Corrosion in Pb-acid batteries-recent developments

Battery-based energy storage systems with high power/energy densities and excellent cycle efficiency are expected to play a key role in our everyday lives. Even though Lead-Acid Batteries (LABs) are the oldest electrochemical energy storage technology, they still attract a lot of interest thanks to their properties: stability, reliability, recyclability, and low cost of the raw materials. Precisely for these reasons, LAB technology will retain its strong position at least until 2030 and remain very competitive, but ongoing investments are needed to improve production and performance. The main weak points of LABs are the limited charge efficiency and cyclability, mostly due to the degradation of electrodes during the charging/discharging process. Corrosion, in particular, represents a severe problem for LABs and has been the subject of many studies. Although LABs inevitably corrode to a certain extent throughout life, runaway corrosion of the positive grid will ultimately lead to failure. This phenomenon results in capacity degradation, often termed “Premature Capacity Loss” (PCL) or in electrical shorts. This chapter, after having given a general overview of LABs, describing their different types, their chemistry, and their failure modes, focuses specifically on the problem of corrosion of the grids stressing the causes of this phenomenon and the different strategies to evaluate and reduce it.