Positive electrode lead paste of lead-sodium storage battery, preparation method of positive electrode lead paste and preparation method of positive electrode plate

Abstract

The invention discloses a lead-sodium storage battery positive electrode lead paste in the technical field of storage batteries. The lead-sodium storage battery positive electrode lead paste comprises the following components in parts by weight: 100 parts of lead oxide powder, 6-10 parts of sulfuric acid, 14-24 parts of deionized water, 0.05-0.07 part of short fibers, 2-8 parts of lead dioxide, 1-2 parts of tetrabasic lead sulfate, 0.5-1.5 parts of calcium sulfate, 0.05-0.15 part of stannous sulfate, 0.05-0.15 part of antimony trioxide, 0.5-1 part of carbon black, 0.1-0.2 part of carboxymethyl cellulose sodium and 0.1-0.5 part of a mixed carbon material. By improving the design of the process, the formation efficiency and low-temperature performance of the storage battery can be effectively improved, and the service life of the storage battery can be effectively prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of storage batteries, and particularly relates to a lead-sodium storage battery. Background Art

[0002] As the core component of a lead-acid storage battery, the performance of the positive electrode plate of a lead-acid storage battery will directly affect the capacity, life, etc. of the battery. Optimizing the positive electrode plate is the key to improving some performances of the battery. During the production process of the storage battery, while ensuring the formation efficiency of the battery, how to reduce the formation power to control the production cost has also been an experimental topic.

[0003] The traditional positive electrode lead paste formula is to dry-mix, water-mix and acid-mix lead oxide powder, sulfuric acid, deionized water, short fibers and additives in a certain proportion with a paste mixer to obtain lead paste, and then fill the lead paste on the positive grid by a pasting machine, and then acid-dip, surface-dry and cure to obtain the positive electrode plate. Additives often use red lead, graphite, etc.; adding red lead to the active material of the positive electrode plate can significantly improve the conversion efficiency of the active material of the positive electrode plate, but the impurities in red lead are uncontrollable, and problems such as poor uniformity and large self-discharge often occur during battery use; although graphite can enhance the conductivity of the electrode plate, the effect of releasing ability under low-temperature conditions is not very obvious. The positive electrode plate additive can also use lead dioxide (referring to the active material of the scrapped positive electrode plate in production), which can improve the formation efficiency, and the self-produced impurities are controllable and can be used instead of red lead; calcium sulfate is beneficial to low-temperature performance, and tetrabasic lead sulfate is beneficial to the cycle life of the electrode plate, but it will increase the formation difficulty. How to solve the mutual restriction between additives and improve the formation efficiency, low-temperature performance and life of the storage battery, so a positive electrode lead paste for a lead-sodium storage battery, its preparation method and a positive electrode plate preparation method are needed to solve the above problems. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention provides a positive electrode lead paste for a lead-sodium storage battery, its preparation method and a positive electrode plate preparation method, which can effectively improve the formation efficiency, low-temperature resistance performance and life of the storage battery.

[0005] The object of the present invention is achieved as follows: A positive electrode lead paste for a lead-sodium storage battery includes the following weight components: 100 parts of lead oxide powder, 6 - 10 parts of sulfuric acid, 14 - 24 parts of deionized water, 0.05 - 0.07 parts of short fibers, 2 - 8 parts of lead dioxide, 1 - 2 parts of tetrabasic lead sulfate, 0.5 - 1.5 parts of calcium sulfate, 0.05 - 0.15 parts of stannous sulfate, 0.05 - 0.15 parts of antimony trioxide, 0.5 - 1 part of carbon black, 0.1 - 0.2 parts of sodium carboxymethyl cellulose, and 0.1 - 0.5 parts of mixed carbon material.

[0006] Further, the oxidation degree of the lead powder is 72 - 80%, and the particle size ≤ 5μm.

[0007] Furthermore, the mixed carbon material includes graphite, acetylene black, and graphene.

[0008] A method for preparing the positive electrode lead paste of a lead - sodium storage battery includes the following steps: Step 1: Premix calcium sulfate, stannous sulfate, and antimony trioxide in proportion to obtain mixture A. Step 2: Add lead dioxide and tribasic lead sulfate to a paste mixer and dry - mix with lead oxide powder in proportion. Step 3: Add mixture A, short fibers in proportion, and the mixed carbon material to the paste mixer and dry - mix with the product of Step 2. Step 4: Add deionized water and sulfuric acid to the paste mixer respectively for water - mixing and acid - mixing to obtain the positive electrode lead paste.

