Lead paste for negative electrode of ultra-low-temperature lead storage battery, and preparation method therefor

Abstract

Disclosed are a lead paste for a negative electrode of an ultra-low-temperature lead storage battery, and a preparation method therefor. The lead paste for a negative electrode of an ultra-low-temperature lead storage battery comprises lead powder, dilute sulfuric acid, water, and an additive. On the basis of 1000 parts by mass of the lead powder, the additive comprises the following component: 8-10 parts of barium sulfate, 2.5-4 parts of sodium lignosulfonate, 3-5 parts of a hydrolyzed tannin, 1-2 parts of nanographene, 1.5-3 parts of nanographyne, 1-2 parts of nanometer lead stannate, and 0.8-1.2 parts of polyester staple fibers. Before use, the nanometer lead stannate and the nanographyne are pre-treated by means of physical intercalation and uniform mixing; therefore, the problem of the agglomeration of lead stannate can be solved, and lead stannate is uniformly mixed to better perform its function.

Description

A low-temperature lead-acid battery negative electrode paste and its preparation method Technical Field

[0001] This invention belongs to the field of lead-acid battery technology, specifically relating to an ultra-low temperature lead-acid battery negative electrode paste and its preparation method. Background Technology

[0002] Low-temperature capacity is a key performance indicator for lead-acid batteries. The low-temperature performance of lead-acid batteries primarily depends on the negative electrode plate. Under low-temperature conditions, the main failure modes of the negative electrode plate are passivation and shrinkage. Adding appropriate additives to the negative electrode active material is one of the main solutions.

[0003] Commonly used negative electrode additives, such as sodium lignosulfonate, are anionic surfactants that readily adsorb onto the spongy, metallic lead of the negative electrode, which has a large surface area. When sodium lignosulfonate is adsorbed onto the spongy metallic lead, it lowers the surface energy of the negative electrode, thereby inhibiting the surface shrinkage of the active material during charge-discharge cycles. This maintains the porosity and high dispersibility of the spongy metallic lead, improving the electrochemical performance of the negative electrode. Especially during high-rate discharge and low-temperature discharge, it delays the passivation of the negative electrode.

[0004] For example, invention application CN108598472A discloses a low-temperature resistant lead-acid battery negative electrode paste and its preparation method. The negative electrode paste is composed of lead powder, negative electrode additives, water, and compounding acid. Based on 100 parts by weight of lead powder, the negative electrode additives include: 0.5-1.0 parts of strontium sulfate or barium sulfate, 0.1-0.15 parts of sodium lignin sulfonate, 0.4-0.8 parts of humic acid, 0.3-0.6 parts of tannin, 0.6-1.2 parts of synthetic binder, 0.1-0.2 parts of carbon nanotubes, 0.05-0.1 parts of nano-Kejtien black, 0.1-0.15 parts of conductive carbon fiber, and 0.1-0.5 parts of sodium hydroxymethyl cellulose. Batteries produced using the negative electrode paste of this invention can have their low-temperature discharge capacity increased by 10%-25%, and their service life in low-temperature environments increased by 20%-30%.

[0005] For example, invention application CN112786843A discloses a negative electrode paste and negative electrode plate for low-temperature lead-acid batteries. The negative electrode paste is composed of lead powder, additives, water, and compound paste acid. Based on 1000 parts by weight of lead powder, the additives include: 0.5-1.0 parts of PE short fiber, 0.5-1.0 parts of sodium carboxymethyl cellulose, 3.0-5.0 parts of modified magnesium trisilicate, 4.0-6.0 parts of sodium stearate, 2.0-3.0 parts of Teflon solution, 0.5-1.5 parts of stannous sulfate, 1.0-2.0 parts of superconducting carbon black, 8-12 parts of ultrafine barium sulfate, 2.5-4.0 parts of lignin, and 1-2 parts of humic acid. This invention, by adding special additives to the negative electrode paste, can significantly improve the low-temperature performance of lead-acid batteries.

