Preparation Of Tetrabasic Lead Sulfate And Its Influence In The Positive Plate Of Pb-C Battery

Lead-carbon battery received wide attention and a lot of study as the latestresearch results of lead-acid battery, which extends the applied range of lead-acidbatteries in micro-hybrid electric vehicles, electric bicycles and other fields.Currently, research on the negative plate of lead-carbon battery has becomecompleted gradually, in contrast, failure problem of positive plate caused by p ositiveactive mass degradation and loss of adherence to the grid became obvious. In thispaper, tetrabasic lead sulfate (4BS) was chosen to solve the positive failure problem.Firstly,4BS was prepared by two ways and analysed the microstructure,morphology and purity by XRD, SEM. Then,4BS was introduced to positive plateof lead-carbon battery as a nucleating agent to improve latter cycle life.Homogeneous4BS with a purity of99.9%and particle size of less than5μmcould be obtained by high temperature sintering process which should optimizefactors like sintering temperature, sintering time, concentration of reactants andstirring. Large prismatic4BS with a purity of99.9%, paricel length of25μm andwidth of10μm was prepared by hydrothemal reaction which should optimize factorslike the concentration of reactant, reaction time, reaction temperature and stirring.Large prismatic4BS could be converted to particles with a purity of98.9%andparticle size of less than500nm through high-speed milling process.When the pure4BS paste was experienced constant current formation, it couldbe seen that the obtained PbO2has the similar structure with the unformed4BS. Themain structures of positive plate doped with4BS seed and cured under conventionalcuring methods were small rod-like particles and large amouts of aggregates, and itshardness was higher than plates undoped with4BS. In the fast curing process,4BSwith content of78.3%could be obtained from plate doped with1%wt4BS seed, andsignificant prismatic4BS particles were found in the plate section.Charge-discharge cycle test showed that doping4BS in the conventiol pastecould not improve positive plate’s cycle life, but dispersing4BS powder or pasting4BS paste on the paste’s surface could improve the capacity retention ratio and cyclelife of positive plate. In this condition, the utilization ratio of positive active mass(PAM) would increase. Especially, when1%wt Al2(SO4)318H2O was added, theutilization ratio under0.05C current and0.1C current would reach43.52%and40.28%separately, increased by13.5%and24.7%compared to the control group.Inthe modified positive plate, any kind of4BS doped in the paste could improve cyclelife of positive plate, as well as for the reduction of PAM’s utilization ratio. Especially, positive plate doped with1%wt hydrothermal4BS got600cycles undera regime of charging with0.25C current to2.42V and discharging with1C current,increased33.3%compared to the control group.