[0009] Furthermore, during the premixing in Step 1, a ball mill is used, the rotation speed of the ball mill is 200 - 300 rpm, and the premixing time is 0.5 - 1 h.

[0010] Furthermore, the dry - mixing time in Step 2 is 1 - 5 min, and the dry - mixing time in Step 3 is 5 - 10 min.

[0011] Furthermore, in Step 4, water - mixing and acid - mixing are carried out with deionized water and sulfuric acid respectively in the paste mixer. The water - adding time is 1 - 3 min, the water - mixing time is 5 - 10 min, the density of the sulfuric acid is 1.4 g / cm 3 , the acid - adding time is 15 - 20 min, and the acid - mixing time is 5 - 10 min.

[0012] A method for preparing the positive electrode plate of a lead - sodium storage battery, using the above - mentioned positive electrode lead paste of the lead - sodium storage battery, includes the following steps: Step 1: Prepare an aqueous solution of carbon black, with the following weight components: 0.5 - 1 part of carbon black, 5 - 10 parts of deionized water, and 0.1 - 0.2 part of thickener. Step 2: Uniformly coat the positive electrode lead paste on the positive electrode alloy grid. Step 3: Spray the aqueous solution of carbon black on the surface of the lead paste, and after acid - spraying and surface drying, carry out a curing treatment to obtain the positive electrode plate.

[0013] Furthermore, the sodium carboxymethyl cellulose is used as the thickener; the dosage of the aqueous solution of carbon black is 10 - 30 mg per gram of lead paste for spraying on both sides, the acid - spraying density is 1.15 g / cm 3 , and the surface drying temperature is 120 - 140 °C.

[0014] Furthermore, the curing and drying treatment process in Step 3 is as follows: Step a: The relative humidity is 95 - 100%, the temperature is 65 - 70 °C, and the controlled time is 4 - 5 h. Step b: The relative humidity is 85 - 90%, the temperature is 70 - 76°C, and the controlled duration is 6 - 8 h; Step c: The relative humidity is 85 - 90%, the temperature is 50 - 55°C, and the controlled duration is 16 - 18 h; Step d: The relative humidity is 5 - 20%, the temperature is 75 - 80°C, and the controlled duration is 30 - 32 h.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Calcium sulfate, stannous sulfate, and antimony trioxide are premixed to obtain mixture A, achieving physical chimerism. The powder particles are of uniform size, ensuring that the ground mixture can be evenly distributed in the active material during pasting. At the same time, the particles of calcium sulfate become smaller, reducing its impact on the formation efficiency, thereby exerting its effect on the low-temperature performance of the battery; Lead dioxide replaces red lead, solving the problems brought by the purity of red lead to the battery and improving the formation efficiency; Lead dioxide and tetrabasic lead sulfate are first dry-mixed with lead oxide powder, effectively achieving uniform distribution; The carbon black aqueous solution is sprayed on the surface of the positive plate, which can effectively increase the initial conductivity of the plate, and the large-current discharge performance at low temperature is more obvious. In summary, through the design improvement of the process, the present invention can effectively improve the formation efficiency, low-temperature performance, and lifespan of the battery. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0017] Figure 1 It is a schematic diagram of the discharge of the embodiments and comparative examples of the present invention under low-temperature conditions of the battery.

[0018] Figure 2 It is a schematic diagram of the discharge of the embodiments and comparative examples of the present invention under normal-temperature conditions of the battery.

[0019] Figure 3 It is a cyclic life curve graph of the embodiments and comparative examples of the present invention applied to the battery. Detailed Embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0021] Example 1 A preparation method of a positive electrode plate for a lead - sodium storage battery, comprising: S1. Prepare positive electrode lead paste.

[0022] The positive electrode lead paste includes 100 parts of lead oxide powder, 6 parts of sulfuric acid, 14 parts of deionized water, 0.05 part of short fiber, 2 parts of lead dioxide, 1 part of tribasic lead sulfate, 0.5 part of calcium sulfate, 0.05 part of stannous sulfate, 0.05 part of antimony trioxide, 0.5 part of carbon black, 0.1 part of sodium carboxymethyl cellulose, and 0.1 part of mixed carbon material.