[0006] Although many existing technologies have disclosed that negative electrode additives can improve the low-temperature performance of lead-acid batteries, the search for new negative electrode additives that can improve low-temperature performance remains of great significance.

[0007] Summary of the Invention

[0008] To address the aforementioned shortcomings in the prior art, this invention provides an ultra-low temperature lead-acid battery negative electrode paste and its preparation method.

[0009] This invention first provides an additive for the negative electrode lead paste of ultra-low temperature lead-acid batteries, comprising, by weight: 8-10 parts barium sulfate, 2.5-4 parts sodium lignin sulfonate, 3-5 parts hydrolyzed tannin, 1-2 parts nano-graphene, 1.5-3 parts nano-graphynylene, 1-2 parts nano-lead stannate, and 0.8-1.2 parts polyester short fiber.

[0010] Preferably, the polyester staple fiber has a fiber length of 3 to 3.5 mm.

[0011] The present invention provides an ultra-low temperature lead-acid battery negative electrode paste, comprising lead powder, dilute sulfuric acid, water and additives. Based on 1000 parts by weight of lead powder, the additive components include: 8-10 parts of barium sulfate, 2.5-4 parts of sodium lignin sulfonate, 3-5 parts of hydrolyzed tannin, 1-2 parts of nano-graphene, 1.5-3 parts of nano-graphynylene, 1-2 parts of nano-lead stannate, and 0.8-1.2 parts of polyester short fiber.

[0012] Preferably, based on 1000 parts by weight of lead powder, the dilute sulfuric acid comprises 70-90 parts and the water 100-125 parts, wherein the density of the dilute sulfuric acid is 1.3-1.5 g / cm³. 3 More preferably, the density of the dilute sulfuric acid is 1.4 g / cm³. 3 .

[0013] Preferably, the oxidation degree of the lead powder is 73% to 80%. In this application, the oxidation degree of the lead powder can be the oxidation degree conventionally used in the prior art.

[0014] Preferably, the polyester staple fiber has a fiber length of 3 to 3.5 mm.

[0015] This invention further provides a method for preparing the negative electrode lead paste of the ultra-low temperature lead-acid battery, comprising the following steps:

[0016] (1) Mix and grind the formulated amounts of nano-graphene, nano-graphyne and nano-lead stannate to obtain a homogeneous mixture;

[0017] (2) The formula amount of lead powder, barium sulfate, sodium lignin sulfonate, hydrolyzed tannin, polyester short fiber and the mixture obtained in step (1) are put into a paste mixing machine for dry mixing. Then, water is added first and the formula amount of water is added and stirred. Then, acid is added first and the formula amount of dilute sulfuric acid is added and stirred. After mixing, the ultra-low temperature lead-acid battery negative electrode lead paste is obtained.

[0018] Preferably, a grinder is used for mixing and grinding in step (1), and the mixing and grinding time is 20 to 30 minutes.

[0019] The present invention also provides an ultra-low temperature lead-acid battery, including a negative electrode plate, the negative electrode plate including negative electrode paste, the negative electrode paste being the negative electrode paste of the ultra-low temperature lead-acid battery.

[0020] Hydrolyzed tannins are produced by the reaction of gallic acid, or gallic acid-derived phenolic carboxylic acids, with polyols, under the action of acids, bases, or enzymes, resulting in polyols and phenolic carboxylic acids. Depending on the different polyphenolic carboxylic acids produced by the hydrolysis reaction, most hydrolyzed tannins can be further subdivided into gallic tannins and ellagitannins. Ellagantannins are preferred in this application.

