Definition: A lead-acid battery whose electrodes are mainly made of lead and its oxides, and whose electrolyte is sulfuric acid solution. In the discharged state, the positive electrode is mainly composed of lead dioxide, and the negative electrode is mainly composed of lead; in the charged state, both the positive and negative electrodes are mainly composed of lead sulfate. They are divided into vented lead-acid batteries and maintenance-free lead-acid batteries.
A battery mainly consists of tubular positive and negative plates, electrolyte, separators, battery case, battery cover, terminals, and filler cap. The electrodes of a vented lead-acid battery are made of lead and lead oxide, and the electrolyte is an aqueous solution of sulfuric acid. Its main advantages are stable voltage and low price; its disadvantages are low specific energy (i.e., the amount of electrical energy stored per kilogram of battery), short lifespan, and frequent maintenance. Older, ordinary lead-acid batteries typically have a lifespan of about two years and require regular checks of the electrolyte level and the addition of distilled water. However, with technological advancements, lead-acid batteries have become longer and easier to maintain.
The most obvious characteristic of lead-acid batteries is the screw-on plastic sealing cap on top, which also has a vent. These caps are used for adding distilled water, checking the electrolyte level, and venting gases. Theoretically, lead-acid batteries require checking the electrolyte density and level at each maintenance check, and adding distilled water if necessary. However, with advancements in battery manufacturing technology, lead-acid batteries have evolved into maintenance-free lead-acid batteries and gel maintenance-free batteries, which do not require the addition of electrolyte or distilled water during use. This is mainly achieved through oxygen cycling, where oxygen generated at the positive electrode is absorbed at the negative electrode, preventing moisture loss. Lead-acid batteries are mostly used in tractors, tricycles, and car starters, while maintenance-free lead-acid batteries have a wider range of applications, including uninterruptible power supplies (UPS), electric vehicle power supplies, and electric bicycle batteries. Lead-acid batteries are further categorized based on application requirements: constant current discharge (e.g., UPS) and instantaneous discharge (e.g., car starter batteries).
Chinese name: lead-acid battery; English name: lead-acid battery; also known as lead-acid water battery.
As the discharge proceeds, the concentration of the sulfuric acid solution will continuously decrease. When the solution density drops to 1.18 g/ml, use should be stopped and recharged.
Charging: 2PbSO₄²⁻ + 2H₂O = PbO₂ + Pb + 2H₂SO₄²⁻ (electrolytic cell)
lead-acid batteries
Lead-acid batteries (4 images)
Discharge: PbO₂ + Pb + 2H₂SO₄ = 2PbSO₄ + 2H₂O (galvanic cell)
Anode: PbSO₄²⁻ + 2H₂O - 2e⁻ === PbO₂ + 4H⁺ + SO₂²⁻
Cathode: PbSO₄²⁻ + 2e⁻ === Pb + SO₄²⁻
Negative electrode: Pb + SO₂ → 2e⁻ === PbSO₄
Positive electrode: PbO₂ + 4H⁺ + SO₄²⁻ + 2e⁻ === PbSO₄ + 2H₂O
history
The storage battery was invented in 1859 by the Frenchman Plante, and has a history of over a century. Since its invention, the lead-acid battery has maintained a dominant position among chemical power sources. This is due to its low cost, readily available raw materials, high reliability, suitability for high-current discharge, and wide operating temperature range.
G. Plante invented the lead-acid battery in 1859, and it has undergone nearly 150 years of development. Lead-acid batteries have made great progress in theoretical research, product types and varieties, and electrical performance. Whether in transportation, communication, power, or navigation and various economic fields, lead-acid batteries have played an indispensable and important role.
By the early 20th century, lead-acid batteries had undergone many significant improvements, enhancing energy density, cycle life, and high-rate discharge performance. However, open-type lead-acid batteries had two main drawbacks: ① During the final stages of charging, water decomposes into hydrogen and oxygen gas is released, requiring frequent addition of acid and water, resulting in heavy maintenance; ② When gas escapes, it carries acid mist, corroding surrounding equipment and polluting the environment, limiting the battery's application. In the past two decades, to address these two problems, countries worldwide have competed to develop sealed lead-acid batteries, hoping to achieve a sealed battery and obtain clean, green energy.
In 1912, Thomas Edison published a patent proposing the use of platinum wire in the upper space of a single-cell battery. When current flows through it, the platinum is heated and becomes a catalyst for the oxidation of hydrogen, causing the released H2 and O2 to recombine and return to the electrolyte. However, this patent was not implemented: ① the platinum catalyst quickly became ineffective; ② the gas was not released in the stoichiometric ratio of hydrogen 2 and oxygen 1, and gas was still generated inside the battery; ③ there was a risk of explosion.