[0023] Specifically, the oxidation degree of the lead oxide powder is 72%, the particle size is 2 - 3μm, and the mixed carbon material is 0.05 of graphite, 0.025 of acetylene black, and 0.025 of graphene.

[0024] The steps for preparing the positive electrode lead paste are as follows: S1 - 1. According to the above ratio, premix 0.5 part of calcium sulfate, 0.05 part of stannous sulfate, and 0.05 part of antimony trioxide through a ball mill. The rotation speed of the ball mill is 200 rpm, and the premixing time is 1 h; S1 - 2. According to the above ratio, add 2 parts of lead dioxide and 1 part of tribasic lead sulfate to a paste mixer and dry - mix with the lead oxide powder for 1 min; S1 - 3. Add the product of S1 - 1, 0.05 part of short fiber, and 0.1 part of mixed carbon material to the paste mixer and dry - mix with the lead powder for 5 min; S1 - 4. In the paste mixer, conduct water mixing and acid mixing with deionized water and sulfuric acid respectively. The water - adding time is 1 min, the water - mixing time is 5 min, the density of sulfuric acid is 1.4 g / cm3, the acid - adding time is 15 min, and the acid - mixing time is 5 min, thereby obtaining the positive electrode lead paste.

[0025] S2. Prepare the positive electrode plate. The positive electrode plate includes positive electrode lead paste and a positive electrode grid.

[0026] The steps for preparing the positive electrode plate are as follows: Step 2 - 1. Prepare an aqueous solution of carbon black, with the following weight components: 0.5 part of carbon black, 5 parts of deionized water, and 0.1 part of thickener sodium carboxymethyl cellulose; Step 2 - 2. Uniformly apply the positive electrode lead paste prepared in S1 to the positive electrode alloy grid; Step 2 - 3. Spray the aqueous solution of carbon black on the surface of the lead paste. After acid drenching and surface drying, conduct a curing treatment to obtain the positive electrode plate. The dosage of the aqueous solution of carbon black is 10 mg per gram of lead paste for spraying on both sides. The density of acid drenching is 1.15 g / cm3, and the surface drying temperature is 120°C.

[0027] Specifically, the curing and drying treatment process is as follows: Step 1: The relative humidity is 95 - 100%, the temperature is 70 °C, and the controlled duration is 4 h; Step 2: The relative humidity is 85 - 90%, the temperature is 76 °C, and the controlled duration is 8 h; Step 3: The relative humidity is 85 - 90%, the temperature is 55 °C, and the controlled duration is 18 h; Step 4: The relative humidity is 5 - 20%, the temperature is 80 °C, and the controlled duration is 30 h.

[0028] Example 2 A preparation method of a positive plate of a lead - sodium storage battery, comprising: S1. Prepare positive - electrode lead paste.

[0029] The positive - electrode lead paste includes 100 parts of lead oxide powder, 8 parts of sulfuric acid, 19 parts of deionized water, 0.06 part of short fiber, 5 parts of lead dioxide, 1.5 parts of tribasic lead sulfate, 1 part of calcium sulfate, 0.1 part of stannous sulfate, 0.1 part of antimony trioxide, 0.75 part of carbon black, 0.15 part of sodium carboxymethyl cellulose, and 0.3 part of mixed carbon material.

[0030] Specifically, the oxidation degree of the lead oxide powder is 76%, the particle size is 3 - 4 μm, and the mixed carbon material is 0.2 of graphite, 0.05 of acetylene black, and 0.05 of graphene.

