An energy storage battery and its preparation method

Abstract

This invention discloses an energy storage battery and its preparation method, relating to the field of lead-acid battery manufacturing technology. The energy storage battery includes a positive electrode grid, positive electrode lead paste, a negative electrode grid, and a negative electrode lead paste. The key to the method of combining the positive and negative electrode lead pastes lies in (1) adjusting the sulfuric acid solution content; and (2) adding sulfuric acid solution to control the temperature. This invention uses the method of adjusting the acid content to produce a high apparent density lead paste, thereby reducing the porosity of the lead paste to ensure the strength of the PAM and NAM framework. Under low porosity conditions, a certain amount of 4BS is generated during the high-temperature paste-combining process to ensure favorable diffusion of the battery electrolyte, thus ensuring the battery's cycle life.

Description

Technical Field

[0001] This invention relates to the field of lead-acid battery manufacturing technology, specifically to an energy storage battery and its preparation method. Background Technology

[0002] In recent years, with the rapid development of lithium batteries, the market space for lead-acid batteries has been squeezed. However, lead-acid batteries still have a place in the energy storage field due to their advantages such as stable voltage characteristics, wide temperature range, large single-cell capacity, high safety, abundant and renewable raw materials, easy recycling, and low price. In particular, compared with lithium iron phosphate batteries used in electrochemical energy storage, lead-acid batteries for energy storage mainly lag behind lithium iron phosphate batteries in terms of cycle life.

[0003] Generally, the apparent density of the positive and negative plates of an energy storage battery is 4.1-4.6 g / cm³. 3 With a porosity of over 50%, high porosity in lead paste can improve the utilization rate of active substances after formation, but it is also a double-edged sword. The higher the porosity, the worse the strength of the lead paste. During the paste preparation process, the dry-mixed lead powder is often stirred with water. Water acts as an unstable microporous fusing agent, forming a temporary water film between PbO particles, causing the PbO particles to adhere to each other. However, this adhesion is not stable. During the curing process, this water film evaporates when heated, forming some micropores in the lead paste. At the same time, during the curing process, PbSO4, 3BS, or 4BS crystals form a solid basic framework for curing the lead paste. This framework is a strong porous material, and fixed, long-term pores are generated inside the framework. These pores support the conversion of battery lead paste into active materials (positive electrode active material PAM and negative electrode active material NAM) and accompany the entire battery cycle. The various "pores" in the active material are channels for the electrolyte to enter the active material of the plates. Maintaining a high porosity can ensure that the positive and negative electrode active materials participate in the reaction, but it will also reduce the strength of the PAM or NAM framework, leading to the collapse of the framework, ultimately causing the active material to soften and the battery to fail.

[0004] Therefore, the higher the apparent density and the lower the porosity of the lead paste, the fewer the pores, and the higher the skeleton strength of the lead paste. The usual method is to control the apparent density of the lead paste by adjusting the water content during the paste mixing process; the less water added to a unit of lead powder, the higher the apparent density of the lead powder.

[0005] However, from the perspective of its influence on the apparent density of lead paste, in a lead paste system composed of lead powder, water, sulfuric acid, and additives, the components influence and interact with each other. Water has the lowest density compared to the other components. If water accounts for 11%-14% of the system's mass percentage, it accounts for over 50% of the system's volume percentage, even approaching 60%. Its volume to mass percentage ratio in the system is approximately 4:1. Therefore, water has the most significant impact on apparent density. Using the penetration value as a measure of lead paste's softness, generally, lead paste can be filled within a penetration value range of 26±6mm. As the amount of water added decreases, the apparent density of the lead paste increases significantly, but the penetration value decreases significantly, meaning the lead paste becomes noticeably harder. When the amount of water added to the lead powder is less than 140g / kg, the apparent density can be higher than 4.4g / cm³, but the penetration value is already below 20mm. At this point, the lead paste is quite hard and difficult to fill; therefore, simply reducing the amount of water added during the paste-making process cannot be used to produce high-apparent-density lead paste. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an energy storage battery and its preparation method.

