95-2.47 g / Ah, and the amount of negative plate alloy used is 0.665-0.845 g / cm 3 The amount of active material used in the negative plate is 9.7~12.9g / Ah, and the amount of active material used in the negative plate is 3.327~4.402g / cm 3 The negative plate includes a negative grid and a negative plate active material. The present invention optimizes the design of the negative plate structure and adopts a large-area positive plate structure to significantly reduce the amount of alloy used. Furthermore, by acid-washing the grid surface and spraying a graphene suspension, the contact resistance between the grid surface and the active material is low, and the conductivity is good.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a negative plate for a lead-acid battery. Background Art

[0002] With evolving market demands, lightweight and high-energy-to-weight designs for electric bicycle batteries are the primary research and development directions for power lead-acid batteries. Stamped grids offer strong corrosion resistance, long service life, and low cost. Utilizing stamping dies and high-speed presses, these grids can be produced continuously and on a large scale, while also being pollution-free during production, such as lead fume and dust. Currently, the majority of power lead-acid battery plates used in electric bicycles are stamped. However, the battery's requirements for lightweight and high energy-to-weight ratios require optimizing plate design to minimize lead consumption while maintaining battery performance.

[0003] To this end, the prior art has proposed a number of solutions to optimize the electrode plates, such as the prior art EP22947448, which proposes a positive electrode plate, a method for preparing the positive electrode plate, and a positive electrode plate, a secondary battery, and an electrical device containing the same. The positive electrode material composition of this patented technology enables the secondary battery to have a higher energy density, while also having improved cycle performance, safety performance, and / or rate performance. However, this technical solution focuses on the preparation materials of the positive electrode plate. Another example is the prior art DE102023126989A1, which proposes a mixed scrim / paper material for a plate-type battery electrode of a lead-acid battery, particularly a positive plate-type battery electrode of a lead-acid battery, wherein the scrim / paper material is made in the form of a non-woven fabric mat or a woven fabric mat. This technology also focuses on the manufacturing or material aspects of the improvement of the positive electrode plate.

[0004] It can be seen that the existing technology focuses more on the manufacturing aspect for the optimization scheme of the electrode plate, and some technologies focus on other aspects, such as the existing technology JP2025039251A, which proposes a liquid lead-acid battery including an electrode plate group, an electrolyte and a battery chamber for accommodating the electrode plate group and the electrolyte. The electrode plate group includes a positive electrode plate, a negative electrode plate and a separator placed between the positive electrode plate and the negative electrode plate. The difference between the sum of the distances s between the positive and negative plates relative to each other in the electrode plate group and the sum of the thicknesses t of the diaphragm: (st) is less than 0.10mm. It can be seen that this technology focuses on the spacing between the positive and negative plates in the optimization of the electrode plate. For example, the existing technology JP2025032525A provides a lead-acid battery and a manufacturing method thereof that can further improve the capacitance while maintaining or improving the yield. The lead-acid battery is a lead-acid battery having a negative electrode plate. The negative electrode plate has a lead alloy lattice body, and the thickness of the lattice body is greater than or equal to 1.6 mm and less than or equal to 2.9 mm. This technical means focuses on the yield of the electrode plate. Summary of the Invention

[0005] The purpose of the present invention is to provide a negative plate for a lead-acid battery, optimize the design of the negative plate structure, adopt a large-area positive plate structure, effectively reduce the number of negative plates configured in a single cell, and the solution of the present invention can achieve a more uniform electrochemical reaction in the manufactured battery during the charging and discharging process.

[0006] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0007] A negative plate for a lead-acid battery, wherein the amount of negative plate alloy used is 1.95-2.47 g / Ah; the amount of negative plate alloy used is 0.665-0.845 g / cm 3 The negative plate includes a negative grid and a negative plate active material. The amount of negative plate active material is 3.327~4.402g / cm 3 ; The amount of active material used in the negative plate is 9.7~12.9g / Ah.

[0008] The negative plate of the present invention has an expanded plate configuration. Compared with the existing plate, while maintaining the same external dimensions, the battery capacity is improved, so that the capacity of a single negative plate reaches 6.67Ah, which is 66.75% higher than the 4Ah capacity of the traditional negative plate design. The enlarged plate surface size of the present invention shortens the current transmission path and reduces the internal resistance by 15-20%. Reducing the number of plates reduces the number of connection points, thereby improving reliability. As the number of plates is reduced, the internal resistance is further reduced, thereby achieving the goal of maintaining the battery discharge performance and cycle life while reducing the amount of lead material used.

[0009] A battery prepared using the negative plate of the present invention, for example, with a capacity of 20 Ah, uses two positive plates and three negative plates. The capacity of the positive plate is 20 Ah / 2 = 10 Ah, and the capacity of the negative plate is 20 Ah / 3 = 6.67 Ah.

