Aluminum-based lead alloy / coated carbon fiber powder-doped cobalt alpha-PbO2 composite positive plate grid and preparation method thereof

Abstract

The present application relates to a kind of aluminum base lead alloy / coated carbon fiber powder-alpha-PbO2 Composite positive electrode grid and its preparation method, belong to battery grid technical field.The aluminum base lead alloy / coated carbon fiber powder-alpha-PbO2 Composite positive electrode grid of the present application is in turn for aluminum alloy matrix, zinc immersion antimony layer, doped nano La2O3-nickel bottom layer, Pb-Sn-Bi-Ag alloy intermediate layer and porous doped carbon fiber powder-alpha-PbO2 Composite active layer.From inside to outside.The high conductivity of aluminum is used, and the current intensity of bearing is large, to improve the catalytic activity of electrode plate, outer layer doped carbon fiber powder-alpha-PbO2, can improve the corrosion resistance of positive electrode grid, prolong the service life of positive electrode grid.Compared with traditional lead alloy, the aluminum base lead alloy composite positive electrode grid of the present application not only reduces weight by more than 50%, but also improves tensile strength by 34%, and improves conductivity by more than 28%.Under the condition of 100% discharge depth (DOD), the cycle period of lead-acid battery using aluminum base lead alloy anode grid is extended by 25%, which can meet the long-term frequent charge-discharge demand of lead-acid energy storage battery.

Description

TECHNICAL FIELD

[0001] The application relates to an aluminum-based lead alloy / coated carbon fiber powder-doped cobalt-alpha-PbO2 composite positive plate grid and a preparation method thereof, and belongs to the technical field of battery plate grids. BACKGROUND

[0002] The lead-carbon battery has the advantages of high safety and high reliability due to no combustible substance, and has been a key development direction of energy storage projects. However, the lead-carbon battery is mainly used in small energy storage systems due to low capacity density, and the research and development of large-capacity pure lead lead-carbon batteries is imminent. The positive plate grid of the large-capacity pure lead lead-carbon battery has a large number of lead ribs, a long length and a small diameter, so a large injection pressure is required during processing, and the unqualified rate of the manufactured positive plate grid is high and the efficiency is low.

[0003] In order to improve the passivation film and corrosion growth problem, many people have done a lot of alloy additive research in recent years. The application patent CN109518017A discloses a lead alloy for a positive plate grid of a maintenance-free lead-acid storage battery and a preparation method thereof. The service life of the battery made of the lead alloy is increased by more than 35% than that of the battery made of ordinary alloy under high temperature environment, and the service life of the battery under high temperature condition is prolonged. The application patent CN107881356A discloses a silver alloy positive plate grid for a lead-acid storage battery and a preparation method thereof. The battery made of the lead alloy can solve the problems of serious intergranular corrosion and large passivation film impedance, and improve the corrosion resistance of the grid alloy. Although the alloys prepared by the above-mentioned application patents have advantages, the comprehensive cost and performance in terms of low cost, high creep resistance, high corrosion resistance and high mechanical performance still need to be improved.

[0004] Therefore, it is urgent to develop a composite positive plate grid with low cost, high creep resistance, corrosion resistance and good mechanical performance to improve the comprehensive market competitiveness of lead-acid storage battery products. SUMMARY

[0005] In view of the fact that there is no composite positive plate grid with low cost, high creep resistance, corrosion resistance and good mechanical performance in the prior art, the application provides an aluminum-based lead alloy / coated carbon fiber powder-doped cobalt-alpha-PbO2 composite positive plate grid and a preparation method thereof. The high conductivity of aluminum can improve the catalytic activity of the electrode plate, and the outer layer of the coated carbon fiber powder-doped cobalt-alpha-PbO2 can improve the corrosion resistance of the positive plate grid and prolong the service life of the positive plate grid. Compared with the traditional lead alloy, the aluminum-based lead alloy composite positive plate grid has a weight reduction of more than 50%, a tensile strength improvement of 34%, and an electric conductivity improvement of more than 28%. Under the condition of 100% discharge depth (DOD), the cycle period of the lead storage battery using the aluminum-based lead alloy anode plate grid is prolonged by 25%, which can meet the long-term frequent charge-discharge demand of the lead-acid energy storage battery.

[0006] An aluminum-based lead alloy / coated cobalt-doped carbon fiber powder-α-PbO2 composite positive plate grid, from inside to outside, is aluminum alloy matrix, zinc-antimony layer 1, nano La2O3-doped nickel underlayer 2, Pb-Sn-Bi-Ag alloy intermediate layer 3, and porous coated cobalt-doped carbon fiber powder-α-PbO2 composite active layer 4.

[0007] The aluminum alloy matrix contains 0.2-0.8% Ca, 0.01-0.2% Zr, 0.01-0.1% Ce, 0.01-0.2% Sc, and 0.001-0.3% Al-5Ti-B, with the balance being Al, by mass percentage;

[0008] The zinc-antimony layer 1 contains 5-10% Sb, with the balance being Zn, by mass percentage;

[0009] The nano La2O3-doped nickel underlayer 2 contains 0.2-5% La2O3, with the balance being Ni, by mass percentage;

[0010] The Pb-Sn-Bi-Ag alloy intermediate layer 3 contains 0.5-5.0% Sn, 0.1-1.0% Bi, and 0.005-0.1% Ag, with the balance being Pb, by mass percentage;

[0011] The porous coated cobalt-doped carbon fiber powder-α-PbO2 composite active layer 4 contains 0.5-5.0% cobalt-coated carbon fiber powder, with the balance being α-PbO2, by mass percentage; the cobalt-coated carbon fiber powder contains 5-20% Co, with the balance being carbon fiber, by mass percentage of the cobalt-coated carbon fiber powder.

[0012] Preferably, the aluminum alloy matrix is a plate-shaped structure, and the surface is pressed with patterns, the pattern depth is 0.05-0.5 mm, the pattern width is 0.05-0.3 mm, and the cross-sectional thickness is 0.5-6 mm;

[0013] The thickness of the zinc-antimony layer 1 is 0.5-3 μm; the thickness of the nano La2O3-doped nickel underlayer 2 is 3-8 μm; the thickness of the Pb-Sn-Bi-Ag alloy intermediate layer 3 is 0.5-4 mm; and the thickness of the porous coated cobalt-doped carbon fiber powder-α-PbO2 composite active layer 4 is 0.1-1.0 mm.

[0014] The preparation method of the aluminum-based lead alloy / coated cobalt-doped carbon fiber powder-α-PbO2 composite positive plate grid, the specific steps are as follows:

[0015] S1. Preparing the aluminum alloy grid immersed Zn-Sb layer: the aluminum alloy grid matrix is immersed in an alkaline solution to remove oil, washed with deionized water, immersed in an alkaline zinc-antimony solution for a first immersion plating reaction, washed with deionized water, activated in an HNO3 solution, washed with deionized water, immersed in an alkaline zinc-antimony solution for a second immersion plating reaction, washed with deionized water to obtain the aluminum alloy grid immersed Zn-Sb layer;

[0016] S2. Preparing the aluminum alloy grid doped with nano La2O3-nickel bottom layer: taking the aluminum alloy grid immersed Zn-Sb layer as the cathode and a pure nickel plate as the anode, composite plating is carried out in a neutral nickel plating solution, and the aluminum alloy grid doped with nano La2O3-nickel bottom layer is obtained after washing with deionized water.