[0021] Sodium lignosulfonate and tannins are both excellent negative electrode expanders for lead-acid batteries, with good low-temperature performance. Sodium lignosulfonate is an internationally used low-temperature expander. In traditional domestic ultra-low temperature formulations, tannins and tannins are used to promote the low-temperature, high-current discharge of batteries by utilizing the tannin components in these two substances. However, due to the limitations of early technology, the purification of tannin components was a major problem. Therefore, using tannin compounds as low-temperature expanders is more effective than using tannins and tannins.

[0022] Graphdiyne, following fullerenes, carbon nanotubes, and graphene, is a novel all-carbon nanostructure material possessing abundant carbon chemical bonds, a large conjugated system, wide interplanar spacing, and excellent chemical stability. The uniform pore structure, excellent electronic conductivity, and chemical stability of graphdiyne endow it with high capacity, excellent rate performance, and superior cycle life, among other electrochemical properties. The primary function of nano-graphdiyne in this invention is electrical conductivity.

[0023] Lead stannate is a novel functional material that possesses excellent ferroelectric and dielectric properties. Its nanoparticles have small particle size, large specific surface area, and numerous surface atoms. These surface atoms exhibit unsaturated properties due to incomplete coordination, and the numerous lattice defects within the nanocrystals act as highly active reaction centers, giving it superior properties in catalysis and adsorption that are unmatched by conventional materials. Lead stannate exhibits excellent adsorption and catalytic effects, promoting chemical reactions, increasing the rate of charge-discharge electrochemical reactions, improving the electrochemical reaction rate of batteries at low temperatures, and enhancing the charge-discharge capacity of batteries at low temperatures.

[0024] In this application, nano-graphite yttrium and nano-lead stannate are added to the negative electrode lead paste simultaneously. The use of the two in the battery and their synergistic effect improve the low-temperature charging and discharging capability of the battery.

[0025] In this application, the pretreatment of nano-lead stannate and nano-graphyne before use, and the physical intercalation and uniform mixing, can solve the problem of lead stannate agglomeration, so that the lead stannate is uniformly mixed and can play a better role. Detailed Implementation

[0026] Example 1

[0027] In the following preparation methods, each substance is added according to its mass percentage.

[0028] (1) Premixing of new substances

[0029] Two parts of nano-graphene, three parts of nano-graphyne, and two parts of nano-lead stannate were placed in a grinder and ground for 30 minutes to obtain a uniformly ground nano-mixture A.

[0030] (2) Mixed paste

[0031] Place 1000 parts lead powder (oxidation degree of 78%), 10 parts barium sulfate, 4 parts sodium lignin sulfonate, 5 parts hydrolyzed tannin (ellagitannin), 0.8 parts polyester staple fiber and mixture A into a lead powder machine and dry stir for 3 minutes. Then pour in 125 parts pure water over 5 minutes. After pouring in the water, stir for 3 minutes. Then pour in 90 parts dilute sulfuric acid over 10 minutes. After pouring in the water, continue stirring for 15 minutes.

[0032] Example 2

[0033] In the following preparation methods, each substance is added according to its mass percentage.

[0034] (1) Premixing of new substances

[0035] Place 1 part of nano-graphene, 1.5 parts of nano-graphyne, and 1 part of nano-lead stannate into a grinder, turn on the machine and grind for 20 minutes to obtain a uniformly ground nano-mixture A.

[0036] (2) Mixed paste

[0037] Place 1000 parts lead powder (oxidation degree of 78%), 8 parts barium sulfate, 2.5 parts sodium lignin sulfonate, 3 parts hydrolyzed tannin (ellagitannin), 1 part polyester staple fiber and mixture A into a lead powder machine and dry stir for 3 minutes. Then pour in 100 parts pure water over 5 minutes. After pouring in the water, stir for 3 minutes. Then pour in 70 parts dilute sulfuric acid over 10 minutes. After pouring in the water, continue stirring for another 10 minutes.

[0038] Example 3

[0039] In the following preparation methods, each substance is added according to its mass percentage.