[0010] Calculation method of plate capacity: refer to the national standard GB / T 22199.1-2017 "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.

[0011] According to one embodiment of the present invention, the negative electrode plate includes at least one negative grid with a tab, which simplifies the electrode plate assembly process and improves production yield.

[0012] According to one embodiment of the present invention, the active material of the negative electrode plate is lead paste, which contains a two-dimensional conductive material and glass nanotubes. The addition of the two-dimensional conductive material creates an efficient three-dimensional conductive network, significantly reducing the internal resistance of the plate, promoting electron transfer, and enabling more complete redox reactions of active materials such as PbSO4 and Pb. While maintaining the same discharge capacity, the amount of active material used can be reduced, thereby reducing plate weight and increasing battery energy density. The porous structure of the glass nanotubes serves as a micron-scale electrolyte channel, rapidly replenishing sulfuric acid electrolyte during discharge and effectively alleviating concentration polarization on the plate surface caused by delayed electrolyte diffusion. This characteristic significantly improves voltage stability during high-rate discharge and reduces ineffective energy loss. The synergistic effect of the two-dimensional conductive material and the glass nanotubes not only ensures electron conduction efficiency but also optimizes ion transport pathways, allowing the plate to maintain a more uniform electrochemical reaction during charge and discharge.

[0013] According to one embodiment of the present invention, the negative grid of the present invention is surface treated, and the surface treatment process is as follows:

[0014] 1.1 Multi-pass rolling process

[0015] The grid is made by rolling approximately 15mm thick lead sheets through 7-9 rolling processes. This multi-rolling process creates an alloy with high density and strength, as well as strong corrosion resistance. This allows for a smaller amount of grid alloy to meet battery life requirements. The rolled grid is then heat-treated at 80-90°C for 12-24 hours, significantly increasing its hardness and improving coating efficiency and yield rates.

[0016] The grid 30 obtained by the multi-pass rolling process has a thickness of 0.3~0.6mm.

[0017] The present invention adopts the rolling process to improve the density and strength of the alloy, and has strong corrosion resistance.

[0018] 1.2 Grid surface pickling process

[0019] After multiple rolling and high-temperature heat treatment, the surface structure of the grid is dense and has strong corrosion resistance. However, the oil film on the surface of the grid will cause the bonding between the grid and the active material to be poor, and it needs to be cleaned. The grid is cleaned by ultrasonic high-frequency oscillation in a weakly acidic solution (citric acid, lactic acid, etc.), and then the cleaned grid is quickly dried at 80~90℃ to obtain a negative grid.

[0020] 1.3 Grid surface spraying process

[0021] The acid-washed negative grid is then sprayed with a uniform amount of graphene suspension. The grid is then rapidly dried in an oven at 90-120°C. The graphene suspension-coated negative grid has a strong bond with the active material, improving conductivity and minimizing interface resistance between the active material and the negative grid.

[0022] 1) Principle:

[0023] Physical barrier effect: The graphene coating acts as a dense barrier, reducing the direct contact between the electrolyte and lead and inhibiting the irreversible deposition of lead sulfate.

[0024] Electrochemical synergy: The conductive network of graphene promotes rapid electron transport and accelerates the reduction reaction of PbSO4→Pb. The reaction formula is as follows:

[0025]

[0026] Porous structure enhancement: The specific surface area of ​​graphene (2630m 2 / g) provides more reaction sites and enhances electrolyte wetting and ion transport.

[0027] 2) Main functions

[0028] Inhibit sulfation: The graphene coating can prevent lead sulfate (PbSO4) crystals from forming large crystals on the surface of the negative electrode, keeping them in a small particle state, making it easier to dissolve back into active lead (Pb) during charging, significantly extending the cycle life.

[0029] Enhanced conductivity: Graphene has high conductivity (electron mobility up to 15000cm 2 / (V·s)) reduces the internal resistance of the negative electrode, improves the charge and discharge efficiency, and especially improves the fast charging capability.

[0030] Stabilize electrode structure: The porous network structure of graphene supports the active material (sponge lead), preventing the active material from falling off during charging and discharging, and improving mechanical strength and cycle stability.

[0031] According to one embodiment of the present invention, the negative grid is composed of a rectangular frame and internal reinforcement ribs. The frame includes two horizontally arranged horizontal frames and two vertically arranged vertical frames, which together form a closed frame. A crisscross network of reinforcement ribs is provided inside the frame. The horizontal ribs are arranged in parallel with equal spacing, and their ends are welded to the two vertical frames respectively. The vertical ribs are arranged in parallel with equal spacing, and their number is significantly greater than that of the horizontal ribs. Their ends are welded to the two horizontal frames respectively. The tabs, as current conducting components, extend vertically outward from the middle of one of the horizontal frames. The intersections of all horizontal and vertical ribs and the edges of the ribs are chamfered to eliminate stress concentration and improve structural reliability.