[0017] S3. Preparing the aluminum alloy grid Pb-Sn-Bi-Ag alloy intermediate layer: taking the aluminum alloy grid doped with nano La2O3-nickel bottom layer as the cathode and a lead-tin alloy plate as the anode, electrodeposition is carried out in a lead fluoborate plating solution, and the aluminum alloy grid Pb-Sn-Bi-Ag alloy intermediate layer is obtained after washing with deionized water.

[0018] S4. Preparing the aluminum alloy grid porous doped cobalt carbon fiber powder-α-PbO2 composite active layer: the aluminum alloy grid Pb-Sn-Bi-Ag alloy intermediate layer is subjected to surface sand blasting treatment, alkali dissolution treatment in a sodium hydroxide solution, and washing with deionized water to obtain a porous anode grid, taking the porous anode grid as the anode and a stainless steel plate as the cathode, electrodeposition is carried out in an alkaline lead plating solution, and the aluminum alloy grid porous doped cobalt carbon fiber powder-α-PbO2 composite active layer is obtained after washing with deionized water.

[0019] Preferably, the preparation method of the aluminum alloy grid matrix in step S1. is as follows:

[0020] S11. According to the composition of the aluminum alloy matrix, pure aluminum ingot, electrolytic calcium, metal zirconium block, metal cerium block, metal scandium block and aluminum titanium boron filaments are uniformly mixed, vacuumized in a vacuum melting furnace, argon is introduced, inducted heating is carried out at a temperature of 580-700℃ until complete melting, a refining agent ZnCl2-KCl is added, slagging and casting are carried out, and an aluminum alloy ingot is obtained; more preferably, the refining agent ZnCl2 is added in an amount of 1-4% and KCl is added in an amount of 1-4% based on 100% of the mass of the aluminum alloy ingot; more preferably, the temperature of the casting mold is 100-200℃.

[0021] S12. The aluminum alloy ingot is subjected to heat treatment at a temperature of 180-250℃ for 0.5-2h, hot rolling is carried out at a deformation rate of 60-80%, aging treatment is carried out for more than 24h after cooling to room temperature, annealing treatment is carried out at a temperature of 80-120℃ for 1-3h after rolling and embossing, and the aluminum alloy grid matrix is obtained by cutting into the required size under laser argon protection.

[0022] Preferably, the step S1. the alkaline solution is a mixed solution of NaOH-Na2CO3, and the mass concentration of NaOH in the alkaline solution is 200-400 g / L, the mass concentration of Na2CO3 is 20-40 g / L.

[0023] 10-40 g / L, and the mass concentration of Na2CO3 is 20-40 g / L.

[0024] The alkaline zinc-antimony solution contains 200-400 g / L of NaOH, 60-80 g / L of ZnO, 30-80 g / L of potassium antimony tartrate, 0.5-2 g / L of FeCl3, and 1-3 g / L of NaNO3.

[0025] The mass concentration of the HNO3 solution is 20-50%.

[0026] Preferably, the temperature of the step S1. oil removal by immersion is 60-80°C, and the time is 1-5 min.

[0027] The temperature of the first immersion plating reaction is 30-50°C, and the time is 10-60 s.

[0028] The activation time is 10-60 s.

[0029] The temperature of the second immersion plating reaction is 30-50°C, and the time is 10-30 s.

[0030] Preferably, the step S2. the neutral nickel plating solution contains 100-300 g / L of nickel sulfate, 10-30 g / L of nickel chloride, 100-300 g / L of citric acid, 10-60 g / L of boric acid, and 5-20 g / L of nano La2O3 powder; and the pH of the neutral nickel plating solution is 5-7.

[0031] The cathode current density of the composite plating is 1-5 A / dm 2 , the temperature is 40-60°C, and the time is 5-20 min.

[0032] Preferably, the step S3. the lead fluoroborate plating solution contains 100-300 g / L of lead acetate, 100-200 g / L of fluoroboric acid, 10-30 g / L of boric acid, 10-50 g / L of stannous fluoroborate, 2-8 g / L of bismuth oxide, and 1-3 g / L of silver oxide; and the pH of the lead fluoroborate plating solution is 1-2.

[0033] The anode current density of the electrodeposition is 1-5 A / dm 2 , the temperature is 30-50°C, and the time is 12-24 h.

[0034] Preferably, the step S4. the concentration of the sodium hydroxide solution is 40-100 g / L, the temperature of the alkaline solution treatment is 40-60°C, and the time is 4-8 h.

[0035] Step S4. The basic lead plating solution contains 30-60 g / L lead oxide, 100-200 g / L sodium hydroxide, 100-300 g / L potassium sodium tartrate, 10-40 g / L sodium ethylenediaminetetraacetate, and 4-16 g / L cobalt-coated carbon fiber powder;

[0036] Anode current density of the electrodeposition is 1-3 A / dm 2 at a temperature of 40-60 DEG C for 4-8 h.

[0037] Preferably, the preparation method of the cobalt-coated carbon fiber powder comprises the following steps:

[0038] S41. The carbon fiber is sequentially subjected to calcination and glue removal treatment, nitric acid solution roughening, stannous chloride-hydrochloric acid sensitization, and silver citrate colloidal activation to obtain pretreated carbon fiber;

[0039] S42. The pretreated carbon fiber is placed in a cobalt sulfate plating solution for chemical cobalt plating to obtain cobalt-coated carbon fiber powder; the cobalt sulfate plating solution contains 5-20 g / L cobalt sulfate, 5-30 g / L ethylenediaminetetraacetic acid, 5-20 g / L sodium hydroxide, 0.2-10 mg / L thiourea, and 5-20 ml / L formaldehyde.

[0040] More preferably, the length-diameter ratio of the carbon fiber powder in S41 is 10-100 μm, and the short-diameter is 0.1-5 μm.

[0041] More preferably, the calcination and glue removal treatment in S41 is performed at a temperature of 300-500 DEG C for 10-30 min; the nitric acid solution has a mass concentration of 10-30 %, and the roughening time is 5-10 min; the stannous chloride-hydrochloric acid contains 5-20 g / L stannous chloride and 5-20 ml / L hydrochloric acid, and the sensitization time is 5-10 min; the silver citrate colloidal solution has a concentration of 5-20 g / L, and the activation time is 1-5 min.

[0042] More preferably, the chemical cobalt plating in S42 is performed at a temperature of 40-70 DEG C for 10-60 min.

[0043] The present application has the following advantages:

[0044] (1) Since the density of aluminum is small, the strength of the aluminum alloy is higher than that of the lead alloy, and the aluminum alloy has good electrical conductivity, the present application uses the aluminum alloy as the base material of the aluminum-based lead alloy / cobalt-coated carbon fiber powder-alpha-PbO2 composite positive grid plate, which can significantly reduce the weight of the battery, improve the tensile strength, and improve the electrical conductivity of the aluminum-based composite lead positive grid, which is better than that of the conventional lead alloy battery positive material, thereby improving the charge-discharge efficiency of the battery; and the cost of aluminum is low, thereby reducing the production cost of the battery positive material.