[0007] By adjusting the acid content, as the acid content of the lead paste increases, the content of basic lead sulfate in the lead paste also increases. This increase in basic lead sulfate content inevitably affects the penetration of the lead paste. Increased acid content also improves the quality of the lead paste. Among the various raw materials for the compound paste, the density of PbO is 9.6 g / cm³. 3 The density of 3BS is 6.5 g / cm³. 3 The density of 4BS is 6.92 g / cm³. 3 During the paste preparation process, water and dilute sulfuric acid are added to the lead powder (mainly PbO, with a small amount of lead) and the formulation mixture. The denser PbO is converted into the relatively less dense 3BS and 4BS, thus changing the density of the lead paste. This demonstrates that changes in the acid content of the lead paste affect its apparent density. As the acid content increases, the penetration value decreases, and the lead paste hardens. Conversely, reducing the acid content increases the penetration value, softens the lead paste, and facilitates filling. Simultaneously, by reducing the acid content of the lead paste, a certain penetration value is maintained while ensuring the filling effect of the lead paste during the coating process.

[0008] In other words, the amount of sulfuric acid added during the paste preparation process determines the amount of 3BS or 4BS generated. The amount of 3BS or 4BS is directly proportional to the number of micropores and mesopores in the generated lead paste. Controlling the amount of sulfuric acid added to the paste plays a decisive role in the porosity of the resulting lead paste, thereby ensuring the strength of the PAM skeleton and avoiding battery failure due to softening of active materials, thus extending the cycle life of the battery.

[0009] Under the premise of low porosity, this invention utilizes the generation of more 4BS within the positive lead paste to ensure the specific pore volume of the lead paste, thereby ensuring that the electrolyte enters the lead paste through the pores during formation and cycling to participate in the reaction of the active materials. Therefore, under low porosity conditions, using a higher pore volume to ensure electrolyte diffusion has a positive effect on battery discharge. This invention also utilizes the generation of a certain amount of 4BS during the paste preparation and curing processes under low porosity conditions to ensure that electrolyte diffusion is facilitated.

[0010] After the paste-making process, the lead paste was analyzed by XRD. Different ratios of sulfuric acid and lead powder (LO) produced different products. At temperatures above 70°C, the lead paste prepared with 4%-6% sulfuric acid was mainly 4BS. Moreover, the process objective of this invention also requires a low H2SO4 / LO ratio to ensure the porosity of the lead paste, thus unifying the two process objectives.

[0011] This invention provides a method for manufacturing an energy storage battery, the energy storage battery comprising a positive electrode plate and a negative electrode plate, the positive electrode plate comprising a positive electrode grid and positive electrode lead paste, and the negative electrode plate comprising a negative electrode grid and negative electrode lead paste.

[0012] The positive electrode lead paste formula, by weight, includes:

[0013]

[0014] The preparation method of positive electrode lead paste includes the following steps:

[0015] (1) Dry mixing and wet mixing: After dry mixing of lead powder, 4BS seed crystal, stannous sulfate, conductive graphite, red lead and short fiber, deionized water is added for wet mixing;

[0016] (2) When adding sulfuric acid solution, stop cooling. When the temperature inside the paste mixing cylinder of the paste mixing machine reaches 73℃, begin cooling. Mix thoroughly to obtain positive electrode lead paste. The apparent density of the positive electrode lead paste is 4.8-4.9 g / cm³. 3 ;

[0017] The negative electrode lead paste formula, by weight, includes:

[0018]

[0019]

[0020] The preparation method of negative electrode lead paste includes the following steps:

[0021] (I) Dry mixing and wet mixing: After dry mixing lead powder, BaSO4, conductive graphite, carbon materials, sodium lignosulfonate and short fibers, deionized water is added for wet mixing;

[0022] (II) When adding sulfuric acid solution, cooling begins when the temperature inside the mixing cylinder of the paste mixing machine reaches 60℃. The paste is then mixed thoroughly to obtain negative electrode lead paste, with an apparent density of 4.90-4.98 g / cm³. 3 .

[0023] Preferably, the carbon material in the negative electrode lead paste formulation is carbon nanotube, carbon fiber, activated carbon, graphene, or carbon black.

[0024] Specifically, the steps in step (2) include:

[0025] When adding sulfuric acid solution, turn off the water cooling and negative pressure ventilation cooling in the paste mixing machine, so that the temperature inside the paste mixing cylinder of the paste mixing machine rises to a range of above 70℃ but below 73℃, and maintains this temperature for more than 5 minutes. When the temperature reaches 73℃, turn on the water cooling and negative pressure ventilation cooling in the paste mixing machine, stir for 8 minutes, and then discharge the lead paste.