[0032] The crisscrossing equally spaced horizontal and vertical ribs form a uniform grid support, which, combined with the rectangular frame of the frame, effectively enhances the grid's ability to resist deformation, reduces stress damage during the charge and discharge cycle, and extends its service life. The densely distributed vertical ribs, which are more numerous than the horizontal ribs, shorten the current conduction path and reduce internal resistance. At the same time, the longitudinal extension design of the tabs further reduces the current collection impedance and improves the charge and discharge efficiency. The equally spaced arrangement and chamfering of the ribs expand the effective area of ​​the electrode reaction, avoid local stress concentration, prevent the active material from falling off, and ensure capacity retention. The chamfered structure reduces the risk of burrs during stamping or casting, improves production yield, and facilitates the uniform filling of lead paste in the paste coating process, thereby improving electrode consistency.

[0033] A single cell battery includes a positive plate, a negative plate and a separator.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows: the negative plate of the present invention has an extended plate configuration. Compared with the existing plate, while maintaining the same external dimensions, the battery capacity is improved, so that the capacity of a single negative plate reaches 6.67Ah, which is 66.75% higher than the 4Ah capacity of the traditionally designed negative plate. The present invention optimizes the design of the negative plate structure and adopts a large-area positive plate structure, which reduces the amount of lead material used while maintaining the battery discharge performance and cycle life, effectively reducing the number of negative plates configured in a single cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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 derive other implementation drawings based on the provided drawings without inventive effort.

[0036] Figure 1 Schematic diagram of a negative plate for a lead-acid battery of the present invention;

[0037] Figure 2 Schematic diagram of the negative grid solution in the negative plate of the present invention;

[0038] Figure 3 A schematic diagram showing another perspective of the negative grid in the negative electrode plate of the present invention;

[0039] Figure 4 Schematic diagram of the connection scheme of vertical reinforcement and horizontal reinforcement of the present invention;

[0040] Figure 5 Schematic diagram of a single-core battery prepared using the negative electrode plate of the present invention;

[0041] Figure 6Schematic diagram of the high internal resistance corrosion layer formed on the grid surface during plate curing and battery formation;

[0042] Figure 7 This is a metallographic image of the grid in Example 3 without roller rolling treatment;

[0043] Figure 8 This is a metallographic image of the grid in Example 3 after 7 to 9 roll rolling processes;

[0044] Figure 9 This is an SEM image of the negative grid in Example 3 without graphene spraying treatment;

[0045] Figure 10 This is an SEM image of the negative grid after graphene spraying treatment in Example 3.

[0046] Explanation of the reference numerals: 10. Negative plate; 20. Pole; 30. Negative grid; 31. Tab; 32. Vertical rib; 33. Frame; 34. Horizontal rib; 40. Packaging bag; 50. Main body; 51. Insert; 52. Clip; 60. Lead paste part; 61. Active material aggregation layer; 62. Corrosion layer; 63. Grid rib part. DETAILED DESCRIPTION

[0047] 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.

[0048] 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.

[0049] Example 1:

[0050] A negative plate for a lead-acid battery, wherein the amount of negative plate alloy used is 1.95-2.47 g / Ah; the amount of negative plate alloy used is 0.665-0.845 g / cm 3 The negative plate includes a negative grid and a negative plate active material. The amount of negative plate active material is 3.327~4.402g / cm 3 ; The amount of active material used in the negative plate is 9.7~12.9g / Ah.

[0051] The negative plate 10 of the present invention has an expanded plate configuration. Compared with the existing plate, while maintaining the same external dimensions, the battery capacity is improved, so that the capacity of a single negative plate reaches 6.67Ah, which is 66.75% higher than the 4Ah capacity of the traditional design negative plate. The enlarged plate surface size of the present invention shortens the current transmission path, reduces the internal resistance by 15-20%, reduces the number of plates, and reduces the number of connection points, thereby improving reliability. As the number of plates is reduced, the internal resistance is further reduced, thereby achieving the goal of maintaining the battery discharge performance and cycle life while reducing the amount of lead material.

[0052] The amount of negative plate alloy used is 1.95~2.47g / Ah, which can be specifically selected from one of the following specific values ​​or a range between any two of them: 1.95, 1.96, 1.97, 1.98...2.40, 2.41, 2.42, 2.43, 2.44, 2.45, 2.46, 2.47.