[0031] The steps for preparing the positive - electrode lead paste are as follows: S1 - 1. According to the above ratio, premix 1 part of calcium sulfate, 0.1 part of stannous sulfate, and 0.1 part of antimony trioxide by a ball mill, with the ball - mill rotation speed of 250 rpm and the premixing time of 45 min; S1 - 2. According to the above ratio, add 5 parts of lead dioxide and 1.5 parts of tribasic lead sulfate to a paste - mixing machine and dry - mix with the lead oxide powder for 3 min; S1 - 3. Add the product of S1 - 1, 0.06 part of short fiber, and 0.3 part of mixed carbon material to the paste - mixing machine and dry - mix with the lead powder for 7.5 min; S1 - 4. Conduct water - mixing and acid - mixing with deionized water and sulfuric acid respectively in the paste - mixing machine. The water - adding time is 2 min, the water - mixing time is 7.5 min, the density of sulfuric acid is 1.4 g / cm3, the acid - adding time is 17.5 min, and the acid - mixing time is 7.5 min, thereby obtaining the positive - electrode lead paste.

[0032] S2. Prepare the positive plate, and the positive plate includes the positive - electrode lead paste and the positive - plate grid.

[0033] The steps for preparing the positive plate are as follows: Step 2 - 1. Prepare an aqueous solution of carbon black, with the following weight components: 0.75 part of carbon black, 7.5 parts of deionized water, and 0.15 part of thickener sodium carboxymethyl cellulose; Step 2-2: Uniformly apply the positive electrode lead paste prepared in S1 onto the positive electrode alloy grid; Step 2-3: Spray an aqueous carbon black solution on the surface of the lead paste. After acid drenching and surface drying, perform a curing treatment to obtain the positive electrode plate. The dosage of the aqueous carbon black solution is 20 mg per gram of lead paste for spraying on both sides. The acid drenching density is 1.15 g / cm3, and the surface drying temperature is 130 °C.

[0034] Specifically, the curing and drying treatment process is as follows: Step 1: The relative humidity is 95 - 100%, the temperature is 67 °C, and the controlled duration is 4.5 h; Step 2: The relative humidity is 85 - 90%, the temperature is 73 °C, and the controlled duration is 7 h; Step 3: The relative humidity is 85 - 90%, the temperature is 53 °C, and the controlled duration is 17 h; Step 4: The relative humidity is 5 - 20%, the temperature is 78 °C, and the controlled duration is 31 h.

[0035] Example 3 A preparation method for the positive electrode plate of a lead-sodium storage battery, including: S1: Prepare the positive electrode lead paste.

[0036] The positive electrode lead paste includes 100 parts of lead oxide powder, 10 parts of sulfuric acid, 24 parts of deionized water, 0.07 part of short fiber, 8 parts of lead dioxide, 2 parts of tribasic lead sulfate, 1.5 parts of calcium sulfate, 0.15 part of stannous sulfate, 0.15 part of antimony trioxide, 1 part of carbon black, 0.2 part of sodium carboxymethyl cellulose, and 0.5 part of mixed carbon material.

[0037] Specifically, the oxidation degree of the lead oxide powder is 80%, the particle size is 4 - 5 μm, and the mixed carbon material is 0.3 of graphite, 0.1 of acetylene black, and 0.1 of graphene.

[0038] The steps for preparing the positive electrode lead paste are as follows: S1-1: According to the above ratio, premix 1.5 parts of calcium sulfate, 0.15 part of stannous sulfate, and 0.15 part of antimony trioxide through a ball mill. The ball mill rotation speed is 300 rpm, and the premixing time is 0.5 h; S1-2: According to the above ratio, add 8 parts of lead dioxide and 2 parts of tribasic lead sulfate to the paste mixer and perform dry mixing with the lead oxide powder for 5 min; S1-3: Add the product of S1-1, 0.07 part of short fiber, and 0.5 part of mixed carbon material to the paste mixer and perform dry mixing with the lead powder for 10 min; S1-4: Perform water mixing and acid mixing with deionized water and sulfuric acid respectively in the paste mixer. The water addition time is 3 min, the water mixing time is 10 min, the sulfuric acid density is 1.4 g / cm3, the acid addition time is 20 min, and the acid mixing time is 10 min, thereby obtaining the positive electrode lead paste.

[0039] Prepare the positive electrode plate, which includes positive electrode lead paste and a positive electrode grid.

