Lead Sulfate Based Negative Electrode Of Lead-carbon Batteries

Lead-acid batteries are widely used as automotive starting power supplies.In recent years,cities are becoming larger and larger and the city’s traffic is increasingly relying on personal transportation means,which has caused the deterioration of urban air quality.It is particularly important that when the lights are blocked at the junctions,the car has to brake until it is allowed to pass.The gasoline engine operation of this process is inefficient and generates serious air pollution.Based on this reason,people have applied a"start-stop technology"to reduce engine emissions when the vehicle is at stationary state.In order to ensure the normal operation of the start-stop technology,the automotive start-up power supply has to be discharged at high-rate partial-state-of-charge（HRPSoC）,which results in the rapid sulfation of the lead-acid battery and end of life.Studies have been found that adding carbon material to the negative of a lead-acid battery can suppress the growth of the lead sulfate crystal and increase its charge acceptance capability,resulting in the formation of a Pb-C battery.However,because the hydrogen evolution over potential of carbon materials is lower than that of lead,it may cause the internal pressure of the battery to rise and also reduce the energy conversion efficiency in the charging process.Different from the existing literature work,this paper mainly studied carbon materials of Pb-C batteries with PbSO₄ as negative electrode active material.In this thesis,we first reported the properties of six commercial carbon materials,and then reported the performance of the synthesized sulfonated graphene.The results are as follows:When carbon materials such as activated carbon,acetylene black,coconut shell carbon,MCNT,graphene and superconducting carbon are applied to the negative electrode with PbSO₄ as the active material,the hydrogen evolution current of activated carbon was the smallest and the conductivity was second only to acetylene black.When 1.0wt.%acetylene black and 1.0wt.%activated carbon were added to the paste,the battery had a higher discharge specific capacity of 96.3 mAh?g^-1 at a current density of 100 mA?g^-1 and the HRPSoC cycle are 2397 times.The battery performance is stable under this formula.Graphite oxide was prepared with Hummers method,and then with 80%hydrazine hydrates pre-reduction.Finally,sulfonated graphene was prepared using the amino benzene sulfonic acid.Fourier infrared characterization and EDS spectrum diagram proved that the sulfonic group was successfully attached to the reduction graphene and then sulfonated graphene was applied to the PbSO₄ negative electrode.The battery performance was the best when the sulfonated graphene was added at 1.0wt.%.The discharge capacity was85.1mAh?g^-1 at a current density of 100 mA?g^-1 after 200 cycles and the HRPSoC cycle reached 11787 times.The rate test as well as showed that the battery is relatively stable under this formula.