[0053] The amount of negative plate alloy is 0.665~0.845g / cm 3 , specifically, it can be selected as one of the following specific values ​​or a range between any two of them: 0.665, 0.666, 0.667, 0.6668...0.839, 0.840, 0.841, 0.842, 0.843, 0.844, 0.845.

[0054] The amount of active material used in the negative plate is 3.327~4.402g / cm 3 , specifically, it can be selected as one of the following specific values ​​or a range between any two of them: 3.327, 3.328, 3.329, 3.330, 3.331...4.397, 4.398, 4.399, 4.400, 4.401, 4.402.

[0055] The amount of active material used in the negative electrode plate is 9.7~12.9g / Ah, which can be specifically selected from one of the following specific values ​​or a range between any two of them: 9.7, 9.8, 9.9, 10.0, 10.1...12.4, 12.5, 12.6, 12.7, 12.8, 12.9.

[0056] The negative electrode plate 10 includes at least one negative grid 30 with a tab 31 , which simplifies the plate assembly process and improves production yield.

[0057] The active material of the negative plate is lead paste, which contains a two-dimensional conductive material and glass nanotubes. The addition of the two-dimensional conductive material creates an efficient three-dimensional conductive network, significantly reducing the internal resistance of the plate, promoting electron transfer, and enabling more complete redox reactions of active materials such as PbSO4 and Pb. While maintaining the same discharge capacity, the amount of active material can be reduced, thereby reducing plate weight and increasing battery energy density. The porous structure of the glass nanotubes acts as a micron-scale electrolyte channel, rapidly replenishing sulfuric acid electrolyte during discharge and effectively alleviating concentration polarization on the plate surface caused by delayed electrolyte diffusion. This characteristic significantly improves voltage stability during high-rate discharge and reduces ineffective energy loss. The synergistic effect of the two-dimensional conductive material and the glass nanotubes not only ensures electron conduction efficiency but also optimizes ion transport pathways, allowing the plate to maintain a more uniform electrochemical reaction during charge and discharge.

[0058] The lead paste in this embodiment is prepared by mixing lead powder, water, sulfuric acid and additives, wherein the additives are two-dimensional conductive materials and glass nanotubes.

[0059] The negative grid 30 consists of a rectangular frame 33 and internal reinforcement ribs. The frame 33 includes two horizontally arranged horizontal frames and two vertically arranged vertical frames, which together form a closed frame. A crisscross network of reinforcement ribs is provided inside the frame. The horizontal ribs 34 are arranged in parallel at equal intervals, and their ends are welded to the two vertical frames. The vertical ribs 32 are arranged in parallel at equal intervals, and their number is significantly greater than that of the horizontal ribs 34. Their ends are welded to the two horizontal frames. The tab 31, as a current conducting component, extends vertically outward from the middle of one of the horizontal frames. The intersections of all horizontal ribs 34 and vertical ribs 32 and the edges of the ribs are chamfered to eliminate stress concentration and improve structural reliability.

[0060] The crisscrossing equally spaced horizontal ribs 34 and vertical ribs 32 form a uniform grid support, which, together with the rectangular frame of the frame 33, effectively enhances the grid's anti-deformation ability, reduces stress damage during the charge and discharge cycle, and extends its service life. The densely distributed vertical ribs 32, which are more in number than the horizontal ribs 34, shorten the current conduction path and reduce internal resistance. At the same time, the longitudinal extension design of the tab 31 further reduces the current collection impedance and improves the charge and discharge efficiency. The equally spaced arrangement and chamfering treatment of the ribs expand the effective area of ​​the electrode reaction, avoid local stress concentration, prevent the active material from falling off, and ensure capacity retention. The chamfered structure reduces the risk of burrs during stamping or casting, improves production yield, and facilitates the uniform filling of lead paste in the paste coating process, thereby improving electrode consistency.

[0061] A single cell battery includes a negative electrode plate 10, a positive electrode plate and a separator.

[0062] Example 2:

[0063] In this embodiment, the negative plate 10 of the present invention utilizes a large-surface structure. This reduces the number of positive and negative plates used in the battery's components. The single negative plate measures 148 mm x 132 mm, compared to conventional plates measuring 140 mm x 66 mm. This area is approximately twice that of a typical lead-acid battery plate used in commercially available electric bicycles. The negative plate 10 has a post 20 and is approximately 1.0 mm thick.

[0064] In this embodiment, the parameters of the positive and negative plates are as follows:

[0065] Positive plate: Single-piece positive plate weight: 20~30g; Single-piece positive electrode active material weight: 150~165g; Single-piece positive plate capacity: 10Ah; Alloy dosage: 2.0~3.0g / Ah, which is approximately 37.5% lower than the alloy dosage of existing single-piece positive plate; Active material dosage: 15.0~16.5g / Ah, which is approximately 9.64% lower than that of existing positive plates.

