Abstract
Lead-acid batteries are widely used for energy storage, due to a well-established and reliable technology. Over the years, various studies for improving the performance of this battery have been performed. The main goal is to replace conventional plates with innovative electrodes having good stability, high capacity and high surface area. In particular, it is necessary to improve the kinetics of electrochemical conversion reactions at the electrode-solution interface, and to guarantee good electrical continuity during repeated charge/discharge cycles. To achieve these goals, the attention was focused on nanostructured electrodes. Up-to-date, two principal approaches have been followed. In the first approach, 3D nanostructured current collector, such as carbon foam or 3D porous titanium, was used in place of conventional lead grid. The second method is based on the fabrication of nanostructured active material, such as nanoparticles. Our idea follows the last approach, making nanostructured active material through the synthesis of nanowires. In particular, we have obtained Pb nanostructured electrodes by template electrosynthesis in nanoporous polycarbonate membrane. These electrodes have high surface area, and allow high utilization of the active material leading to high specific energy.
Here, we show that battery with nanostructured Pb electrode works at 1C charge and discharge with very good stability for over 1200 cycles, and discharge efficiency around 90%. It is important to highlight that the C- rate here tested is far higher than that of commercial batteries, whose highest operative rate is C/5 while at 1C typically provide a capacity of 30 mAh g-1 for only 20-30 cycles.