[0045] (2) The aluminum-based lead composite material has stable electrochemical performance, can reduce the oxygen evolution overpotential of the positive electrode, increase the anode electrocatalytic performance, promote the conversion of active substances, improve the utilization rate, reduce the water loss, and prolong the cycle life of the battery;

[0046] (3) The battery using the aluminum-based composite lead positive grid has improved rate discharge performance and active substance utilization rate, and the internal resistance of the lead-acid battery is significantly reduced by reducing the physical resistance and electrochemical reaction impedance of the grid;

[0047] (4) The transition layer (zinc-antimony immersion layer, nano-La2O3-doped nickel bottom layer) has a certain flattening effect, can effectively repair the surface of the aluminum base, and makes the prepared lead plating layer uniform in thickness; the two form a metallurgical bond to strengthen the bonding force between the aluminum base and the lead alloy;

[0048] (5) The Ag has good conductivity, so that the Pb-Sn-Bi-Ag alloy intermediate layer and the porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer are firmly combined, the interface resistance is reduced, and the cobalt-doped carbon fiber powder-α-PbO2 composite active layer has good activity and strong corrosion resistance, greatly improving the corrosion resistance and activity of the positive grid. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 A structure diagram of an aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive grid is shown in the figure.

[0050] Figure 2 A-A cross-sectional view of Figure 1 .

[0051] In the figure: 1-zinc-antimony immersion layer, 2-nano-La2O3-doped nickel bottom layer, 3-Pb-Sn-Bi-Ag alloy intermediate layer, 4-porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer.

[0052] Figure 3 A cycle performance diagram of a lead storage battery of the aluminum-based lead alloy positive grid of Example 3 is shown in the figure. DETAILED DESCRIPTION

[0053] The application will be further described in detail below in conjunction with specific embodiments, but the scope of protection of the application is not limited to the described content.

[0054] SUMMARY

[0055] An aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive grid (see Figure 1 and 2), from inside to outside are aluminum alloy base, zinc-antimony layer 1, nano-La2O3-doped nickel underlayer 2, Pb-Sn-Bi-Ag alloy intermediate layer 3 and porous Co-doped carbon fiber powder-α-PbO2 composite active layer 4;

[0056] The aluminum alloy base contains 0.2-0.8% Ca, 0.01-0.2% Zr, 0.01-0.1% Ce, 0.01-0.2% Sc and 0.001-0.3% Al-5Ti-B by mass percentage, and the balance is Al;

[0057] The zinc-antimony layer 1 contains 5-10% Sb by mass percentage, and the balance is Zn;

[0058] The nano-La2O3-doped nickel underlayer 2 contains 0.2-5% La2O3 by mass percentage, and the balance is Ni;

[0059] The Pb-Sn-Bi-Ag alloy intermediate layer 3 contains 0.5-5.0% Sn, 0.1-1.0% Bi and 0.005-0.1% Ag by mass percentage, and the balance is Pb;

[0060] The porous Co-doped carbon fiber powder-α-PbO2 composite active layer 4 contains 0.5-5.0% Co-doped carbon fiber powder by mass percentage, and the balance is α-PbO2; the Co-doped carbon fiber powder contains 5-20% Co by mass percentage of the Co-doped carbon fiber powder, and the balance is carbon fiber;

[0061] The aluminum alloy base is in a plate-shape structure, and the surface is pressed with patterns, the pattern depth is 0.05-0.5 mm, the pattern width is 0.05-0.3 mm, and the cross-section thickness is 0.5-6 mm;

[0062] The thickness of the zinc-antimony layer 1 is 0.5-3 μm, the thickness of the nano-La2O3-doped nickel underlayer 2 is 3-8 μm, the thickness of the Pb-Sn-Bi-Ag alloy intermediate layer 3 is 0.5-4 mm, and the thickness of the porous Co-doped carbon fiber powder-α-PbO2 composite active layer 4 is 0.1-1.0 mm.

[0063] The preparation method of the aluminum-based lead alloy / Co-doped carbon fiber powder-α-PbO2 composite positive grid comprises the following specific steps:

[0064] S1. Preparing the aluminum alloy plate grid immersed Zn-Sb layer: placing the aluminum alloy plate grid matrix in an alkaline solution to soak and remove oil, washing with deionized water, then placing in an alkaline zinc antimony solution to carry out a first immersion plating reaction, washing with deionized water, then placing in an HNO3 solution to activate, washing with deionized water, then placing in an alkaline zinc antimony solution to carry out a second immersion plating reaction, washing with deionized water to obtain the aluminum alloy plate grid with the immersed Zn-Sb layer; the alkaline solution is a NaOH-Na2CO3 mixed solution, the NaOH in the alkaline solution is 10-40 g / L, the Na2CO3 is 20-40 g / L; the alkaline zinc antimony solution contains 200-400 g / L NaOH, 60-80 g / L ZnO, 30-80 g / L potassium antimony tartrate, 0.5-2 g / L FeCl3, and 1-3 g / L NaNO3; the mass concentration of the HNO3 solution is 20-50%;

[0065] 20-40 g / L; the alkaline zinc antimony solution contains 200-400 g / L NaOH, 60-80 g / L ZnO, 30-80 g / L potassium antimony tartrate, 0.5-2 g / L FeCl3, and 1-3 g / L NaNO3; the mass concentration of the HNO3 solution is 20-50%;

[0066] Preferably, the soaking and oil removal temperature is 60-80℃, and the time is 1-5 min; the temperature of the first immersion plating reaction is 30-50℃, and the time is 10-60 s; the activation time is 10-60 s; the temperature of the second immersion plating reaction is 30-50℃, and the time is 10-30 s;

[0067] The preparation method of the aluminum alloy plate grid matrix in step S1. is specifically as follows:

[0068] S11. According to the composition of the aluminum alloy matrix, pure aluminum ingot, electrolytic calcium, metal zirconium block, metal cerium block, metal scandium block, and aluminum titanium boron filaments are uniformly mixed, placed in a vacuum melting furnace to be vacuumized, argon is introduced, inducted heating is carried out at a temperature of 580-700℃ until complete melting, a refining agent ZnCl2-KCl is added, slagging and casting are carried out, and an aluminum alloy ingot is obtained; more preferably, the refining agent ZnCl2 is added in an amount of 1-4% and KCl is added in an amount of 1-4% based on 100% of the mass of the aluminum alloy ingot; more preferably, the temperature of the casting mold is 100-200℃;

[0069] S12. The aluminum alloy ingot is placed in a heat treatment at a temperature of 180-250℃ for 0.5-2 h, hot rolling is carried out at a deformation of 60-80%, aging treatment is carried out for more than 24 h after cooling to room temperature, annealing treatment is carried out at a temperature of 80-120℃ for 1-3 h after rolling and embossing, cutting into the required size of the aluminum alloy plate grid under the protection of laser argon, and an aluminum alloy plate grid matrix is obtained.

