Lead oxide is mainly used as positive electrode in lead-acid batteries, that are characterized by long life and safety in comparison with other kinds of batteries Unfortunately, the main drawback of PbO2 electrode is the low utilization coefficient leading to a low value of specific capacity (Ah Kg-1), and fast failure in the case of high discharge rate. Nanostuctured electrodes emerged as an alternative to the conventional ones because both high aspect ratio and high superficial area allow the fabrication of batteries with high specific energy (Wh Kg-1) and power density (Wh L-1).
Electrochemical deposition is one of the possible techniques to produce PbO2. Electrodeposition offer several advantages such as low price and rapidity of the process. Moreover, it can facilitate the use of lighter weight substrates as compared to a lead alloy grid. Lead oxide nanowires was electrochemically deposited within the pores of nanoporous membrane. Morphology and chemical composition of PbO2 nanowires were investigated by scanning electron microscopy (SEM) and x-ray diffraction (XRD). The performances tests were conducted by assembling experimental electrodes with a commercial Pb plate, in 1.28 sp gr sulfuric acid solution at 25°C.
At a 1C discharge rate, a capacity of about 190 mAh/g was delivered with very good cycling stability was maintained for more than 300 cycles. This is a significant improvement in comparison to commercial PbO2 electrodes that usually deliver about 30 mAh/g for only 15-20 cycles, whilst capacity of 125mAh/g can be delivered at a C/10 discharge rate. Our nanostructured electrodes show better performances without time-consuming curing and formation processes.