An additive for paste-making of lead-acid batteries

Abstract

The present invention discloses an additive for lead-acid battery paste-making, belonging to the technical field of lead-acid battery lead paste and plate additives. The paste-making additive of the present invention comprises the following components by weight parts: 7-9 parts of chemical fiber, 5-8 parts of strontium titanate, 4-7 parts of silicide, 3-4 parts of tannic acid, and 4-6 parts of humic acid; on the one hand, this additive can effectively inhibit the passivation and shrinkage of the negative active material of the lead-acid battery, and on the other hand, it can regulate the crystal form of lead sulfate during the charge and discharge process of the battery, thereby greatly delaying the process of battery plate sulfation. The present invention also prepares a negative lead paste with this additive. The lead-acid battery made of this negative lead paste has more excellent charge and discharge performance and longer cycle service life compared with the conventional lead-acid battery, and has good market competitiveness.

Description

Technical Field

[0001] The present invention belongs to the technical field of lead-acid battery lead paste and plate additives, and particularly relates to an additive for lead-acid battery paste making. Background Art

[0002] Nowadays, large-scale industrialized storage batteries mainly include lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and lithium-ion batteries. Among them, lead-acid batteries are still the most important secondary batteries due to advantages such as low unit energy price, high recycling value, low comprehensive cost, and mature technology, and are widely used in many fields.

[0003] Currently, the more widely used one is the valve-regulated sealed lead-acid battery, which has the advantages of high sealing degree and small maintenance workload. However, during the charge and discharge process of sealed lead-acid batteries, phenomena such as positive electrode expansion and softening failure, negative electrode shrinkage and passivation failure, and irreversible sulfation will occur, resulting in premature termination of battery life. Lead paste is the matrix of the active substances of the positive / negative plates of the battery, and the main role of lead paste in lead-acid batteries is to provide and store the substances required for electrochemical reactions. For the above various failure defects, the current main treatment method is to incorporate additives into the positive / negative plate active substances during paste making; the commonly used plate additives currently mainly include short fibers, barium sulfate, carbon black, humic acid, lignosulfonate, etc., and these conventional additives can only play a limited role in improving battery performance and still cannot effectively solve the conventional failure defects of lead-acid batteries.

[0004] In view of this, aiming at the limitations of the existing plate additives, in order to greatly extend the service performance and life of lead-acid batteries, further research and improvement on plate additives are still needed. Summary of the Invention

[0005] Aiming at the problems mentioned in the background art, the purpose of the present invention is to provide an additive for lead-acid battery paste making and a method for preparing the negative lead paste of lead-acid batteries using this additive, aiming to solve the failure problems that occur during the charge and discharge process of sealed lead-acid batteries.

[0006] To achieve the above purpose, the present invention specifically adopts the following technical solutions:

[0007] The present invention provides an additive for lead-acid battery paste making, and the paste-making additive includes the following components by weight:

[0008] Chemical fiber 7-9 parts,

[0009] Strontium titanate 5-8 parts,

[0010] Silicide 4-7 parts,

[0011] Tannic acid 3-4 parts,

[0012] 4 - 6 parts of humic acid.

[0013] Preferably, the paste - making additive comprises the following components by weight: 8 parts of chemical fiber, 6.4 parts of strontium titanate, 5.5 parts of silicide, 3.6 parts of tannic acid, and 5 parts of humic acid.

[0014] Preferably, the chemical fiber is ethylene - ethyl acrylate copolymer fiber, and the content of ethyl acrylate is 24%; the fiber specification is 45 mm and 1.33 dtex.

[0015] Preferably, the silicide includes cobalt disilicide and nickel silicide, and the mass ratio thereof is (2 - 5):2.

[0016] The present invention also provides a negative - electrode lead paste for lead - acid batteries, which is prepared from lead powder and the above - mentioned paste - making additive.

[0017] Preferably, the preparation method of the negative - electrode lead paste for lead - acid batteries comprises the following steps:

[0018] Step 1): Weigh each component of the paste - making additive, lead powder, sulfuric acid, and water according to the formula for standby;

[0019] Step 2): Put each component of the paste - making additive and part of the lead powder into a paste mixer, add water and mix and stir to obtain a mixed slurry;

[0020] Step 3): Continuously add the remaining lead powder into the paste mixer, then slowly add sulfuric acid while stirring and mixing. After adding the acid, cool and discharge the paste to obtain the negative - electrode lead paste for lead - acid batteries.

[0021] Preferably, in step 1), based on 100 parts by weight of lead powder, the dosage of the paste - making additive is 1.6 - 2.8 parts, the dosage of sulfuric acid is 11 - 14 parts, and the dosage of water is 12 - 18 parts.

[0022] Preferably, the temperature of the added water in step 2) is 75 - 95 °C.