[0070] S2. Preparing aluminum alloy grid doped with nano-La2O3-nickel underlayer: taking the aluminum alloy grid plated with Zn-Sb layer as cathode, pure nickel plate as anode, composite plating in neutral nickel plating solution, and then washing with deionized water to obtain the aluminum alloy grid doped with nano-La2O3-nickel underlayer; the neutral nickel plating solution contains 100-300 g / L nickel sulfate, 10-30 g / L nickel chloride, 100-300 g / L citric acid, 10-60 g / L boric acid, and 5-20 g / L nano-La2O3 powder; the pH of the neutral nickel plating solution is 5-7; the cathode current density of the composite plating is 1-5 A / dm 2 , the temperature is 40-60℃, and the time is 5-20 min;

[0071] S3. Preparing aluminum alloy grid Pb-Sn-Bi-Ag alloy intermediate layer: taking the aluminum alloy grid doped with nano-La2O3-nickel underlayer as cathode, lead-tin alloy plate as anode, and electrodeposition in lead fluoroborate plating solution, and then washing with deionized water to obtain the aluminum alloy grid Pb-Sn-Bi-Ag alloy intermediate layer; the lead fluoroborate plating solution contains 100-300 g / L lead acetate, 100-200 g / L fluoroboric acid, 10-30 g / L boric acid, 10-50 g / L stannous fluoroborate, 2-8 g / L bismuth oxide, and 1-3 g / L silver oxide; the pH of the lead fluoroborate plating solution is 1-2; the anode current density of the electrodeposition is 1-5 A / dm 2 , the temperature is 30-50℃, and the time is 12-24 h;

[0072] S4. Preparing aluminum alloy grid porous doped cobalt carbon fiber powder-α-PbO2 composite active layer: the aluminum alloy grid Pb-Sn-Bi-Ag alloy intermediate layer is subjected to sand blasting treatment, and then is placed in sodium hydroxide solution for alkali dissolution treatment, and then is washed with deionized water to obtain a porous anode grid; taking the porous anode grid as anode and stainless steel plate as cathode, and then electrodeposition in alkaline lead plating solution, and then washing with deionized water to obtain the aluminum alloy grid porous doped cobalt carbon fiber powder-α-PbO2 composite active layer; the concentration of the sodium hydroxide solution is 40-100 g / L, the alkali dissolution treatment temperature is 40-60℃, and the time is 4-8 h; the alkaline lead plating solution contains 30-60 g / L lead oxide, 100-200 g / L sodium hydroxide, 100-300 g / L potassium sodium tartrate, 10-40 g / L sodium ethylenediaminetetraacetate, and 4-16 g / L cobalt carbon fiber powder; the anode current density of the electrodeposition is 1-3 A / dm 2 , the temperature is 40-60℃, and the time is 4-8 h;

[0073] Preferably, the preparation method of the cobalt carbon fiber powder comprises the following steps:

[0074] S41. Carbon fibers are sequentially subjected to calcination to remove sizing, nitric acid solution roughening, stannous chloride-hydrochloric acid sensitization, and silver citrate colloid activation to obtain pretreated carbon fibers; the carbon fiber powder has a major diameter of 10–100 μm and a minor diameter of 0.1–5 μm; the calcination to remove sizing temperature is 300–500℃, and the time is 10–30 min; the nitric acid solution mass concentration is 10–30%, and the roughening time is 5–10 min; the stannous chloride-hydrochloric acid contains 5–20 g / L stannous chloride and 5–20 ml / L hydrochloric acid, and the sensitization time is 5–10 min; the silver citrate colloid concentration is 5–20 g / L, and the activation time is 1–5 min;

[0075] S42. Pretreated carbon fibers are placed in a cobalt sulfate plating solution for cobalt electroplating to obtain cobalt-coated carbon fiber powder; the cobalt sulfate plating solution contains 5-20 g / L cobalt sulfate, 5-30 g / L ethylenediaminetetraacetic acid, 5-20 g / L sodium hydroxide, 0.2-10 mg / L thiourea, and 5-20 ml / L formaldehyde; the temperature of the electroplating is 40-70℃ and the time is 10-60 min.

[0076] Example 1: An aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite cathode grid (see...) Figure 1 and 2 From the inside out, the structure consists of an aluminum alloy substrate, a zinc-antimony impregnation layer 1, a nano-La2O3-nickel bottom layer 2, a Pb-Sn-Bi-Ag alloy intermediate layer 3, and a porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer 4.

[0077] The aluminum alloy matrix contains, by mass percentage, 0.2% Ca, 0.01% Zr, 0.01% Ce, 0.01% Sc, 0.001% Al-5Ti-B, with the balance being Al;

[0078] By mass percentage, Sb accounts for 5% of the zinc-antimony layer 1, with the balance being Zn;

[0079] By mass percentage, the nano-La2O3-nickel bottom layer 2 contains 0.2% La2O3 and the balance is Ni;

[0080] By mass percentage, the Pb-Sn-Bi-Ag alloy intermediate layer 3 contains 0.5% Sn and 0.1% Bi.

[0081] 0.005% Ag, balance Pb;

[0082] By mass percentage, the porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer 4 contains 0.5% cobalt-doped carbon fiber powder and the remainder is α-PbO2; by mass percentage, the cobalt-doped carbon fiber powder contains 5% Co and the remainder is carbon fiber.

[0083] The aluminum alloy base is a plate-shaped structure, and the surface is pressed with patterns, the pattern depth is 0.05 mm, the pattern width is 0.05 mm, and the cross-section thickness is 0.5 mm;

[0084] The thickness of the zinc-antimony immersion layer 1 is 0.5 μm; the thickness of the nano-La2O3-doped nickel underlayer 2 is 3 μm; the thickness of the Pb-Sn-Bi-Ag alloy intermediate layer 3 is 0.5 mm; and the thickness of the porous cobalt-doped carbon-coated fiber powder-α-PbO2 composite active layer 4 is 0.1 mm;

[0085] The preparation method of the aluminum-based lead alloy / cobalt-doped carbon-coated fiber powder-α-PbO2 composite positive plate grid comprises the following specific steps:

[0086] S1. Preparing an aluminum alloy plate grid immersed with a Zn-Sb layer: placing the aluminum alloy plate grid base in an alkaline solution (a mixed solution of NaOH and Na2CO3, NaOH 10 g / L and Na2CO3 20 g / L) to soak for 1 min for oil removal at a temperature of 60 ℃, washing with deionized water, and then placing in an alkaline zinc-antimony solution to perform a first immersion plating reaction for 10 s at a temperature of 30 ℃, washing with deionized water, and then placing in a HNO3 solution with a mass concentration of 20% to activate for 10 s, washing with deionized water, and then placing in an alkaline zinc-antimony solution to perform a second immersion plating reaction for 10 s at a temperature of 30 ℃, washing with deionized water, and obtaining an aluminum alloy plate grid immersed with a Zn-Sb layer; the alkaline zinc-antimony solution contains 200 g / L of NaOH, 60 g / L of ZnO, 30 g / L of antimony potassium tartrate, 0.5 g / L of FeCl3, and 1 g / L of NaNO3;

[0087] The preparation method of the aluminum alloy plate grid base in step S1. comprises the following specific steps:

[0088] S11. According to the composition of the aluminum alloy base, pure aluminum ingots, electrolytic calcium, metal zirconium blocks, metal cerium blocks, metal scandium blocks, and aluminum titanium boron filaments are uniformly mixed, vacuumized in a vacuum melting furnace, and argon is introduced to heat to complete melting under electromagnetic induction at a temperature of 580 ℃, and a refining agent ZnCl2-KCl is added (the mass of the aluminum alloy ingot is 100%, the addition amount of the refining agent ZnCl2 is 1%, and the addition amount of KCl is 1%), slag is removed, and casting is performed (the temperature of the mold is 100 ℃), to obtain an aluminum alloy ingot;

[0089] S12. The aluminum alloy ingot is placed for heat treatment at a temperature of 180 ℃ for 0.5 h, hot-rolled at a deformation rate of 60%, and then aged for 24 h after cooling to room temperature, and then annealed at a temperature of 80 ℃ for 1 h after rolling and embossing, and then cut into the required size of the aluminum alloy plate grid under laser argon protection, to obtain an aluminum alloy plate grid base;

