Experimental Research On The Preparation Of PbO₂ Electrode From Waste Lead-acid Battery Paste

The lead content of spent lead acid batteries are very high and meanwhile they are the main raw materials in the secondary lead industrial.Serious environmental pollution and resource waste would be caused by lead,a kind of heay mental,if it’s abandoned in the environment.The main components of spent paste include lead lead sulfate,lead oxide and lead dioxide.In this paper,the lead paste of waste lead-acid battery is used as raw material and the waste lead paste is transformed into lead carbonate by desulfurization conversion.The lead-rich electrolyte is prepared by methanesulfonic acid and lead carbonate,and the lead dioxide electrode is prepared by electrodeposition.The main experimental parameters are discussed and studied.It is beneficial to the environment and human society by recycling the spent lead paste of lead acid battery.In order to improve the conversion efficiency of spent lead paste into lead carbonate,the effects of Pb⁴⁺/H₂O₂、H₂SO₄/PbO and time on the sulphuration rate of waste lead paste were studied.The experimental results show that the best sulphuration rate of spent lead paste is 97%when Pb⁴⁺/H₂O₂ is:1:1.4;H₂SO₄/PbO is 1.2:1;time is50min.At the same time,the effects of C/S ratio,desulfurizing agent and time on the desulfurizing rate of lead paste were also studied.The results show that the desulfurization efficiency of sodium carbonate is better than that of ammonium bicarbonate.So the best desulfurization efficiency of 95.4%can be obtained when the ratio of C/S is 1:1.5 and the time is 10 hours.The effects of time,temperature,electrode spacing,current density and initial electrolyte concentration on energy efficiency and energy consumption were studied.The experimental results show that the optimal process parameters are:electrolyte temperature:40℃,electrode spacing:20mm,current density 30m A/cm^-2,initial electrolyte concentration 0.25 mol/L,electrodeposition time2.5 h.Compared withβ-PbO₂ electrode,α/-βPbO₂ electrode has a higher specific surface area and a higher oxygen evolution over-potential,and it has a stronger oxidation removal ability for benzoic acid in water.The preparation of lead dioxide electrode from spent lead acid battery paste provides a new attempt for the recovery of lead-acid battery from the perspective of terminal products,which has certain reference significance.