Lead-acid storage batteries

The lead-acid battery, commonly used in automobiles, is one of the world’s most widely used rechargeable power sources, and can also act as a backup power supply.A lead-acid battery consists of cells containing lead as the anode and lead coated with lead oxide as the cathode, along with some other metals used for doping.

Both the anode and cathode are contained in sulfuric acid; as electrical energy is generated by the battery, sulfuric acid is reduced to water. To regenerate sulfuric acid, an external power source must be used to recharge the battery. Because the anode and cathode plates are oxidized over time, corrosion occurs that decreases the size of the plates, reduces the capacity of the battery, and eventually the battery life.Additives known as expanders are used to maintain the performance of the battery through numerous charge and discharge cycles.

To expand the size of the plates, and thereby the battery capacity and lifespan, the use of organic materials has been studied.Organic matter, such as lignocellulosic materials, is inert and aids in preventing the corrosion of active materials used in recharging the battery.

In this respect, lignosulfonates can be used, but high solubility has hindered their potential application in batteries. The acid insolubility of lignosulfonates may be increased by reducing the sulfur content of the lignosulfonates, which may widen their application in the batteries.

By adding reduced-sulfur lignosulfonates at 0.1–0.2 wt % of the lead compound to a battery, foaming was reduced during battery use, which allowed for more efficient battery usage and less degradation due to reduced acidic foam formation. It was claimed that the application of lignosulfonates in batteries improved their life span to years, whereas batteries with no lignosulfonates were claimed to work for days due to the corrosion of the lead plates.