Methanothermal treatment of carbonated mixtures of PbSO_4 and PbO_2 to synthesize α-PbO for lead acid batteries

摘要

We have developed a novel route to make new batteries from spent ones, in which we obtain and regenerate the active materials of positive electrode and negative electrode respectively. For the spent lead acid batteries, the positive electrode active materials contain both PbSO_4 and PbO_2. To make full use of them, we have to investigate the treatment of the mixtures rather than only PbO_2, which we have reported previously. Here we report our investigation on three mixtures of PbSO_4 and PbO_2 in different mole ratios, as well as the electrode materials directly from the spent batteries. The mixtures are firstly desulphated, and then solvothermally processed in methanol at 140 ℃ for 24 h. The as-obtained solids contain both PbO·PbCO_3 and PbCO_3, which have been calcined to form α-PbO. The α-PbO powders are similar irregular particles and highly electrochemically active, which discharge around 170 mAh g~(-1) at 5 mA g~(-1), 80 mAh g~(-1) at 200 mA g~(-1) and 60 mAh g~(-1) at 400 mA g~(-1) with excellent cyclic stability in 50 cycles.