Application Of Capacitive Active Carbon In Cathode Of Lead-acid Battery

Energy crisis and environmental pollution have become the major problems faced by thehuman being. Hybrid electric vehicle, therefore, has attracted much attention and hasdeveloped very quickly in recent years. In order to meet the requirements of hybrid electricvehicle in extreme conditions, the electric battery with excellent high current charge anddischarge properties as well as long cycle life is urgently in need. In this work, theapplications of capacitive active carbon materials with large specific surface area in lead-acidbattery cathode have been studied in detail.Lead-carbon batteries using the active carbon with specific surface area of2000cm²/g asthe additive in cathode were fabricated in this work. The effects of active carbon withvariouscontents from1%to5%on the properties of the battery were investigated. The resultsshowed that the addition of3%active carbon in the cathode material can form more activematerial of secondary lead structure after formation, increase discharge capacity in differentdischage rates, improve the efficiency of the active material, and also reduce the content leadin cathode. During high current charging, the active carbon can reduce charging voltage ininitial process, and improve the charging efficiency. During high current discharging, it canreduce the polarization in cathode and improve discharging voltage. Lead-carbon battery alsohas reduced sulfate and anode passivation in high rate partial state of charge cycles.Lead-carbon battery with3%active carbon addition in cathode has the highest cycle life ofHRPSoC of4418times. The recoverd capacity is also as high as80%. The cycle life of thesecond HRPSoC is1324times.Cathode is parallel connected by cathode of lead-acid battery and carbon electrode ofsuper capacitor, and anode is still the traditional lead-acid battery anode—“ultrabattery”.The study finds that active carbon electrode can not work well in the state of lead-acid batterycondition, and make the hydrogen evolution behavior. Active carbon electrode has lowerspecific capacity in1.28g/cm³H₂SO₄, and hydrogen evolution increases with increasingconcentration of sulfuric acid; It has larger specific capacity in the relative positive range, buthas a lower specific capacity in-0.4⁰.4V range of lead-acid battery working condition.However, the study of the parallel electrode with Pb and active carbon electrode and PbO₂/AC hybrid capacitor found active carbon electrode can own buffer action in ultrabattery.It was also demonstrate that the ultrabattery is superior to the traditional lead-acid batteryregarding to its high current charge and discharge behavior. The capacity of the ultrabattery isreduced by only7%after3000times HRPSoC cycles. For comparison, the traditionallead-acid battery capacity is reduced by30%. Hence, the addition of active carbon in cathodecan produce buffer effect, and improve the cycle life of the cell in high rate current. Comparedto traditional battery, Lead-carbon ultrabattery with active carbon addition has better chargingand discharging capability, and increased cycle life. The present work provides a feasibleapproach to prepared untrabattery with excellent properties.