[0066] Negative plate: Single-piece negative plate weight: 13~16.5g; Single-piece negative electrode active material weight: 65~86g; Single-piece negative plate capacity: 6.67Ah; Alloy dosage: 1.95~2.47g / Ah, which is approximately 29.1% lower than the alloy dosage of existing single-piece negative plate; Active material dosage: 9.7~12.9g / Ah, which is approximately 33.1% lower than that of existing negative plates.

[0067] In this embodiment, the configuration of the single cell plates is as follows:

[0068] Number of positive plates: 2, total alloy weight: 40~60g, total active material weight: 300~330g.

[0069] Number of negative plates: 3, total alloy weight: 39~49.5g, total active material weight: 195~258g.

[0070] The single cell battery of the present invention uses two positive plates and three negative plates. Compared with the prior art solution that requires four positive plates and five negative plates for a single cell battery, the solution of the present invention optimizes the size structure of the positive and negative plates and reduces the number of positive and negative plates, thereby achieving lightweighting of the single cell battery, reducing internal resistance, improving assembly efficiency and ensuring battery performance.

[0071] Table 1 shows a comparison between a single cell solution made with the negative electrode plate of the present invention and an existing battery.

[0072] Table 1

[0073]

[0074] Note: Calculation method of plate capacity: refer to the national standard GB / T 22199.1-2017 "Valve-regulated lead-acid batteries for electric power-assisted vehicles" Part 1: Technical conditions. The capacity is the 2-hour rate capacity. Plate capacity = capacity / number of plates per cell.

[0075] Currently, the power batteries on the market with a capacity of 20Ah use 4 positive plates and 5 negative plates, and the positive plate capacity = 20Ah / 4 = 5Ah, and the negative plate capacity = 20Ah / 5 = 4Ah; the battery prepared with the negative plate of the present invention, such as a battery with a capacity of 20Ah, uses 2 positive plates and 3 negative plates, and the positive plate capacity = 20Ah / 2 = 10Ah, and the negative plate capacity = 20Ah / 3 = 6.67Ah.

[0076] As can be seen from Table 1 above, the solution of this aspect significantly reduces the amount of alloy and active material used per unit capacity through a large plate design. The negative plate alloy content g / Ah is reduced by approximately 29.1%, and the negative electrode active material is reduced by 33.1%. The number of plates used in the present invention is reduced, from 4 positive plates to 2 plates, and from 5 negative plates to 3 plates, reducing internal resistance and improving assembly efficiency. The solution of the present invention achieves an increase in the capacity of a single negative plate from 4Ah to 6.67Ah, while optimizing material distribution to ensure high energy density.

[0077] The length of the single negative plate in this embodiment is not limited to 148 mm, and may also be 60 mm, 60.1 mm, 60.2 mm, ... 65 mm, 65.1 mm, 65.2 mm, 65.3 mm, ... 75 mm, 75.1 mm, 75.2 mm, 75.3 mm, 75.4 mm, ... 90 mm, 90.1 mm, 90.2 mm, 90.3 mm, 90.4 mm, 90. 5mm, 90.6mm……120mm, 120.1mm, 120.2mm, 120.3mm, 120.4mm, 120.5mm, 120.6mm, 120.7mm……1 48mm, 148.1mm, 148.2mm, 148.3mm, 148.4mm, 148.5mm, 148.6mm, 148.7mm, 148.8mm...200mm.

[0078] The width of the plate surface of the single negative plate in this embodiment includes but is not limited to 132 mm, and can also be 60 mm, 60.1 mm, 60.2 mm... 65 mm, 65.1 mm, 65.2 mm, 65.3 mm... 75 mm, 75.1 mm, 75.2 mm, 75.3 mm, 75.4 mm,... 90 mm, 90.1 mm, 90.2 mm, 90.3 mm, 90.4 mm, 90.5 mm, 90.6 mm... 120 mm, 120.1 mm, 120.2 mm, 120.3 mm, 120.4 mm, 120.5 mm, 120.6 mm, 120.7 mm... 148 mm, 148.1 mm, 148.2 mm, 148.3 mm, 148.4 mm, 148.5 mm, 148.6 mm, 148.7 mm, 148.8 mm... 200 mm.

[0079] Embodiment 3:

[0080] See the appendix Figure 6 As shown, between the grid rib part 63 and the active material aggregation layer 61 is the corrosion layer 62, and outside the active material aggregation layer 61 is the paste part 60. During the plate curing and battery formation processes, a corrosion layer with a high internal resistance is likely to form on the grid surface, increasing the battery internal resistance, resulting in a reduction in battery capacity and a shortening of battery life.

[0081] During plate curing, a corrosion layer 62 of a mixture of PbO and Pb(OH)2 forms on the grid surface.