[0026] 4BS is generated from 3BS during the paste preparation and curing process. During paste preparation, lead powder (LO) and water are wet-stirred and then mixed with sulfuric acid solution to initially form 3BS. However, the conversion temperature from 3BS to 4BS is found above 70°C. Therefore, the paste preparation method of this invention employs a high-temperature method. Due to the short paste preparation time, 3BS is thermodynamically stable below 80°C, resulting in a small amount of 4BS generated, and the generated 4BS particles are irregular in size and have poor consistency. Therefore, a certain amount of 4BS powder with a length less than 5μm and a particle size no greater than 2μm is added as seed crystals, acting as nuclei or crystal initiators. These small-diameter 4BS nuclei gradually grow during paste preparation until curing, generating 4BS particles with a length of 15-25μm and a diameter of 3-5μm, optimal for battery formation. The nuclei are evenly distributed during paste preparation, and during subsequent curing, the generated 4BS particles are replicated according to the particle size of the nuclei acting as "templates," producing 4BS particles of similar length and size.

[0027] Preferably, the time for adding the sulfuric acid solution is not less than 12 minutes.

[0028] Specifically, the specific steps in step (II) include:

[0029] When adding sulfuric acid solution, when the temperature inside the paste mixing cylinder of the paste mixing machine rises to 60℃, turn on the water cooling and negative pressure ventilation of the paste mixing machine, and then discharge the lead paste after stirring for 8 minutes.

[0030] Preferably, the time for adding sulfuric acid solution is not less than 12 minutes.

[0031] Preferably, the oxidation degree of the lead powder is 72-78%.

[0032] Preferably, in steps (2) and (II), the lead paste is applied to the electrode plate under the condition that the system temperature is 45-50℃.

[0033] Preferably, the amount of sulfuric acid solution added is 4%-6% of the lead powder content.

[0034] Different ratios of sulfuric acid and lead powder (LO) produce different products. Lead paste prepared at temperatures above 70°C with an addition of 4%-6% sulfuric acid is mainly 4BS.

[0035] The present invention also provides an energy storage battery prepared by the above preparation method.

[0036] The beneficial effects of this invention are:

[0037] (1) This invention manufactures high apparent density lead paste by controlling the amount of acid added during the paste mixing process to ensure low porosity, thereby ensuring the strength of the PAM / NAM skeleton and preventing premature collapse of the PAM / NAM skeleton during long-term cycling, which would lead to the failure of the active material. In addition, the battery assembled with the green plate prepared by the high-temperature paste mixing method promotes the softening time of the positive electrode active material of the battery by greatly delaying the softening time of the positive electrode active material in terms of PAM skeleton, porosity to ensure electrolyte diffusion, and lead paste phase composition, thereby ensuring the cycle life of the battery.

[0038] (2) The raw lead paste produced by this invention has a porosity of about 38%-41%, a 4BS content of more than 30%, good bonding between the lead paste and the grid, and a free lead content of less than 3%. Detailed Implementation

[0039] Example 1

[0040] (1) Preparation of positive electrode lead paste.

[0041] The composition is as follows: 100 kg of lead powder (oxidation degree 72%-78%), 1 kg of 4BS seed crystals, 0.25 kg of stannous sulfate, 0.3 kg of conductive graphite, 1 kg of red lead, and 0.15 kg of short fibers.

[0042] Place the above components into the hopper of the paste mixing machine and dry mix for 5 minutes. Add 12.8 kg of deionized water and wet mix for 5 minutes. Then slowly add 4.2 kg of dilute sulfuric acid (density 1.4 g / cm³). 3Turn off the water cooling and negative pressure exhaust cooling in the paste mixing machine. When the temperature inside the cylinder reaches 73℃, turn on the water cooling and negative pressure exhaust cooling. The highest temperature inside the paste mixing cylinder reaches 75℃ (heat is continuously released during the formation of lead sulfate, and the thermal inertia during the paste mixing process causes the temperature inside the paste mixing cylinder to continue to rise). Maintain the high-temperature paste mixing process for 5 minutes, and add sulfuric acid for 12 minutes. After adding acid, stir the lead paste in the hopper for 8 minutes before discharging. The temperature of the paste at the discharge point is 45℃. Before discharging, turn off the paste mixing machine and check the apparent density of the lead paste. The apparent density of the lead paste is 4.87 g / cm³. 3 The lead paste penetration was tested and found to be 29 mm, which is suitable for coating.

[0043] After the lead paste is applied to the electrode plates using a coating machine, the plates are suspended on drying racks and placed into a curing chamber for curing. A high-temperature curing process is used to obtain the positive electrode plate. The high-temperature curing process parameters are shown in Table 1.

