Lead-acid batteries are enjoying steady yearly production growth. The Eirich vacuum technology known as the EVACTHERM method has been available for production for several decades, and around 120 EVACTHERM plants are currently operational around the world. Manufacturers are regularly opting for this preparation technology, which is the best available.
Lead-acid batteries were first invented in the middle of the 19th century. Today, lead-acid battery technology is the most important type of electrochemical energy storage system available. Thanks to the high recycling rate of almost 100 percent, the technology is sustainable and saves resources – which makes it future-proof.
In many applications including e.g. starter batteries in motor vehicles and as traction batteries for forklift trucks and stackers, lead-acid batteries simply cannot be replaced cost-effectively with any other type of battery system; likewise, they also represent an inexpensive energy storage solution for photovoltaics systems – and here again, new and growing markets are emerging.
One of the defining factors for the quality of the battery is the quality of the lead paste compound used to manufacture the electrodes. The process of converting the starting materials with sulfuric acid to lead paste compounds was long performed using open systems, where the reaction heat was dissipated by cooling the compound with overflowing air. One disadvantage of this evaporation cooling method is its strong dependency on climatic conditions; if the humidity of the cooling air is high then its capacity to absorb evaporated water is low and cooling times will be longer. This materially affects the characteristics of the compound, making it impossible to accurately control them.
In the late 1980s Eirich developed an improved method based on vacuum technology, which not only enables accurate temperature control, but also allows the moisture of the material to be precisely controlled. Evaporation, condensation, and re-mixing processes take place during the cooling phase. For this reason, the process is also known as vacuum reflux cooling. With the aid of the EVACTHERM system, it is possible to cool the paste independently of the ambient conditions. In addition, the technology is also superior in terms of a number of environmental aspects. Processing takes place with zero emissions inside an enclosed system, where it is impossible for dusts or vapors to escape.
In 2001, a scientific paper was published with the title “Semi-suspension technology for preparation of tetrabasic lead sulfate pastes for lead-acid batteries” (D. Pavlov, S. Ruevski, Central Laboratory of Electrochemical Power Sources, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria, in Journal of Power Sources, Volume 95, Issues 1–2, 15 March 2001, Pages 191–202). The authors showed that the Eirich technology delivers a high capacity and long service life for the lead-acid batteries. The technology has since been adopted by many battery manufacturers – and lead-acid batteries have improved significantly since as a result.
Customers regularly opt for the best available manufacturing technology when constructing new plants or when upgrading their existing production facilities – i.e. for the EVACTHERM method, e.g. with a mixer in the size RV11VAC (900 kg batch size) or RV15VAC (1500 kg batch size). This enables the manufacturers to continue to produce lead-acid batteries cost-effectively and to high quality standards.
Universities around the world are working on refining and developing lead-acid battery technology. Parameters that need to be optimized include performance, cyclic stability, mass utilization, and charging current so that even better energy storage systems for renewable energy sources can be manufactured. Small vacuum mixers are available for applications at laboratory scale (e.g. with a capacity of 5 liters).
Contact: Juergen Klemke e-mail: firstname.lastname@example.org