[0023] Preferably, the discharging temperature in step 3) needs to be controlled below 42 °C.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] The present invention provides an additive for negative plate pasting, and its components include strontium titanate, silicide, chemical fiber, etc. On the one hand, this additive can effectively inhibit the passivation and shrinkage of the negative active material of lead-acid batteries. On the other hand, it can also regulate the crystal form of lead sulfate during the charge and discharge process of the battery, thereby greatly delaying the process of sulfate formation on the battery plate. The present invention also prepares a negative lead paste using this additive. The lead-acid battery made with this negative lead paste has more excellent charge and discharge performance and a longer cycle service life compared to conventional lead-acid batteries. Detailed Embodiments

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can all be obtained as conventional products through commercial purchase.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0028] Example 1

[0029] 1. An additive for pasting lead-acid batteries, comprising:

[0030] Precisely weigh 8 parts by weight of ethylene-ethyl acrylate copolymer fiber, 6.4 parts of strontium titanate, 5.5 parts of silicide (cobalt disilicide: nickel silicide = 3.5:2), 3.6 parts of tannic acid, and 5 parts of humic acid.

[0031] 2. A negative lead paste for lead-acid batteries, comprising:

[0032] 1) Take 100 parts of lead powder (oxidation degree 70%), 2.4 parts of the above-mentioned pasting additive, 12 parts of sulfuric acid, and 16 parts of water for standby;

[0033] 2) Put the pasting additive and 75 parts of lead powder into a pasting machine, add water at 85°C and mix and stir for 30 minutes to obtain a mixed slurry;

[0034] 3) Continuously add the remaining 25 parts of lead powder to the mixed slurry, then slowly add sulfuric acid and continuously stir, control the time for 15 minutes, and after the acid addition and stirring are completed, cool to 40°C to take out the paste to obtain a negative lead paste for lead-acid batteries.

[0035] Example 2

[0036] 1. A paste additive for lead-acid batteries, comprising:

[0037] Accurately weigh 8 parts by weight of ethylene-ethyl acrylate copolymer fiber, 5 parts of strontium titanate, 7 parts of silicide (cobalt disilicide: nickel silicide = 5:2), 3.6 parts of tannic acid, and 4 parts of humic acid.

[0038] 2. A negative electrode lead paste for lead-acid batteries, comprising:

[0039] 1) Take 100 parts of lead powder (oxidation degree 70%), 1.6 parts of the above paste additive, 12 parts of sulfuric acid, and 16 parts of water for standby;

[0040] 2) Put the paste additive and 75 parts of lead powder into a paste mixer, add water at 85 °C and mix and stir for 30 minutes to obtain a mixed slurry;

[0041] 3) Continuously add the remaining 25 parts of lead powder to the mixed slurry, then slowly add sulfuric acid and continuously stir, control the time for 15 minutes, and after the acid addition and stirring are completed, cool to 40 °C to take out the paste, obtaining the negative electrode lead paste for lead-acid batteries.

[0042] Example 3

[0043] 1. A paste additive for lead-acid batteries, comprising:

[0044] Accurately weigh 9 parts by weight of ethylene-ethyl acrylate copolymer fiber, 8 parts of strontium titanate, 4 parts of silicide (cobalt disilicide: nickel silicide = 1:1), 3 parts of tannic acid, and 6 parts of humic acid.

[0045] 2. A negative electrode lead paste for lead-acid batteries, comprising:

[0046] 1) Take 100 parts of lead powder (oxidation degree 80%), 2.8 parts of the above paste additive, 11 parts of sulfuric acid, and 18 parts of water for standby;

[0047] 2) Put the paste additive and 75 parts of lead powder into a paste mixer, add water at 85 °C and mix and stir for 30 minutes to obtain a mixed slurry;

[0048] 3) Continuously add the remaining 25 parts of lead powder to the mixed slurry, then slowly add sulfuric acid and continuously stir, control the time for 15 minutes, and after the acid addition and stirring are completed, cool to 40 °C to take out the paste, obtaining the negative electrode lead paste for lead-acid batteries.

[0049] Comparative Example 1

[0050] 1. A paste additive for lead-acid batteries, comprising:

[0051] Accurately weigh 8 parts by weight of ethylene-ethyl acrylate copolymer fiber, 6.4 parts of strontium titanate, 5.5 parts of titanium disilicide, 3.6 parts of tannic acid, and 5 parts of humic acid.