[0082] During plate curing, a corrosion layer 62 forms on the grid surface. At the beginning, the corrosion layer is very thin, and as the curing time extends, oxygen diffuses through the corrosion layer to continue oxidizing the grid rib part 63 of the grid matrix, and the corrosion layer 62 gradually thickens. During battery formation, oxygen passes through the corrosion layer 62 and enters the grid surface, and the Pb on the grid surface is oxidized to PbO, and the generated PbO has a very high internal resistance. PbO is continuously oxidized to PbO<00000​​​​​​​​​The grid is made by rolling approximately 15mm thick lead sheets through 7-9 rolling processes. This multi-rolling process creates an alloy with high density and strength, as well as strong corrosion resistance. This allows for a smaller amount of grid alloy to meet battery life requirements. The rolled grid is then heat-treated at 80-90°C for 12-24 hours, significantly increasing its hardness and improving coating efficiency and yield rates.

[0086] The grid 30 obtained by the multi-pass rolling process has a thickness of 0.3~0.6mm.

[0087] The present invention adopts the rolling process to improve the density and strength of the alloy, and has strong corrosion resistance. Figure 7 The metallographic diagram of the grid shown without rolling treatment is similar to the attached Figure 8 The metallographic diagram of the grid after 7 to 9 rolling processes shows that the density of the grid alloy is improved after 7 to 9 rolling processes, and its surface structure is dense.

[0088] 1.2 Grid surface pickling process

[0089] After multiple rolling and high-temperature heat treatment, the surface structure of the grid is dense and has strong corrosion resistance. However, the oil film on the surface of the grid will cause the bonding between the grid and the active material to be poor, and it needs to be cleaned. The grid is cleaned by ultrasonic high-frequency oscillation in a weakly acidic solution (citric acid, lactic acid, etc.), and then the cleaned grid is quickly dried at 80~90℃ to obtain a negative grid.

[0090] 1.3 Grid surface spraying process

[0091] The acid-washed negative grid is then sprayed with a uniform amount of graphene suspension. The grid is then rapidly dried in an oven at 90-120°C. The graphene suspension-coated negative grid has a strong bond with the active material, improving conductivity and minimizing interface resistance between the active material and the negative grid.

[0092] The mass percentage of the graphene suspension is 0.1-0.4%, and the components of the graphene suspension are: graphene nanosheets and water; the spraying speed is 10-30 m / min.

[0093] 1) Principle:

[0094] Physical barrier effect: The graphene coating acts as a dense barrier, reducing the direct contact between the electrolyte and lead and inhibiting the irreversible deposition of lead sulfate.

[0095] Electrochemical synergy: The conductive network of graphene promotes rapid electron transport and accelerates the reduction reaction of PbSO4→Pb. The reaction formula is as follows:

[0096]

[0097] Porous structure enhancement: The specific surface area of ​​graphene (2630m 2 / g) provides more reaction sites and enhances electrolyte wetting and ion transport.

[0098] 2) Main functions

[0099] Inhibit sulfation: The graphene coating can prevent lead sulfate (PbSO4) crystals from forming large crystals on the surface of the negative electrode, keeping them in a small particle state, making it easier to dissolve back into active lead (Pb) during charging, significantly extending the cycle life.

[0100] Enhanced conductivity: Graphene has high conductivity (electron mobility up to 15000cm 2 / (V·s)) reduces the internal resistance of the negative electrode, improves the charge and discharge efficiency, and especially improves the fast charging capability.

[0101] Stabilize electrode structure: The porous network structure of graphene supports the active material (sponge lead), preventing the active material from falling off during charging and discharging, and improving mechanical strength and cycle stability.

[0102] See also Figure 9 SEM image of the negative grid without graphene spraying treatment, and Figure 10 This is an SEM image of the negative grid after graphene spraying treatment. It can be seen that the graphene coating can prevent lead sulfate (PbSO4) crystals from forming large crystals on the negative electrode surface.

[0103] Example 4:

[0104] This embodiment provides a process for manufacturing a negative plate for a lead-acid battery using the present invention. The process steps are as follows:

[0105] Step 1: Plate Manufacturing

[0106] The positive and negative plates are manufactured. The dimensions of the positive plate are: length 148 mm × width 132 mm × thickness 0.50 mm; grid weight: 20 g; active material weight: 165 g; single plate capacity: 10 Ah;

[0107] The negative plate dimensions are: length 148mm × width 132mm × thickness 0.30mm; grid weight: 13g; active material weight: 86g; single plate capacity: 6.67Ah.

[0108] Plate preparation process: Use a plate coating machine to evenly coat the active material on the grid to form a wet plate. The wet plate is cured and dried in a curing and drying furnace to finally obtain a dry plate for battery assembly.