[0044] Table 1

[0045]

[0046] After the electrode plates were cured at high temperature, samples were taken and XRD analysis was performed using a Bruker X-ray diffractometer. The results are shown in Table 2, and the 4BS content was found to be 33.9%.

[0047] The porosity of the lead paste on the positive electrode plate after curing was measured using the mercury porosimetry method, and it was found to be 39.4%.

[0048] (2) Preparation of negative electrode lead paste.

[0049] The components are: 100 kg of lead powder (oxidation degree 72%-78%), 0.6 kg of BaSO4, 0.25 kg of conductive graphite, 0.46 kg of carbon black, 0.3 kg of sodium lignosulfonate, and 0.12 kg of short fibers.

[0050] Place the above components into the hopper of the paste mixing machine and dry mix for 5 minutes. Then add 12.7 kg of deionized water and wet mix for 5 minutes. After that, slowly add 3.6 kg of dilute sulfuric acid (density 1.4 g / cm³). 3 When the temperature inside the mixing tank of the paste mixing machine reaches 60℃, turn on the negative pressure fan and cooling circulating water. Add sulfuric acid for 12 minutes, then stir for 8 minutes after acid addition before removing the paste from the heat. The outlet temperature is 45℃. Before removing the paste, turn off the paste mixing machine and check the apparent density. The apparent density of the lead paste is 4.93 g / cm³. 3 The lead paste penetration was tested and found to be 30 mm, which is suitable for coating.

[0051] After the lead paste is applied to the electrode plates by the coating machine, the plates are suspended on the drying rack and placed into the curing chamber for curing. The medium-temperature curing process is used, and the process parameters are shown in Table 3.

[0052] Table 2

[0053]

[0054]

[0055] Table 3

[0056]

[0057] The porosity of the lead paste on the cured raw electrode plate was measured to be 38.2% using the mercury porosimetry method.

[0058] Example 2

[0059] (1) Preparation of positive electrode lead paste.

[0060] The composition is as follows: 100 kg of lead powder (oxidation degree 72%-78%), 1 kg of 4BS seed crystals, 0.25 kg of stannous sulfate, 0.3 kg of conductive graphite, 1 kg of red lead, and 0.15 kg of short fibers.

[0061] Place the above components into the hopper of the paste mixing machine and dry mix for 5 minutes. Add 12.4 kg of deionized water and wet mix for 5 minutes. Then slowly add 5 kg of dilute sulfuric acid (density 1.4 g / cm³). 3 Turn off the water cooling and negative pressure exhaust cooling in the paste mixing machine. When the temperature inside the cylinder reaches 73℃, turn on the water cooling and negative pressure exhaust cooling. The highest temperature inside the paste mixing cylinder reaches 75℃. Maintain the high-temperature paste mixing process for 5 minutes, and add sulfuric acid for 12 minutes. After adding acid, stir the lead paste in the hopper for 8 minutes before discharging to ensure the paste discharge temperature is 45℃. Before discharging, turn off the paste mixing machine and check the apparent density of the lead paste. The apparent density of the lead paste is 4.80 / cm³. 3 The lead paste penetration was tested and found to be 28 mm, which is suitable for coating.

[0062] After the lead paste is applied to the electrode plates using a coating machine, the plates are suspended on drying racks and placed into a curing chamber for curing. A high-temperature curing process is used to obtain the positive electrode plate. The high-temperature curing process parameters are shown in Table 1.

[0063] After the electrode plate was cured at high temperature, a sample was taken and XRD was performed using a Bruker X-ray diffractometer. The results are shown in Table 2, and the 4BS content was found to be 33%.

[0064] The lead paste of the positive electrode plate after curing was measured using the mercury intrusion porosimetry method, and the porosity of the lead paste was 41%.

[0065] (2) Preparation of negative electrode lead paste.

[0066] The components are: 100 kg of lead powder (oxidation degree 72%-78%), 0.6 kg of BaSO4, 0.25 kg of conductive graphite, 0.46 kg of activated carbon, 0.3 kg of sodium lignosulfonate, and 0.12 kg of short fibers.

