Effect Mechanism Of Organic/inorganic Additives On The Performance Of Lead-carbon Batterie

The conventional lead-acid battery has a short cycle life due to sulfation of the negative electrode during cycles,so carbon material was introduced to the negative electrode and then iteratively upgraded to lead-carbon batteries.However,the negative electrode of lead carbon batteries has been greatly enhanced,resulting in an excessive gap between the performance of positive electrode and negative electrode,how to improve the performance of positive electrode is the focus of current research at present.This thesis mainly focuses on the problems of low utilization rate of active material and softening off of lead paste that exist in positive active material,taking organic additive（conductive polyaniline）,inorganic additive（tetrabasic lead sulfate and manganese dioxide）as the research objects,investigates the effects of polyaniline,tetrabasic lead sulfate and manganese dioxide on capacitive characteristics,cycling stability performance and electrochemical activity of lead-carbon batteries,and further investigates the mechanism of the role of positive additives in the charging and discharging process in batteries,with the following findings:（1）The positive active materials content generated during the curing process is mainly affected by the curing temperature,and the level of positive active materials content can make a difference in the charge and discharge performance of the cured battery.The four temperatures of 60°C,65°C,70°C and 75°C were used as variables to study the effect of curing temperature on positive active materials content.When the solidification temperature is 65℃,the content of tri-basic lead sulfate within the cured positive active materials can be made to reach a maximum（51.6%）,and the chemistry has moreβ-Pb O₂,and the initial discharge and discharge under high magnification conditions of the battery exhibit higher capacities of 2.0611Ah（0.1C）and 0.8096Ah（1C）,respectively.（2）The doping of 0.2%-1.5%polyaniline as an additive into the positive active materials of lead-carbon batteries promotes the conversion efficiency of Pb O₂/Pb SO₄during charging and discharging,which in turn improves the conductivity and utilization of the positive active materials.The battery performance is best when the doping amount is 0.5%,which improves the initial discharge capacity of the battery by 68%and 136.6%at high multiplier conditions（1C）.the capacity retention of battery can be maintained at more than 92%after 100 cycles.Conductive polyaniline forms a highly efficient conductive network inside the electrode plate to improve the utilization efficiency of the positive active materials and enhance the overall battery capacity and cycling stability.（3）The waste lead paste was recycled to prepare tetrabasic lead sulfate crystal seeds,which were used as an additive for the positive of lead carbon batteries.The tetrabasic lead sulfate crystal seeds were doped into the positive electrode at 0.6%-2.0%by mass ratio.Tetrabasic lead sulfate crystal seeds as lead compounds could improve the production of low crystalline tri-basic lead sulfate during the curing process and increase theβ-Pb O₂ content within the positive active materials after chemistry.When the doping amount of tetrabasic lead sulfate crystal seeds was 1.0%,the initial discharge capacity of the lead-carbon battery could be improved by 0.3times and 1.4 times at high magnification（1C）.The capacity retention of the modified battery can be maintained at about 100%after 100 cycles in the first stage（0.5C）,and decays to failure at 40-60 cycles in the second stage（1C）.Tetrabasic lead sulfate crystal seeds constitute a conductive skeleton structure inside the electrode plate as a conductive lead compound,which reduces the corrosion of the current on the plate grid and improves the cycle life of the battery.（4）The α-Mn O₂ additive was doped into the lead carbon batteries positive electrode at the mass ratio of 0.08%-0.5%.The best performance battery can be obtained at 0.1%doping.The doping ofα-Mn O₂ material into the cathode of lead carbon batteries improves the utilization within the positive active materials and the overall conductivity of the positive active materials,promotes positive active materials conversion,and can improve electrocatalytic activity.The initial discharge capacity of the modified lead-carbon battery increased by 0.49 Ah,and the discharge capacity increased by 1.02 Ah at high magnification（1C）.the capacity retention of the Mn O₂ battery after 100 cycles is only reduced by about 2%.The Mn O₂ constitutes a tunneling structure on the surface and inside of the electrode plate to enhance the electrochemical activity and capacity of the overall battery.In addition,the above three additives were mixed and doped in the ratio of 0.5%,1.0%and 0.1%by mass to prepare the new lead-carbon batteries.The new lead-carbon batteries have an initial discharge capacity of 2.88Ah,which is a 40%improvement compared to blank batteries.The electrical capacity under 1C reaches 1.92Ah,which is 138%higher than the blank batteries.The battery capacity remains stable at around100%at all times during the cycle.The new lead-carbon batteries combine the advantages of the three additives to optimize the capacitive characteristics,electrochemical performance and cycling stability of the batteries.