[0052] 2. A negative paste for lead-acid battery, comprising:

[0053] 1) Take 100 parts of lead powder (oxidation degree 70%), 2.4 parts of the above-mentioned paste additive, 12 parts of sulfuric acid, and 16 parts of water for standby;

[0054] 2) Put the paste additive and 75 parts of lead powder into a paste mixer, add water at 85°C and mix and stir for 30 minutes to obtain a mixed slurry;

[0055] 3) Continuously add the remaining 25 parts of lead powder to the mixed slurry, then slowly add sulfuric acid and continuously stir, control the time for 15 minutes, and after the acid addition and stirring are completed, cool to 40°C to discharge the paste, obtaining the negative paste for lead-acid battery.

[0056] Comparative Example 2

[0057] 1. A paste additive for lead-acid battery, comprising:

[0058] Accurately weigh 8 parts of ethylene-ethyl acrylate copolymer fiber, 5.5 parts of silicide (cobalt disilicide: nickel silicide = 3.5:2), 3.6 parts of tannic acid, and 5 parts of humic acid by weight.

[0059] 2. A negative paste for lead-acid battery, comprising:

[0060] 1) Take 100 parts of lead powder (oxidation degree 70%), 2.4 parts of the above-mentioned paste additive, 12 parts of sulfuric acid, and 16 parts of water for standby;

[0061] 2) Put the paste additive and 75 parts of lead powder into a paste mixer, add water at 85°C and mix and stir for 30 minutes to obtain a mixed slurry;

[0062] 3) Continuously add the remaining 25 parts of lead powder to the mixed slurry, then slowly add sulfuric acid and continuously stir, control the time for 15 minutes, and after the acid addition and stirring are completed, cool to 40°C to discharge the paste, obtaining the negative paste for lead-acid battery.

[0063] Test Example

[0064] Take the negative pastes prepared in the above examples and comparative examples, and scrape them evenly on the grid; the scraping thickness is 4 ± 0.3 mm, and after scraping, cure at 60°C for 3 days, and after drying, obtain the negative plate. Weld the obtained negative plate, positive plate (PbO2), and PE diaphragm to form a sealed test lead-acid battery (3 positive plates and 2 negative plates, and the electrolyte is sulfuric acid solution with a density of 1.33 g / cm 3 .

[0065] The above-obtained test lead-acid batteries are discharged at 0.1C, 0.5C, and 1C currents respectively in a fully charged state, and the discharge capacities of the batteries at different discharge rates are calculated. The above-obtained test lead-acid batteries are discharged at 0.1C current to 50% state of charge in a fully charged state, and then a cycle test of discharging at a 2C discharge rate for 2 minutes, standing for 0.5 minutes, and charging for 2 minutes is carried out, and the number of cycles before the battery life ends is counted. The test results are shown in Table 1.

[0066] Table 1

[0067]

[0068] The embodiments described above only represent several preferred embodiments of the present invention. The description is relatively specific and detailed, but it does not limit the present invention. It should be pointed out that for those skilled in the art, the present invention can also have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the concept and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A negative electrode lead paste for lead-acid batteries is prepared from lead powder and additives for paste making; The additives for paste making are composed of the following components by weight parts: 7-9 parts of chemical fiber, 5-8 parts of strontium titanate, 4-7 parts of silicide, 3-4 parts of tannic acid, 4-6 parts of humic acid; Among them, the chemical fiber is ethylene-ethyl acrylate copolymer fiber, and the content of ethyl acrylate is 24%; the silicide is composed of cobalt disilicide and nickel silicide, and the mass ratio thereof is (2-5):

2.

2. The negative electrode lead paste of the lead-acid battery according to claim 1, wherein The additives for paste making are composed of the following components by weight parts: 8 parts of chemical fiber, 6.4 parts of strontium titanate, 5.5 parts of silicide, 3.6 parts of tannic acid, and 5 parts of humic acid.

3. The preparation method of the negative electrode lead paste of the lead-acid battery according to claim 1 or 2, characterized in that, It includes the following steps: Step 1): Weigh each component of the additives for paste making, as well as lead powder, sulfuric acid, and water according to the formula for standby; Step 2): Put each component of the additives for paste making and part of the lead powder into a paste mixer, add water and mix and stir to obtain a mixed slurry; Step 3): Continue to add the remaining lead powder to the paste mixer, then slowly add sulfuric acid while stirring and mixing. After adding the acid, cool and take out the paste to obtain the negative electrode lead paste for lead-acid batteries.

4. The preparation method of the negative electrode lead paste of the lead-acid battery according to claim 3, wherein, In step 1), based on 100 weight parts of lead powder, the dosage of the additives for paste making is 1.6-2.8 parts, the dosage of sulfuric acid is 11-14 parts, and the dosage of water is 12-18 parts.

5. The preparation method of the negative electrode lead paste of the lead-acid battery according to claim 3, characterized in that, The temperature of the added water in step 2) is 75-95°C.

6. The preparation method of the negative lead paste of the lead-acid battery according to claim 3, wherein, The paste taking-out temperature in step 3) is controlled below 42°C.

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