[0067] Place the above components into the hopper of the paste mixing machine and dry mix for 5 minutes. Then add 12.7 kg of deionized water and wet mix for 5 minutes. After that, slowly add 3.6 kg of dilute sulfuric acid (density 1.4 g / cm³). 3 When the temperature inside the mixing tank of the paste mixing machine reaches 60℃, turn on the negative pressure fan and cooling circulating water. Add sulfuric acid for 12 minutes, then stir for 8 minutes after acid addition before removing the paste from the heat. The outlet temperature is 50℃. Before removing the paste, turn off the paste mixing machine and check the apparent density of the lead paste. The apparent density of the lead paste is 4.93 g / cm³. 3 The lead paste penetration was tested and found to be 30 mm, which is suitable for coating.

[0068] After the lead paste is applied to the electrode plates by the coating machine, the plates are suspended on the drying rack and placed into the curing chamber for curing. The medium-temperature curing process is used, and the process parameters are shown in Table 3.

[0069] The porosity of the lead paste on the cured raw electrode plate was measured to be 38.2% using the mercury porosimetry method.

[0070] Comparative Example 1

[0071] (1) Preparation of positive electrode lead paste.

[0072] The composition is as follows: 100 kg of lead powder (oxidation degree 72%-78%), 1 kg of 4BS seed crystals, 0.25 kg of stannous sulfate, 0.3 kg of conductive graphite, 1 kg of red lead, and 0.15 kg of short fibers.

[0073] Place the above components into the hopper of the paste mixing machine and dry mix for 5 minutes to ensure that all components in the additive are evenly distributed in the lead powder. Then add 13 kg of deionized water and wet mix for 5 minutes. After wet mixing, slowly add 6.1 kg of dilute sulfuric acid (density 1.4 g / cm³). 3 Turn off the water cooling and negative pressure exhaust cooling in the paste mixing machine. When the temperature inside the cylinder reaches 73℃, turn on the water cooling and negative pressure exhaust cooling. The highest temperature inside the paste mixing cylinder reaches 75℃. Maintain this high temperature for 5 minutes, then add sulfuric acid for 12 minutes. After adding the acid, stir the lead paste in the hopper for 8 minutes before discharging. The temperature of the paste at the discharge point is 45℃. Before discharging, turn off the paste mixing machine and check the apparent density of the lead paste. The apparent density of the lead paste is 4.48 g / cm³. 3 The lead paste penetration was tested and found to be 29 mm, which is suitable for coating.

[0074] After the lead paste is applied to the electrode plates by the coating machine, it is suspended on the drying rack and placed into the curing chamber for curing. The curing process is carried out using high temperature curing, and the process parameters for high temperature curing are shown in Table 1.

[0075] After the electrode plates were cured at high temperature, samples were taken and XRD analysis was performed using a Bruker X-ray diffractometer. The results are shown in Table 2, and the 4BS content was found to be 2.3%.

[0076] The porosity of the lead paste on the positive electrode plate after curing was measured using the mercury porosimetry method, and it was found to be 48.6%.

[0077] (2) Preparation of negative electrode lead paste.

[0078] The components are: 100 kg of lead powder (oxidation degree 72%-78%), 0.6 kg of BaSO4, 0.25 kg of conductive graphite, 0.46 kg of activated carbon, 0.3 kg of sodium lignosulfonate, and 0.12 kg of short fibers.

[0079] Place the above components into the hopper of the paste mixing machine and dry mix for 5 minutes to ensure that all components in the additive are evenly distributed in the lead powder. Then add 12.7 kg of deionized water for wet mixing for 5 minutes. After wet mixing, slowly add 8 kg of dilute sulfuric acid (density 1.4 g / cm³). When the temperature inside the paste mixing cylinder of the mixing machine reaches 60℃, turn on the negative pressure fan and cooling circulating water. The time for adding dilute sulfuric acid is 12 minutes. After adding acid, stir for 8 minutes before discharging. The discharging temperature is 45℃. Before discharging, turn off the paste mixing machine and check the apparent density of the lead paste. The apparent density of the lead paste is 4.53 g / cm³. 3 The lead paste penetration was tested and found to be 30 mm, which is suitable for coating.

[0080] After the lead paste is applied to the electrode plates by the coating machine, the plates are suspended on the drying rack and placed into the curing chamber for curing. The medium-temperature curing process is used, and the process parameters are shown in Table 3.

[0081] The porosity of the lead paste on the cured plate was measured to be 51.2% using the mercury porosimetry method.

[0082] Based on Comparative Example 1, the H2SO4 / LO value is greater than 6%, and even after high-temperature curing, the amount of 4BS produced is very low. The porosity of the lead paste is even higher than 50%, making it unsuitable for use as a long-life battery for cycling.