[0090] S2. Preparation of aluminum alloy grid doped with nano La2O3-nickel underlayer: aluminum alloy grid with Zn-Sb layer by immersion plating is used as cathode, pure nickel plate is used as anode, composite plating is carried out in neutral nickel plating solution at cathode current density 1 A / dm 2 , temperature 40℃ for 5 min, and deionized water washing to obtain aluminum alloy grid doped with nano La2O3-nickel underlayer; the neutral nickel plating solution contains 100 g / L nickel sulfate, 10 g / L nickel chloride, 100 g / L citric acid, 10 g / L boric acid, and 5 g / L nano La2O3 powder; the pH of the neutral nickel plating solution is 7;

[0091] S3. Preparation of aluminum alloy grid Pb-Sn-Bi-Ag alloy intermediate layer: aluminum alloy grid doped with nano La2O3-nickel underlayer is used as cathode, lead-tin alloy plate is used as anode, and electrodeposition is carried out in lead fluoroborate plating solution at stirring speed 100 rpm, anode current density 1 A / dm 2 , temperature 30℃ for 12 h, and deionized water washing to obtain aluminum alloy grid with Pb-Sn-Bi-Ag alloy intermediate layer; the lead fluoroborate plating solution contains 100 g / L lead acetate, 100 g / L fluoroboric acid, 10 g / L boric acid, 10 g / L stannous fluoroborate, 2 g / L bismuth oxide, and 1 g / L silver oxide; the pH of the lead fluoroborate plating solution is 2;

[0092] S4. Preparation of aluminum alloy grid porous doped cobalt carbon fiber powder-α-PbO2 composite active layer: the aluminum alloy grid with Pb-Sn-Bi-Ag alloy intermediate layer is subjected to sand blasting treatment (sand is silica particles with particle size of 0.5 mm), placed in sodium hydroxide solution with concentration of 40 g / L, and subjected to alkali solution treatment at temperature 40℃ for 4 h, and deionized water washing to obtain porous anode grid, which is used as anode, and stainless steel plate is used as cathode, and electrodeposition is carried out in alkaline lead plating solution at anode current density 1 A / dm 2 , temperature 40℃ for 4 h, and deionized water washing to obtain aluminum alloy grid with porous doped cobalt carbon fiber powder-α-PbO2 composite active layer; the alkaline lead plating solution contains 30 g / L lead oxide, 100 g / L sodium hydroxide, 100 g / L potassium sodium tartrate, 10 g / L sodium ethylenediaminetetraacetate, and 4 g / L cobalt carbon fiber powder;

[0093] The preparation method of the cobalt carbon fiber powder is specifically as follows:

[0094] S41. Carbon fiber (length-diameter ratio is 10 μm, and short-diameter ratio is 0.1 μm) is sequentially subjected to temperature 300℃ calcination for removing glue, 10% nitric acid solution roughening for 5 min, stannous chloride-hydrochloric acid (5 g / L stannous chloride and 5 ml / L hydrochloric acid) sensitization for 5 min, and 5 g / L silver citrate colloidal activation for 1 min to obtain pretreated carbon fiber;

[0095] S42. The pretreated carbon fiber is placed in a cobalt sulfate plating solution containing 5 g / L cobalt sulfate, 5 g / L ethylenediaminetetraacetic acid, 5 g / L sodium hydroxide, 0.2 mg / L thiourea, and 5 ml / L formaldehyde, and is electroless plated with cobalt at 40°C for 10 minutes to obtain cobalt-coated carbon fiber powder;

[0096] Compared with the traditional lead alloy positive plate grid, the aluminum-based lead alloy / cobalt-doped carbon-coated fiber powder-α-PbO2 composite positive plate grid has a weight reduction of 50%, an increase in tensile strength of 34%, and an increase in electrical conductivity of 28%;

[0097] The assembled lead-acid battery is prepared according to a conventional method: the plate is manufactured through processes such as grid casting, paste preparation, and paste coating; the plates are weighed and assembled, and the positive and negative plates are alternately wrapped with separators; the assembled plates are welded to form a plate group; the plate group is placed in a clean battery tank, the battery shell is sealed by injecting glue, the prepared electrolyte is added from the acid injection port, and the acid injection port is sealed after the battery is formed; finally, the assembled battery is tested for performance to ensure the quality and performance of the battery;

[0098] Formation treatment: after the electrolyte is injected, the battery is left to stand for a period of time, allowing the separator and the plate to fully absorb the acid solution. The battery is activated by multiple charging and discharging with a large current. After activation, the battery is in a preliminary state that can be used;

[0099] Capacity test: the actual capacity of the battery is measured and calculated by constant current discharge. The discharge current is generally 0.1C, and the battery is discharged to the terminal voltage, such as 1.8V, for 10 hours. The capacity test can accurately evaluate whether the battery's energy storage capacity meets the design requirements;

[0100] Internal resistance test: the battery's AC impedance is measured using an electrochemical workstation or a battery test system. The internal resistance test is usually conducted at different frequency ranges to obtain the impedance spectrum of the battery. The internal resistance directly affects the charging and discharging efficiency and thermal management performance of the battery;

[0101] Rate performance test: the battery is tested at different discharge rates, such as 0.05C, 0.1C, 0.5C, 1C, and 2C. The rate performance test can evaluate the battery's performance at different discharge rates, providing guidance for the battery's suitability in different application scenarios;

[0102] Cycle life test: the battery is subjected to multiple charging and discharging cycles, and parameters such as capacity, voltage, and internal resistance are recorded for each cycle. The cycle life test can evaluate the battery's performance stability and lifespan during long-term use. A fixed discharge value and discharge depth are usually set to detect the number of cycles, such as setting the cycle discharge conditions to 0.1C and 70% DOD (depth of discharge), and observing the trend of the battery's performance;

[0103] The lead storage battery using the aluminum-based lead alloy positive plate grid of the embodiment can meet the long-term frequent charge-discharge requirement of lead-acid energy storage batteries, with the cycle life of the lead storage battery being extended by 15% under the condition of 70% depth of discharge (DOD).

[0104] Embodiment 2: An aluminum-based lead alloy / nano-La2O3-doped carbon fiber powder-α-PbO2 composite positive plate grid (see Figure 1 and 2 ), from inside to outside, sequentially being an aluminum alloy base, a zinc-antimony layer 1, a nano-La2O3-doped nickel underlayer 2, a Pb-Sn-Bi-Ag alloy intermediate layer 3, and a porous nano-La2O3-doped carbon fiber powder-α-PbO2 composite active layer 4;

[0105] The aluminum alloy base contains 0.8% Ca, 0.2% Zr, 0.1% Ce, 0.2% Sc, and 0.3% Al-5Ti-B, with the balance being Al, in terms of mass percentage;

[0106] The zinc-antimony layer 1 contains 10% Sb, with the balance being Zn, in terms of mass percentage;

[0107] The nano-La2O3-doped nickel underlayer 2 contains 5% La2O3, with the balance being Ni, in terms of mass percentage;

[0108] The Pb-Sn-Bi-Ag alloy intermediate layer 3 contains 5.0% Sn, 1.0% Bi, and 0.1% Ag, with the balance being Pb, in terms of mass percentage;

