Study On The Effect Of Stereotaxically-Constructed Graphene On The Cathode Performance Of Lead-Acid Batteries

Lead-acid batteries are a mature commercial battery which has been widely used in energy storage systems.With the popularization and application of renewable energy sources such as wind and solar energy,energy storage systems has received widespread attention as the key for the use of renewable energy,indicating that choice of energy storage batteries is critical for the use of renewable energy.Lead-acid batteries with higher energy density and longer cycle life are needed to meet the battery requirements of large-scale energy storage systems.According to the principle of chemistry,the theoretical energy density of lead-acid battery is about 170 Wh kg^-1,unfortunately,the energy density of the currently used lead-acid battery is only 30 to 40 Wh kg^-1 because of low utilization and irreversible sulphate of the negative active materials,coupling with electrolyte,housing and other factors.There is a great potential for improvement.The addition of carbon material to the negative electrode of lead-acid battery can effectively inhibit the irreversible sulphate of the negative active material?NAM?.Graphene has large surface area,excellent conductivity and chemical stability,being an excellent additive for NAM of lead-acid battery.In this paper,we added a stereotaxically-constructed graphene material which is synthesized by a cost-effective thermal pyrolysis method into the NAM of lead acid battery to improve the utilization rate of the NAM of the lead acid battery and extend the cycle life of the battery.The specific research contents are as follows:1.Using a pre-dispersion method:firstly,the stereotaxically-constructed graphene material and other additives of NAM are were ground for half an hour and dispersed in ethanol?10 m L?by sonicating,then lead powder was added into the solution and stired one hours until all kinds of additives can be evenly distributed in lead powder.By comparing the experiment,the most effective addition for SCG in the NAM of lead-acid battery was explored,and the amount added was 0.1wt%?versus the lead oxide?.As an addition for the NAM,the SCG electrode exhibits an initial discharge capacity up to 173.8 m Ahg^-1 at the current density of 0.1C.Under the high-rate partial-state-of-charge?HRPSo C?condition,the SCG text battery shown an outstanding cycles life of 10,077 cycles.With the addition of SCG materials,the NAM demonstrated a high utilization rate and good cycle life.2.Through solvent thermal method,we obtained nano-lead deposits on the surface of the SCG?Pb@MSCG?with modified SCG?MSCG?,which was treated with nitric acid.Compared with the SCG material,Pb@MSCG material has a higher density,which reduces the specific gravity difference with lead powder and helps the material disperse evenly in lead powder.Because of the deposition of Pb nanoparticles,it will be a better affinity between Pb@MSCG and NAM,and help inhibit hydrogen evolution reaction.