Lead phosphate prepared from spent lead compounds as a negative additive for lead-acid batteries
摘要
Agglomerated nanorods of lead phosphate have been synthesized from the reaction of lead acetate prepared from waste lead paste and Na2HPO4, which is used as an additive for the PbSO4-negative electrode of a lead-acid cell. It has been found that lead phosphate can be all converted to lead sulfate in 36 wt.% sulfuric acid electrolyte and generate phosphoric acid, and the negative active material containing 1 wt.% lead phosphate discharges a capacity of 111 mAh g−1 at 100 mA g−1 till 1.75 V; it still discharges 78 mAh g−1 after 1200 cycles, which is 10.1% higher than the blank PbSO4 electrode. It is believed that phosphoric acid could remove the non-conductive oxide on the lead alloy grid; thus, a better conductive network could be built. Also, phosphoric acid is adsorbed on PbSO4 particles, which can improve the reversibility of the electrode and diminish the shedding of PbSO4.