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Abstract

This article conducts an in-depth study on enhancing the anti-sulfation ability of lead-acid batteries, elaborating on the mechanism, hazards of sulfation in lead-acid batteries and its impact on battery performance and lifespan. By analyzing the advantages and disadvantages of the existing anti-sulfidation technologies, this paper explores the application of new materials, processes and management strategies in enhancing the anti-sulfidation capacity of lead-acid batteries, aiming to provide theoretical basis and practical guidance for improving the reliability and extending the service life of lead-acid batteries, and to facilitate their wider and more efficient application in fields such as energy storage and transportation.

1. Introduction

Lead-acid batteries, as a type of chemical power source with a long history and wide application, have occupied an important position in many fields such as car starting, electric bicycles, backup power for communication base stations, and solar and wind energy storage systems, thanks to their advantages of low cost, good high-current discharge performance, and stable performance at high and low temperatures. However, lead-acid batteries are prone to sulfation during use, which is one of the main reasons for the decline in battery performance and the shortening of their lifespan. The occurrence of sulfidation not only increases the usage cost but also limits the application of lead-acid batteries in more high-performance fields. Therefore, conducting in-depth research and enhancing the anti-sulfation capacity of lead-acid batteries is of great significance for promoting the development of the lead-acid battery industry, improving resource utilization efficiency, and reducing environmental pollution.

2. Sulfation Mechanism and Hazards of Lead-Acid Batteries

2.1 Vulcanization Mechanism

The working principle of lead-acid batteries is based on the electrochemical reaction between lead dioxide at the positive electrode and spongy lead at the negative electrode in a sulfuric acid solution. During normal charging and discharging processes, the active substances on the plates react with sulfuric acid to form lead sulfate, which is then reconverted into lead dioxide and spongy lead during charging. When a battery experiences over-discharge, remains in a state of low charge for a long time, or is undercharged, the lead sulfate on the plates cannot be completely transformed and will crystallize on the surface of the plates, forming large and hard lead sulfate crystals. This process is known as sulfation. From the perspective of chemical kinetics, under overdischarge or underdischarge conditions, the generation rate of lead sulfate is greater than its transformation rate, causing lead sulfate to continuously accumulate and crystallize on the surface of the plates.

2.2 Hazards

After sulfation, the lead sulfate crystals on the surface of the plates of lead-acid batteries occupy the positions of the active substances, reducing the surface area involved in electrochemical reactions, resulting in an increase in the internal resistance of the battery and a decrease in the charging and discharging efficiency. During the discharge process, the rate at which the battery voltage drops accelerates and the output capacity significantly decreases. During charging, the battery gets extremely hot, has difficulty accepting the charging current, prolongs the charging time and is hard to fully charge. In addition, sulfidation will accelerate the corrosion and aging of the plates, further shortening the service life of the battery. In severe cases, it may even cause the battery to fail to work properly and need to be scrapped in advance.

3. Analysis of Existing Anti-sulfidation Technologies

3.1 Additive Technology

Adding various additives during the manufacturing process of electrolyte or plates is one of the common anti-sulfidation methods. For instance, adding organic macromolecular compounds such as humic acid and sodium lignosulfonate, these additives can adsorb on the surface of lead sulfate crystals, inhibit their crystal growth, and keep the lead sulfate crystals in a fine and loose state, which is conducive to their re-transformation during the charging process. However, the effectiveness of additives can be affected by factors such as the dosage used and the battery's working environment. Improper dosage may have a negative impact on other battery performances, and the effect of additives may gradually weaken after long-term use.

3.2 Charging Control technology

Adopting a reasonable charging control strategy can effectively prevent and reduce sulfation phenomena. Pulse charging technology disrupts the growth balance of lead sulfate crystals by periodically applying forward charging pulses and reverse discharging pulses, partially dissolving the formed lead sulfate crystals and simultaneously enhancing the charging efficiency. The intelligent charging control system can adjust the charging parameters in real time according to the battery status, avoiding overcharging and undercharging, thereby reducing the risk of sulfation. However, the cost of pulse charging equipment is relatively high, and the accuracy and stability of the intelligent charging control system also need to be further improved to meet the battery charging requirements under different working conditions.