[0109] The porous nano-La2O3-doped carbon fiber powder-α-PbO2 composite active layer 4 contains 5.0% Co-doped carbon fiber powder, with the balance being α-PbO2, in terms of mass percentage; the Co-doped carbon fiber powder contains 20% Co, with the balance being carbon fiber, in terms of mass percentage of the Co-doped carbon fiber powder;

[0110] The aluminum alloy base has a plate structure, with patterns pressed on the surface, the pattern depth being 0.5 mm, the pattern width being 0.3 mm, and the cross-sectional thickness being 6 mm;

[0111] The thickness of the zinc-antimony layer 1 is 3 μm; the thickness of the nano-La2O3-doped nickel underlayer 2 is 8 μm; the thickness of the Pb-Sn-Bi-Ag alloy intermediate layer 3 is 4 mm; and the thickness of the porous nano-La2O3-doped carbon fiber powder-α-PbO2 composite active layer 4 is 1.0 mm;

[0112] The preparation method of the aluminum-based lead alloy / nano-La2O3-doped carbon fiber powder-α-PbO2 composite positive plate grid includes the following specific steps:

[0113] S1. Preparing the aluminum alloy grid immersion plated Zn-Sb layer: placing the aluminum alloy grid substrate in an alkaline solution (NaOH-Na2CO3 mixed solution, NaOH 40 g / L, Na2CO3 40 g / L) to soak for 5 min for oil removal at a temperature of 80℃, washing with deionized water, and then placing in an alkaline zinc antimony solution to carry out a first immersion plating reaction for 60 s at a temperature of 50℃, washing with deionized water, and then placing in a 50% mass concentration HNO3 solution to activate for 60 s, washing with deionized water, and then placing in an alkaline zinc antimony solution to carry out a second immersion plating reaction for 30 s at a temperature of 50℃, washing with deionized water to obtain the aluminum alloy grid with the immersion plated Zn-Sb layer; the alkaline zinc antimony solution contains 400 g / L NaOH, 80 g / L ZnO, 80 g / L potassium antimony tartrate, 2 g / L FeCl3, and 3 g / L NaNO3;

[0114] The step S1. The preparation method of the aluminum alloy grid substrate includes the following specific steps:

[0115] S11. According to the composition of the aluminum alloy substrate, pure aluminum ingot, electrolytic calcium, metal zirconium block, metal cerium block, metal scandium block, and aluminum titanium boron filaments are uniformly mixed, vacuumized in a vacuum melting furnace, argon is introduced, electromagnetic induction heating is carried out to completely melt at a temperature of 700℃, a refining agent ZnCl2-KCl is added (the mass of the aluminum alloy ingot is 100%, the addition amount of the refining agent ZnCl2 is 4%, and the addition amount of KCl is 4%), slag is removed, and casting is carried out (the temperature of the mold is 200℃) to obtain an aluminum alloy ingot;

[0116] S12. The aluminum alloy ingot is placed for heat treatment at a temperature of 250℃ for 2 h, hot rolling is carried out at a deformation rate of 80%, aging treatment is carried out for 25 h after cooling to room temperature, annealing treatment is carried out at a temperature of 120℃ for 3 h after rolling and embossing, and the aluminum alloy grid substrate is obtained by cutting to the required size under laser argon protection.

[0117] S2. Preparing the aluminum alloy grid with a nano La2O3-doped nickel bottom layer: using the immersion plated Zn-Sb layer aluminum alloy grid as the cathode and a pure nickel plate as the anode, composite plating is carried out in a neutral nickel plating solution at a cathode current density of 4 A / dm 2

[0118] ​S3. Preparing the aluminum alloy grid Pb-Sn-Bi-Ag alloy interlayer: taking the aluminum alloy grid with nano La2O3-doped nickel underlayer as cathode, the lead-tin alloy plate as anode, and depositing in the lead fluoborate plating solution for 24 h at a stirring speed of 300 rpm, anode current density of 5 A / dm 2 , and temperature of 50℃, and then washing with deionized water to obtain the aluminum alloy grid with Pb-Sn-Bi-Ag alloy interlayer; the lead fluoborate plating solution contains 300 g / L lead acetate, 200 g / L fluoboric acid, 30 g / L boric acid, 50 g / L stannous fluoborate, 8 g / L bismuth oxide, and 3 g / L silver oxide; the pH value of the lead fluoborate plating solution is 1;

[0119] S4. Preparing the aluminum alloy grid porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer: the aluminum alloy grid with Pb-Sn-Bi-Ag alloy interlayer is subjected to sand blasting treatment (the sand is silica particles with a particle size of 4 mm), and is placed in a 100 g / L sodium hydroxide solution for alkaline solution treatment at a temperature of 60℃ for 8 h, and then washed with deionized water to obtain a porous anode grid, taking the porous anode grid as anode and a stainless steel plate as cathode, and depositing in an alkaline lead plating solution at a stirring speed of 600 rpm, anode current density of 3 A / dm 2 , and temperature of 60℃ for 8 h, and then washing with deionized water to obtain the aluminum alloy grid with porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer; the alkaline lead plating solution contains 60 g / L lead oxide, 200 g / L sodium hydroxide, 300 g / L potassium sodium tartrate, 40 g / L sodium ethylenediaminetetraacetate, and 16 g / L cobalt-coated carbon fiber powder;

[0120] The preparation method of the cobalt-coated carbon fiber powder is specifically as follows:

[0121] S41. Carbon fiber (aspect ratio of 100 μm and minor axis of 5 μm) is subjected to temperature 500℃ calcination for glue removal, 30% nitric acid solution roughening for 10 min, stannous chloride-hydrochloric acid (20 g / L stannous chloride and 20 ml / L hydrochloric acid) sensitization for 10 min, and 20 g / L silver citrate colloidal activation for 5 min in sequence to obtain pretreated carbon fiber;

[0122] S42. The pretreated carbon fiber is placed in a cobalt sulfate plating solution for chemical cobalt plating at a temperature of 70℃ for 60 min to obtain cobalt-coated carbon fiber powder; the cobalt sulfate plating solution contains 20 g / L cobalt sulfate, 30 g / L ethylenediaminetetraacetic acid, 20 g / L sodium hydroxide, 10 mg / L thiourea, and 20 ml / L formaldehyde;

[0123] Compared with the traditional lead alloy positive plate grid, the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive plate grid in the example has a weight reduction of 53%, a tensile strength increase of 37%, and an electric conductivity enhancement of 30%;

[0124] The lead storage battery using the aluminum-based lead alloy anode grid of the embodiment can meet the long-term frequent charge-discharge requirement of lead-acid storage batteries, with the cycle period prolonged by 20% under the condition of 70% depth of discharge (DOD).