[0040] The steps for preparing the positive electrode plate are as follows: Step 2-1: Prepare an aqueous solution of carbon black with the following weight components: 1 part of carbon black, 10 parts of deionized water, and 0.2 part of sodium carboxymethyl cellulose as a thickening agent; Step 2-2: Evenly apply the positive electrode lead paste prepared in S1 to the positive electrode alloy grid; Step 2-3: Spray the aqueous solution of carbon black on the surface of the lead paste. After acid drenching and surface drying, perform a curing treatment to obtain the positive electrode plate. The dosage of the aqueous solution of carbon black is 20 mg per gram of lead paste for spraying on both sides. The acid drenching density is 1.15 g / cm3, and the surface drying temperature is 140 °C.

[0041] Specifically, the curing and drying treatment process is as follows: Step 1: The relative humidity is 95 - 100%, the temperature is 65 °C, and the controlled duration is 5 h; Step 2: The relative humidity is 85 - 90%, the temperature is 70 °C, and the controlled duration is 6 h; Step 3: The relative humidity is 85 - 90%, the temperature is 50 °C, and the controlled duration is 18 h; Step 4: The relative humidity is 5 - 20%, the temperature is 75 °C, and the controlled duration is 32 h.

[0042] Comparative example The positive electrode lead paste includes 100 parts of lead oxide powder, 8 parts of sulfuric acid, 12 parts of deionized water, 0.06 part of short fiber, 0.1 part of stannous sulfate, 0.1 part of antimony trioxide, and 0.3 part of graphite. The oxidation degree of the lead powder is 76%, and the particle size is 3 - 4 μm.

[0043] The steps for preparing the positive electrode lead paste are as follows: According to the ratio, add 0.06 part of short fiber, 0.1 part of stannous sulfate, 0.1 part of antimony trioxide, and 0.3 part of graphite to a paste mixer and perform dry mixing with the lead powder for 7.5 min; perform water mixing and acid mixing with deionized water and sulfuric acid respectively in the paste mixer. The water addition time is 2 min, the water mixing time is 7.5 min, the sulfuric acid density is 1.4 g / cm3, the acid addition time is 17.5 min, and the acid mixing time is 7.5 min.

[0044] The steps for preparing the positive electrode plate are as follows: Evenly apply the prepared positive electrode lead paste to the positive electrode alloy grid. After acid drenching and surface drying, perform a curing treatment to obtain the positive electrode plate. Among them, the acid drenching density is 1.15 g / cm3, and the surface drying temperature is 130 °C.

[0045] The solidification and drying treatment process is as follows: Step 1, relative humidity is 95 - 100%, temperature is 70°C, and the controlled duration is 4h; Step 2, relative humidity is 85 - 90%, temperature is 50°C, and the controlled duration is 30h; Step 3, relative humidity is 5 - 20%, temperature is 75°C, and the controlled duration is 30h.

[0046] For the above positive electrode plate Examples 1, 2, 3 and the comparative example, under the condition that the plate ratio, separator and battery case are exactly the same, acid filling and formation are carried out to make a storage battery. The following test methods are adopted: Test method for lead dioxide content: After the in - formation battery is dissected after formation, according to the lead dioxide content determination method in 6.4.1 of GB / T 23636 - 2017.

[0047] 10 - hour rate capacity test: After the fully charged storage battery, within 1h - 24h after the end of charging, discharge with a current of I10 (A), and the temperature around the storage battery is kept between 20 - 25°C. During the discharge time, the change in the current value should not be greater than 1%. When the single - cell voltage of the storage battery reaches 1.80V, stop discharging and record the discharge time, and calculate the discharge capacity.

[0048] -40°C low - temperature capacity test: Place the fully charged storage battery in an environment of -40°C ± 2°C and let it stand for 20h, and discharge the storage battery with a current of I10 (A). During the discharge process, the temperature around the storage battery is kept between -40°C ± 2°C, and the change in the current value should not be greater than 1%. When the single - cell voltage of the storage battery reaches 1.80V, stop discharging and record the discharge time, and calculate the discharge capacity.

[0049] Cycle life test: Keep the temperature around the storage battery between 20 - 25°C. a) Discharge with a current of I10 (A) until the single - cell voltage of the storage battery reaches 1.80V; b) Limit the voltage to 2.35V / cell and charge with 2.5I10 (A) for 12h; c) Repeat steps a) and b). (When the discharge time in step a is less than 8 hours, the life test terminates).

