EQCM study of hydrated PbO2 content and its influence on cycling performance of lead-acid batteries

Abstract In order to investigate the content of hydrated PbO 2 and its influence on lead acid batteries cycle life performance, PbO 2 films with four typical α -PbO 2 / β -PbO 2 ratios (pure α -PbO 2 , α -PbO 2 / β -PbO 2  = 0.3, α -PbO 2 / β -PbO 2  = 1, and pure β -PbO 2 ) on gold or graphite substrates were characterized by X-ray diffraction, scanning electron microscopy, and electrochemical quartz crystal microbalance. The effects of electrodeposition parameters on the morphologies and crystal phases of electrodeposited PbO 2 samples were investigated. The hydrated PbO 2 contents of the four samples were determined by electrochemical quartz crystal microbalance. The samples with α -PbO 2 / β -PbO 2  = 1 and 0.3 exhibited the smallest and the highest contents of hydrated PbO 2 among the four samples. Samples with almost pure α -PbO 2 and pure β -PbO 2 exhibited similar amounts of hydrated PbO 2 . The PbO 2 film electrode with initial α -PbO 2 / β -PbO 2  = 1 was still stable after 750 cycles.