[0109] Step 2: Battery Pack Assembly

[0110] Plate combination: 2 positive plates and 3 negative plates are stacked alternately to optimize current distribution and active material utilization.

[0111] -Separator setting: Two 0.6mm thick AGM separators are wrapped around the outside of the positive plate. The separator size is slightly larger than the electrode to ensure effective isolation and prevent short circuit.

[0112] Tab welding: Weld the tabs of two positive plates in parallel and connect the positive lead terminal; weld the tabs of three negative plates in parallel and connect the negative lead terminal; Battery capacity: Since two 10Ah positive plates are connected in parallel, the nominal capacity of the battery is 20Ah.

[0113] Step 3: Battery formation and performance testing

[0114] Electrolyte injection: Add an appropriate amount of dilute sulfuric acid with a density of 1.260g / ml to the battery plastic container.

[0115] Formation process: The "three charges and two discharges" formation process is used for charging to optimize the plate activation effect.

[0116] Capacity test:

[0117] Test conditions: 10A constant current discharge, termination voltage 1.75V.

[0118] -Test results: The discharge time reached 2 hours and 5 minutes, and the calculated capacity was 20.8Ah, exceeding the nominal capacity by 20Ah, indicating that the battery has good active material utilization and discharge performance.

[0119] This battery utilizes an optimized plate design, precise coating process, and rational assembly method to ensure high energy density and stable discharge performance. The measured capacity exceeds the nominal value.

[0120] Example 5:

[0121] This embodiment provides a process for manufacturing a negative plate for a lead-acid battery using the present invention. The process steps are as follows:

[0122] Step 1: Plate Manufacturing

[0123] The positive and negative plates are manufactured. The dimensions of the positive plate are: length 148 mm × width 132 mm × thickness 0.55 mm; grid weight: 25 g; active material weight: 160 g; single plate capacity: 10 Ah;

[0124] The negative plate dimensions are: length 148mm × width 132mm × thickness 0.35mm; grid weight: 14.5g; active material weight: 80g; single plate capacity: 6.67Ah.

[0125] Plate preparation process: Use a plate coating machine to evenly coat the active material on the grid to form a wet plate. The wet plate is cured and dried in a curing and drying furnace to finally obtain a dry plate for battery assembly.

[0126] Step 2: Battery Pack Assembly

[0127] Plate combination: 2 positive plates and 3 negative plates are stacked alternately to optimize current distribution and active material utilization.

[0128] -Separator setting: Two 0.6mm thick AGM separators are wrapped around the outside of the positive plate. The separator size is slightly larger than the electrode to ensure effective isolation and prevent short circuit.

[0129] Tab welding: Weld the tabs of two positive plates in parallel and connect the positive lead terminal; weld the tabs of three negative plates in parallel and connect the negative lead terminal; Battery capacity: Since two 10Ah positive plates are connected in parallel, the nominal capacity of the battery is 20Ah.

[0130] Step 3: Battery formation and performance testing

[0131] Electrolyte injection: Add an appropriate amount of dilute sulfuric acid with a density of 1.260g / ml to the battery plastic container.

[0132] Formation process: The "three charges and two discharges" formation process is used for charging to optimize the plate activation effect.

[0133] Capacity test:

[0134] Test conditions: 10A constant current discharge, termination voltage 1.75V.

[0135] -Test results: The discharge time reached 2 hours and 4 minutes, and the calculated capacity was 20.6Ah, exceeding the nominal capacity by 20Ah, indicating that the battery has good active material utilization and discharge performance.

[0136] This battery utilizes an optimized plate design, precise coating process, and rational assembly method to ensure high energy density and stable discharge performance. The measured capacity exceeds the nominal value.

[0137] Example 6:

[0138] This embodiment provides a process for manufacturing a negative plate for a lead-acid battery using the present invention. The process steps are as follows:

[0139] Step 1: Plate Manufacturing

[0140] The positive and negative plates are manufactured. The dimensions of the positive plate are: length 148 mm × width 132 mm × thickness 0.60 mm; grid weight: 30 g; active material weight: 150 g; single plate capacity: 10 Ah;

[0141] The negative plate dimensions are: length 148mm × width 132mm × thickness 0.40mm; grid weight: 16.5g; active material weight: 65g; single plate capacity: 6.67Ah.

[0142] Plate preparation process: Use a plate coating machine to evenly coat the active material on the grid to form a wet plate. The wet plate is cured and dried in a curing and drying furnace to finally obtain a dry plate for battery assembly.

[0143] Step 2: Battery Pack Assembly

[0144] Plate combination: 2 positive plates and 3 negative plates are stacked alternately to optimize current distribution and active material utilization.

