Nanodendritic PbO 2 has been the attractive electrode material with unique morphology and enhanced electrochemical performance for lead-acid electrochemical storage devices. However, numerous studies have only investigated this unique material via electrodeposition technique. In this paper, flower-like PbO consisting three dimensional (3D) nanoflakes was successfully synthesized and used as a starting precursor to form nanodendritic PbO 2 via electrochemical oxidation at constant voltage. The improved electrochemical results displayed by the formed nanodendritic PbO 2 in cyclic voltammetry (CV) and initial discharge capacity, which is able to deliver 170mAhg −1 at 200mAg −1 , is significantly suggesting that the formation of nanodendrites on the primary surface of agglomerated PbO 2 provides larger crystallite network structures for better material utilization at high discharge rate.