[0125] Embodiment 3: An aluminum-based lead alloy / nano-La2O3-doped carbon fiber powder-α-PbO2 composite positive electrode grid (see Figure 1 and 2 ), from inside to outside, sequentially being an aluminum alloy base, a zinc-antimony layer 1, a nano-La2O3-doped nickel underlayer 2, a Pb-Sn-Bi-Ag alloy intermediate layer 3, and a porous nano-La2O3-doped carbon fiber powder-α-PbO2 composite active layer 4;

[0126] The aluminum alloy base contains 0.4% Ca, 0.1% Zr, 0.05% Ce, 0.1% Sc, and 0.15% Al-5Ti-B, with the balance being Al, in terms of mass percentage;

[0127] The zinc-antimony layer 1 contains 7% Sb, with the balance being Zn, in terms of mass percentage;

[0128] The nano-La2O3-doped nickel underlayer 2 contains 2.5% La2O3, with the balance being Ni, in terms of mass percentage;

[0129] The Pb-Sn-Bi-Ag alloy intermediate layer 3 contains 2.7% Sn, 0.5% Bi, and 0.05% Ag, with the balance being Pb, in terms of mass percentage;

[0130] The porous nano-La2O3-doped carbon fiber powder-α-PbO2 composite active layer 4 contains 2.8% Co-doped carbon fiber powder, with the balance being α-PbO2, in terms of mass percentage; the Co-doped carbon fiber powder contains 12% Co, with the balance being carbon fiber, in terms of mass percentage of the Co-doped carbon fiber powder;

[0131] The aluminum alloy base is in a plate structure, with patterns pressed on the surface, the pattern depth being 0.25 mm, the pattern width being 0.15 mm, and the cross-sectional thickness being 3 mm;

[0132] The thickness of the zinc-antimony layer 1 is 1.8 μm; the thickness of the nano-La2O3-doped nickel underlayer 2 is 6 μm; the thickness of the Pb-Sn-Bi-Ag alloy intermediate layer 3 is 2 mm; and the thickness of the porous nano-La2O3-doped carbon fiber powder-α-PbO2 composite active layer 4 is 0.5 mm;

[0133] The preparation method of the aluminum-based lead alloy / nano-La2O3-doped carbon fiber powder-α-PbO2 composite positive electrode grid, and the specific steps are as follows:

[0134] S1. Preparing the aluminum alloy grid immersion plated Zn-Sb layer: placing the aluminum alloy grid substrate in an alkaline solution (NaOH-Na2CO3 mixed solution, NaOH 25 g / L, Na2CO3 30 g / L) to soak for 3 min for oil removal at a temperature of 70℃, washing with deionized water, and then placing in an alkaline zinc antimony solution to carry out a first immersion plating reaction for 30 s at a temperature of 40℃, washing with deionized water, and then placing in a 35% mass concentration HNO3 solution to activate for 30 s, washing with deionized water, and then placing in an alkaline zinc antimony solution to carry out a second immersion plating reaction for 20 s at a temperature of 40℃, washing with deionized water to obtain the aluminum alloy grid with the immersion plated Zn-Sb layer; the alkaline zinc antimony solution contains 300 g / L NaOH, 70 g / L ZnO, 50 g / L potassium antimony tartrate, 1.2 g / L FeCl3, and 2 g / L NaNO3;

[0135] The step S1. The preparation method of the aluminum alloy grid substrate, and the specific steps are as follows:

[0136] S11. According to the composition of the aluminum alloy substrate, pure aluminum ingot, electrolytic calcium, metal zirconium block, metal cerium block, metal scandium block and aluminum titanium boron filaments are uniformly mixed, vacuumized in a vacuum melting furnace, argon is introduced, heated to complete melting by electromagnetic induction at a temperature of 650℃, refining agent ZnCl2-KCl is added (based on 100% of the mass of the aluminum alloy ingot, the addition amount of refining agent ZnCl2 is 2%, and the addition amount of KCl is 2%), slagging and casting (the temperature of the mold is 150℃), and the aluminum alloy ingot is obtained;

[0137] S12. The aluminum alloy ingot is placed in a temperature of 210℃ for heat treatment for 1 h, hot rolled at a deformation rate of 70%, and then aged for 26 h after cooling to room temperature, and then annealed at a temperature of 100℃ for 2 h after embossing and rolling, and then cut into the required size of the aluminum alloy grid under the protection of laser argon to obtain the aluminum alloy grid substrate;

[0138] S2. Preparing the aluminum alloy grid with a nano La2O3-doped nickel bottom layer: using the immersion plated Zn-Sb layer aluminum alloy grid as the cathode and a pure nickel plate as the anode, composite plating is carried out in a neutral nickel plating solution at a cathode current density of 2 A / dm 2

[0139] ​S3. Preparation of aluminum alloy grid Pb-Sn-Bi-Ag alloy interlayer: aluminum alloy grid with nano La2O3-doped nickel underlayer as cathode, lead-tin alloy plate as anode, in lead fluoborate plating solution, under stirring speed of 200 rpm, anode current density of 3 A / dm 2 , temperature of 40℃ for 18h, and then washed with deionized water to obtain the aluminum alloy grid with Pb-Sn-Bi-Ag alloy interlayer; the lead fluoborate plating solution contains 200g / L lead acetate, 150g / L fluoboric acid, 20g / L boric acid, 30g / L fluoro stannous acid, 5g / L bismuth oxide, and 2g / L silver oxide; the pH value of the lead fluoborate plating solution is 1.5;

[0140] S4. Preparation of aluminum alloy grid porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer: the aluminum alloy grid with Pb-Sn-Bi-Ag alloy interlayer is subjected to sand blasting treatment (sand is silica particles with a particle size of 2.3mm), placed in a 70g / L sodium hydroxide solution, and subjected to alkali solution treatment at a temperature of 50℃ for 6h, and then washed with deionized water to obtain a porous anode grid, and the porous anode grid is used as anode and a stainless steel plate is used as cathode, in an alkaline lead plating solution, under stirring speed of 400 rpm, anode current density of 2 A / dm 2 , temperature of 50℃ for 6h, and then washed with deionized water to obtain the aluminum alloy grid with porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer; the alkaline lead plating solution contains 45g / L lead oxide, 150g / L sodium hydroxide, 200g / L potassium sodium tartrate, 25g / L sodium ethylenediaminetetraacetate, and 10g / L cobalt-coated carbon fiber powder;

[0141] The preparation method of the cobalt-coated carbon fiber powder is specifically as follows:

[0142] S41. Carbon fiber (aspect ratio of 50μm, minor axis of 2.5μm) is sequentially subjected to temperature 400℃ calcination for removing glue, 20% nitric acid solution roughening for 7min, stannous chloride-hydrochloric acid (12g / L stannous chloride, 13ml / L hydrochloric acid) sensitization for 7min, and 13g / L silver citrate colloidal activation for 3min to obtain pretreated carbon fiber;

[0143] S42. The pretreated carbon fiber is placed in a cobalt sulfate plating solution, and chemically plated with cobalt at a temperature of 60℃ for 30min to obtain cobalt-coated carbon fiber powder; the cobalt sulfate plating solution contains 12g / L cobalt sulfate, 17g / L ethylenediaminetetraacetic acid, 13g / L sodium hydroxide, 5mg / L thiourea, and 13ml / L formaldehyde;

[0144] Compared with the traditional lead alloy positive plate grid, the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive plate grid of the embodiment has a weight reduction of 55%, a tensile strength increase of 39%, and an electric conductivity enhancement of 32%.

[0145] The cycle performance diagram of the lead-acid battery with the aluminum-based lead alloy anode grid in this embodiment is shown below. Figure 3 ,from Figure 3 It can be seen that under the conditions of discharge current of 0.5C and 100% DOD, the performance change of a battery with rated capacity and voltage of 2V / 2Ah was tested during 100 cycles. The cycle life of the lead-acid battery using the aluminum-based lead alloy anode grid of this embodiment is extended by 25%, which can meet the long-term frequent charge and discharge requirements of lead-acid energy storage batteries.