[0083] Comparative Example 2

[0084] (1) Preparation of positive electrode lead paste without 4BS seed crystals.

[0085] The components are: 100 kg of lead powder (oxidation degree 72%-78%), 0.25 kg of stannous sulfate, 0.3 kg of conductive graphite, 1 kg of red lead, and 0.15 kg of short fibers.

[0086] Place the above components into the hopper of the paste mixing machine and dry mix for 5 minutes. Then add 13 kg of deionized water and wet mix for 5 minutes. After wet mixing, slowly add 4.2 kg of dilute sulfuric acid (density 1.4 g / cm³). 3 When the temperature inside the mixing tank of the paste mixing machine reaches 60℃, turn on the negative pressure fan and cooling circulating water. Add sulfuric acid for 12 minutes, then stir for 8 minutes after acid addition before removing the paste from the heat. The outlet temperature is 45℃. Before removing the paste, turn off the paste mixing machine and check the apparent density of the lead paste. The apparent density of the lead paste is 4.91 g / cm³. 3 The lead paste penetration was tested and found to be 30 mm, which is suitable for coating.

[0087] After the lead paste is applied to the electrode plates by the coating machine, the plates are suspended on the drying rack and placed into the curing chamber for curing. The medium-temperature curing process is used, and the process parameters are shown in Table 3.

[0088] After medium-temperature curing, the electrode plates were subjected to XRD testing. The results are shown in Table 2. The 4BS content was 0, and the 3BS content was 59.3%. The porosity of the lead paste of the upright electrode plate after curing was measured to be 39.1% using mercury intrusion porosimetry.

Claims

1. A method for preparing a storage battery, the storage battery comprising a positive plate and a negative plate, the positive plate comprising a positive plate grid and a positive lead paste, the negative plate comprising a negative plate grid and a negative lead paste, characterized in that, the positive lead paste formula comprises, by weight parts: lead powder 100 parts, deionized water 10-14 parts, Density 1.4 g / cm 3 4-5 parts of a sulfuric acid solution 4BS seed crystal 1-1.5 parts, stannous sulfate 0.2-0.4 parts, conductive graphite 0.2-0.4 parts, red lead 1 part, short fibers 0.12-0.16 parts; the method for preparing the positive lead paste comprises the following steps: (1) dry mixing and wet mixing: dry mix the lead powder, 4BS seed crystal, stannous sulfate, conductive graphite, red lead and short fibers, and then add deionized water for wet mixing; (2) When the sulfuric acid solution is added, the water cooling and negative pressure exhaust cooling in the paste mixer are closed, the temperature in the paste mixing cylinder of the paste mixer is raised to above 70°C, less than 73°C, and the temperature is maintained for more than 5 min. When the temperature reaches 73°C, the water cooling and negative pressure exhaust cooling of the paste mixer are opened, and the positive electrode lead paste is discharged after stirring for 8 min. The apparent density of the positive electrode lead paste is 4.8-4.9 g / cm 3 ; the negative lead paste formula comprises, by weight parts: lead powder 100 parts, deionized water 11-14 parts, Density 1.4 g / cm 3 3-4 parts of a sulfuric acid solution BaSO4 0.5-1 parts, conductive graphite 0.2-0.4 parts, carbon material 0.3-0.6 parts, sodium lignosulfonate 0.2-0.4 parts, short fibers 0.12-0.16 parts; the method for preparing the negative lead paste comprises the following steps: (I) dry mixing and wet mixing: dry mix the lead powder, BaSO4, conductive graphite, carbon material, sodium lignosulfonate and short fibers, and then add deionized water for wet mixing; (II) when the sulfuric acid solution is added, the water cooling and negative pressure air draft of the paste mixer are started when the temperature in the paste mixing cylinder of the paste mixer rises to 60°C, and the negative electrode lead paste is discharged after stirring for 8 min, and the apparent density of the negative electrode lead paste is 4.90-4.98 g / cm 3 ; wherein the oxidation degree of the lead powder is 72-78%, the time for adding the sulfuric acid solution in steps (2) and (II) is not less than 12 min, and the paste temperature is controlled at 45-50℃.

2. The method of claim 1, wherein the method further comprises: The carbon material in the negative lead paste formula is carbon nanotubes, carbon fibers, activated carbon, graphene or carbon black.

3. A storage battery prepared using the method for preparing a storage battery according to claim 1 or 2.

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