Recent improvements in PbO2 nanowire electrodes for lead-acid battery

Lead oxide nanowires are an attractive alternative to conventional pasted electrodes, owing to their high surface area leading to high specific energy batteries. Here, we report the performance of template electrodeposited PbO2 nanowires used as positive electrodes. Nanostructured electrodes were tested at constant charge/discharge rate from 2 C to 10 C, with a cut-off potential of 1.2 V and discharge depth up to 90% of the gravimetric charge. These new type of electrodes are able to work at very high C-rate without fading, reaching an efficiency of about 90% with a very good cycling stability. In particular, after an initial stabilization, a specific capacity of about 200 mAh g-1, very close to the theoretical one of 224 mAh g-1, was drained for more than 1000 cycles at a C-rate higher than 1 C with an efficiency close to 90%. This behaviour significantly distinguishes PbO2 nanostructured electrodes from the conventional ones with pasted active material. In addition, discharge at a quasi-constant voltage of about 2.1 V, without reaching the cut-off potential also at high C-rate, occurs. This implies a quasi-constant energy supply during fast discharge. According to these findings, innovative applications as hybrid or electrical mobility or buffer in renewable energy plants can be envisaged.