In the 1960s, Gates Corporation of the United States invented lead-calcium alloy, which sparked a boom in the development of sealed lead-acid batteries, and major battery companies around the world invested a lot of human and material resources in its development.
In 1969, the United States launched its lunar landing program, and sealed valve-regulated lead-acid batteries and nickel-cadmium batteries were included in the list of power sources for the lunar rover. Ultimately, nickel-cadmium batteries were adopted, but sealed lead-acid battery technology was developed from then on.
In 1969-1970, EC Corporation of the United States manufactured approximately 350,000 small sealed lead-acid batteries. These batteries used glass fiber separators and a starved electrolyte system. They were the earliest commercially available valve-regulated lead-acid batteries, but their oxygen recombination principle was not yet understood at the time.
In 1975, after many years of effort and at great expense, GatesRutter obtained a patent for a D-type sealed lead-acid dry cell, which became the prototype of today's VRLA battery.
In 1979, after purchasing Gates' patent, GNB invented the MFX positive grid patent alloy and began to promote and produce large-capacity absorbing sealed maintenance-free lead-acid batteries on a large scale.
In 1984, VRLA batteries were used on a small scale in the United States and Europe.
In 1987, with the rapid development of the telecommunications industry, VRLA batteries were quickly adopted and used in the telecommunications sector.
In 1991, the British telecommunications sector inspected and tested the VRLA batteries in use and found that they did not exhibit the thermal runaway, combustion, and early capacity failure phenomena that manufacturers had claimed. This sparked widespread discussion in the battery industry and raised questions about the future development of VRLA batteries, capacity monitoring technology, thermal runaway, and reliability. At that time, the market share of VRLA batteries was less than 50% of that of flooded batteries. The previously mentioned name "sealed maintenance-free lead-acid battery" was officially replaced by "VRLA battery" because VRLA batteries were a type of battery that still required management, and using the term "maintenance-free" could easily lead to misunderstandings.
In 1992, in response to the problems raised in 1991, battery experts and technicians from manufacturers published articles proposing solutions and perspectives. Dr. Darid Feder suggested using conductivity measurement to monitor VRLA batteries. Ic Bearinger provided a technical review of the advanced features of VRLA batteries. These articles greatly promoted the development and widespread application of VRLA batteries.
In 1992, the global use of VRLA batteries increased significantly in Europe and the Americas, and telecommunications departments in Asian countries promoted the adoption of VRLA batteries. By 1996, VRLA batteries had basically replaced traditional flooded batteries, and VRLA batteries had gained widespread acceptance among users.
develop
During the 11th Five-Year Plan period, my country's lead-acid battery market expanded rapidly, with production growing at an average annual rate of about 20%, and the overall scale doubled, rising from about 70 million KVAh in 2005 to 144.1668 million KVAh in 2010.
In 2011, my country's lead-acid battery industry saw expansion in both production and sales, with significant increases in profits and sales revenue, resulting in good industry performance. In 2011, the total assets of my country's lead-acid battery industry reached 88.091 billion yuan, a year-on-year increase of 39.35%; sales revenue reached 96.515 billion yuan, a year-on-year increase of 32.40%; and total profit reached 5.72 billion yuan, a year-on-year increase of 10.81%. For details, please refer to the "China Lead-Acid Battery Industry Market Outlook and Investment Strategy Planning Analysis Report" published by Qianzhan Industry Research Institute.
Meanwhile, after years of development, lead-acid battery technology has made breakthroughs in areas such as specific energy, cycle life, and adaptability to high and low temperatures. Currently, my country is gradually narrowing the gap with leading international technologies, has reached international standards in some core technologies, and is increasingly entering the international market.
As competition intensifies in the lead-acid battery industry, mergers, acquisitions, and capital operations among large lead-acid battery manufacturers are becoming increasingly frequent. Leading domestic lead-acid battery manufacturers are placing greater emphasis on market research, particularly in-depth analysis of the business environment and evolving customer needs. Consequently, a large number of excellent domestic lead-acid battery brands have rapidly emerged, gradually becoming leaders in the industry!
Currently, the lead-acid battery industry faces three main problems: First, illegal lead-acid battery and recycled lead production enterprises still exist, with low levels of technology and equipment. Even compliant enterprises remain at a disadvantage in market competition, hindering the healthy development of the industry. Second, a few enterprises disregard national hazardous waste management requirements, engaging in the collection, storage, and disposal of waste lead-acid batteries. A large number of waste lead-acid batteries flood illegal recycling channels, making compliant recycling companies lack a price competitive advantage. Third, the lead-acid battery industry lacks technological support. The industrialization of economically sound pollution control technologies, especially clean production technologies for batteries, is significantly insufficient, and the promotion of advanced technologies is inadequate, restricting technological progress in the industry.