[0040] (1) Premixing of new substances

[0041] Place 1.5 parts of nano-graphene, 2 parts of nano-graphyne, and 1.5 parts of nano-lead stannate into a grinder, turn on the machine and grind for 25 minutes to obtain a uniformly ground nano-mixture A.

[0042] (2) Mixed paste

[0043] Place 1000 parts lead powder (oxidation degree of 78%), 9 parts barium sulfate, 3 parts sodium lignin sulfonate, 4 parts hydrolyzed tannin (ellagitannin), 1.2 parts polyester staple fiber and mixture A into a lead powder machine and dry stir for 3 minutes. Then pour in 110 parts pure water over 5 minutes. After pouring in the water, stir for 3 minutes. Then pour in 80 parts dilute sulfuric acid over 10 minutes. After pouring in the water, continue stirring for 15 minutes.

[0044] Comparative Example 1

[0045] In the following preparation methods, each substance is added according to its mass percentage.

[0046] (1) Premixing of new substances

[0047] Place 1.5 parts of nano-graphene and 2 parts of nano-graphyne into a grinder, turn on the machine and grind for 25 minutes to obtain a uniformly ground nano-mixture A.

[0048] (2) Mixed paste

[0049] Place 1000 parts lead powder (oxidation degree of 78%), 9 parts barium sulfate, 3 parts sodium lignin sulfonate, 4 parts hydrolyzed tannin (ellagitannin), 1.2 parts polyester staple fiber and mixture A into a lead powder machine and dry stir for 3 minutes. Then pour in 110 parts pure water over 5 minutes. After pouring in the water, stir for 3 minutes. Then pour in 80 parts dilute sulfuric acid over 10 minutes. After pouring in the water, continue stirring for 15 minutes.

[0050] Comparative Example 2

[0051] In the following preparation methods, each substance is added according to its mass percentage.

[0052] (1) Premixing of new substances

[0053] Place 1.5 parts of nano-graphene and 1.5 parts of nano-lead stannate into a grinder, turn on the machine and grind for 25 minutes to obtain a uniformly ground nano-mixture A.

[0054] (2) Mixed paste

[0055] Place 1000 parts lead powder (oxidation degree of 78%), 9 parts barium sulfate, 3 parts sodium lignin sulfonate, 4 parts hydrolyzed tannin (ellagitannin), 1.2 parts polyester staple fiber and mixture A into a lead powder machine and dry stir for 3 minutes. Then pour in 110 parts pure water over 5 minutes. After pouring in the water, stir for 3 minutes. Then pour in 80 parts dilute sulfuric acid over 10 minutes. After pouring in the water, continue stirring for 15 minutes.

[0056] Comparative Example 3

[0057] In the following preparation methods, each substance is added according to its mass percentage.

[0058] Place 1000 parts lead powder (oxidation degree of 78%), 9 parts barium sulfate, 3 parts sodium lignin sulfonate, 4 parts hydrolyzed tannin (ellagitannin), 1.2 parts polyester staple fiber and 1.5 parts nano graphene into a lead powder machine and dry stir for 3 minutes. Then pour in 110 parts pure water over 5 minutes. After pouring in the water, stir for 3 minutes. Then pour in 80 parts dilute sulfuric acid over 10 minutes. After pouring in the water, continue stirring for 15 minutes.

[0059] Detection Example 1

[0060] The negative electrode plates prepared using the negative electrode lead paste in each embodiment and comparative example were assembled into 6-DZF-20 batteries and tested.

[0061] (1) 2h rate discharge (room temperature capacity): According to Clause 5.5 of the national standard GB / T22199-2017 for batteries, after the battery is fully charged, it is left to stand for 1 to 24 hours in an environment with a temperature of 25±2℃. When the battery voltage is 10.5V, the 2h rate capacity Ca should reach the C2 standard within three cycles.