[0145] -Separator setting: Two 0.6mm thick AGM separators are wrapped around the outside of the positive plate. The separator size is slightly larger than the electrode to ensure effective isolation and prevent short circuit.

[0146] Tab welding: Weld the tabs of two positive plates in parallel and connect the positive lead terminal; weld the tabs of three negative plates in parallel and connect the negative lead terminal; Battery capacity: Since two 10Ah positive plates are connected in parallel, the nominal capacity of the battery is 20Ah.

[0147] Step 3: Battery formation and performance testing

[0148] Electrolyte injection: Add an appropriate amount of dilute sulfuric acid with a density of 1.260g / ml to the battery plastic container.

[0149] Formation process: The "three charges and two discharges" formation process is used for charging to optimize the plate activation effect.

[0150] Capacity test:

[0151] Test conditions: 10A constant current discharge, termination voltage 1.75V.

[0152] -Test results: The discharge time reached 2 hours and 1 minute, and the calculated capacity was 20.2Ah, exceeding the nominal capacity of 20Ah, indicating that the battery has good active material utilization and discharge performance.

[0153] This battery utilizes an optimized plate design, precise coating process, and rational assembly method to ensure high energy density and stable discharge performance. The measured capacity exceeds the nominal value.

[0154] Example 7:

[0155] This embodiment provides a further optimization solution based on embodiment 1. Figure 1 , Attachment Figure 5As shown, the positive electrode plate of the present invention forms a single-cell battery after battery assembly. The end of the single-cell battery is provided with a main body 50, which is a long strip structure. The main body 50 is provided with at least two annular cavities. The annular cavities have a cylindrical inner cavity that penetrates the main body 50, and the pole 20 can pass through the cylindrical inner cavity. An insert 51 is provided on the annular cavity. The pole 20 is detachably provided with a pole cap 51. The insert 51 has a circular hole that allows the pole cap 51 and the pole 20 to pass through. The annular cavity can store glue. The edge of the circular hole of the insert 51 has a groove. The groove is provided to facilitate the removal of the pole cap 51 so that the pole 20 can be welded to the connecting piece later, thereby minimizing damage to the glue sealing layer.

[0156] Buckles and clamping heads 52 are provided on both sides of the main body 50. The clamping heads 52 correspond to the buckle structure and can form a snap-fit ​​relationship between the two. Adjacent single-cell batteries can be snap-fitted to the buckles through the clamping heads 52. The single-cell batteries are covered with a packaging bag 40 that is partially connected to the main body 50.

[0157] In this specification, Pb refers to lead, PbO refers to lead oxide, and PbO n It is a higher-order oxide of lead, PbO2 is lead dioxide, and Pb(OH)2 is lead hydroxide.

[0158] 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.

[0159] 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 or modifications 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.

[0160] 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 negative plate for a lead-acid battery, characterized in that: The negative plate alloy dosage is 1.95~2.47g / Ah; The negative plate includes a negative grid and a negative plate active material. The weight of a single negative grid is 13-16.5 g; the weight of a single negative active material is 65-86 g; and the capacity of a single negative plate is 6.67 Ah. The negative grid is surface treated, and the surface treatment process is as follows: 1) Multi-pass rolling process: the negative grid is made by rolling a 15mm thick lead plate through 7 to 9 rolling processes, and then heat treating the rolled grid at a high temperature of 80 to 90 degrees for 12 to 24 hours. The thickness of the grid obtained by the multi-pass rolling process reaches 0.3 to 0.6mm. 2) The grid surface is pickled and cleaned with ultrasonic high-frequency oscillation in a weakly acidic solution, and then the cleaned grid is dried at 80-90°C to obtain a negative grid; 3) Spraying the grid surface: spray the acid-washed negative grid surface with a uniform graphene suspension, and then dry the grid at a high temperature of 90-120 degrees; The components of graphene suspension are: graphene nanosheets and water; Spraying speed 10m~30m / min.

2. A negative plate for a lead-acid battery according to claim 1, characterized in that: The amount of negative plate alloy used is 0.665~0.845g / cm 3 .

3. A negative plate for a lead-acid battery according to claim 1, characterized in that: The amount of the negative plate active material is 3.327~4.402g / cm 3 .

4. A negative plate for a lead-acid battery according to claim 1, characterized in that: The amount of the negative plate active material used is 9.7-12.9 g / Ah.

5. A negative plate for a lead-acid battery according to claim 1, characterized in that: The active material of the negative electrode plate is lead paste, which contains two-dimensional conductive material and glass nanotubes.

6. A single cell battery, characterized in that: The single cell comprises the negative electrode plate, the positive electrode plate and the separator for the lead-acid battery according to any one of claims 1 to 5.

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