3.3 Physical processing technology

Physical processing technologies include ultrasonic processing, electromagnetic processing, etc. Ultrasonic treatment utilizes the cavitation effect of ultrasonic waves and mechanical vibrations to break the lead sulfate crystals on the surface of the plates through impact and vibration, promoting their dissolution and transformation. Electromagnetic treatment involves applying electromagnetic fields of specific frequencies and intensities to alter the growth direction and morphology of lead sulfate crystals and inhibit their growth. However, physical processing technology requires specialized equipment, is relatively complex to operate, and the uniformity and sustainability of the processing effect in practical applications need to be improved.

4. New materials and processes enhance the ability to resist vulcanization

4.1 New plate materials

The development of new plate materials is an important direction for enhancing the anti-sulfation ability of lead-acid batteries. Nanomaterials have shown great application potential in the field of lead-acid batteries due to their unique physicochemical properties. For instance, when nano-lead dioxide is added to the positive electrode active material, it has a larger specific surface area and higher activity, which can enhance the charging and discharging performance and anti-sulfidation ability of the positive electrode. In addition, graphene has excellent electrical conductivity and mechanical properties. When it is combined with lead alloy to prepare the negative electrode plate, the electron transport performance of the negative electrode can be improved and the formation of lead sulfate crystals can be reduced.

4.2 Electrolyte improvement

Optimizing the electrolyte formula also helps to enhance the battery's resistance to sulfation. Using high-purity sulfuric acid as the electrolyte and adding an appropriate amount of functional additives, such as sulfate buffers and anti-sulfidation agents, can adjust the pH and ion concentration of the electrolyte and inhibit the growth of lead sulfate crystals. Meanwhile, new electrolyte systems, such as gel electrolytes and solid electrolytes, are studied. Gel electrolytes can effectively fix sulfuric acid, reduce the stratification phenomenon of the electrolyte, and improve the charging and discharging uniformity and anti-sulfation performance of the battery. Solid electrolytes fundamentally avoid problems such as electrolyte leakage and are expected to significantly enhance the safety and anti-sulfation ability of batteries.

4.3 Optimization of Plate manufacturing process

Improving the manufacturing process of the plates is equally crucial. The adoption of new paste coating processes, such as vacuum paste coating and extrusion paste coating, can make the active substances more evenly distributed on the plates, increase the porosity and specific surface area of the plates, facilitate the electrochemical reaction, and reduce the deposition of lead sulfate crystals. During the curing and drying process of the plates, precise control of process parameters such as temperature, humidity and time can promote the crystal form transformation of active substances, form a more stable structure that is more conducive to charge and discharge reactions, thereby enhancing the anti-sulfation ability of the plates.

5. The Role of Management Strategies in Enhancing Sulfidation Resistance

Reasonable use and maintenance

Correct use and maintenance are important measures to prevent sulfation of lead-acid batteries. During use, over-discharge should be avoided. When the battery power drops to a certain level, it should be charged in time. Avoid prolonged high-current discharge to prevent excessively high plate temperature and excessive formation of lead sulfate. Regular deep discharge and equalization charging of the battery can help activate the active substances on the plates and reduce the accumulation of lead sulfate. At the same time, keep the battery surface clean and dry to prevent electrolyte leakage and external impurities from entering the battery interior, which may affect battery performance.

6. Conclusion

In conclusion, enhancing the anti-sulfation capacity of lead-acid batteries is a comprehensive issue that requires efforts from multiple aspects such as materials, processes, and management. Through in-depth research on the sulfation mechanism, continuous improvement of existing anti-sulfation technologies, development of new materials and processes, and strengthening of battery usage management and intelligent monitoring, the anti-sulfation capacity of lead-acid batteries can be effectively enhanced, their service life can be prolonged, and their performance and reliability can be improved.