[0146] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive plate grid characterized by: From inside to outside are aluminum alloy matrix, zinc-antimony layer (1), nano-La2O3-doped nickel underlayer (2), Pb-Sn-Bi-Ag alloy intermediate layer (3) and porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer (4).

2. The aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive grid according to claim 1, characterized in that: The aluminum alloy matrix contains 0.2-0.8% Ca, 0.01-0.2% Zr, 0.01-0.1% Ce, 0.01-0.2% Sc and 0.001-0.3% Al-5Ti-B by mass percentage, and the balance is Al; The zinc-antimony layer (1) contains 5-10% Sb by mass percentage, and the balance is Zn; The nano-La2O3-doped nickel underlayer (2) contains 0.2-5% La2O3 by mass percentage, and the balance is Ni; The Pb-Sn-Bi-Ag alloy intermediate layer (3) contains 0.5-5.0% Sn, 0.1-1.0% Bi and 0.005-0.1% Ag by mass percentage, and the balance is Pb; The porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer (4) contains 0.5-5.0% cobalt-doped carbon fiber powder by mass percentage, and the balance is α-PbO2; the cobalt-doped carbon fiber powder contains 5-20% Co by mass percentage of the cobalt-doped carbon fiber powder, and the balance is carbon fiber. The aluminum alloy matrix is in a plate shape structure, and the surface is pressed with patterns, the pattern depth is 0.05-0.5 mm, the pattern width is 0.05-0.3 mm, and the cross-section thickness is 0.5-6 mm; 3. The aluminum-based lead alloy / coated carbon fiber powder with cobalt additive / α-PbO2 composite positive grid of claim 1, wherein: The thickness of the zinc-antimony layer (1) is 0.5-3 μm, the thickness of the nano-La2O3-doped nickel underlayer (2) is 3-8 μm, the thickness of the Pb-Sn-Bi-Ag alloy intermediate layer (3) is 0.5-4 mm, and the thickness of the porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer (4) is 0.1-1.0 mm. The specific steps are as follows:

4. The method of making an aluminum-based lead alloy / coated carbon fiber powder with cobalt doping - α-PbO2 composite positive grid according to any one of claims 1 to 3, characterized in that, S1. Preparing aluminum alloy grid immersed with Zn-Sb layer: placing the aluminum alloy grid matrix in an alkaline solution to soak and remove oil, washing with deionized water, then placing in an alkaline zinc-antimony solution to perform a first immersion plating reaction, washing with deionized water, then placing in an HNO3 solution to activate, washing with deionized water, then placing in an alkaline zinc-antimony solution to perform a second immersion plating reaction, washing with deionized water to obtain an aluminum alloy grid immersed with Zn-Sb layer; S2. Preparing aluminum alloy grid with nano-La2O3-doped nickel underlayer: taking the aluminum alloy grid immersed with Zn-Sb layer as cathode and pure nickel plate as anode, performing composite plating in a neutral nickel plating solution, and washing with deionized water to obtain an aluminum alloy grid with nano-La2O3-doped nickel underlayer; S3. Preparing aluminum alloy grid with Pb-Sn-Bi-Ag alloy intermediate layer: taking the aluminum alloy grid with nano-La2O3-doped nickel underlayer as cathode and lead-tin alloy plate as anode, performing electrodeposition in a lead fluoroborate plating solution, and washing with deionized water to obtain an aluminum alloy grid with Pb-Sn-Bi-Ag alloy intermediate layer; ​ S4. Preparation of aluminum alloy grid porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer: the aluminum alloy grid of Pb-Sn-Bi-Ag alloy interlayer is treated by sand blasting, immersed in sodium hydroxide solution for alkali dissolution, washed with deionized water to obtain a porous anode grid, the porous anode grid is used as an anode, a stainless steel plate is used as a cathode, and the porous cobalt-doped carbon fiber powder-α-PbO2 composite active layer of the aluminum alloy grid is obtained by electrodeposition in an alkaline lead plating solution and then washed with deionized water.

5. The preparation method of the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive electrode grid according to claim 4, characterized in that: Step S1. The alkaline solution is a mixed solution of NaOH and Na2CO3, and the concentration of NaOH in the alkaline solution is 10-40 g / L 10-40 g / L, and the concentration of Na2CO3 is 20-40 g / L; The alkaline zinc antimony solution contains 200-400 g / L NaOH, 60-80 g / L ZnO, 30-80 g / L potassium antimony tartrate, 0.5-2 g / L FeCl3, and 1-3 g / L NaNO3; The mass concentration of the HNO3 solution is 20-50%.

6. The preparation method of the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive electrode grid according to claim 4 or 5, characterized in that: Step S1. The oil removal temperature is 60-80°C, and the immersion time is 1-5 min; The temperature of the first immersion plating reaction is 30-50°C, and the time is 10-60 s; The activation time is 10-60 s; The temperature of the second immersion plating reaction is 30-50°C, and the time is 10-30 s.

7. The preparation method of the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive electrode grid according to claim 4, characterized in that: Step S2. The neutral nickel plating solution contains 100-300 g / L nickel sulfate, 10-30 g / L nickel chloride, 100-300 g / L citric acid, 10-60 g / L boric acid, and 5-20 g / L nano La2O3 powder; the pH of the neutral nickel plating solution is 5-7; The cathode current density of the composite plating is 1-5 A / dm2 2 at a temperature of 40-60°C for 5-20 min.

8. The preparation method of the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive electrode grid according to claim 4, characterized in that: Step S3. The lead fluoroborate plating solution contains 100-300 g / L lead acetate, 100-200 g / L fluoroboric acid, 10-30 g / L boric acid, 10-50 g / L stannous fluoroborate, 2-8 g / L bismuth oxide, and 1-3 g / L silver oxide; the pH of the lead fluoroborate plating solution is 1-2; Anodic current density for electrodeposition 1-5 A / dm 2 at a temperature of 30-50 °C for a period of 12-24 h.

9. The preparation method of the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive electrode grid according to claim 4, characterized in that: Step S4. The concentration of the sodium hydroxide solution is 40-100 g / L, the alkali dissolution treatment temperature is 40-60°C, and the time is 4-8 h; Step S4. The alkaline lead plating solution contains 30-60 g / L lead oxide, 100-200 g / L sodium hydroxide, 100-300 g / L potassium sodium tartrate, 10-40 g / L sodium ethylenediaminetetraacetate, and 4-16 g / L cobalt-coated carbon fiber powder; Anodic current density for electrodeposition 1-3 A / dm 2 at a temperature of 40-60 °C for a time of 4-8 h.

10. The preparation method of the aluminum-based lead alloy / cobalt-doped carbon fiber powder-α-PbO2 composite positive electrode grid according to claim 9, characterized in that: The preparation method of the cobalt-coated carbon fiber powder comprises the following specific steps: S41. The carbon fiber is sequentially subjected to a baking glue removal treatment, a nitric acid solution roughening, a stannous chloride-hydrochloric acid sensitization, and a silver citrate colloidal activation to obtain pretreated carbon fiber; S42. The pretreated carbon fiber is placed in a cobalt sulfate plating solution to electrolessly plate cobalt, so as to obtain the cobalt-coated carbon fiber powder; the cobalt sulfate plating solution contains 5-20 g / L of cobalt sulfate, 5-30 g / L of ethylenediaminetetraacetic acid, 5-20 g / L of sodium hydroxide, 0.2-10 mg / L of thiourea, and 5-20 ml / L of formaldehyde.

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