[0050] As can be seen from the above, as Figures 1-3 shown, by comparing the solutions of Examples 1 - 3 with the comparative example, the lead dioxide content in the positive electrode plate does not cause poor formation problems due to the addition of calcium sulfate, achieving the same effect as the comparative example. At the same time, it can be concluded that its low - temperature performance and cycle life are better. The components of the present invention are simple, the production cost is relatively low, the positive electrode plate prepared has good low - temperature resistance performance and cycle life, and has a wide application range.

[0051] The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A lead paste for positive electrode of a lead-sodium battery, characterized in that: The invention comprises the following components by weight: 100 parts of lead oxide powder, 6-10 parts of sulfuric acid, 14-24 parts of deionized water, 0.05-0.07 parts of short fibers, 2-8 parts of lead dioxide, 1-2 parts of tetrabasic lead sulfate, 0.5-1.5 parts of calcium sulfate, 0.05-0.15 parts of stannous sulfate, 0.05-0.15 parts of antimony trioxide, 0.5-1 parts of carbon black, 0.1-0.2 parts of sodium hydroxymethyl cellulose and 0.1-0.5 parts of mixed carbon materials.

2. The positive electrode lead paste for lead-sodium storage battery according to claim 1, characterized in that: The lead powder has an oxidation degree of 72-80% and a particle size of ≤5 μm.

3. The positive electrode lead paste for lead-sodium storage battery according to claim 1 or 2, characterized in that: The mixed carbon material includes graphite, acetylene black and graphene.

4. A method for preparing a positive electrode lead paste for a lead-sodium battery as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: premix calcium sulfate, stannous sulfate and antimony trioxide according to a proportion to obtain a mixture A; Step 2: Add lead dioxide and tetrabasic lead sulfate into a paste mixer and dry mix with lead oxide powder according to the proportion; Step 3, adding mixture A, short fibers and mixed carbon materials in proportion into a paste mixer and dry mixing with the product of step 2; Step 4: Add deionized water and sulfuric acid into a paste mixing machine, mix them with water and acid, and prepare positive electrode lead paste.

5. The method for preparing the positive lead paste for lead-sodium storage battery according to claim 4, characterized in that: In step 1, a ball mill is used for premixing, the speed of the ball mill is 200-300 rpm, and the premixing time is 0.5-1 h.

6. The method for preparing the positive lead paste for lead-sodium storage battery according to claim 4 or 5, characterized in that: The dry mixing time in step 2 is 1 to 5 minutes, and the dry mixing time in step 3 is 5 to 10 minutes.

7. The method for preparing the positive lead paste for lead-sodium storage battery according to claim 4 or 5, characterized in that: In step 4, deionized water and sulfuric acid are mixed with water and acid in a paste mixer, respectively, the water adding time is 1-3 minutes, the water mixing time is 5-10 minutes, and the density of the sulfuric acid is 1.4 g / cm 3 , acid adding time is 15~20min, and acid mixing time is 5~10min.

8. A method for preparing a positive plate of a lead-sodium battery, using the positive lead paste for a lead-sodium battery according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1, prepare a carbon black aqueous solution according to the following weight components: 0.5-1 part of carbon black, 5-10 parts of deionized water, and 0.1-0.2 parts of sodium hydroxymethyl cellulose; Step 2, evenly apply the positive electrode lead paste to the positive electrode alloy grid; Step 3: spray a carbon black aqueous solution on the surface of the lead paste, and then perform a curing treatment after acid rinsing and surface drying to obtain a positive electrode plate.

9. The method for preparing a positive plate for a lead-sodium battery according to claim 8, characterized in that: The sodium hydroxymethyl cellulose is a thickener; the amount of the carbon black aqueous solution is 10-30 mg per gram of lead paste for spraying on both sides, and the acid spraying density is 1.15 g / cm 3 , the surface drying temperature is 120~140℃.

10. The method for preparing a positive plate for a lead-sodium battery according to claim 8 or 9, characterized in that: The curing and drying process in step 3 is as follows: Step a, relative humidity is 95-100%, temperature is 65-70°C, and control time is 4-5h; Step b, relative humidity is 85-90%, temperature is 70-76°C, and control time is 6-8h; Step c, relative humidity is 85-90%, temperature is 50-55°C, and control time is 16-18h; Step d: relative humidity is 5-20%, temperature is 75-80°C, and control time is 30-32 hours.

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