[0062] (2) Low temperature high current discharge, in accordance with Clause 5.9 of the national standard for batteries GB / T22199-2017, the battery was placed in a low temperature chamber at -18℃ for 12 hours, and then discharged at a current of 10A in an environment at -18℃. The discharge was terminated when the battery voltage reached 10.5V, and the average discharge time was recorded.

[0063] (3) Cycle life: According to Clause 5.12 of the national standard GB / T22199-2017 for batteries, in an environment with a temperature of 25±5℃, discharge at a current of 10A for 1.6h, and then charge at a constant voltage of 16V (current limited to 4A) for 6.4h, which is one cycle. When the battery terminal voltage drops below 10.5V for three consecutive times after discharging for 1.6h, the battery cycle life ends. The total cycle life shall not be less than 350 cycles.

[0064] The test results are shown in Table 1 below.

[0065] Table 1

[0066] As shown in Table 1, the use of lead stannate and the additive graphdiyne of the present invention can significantly improve the capacity at room temperature by about 8%, the low-temperature high-current discharge by about 10%, and the cycle life by about 8%.

Claims

1. An additive for lead paste used in the negative electrode of an ultra-low temperature lead-acid battery, characterized in that, By weight, it includes: 8-10 parts barium sulfate, 2.5-4 parts sodium lignin sulfonate, 3-5 parts hydrolyzed tannin, 1-2 parts nano-graphene, 1.5-3 parts nano-graphyne, 1-2 parts nano-lead stannate, and 0.8-1.2 parts polyester staple fiber.

2. The additive according to claim 1, characterized in that, The polyester staple fiber has a fiber length of 3 to 3.5 mm.

3. A negative electrode paste for an ultra-low temperature lead-acid battery, comprising lead powder, dilute sulfuric acid, water, and additives, characterized in that, Based on 1000 parts by weight of lead powder, the additive components include: 8-10 parts of barium sulfate, 2.5-4 parts of sodium lignin sulfonate, 3-5 parts of hydrolyzed tannin, 1-2 parts of nano-graphene, 1.5-3 parts of nano-graphyne, 1-2 parts of nano-lead stannate, and 0.8-1.2 parts of polyester staple fiber.

4. The ultra-low temperature lead-acid battery negative electrode paste according to claim 3, characterized in that, Based on 1000 parts by weight of lead powder, the dilute sulfuric acid comprises 70-90 parts, and the water comprises 100-125 parts, wherein the density of the dilute sulfuric acid is 1.3-1.5 g / cm³. 3 .

5. The ultra-low temperature lead-acid battery negative electrode paste according to claim 3, characterized in that, The oxidation degree of the lead powder is 73% to 80%.

6. The ultra-low temperature lead-acid battery negative electrode paste according to claim 3, characterized in that, The polyester staple fiber has a fiber length of 3 to 3.5 mm.

7. The method for preparing the negative electrode lead paste of the ultra-low temperature lead-acid battery according to any one of claims 3 to 6, characterized in that, Includes the following steps: (1) Mix and grind the formulated amounts of nano-graphene, nano-graphyne and nano-lead stannate to obtain a homogeneous mixture; (2) The formula amount of lead powder, barium sulfate, sodium lignin sulfonate, hydrolyzed tannin, polyester short fiber and the mixture obtained in step (1) are put into a paste mixing machine for dry mixing. Then, water is added first and the formula amount of water is added and stirred. Then, acid is added first and the formula amount of dilute sulfuric acid is added and stirred. After mixing, the ultra-low temperature lead-acid battery negative electrode lead paste is obtained.

8. The preparation method according to claim 7, characterized in that, In step (1), a grinder is used for mixing and grinding, and the mixing and grinding time is 20 to 30 minutes.

9. An ultra-low temperature lead-acid battery, characterized in that, Includes a negative electrode plate, the negative electrode plate including negative electrode paste, the negative electrode paste using the ultra-low temperature lead-acid battery negative electrode paste according to any one of claims 3 to 6.

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