In-situ Confocal Laser Microscopy Study of Lead Sulfate Crystal Growth on Negative Electrode of Lead-acid Batteries

Confocal Laser Scanning Microscopy (CLSM) is a widely used technique mainly in fields of biology or multidisciplinary material sciences. Although CLSM has the ability to monitor also electrochemical processes like lead sulfate-crystal growth, nobody used CLSM for such application. We performed operando observation of the pasted active mass of negative electrode for lead-acid batteries during deep cycling. Electrode with pasted negative active mass was optimized for cycling in ECC-opto-std electrochemical cell by EL-CELL. Lead sulfate crystal growth and changes of electrode surface during cycling were observed using a laser scanning confocal microscope Olympus Lext OLS4100. We evaluate the surface changes and sulfate crystal growth. The cycling mode leads to fast gradual degradation of the negative electrode and massive growth of lead sulfate crystals. Confocal laser scanning microscopy was identified as a powerful technique for visualization of lead sulfate crystal promotion during battery cycling.