Preparation And Performance Research Of Two Kinds Of Porous Carbon Derived From Biomass With High Capacitance

The population’s expansion and the over-abundance of fossil fuels have caused a plethora of unforeseen crises and difficulties to befall human civilization in recent times.The pressing necessity of energy in our current society has become ever more pressing,necessitating the development of pollution-free,high efficiency,and sustainable energy storage systems.Attracting much attention due to their high power density and excellent cycle stability,supercapacitors have become the most promising energy of recent years.Despite their low energy density,supercapacitors are restricted in their growth.The influence of electrode materials is the essential factor in supercapacitors’performance.In this paper,we successfully prepared two kinds of porous carbon derived from biomass with high capacitance through simple pyrolysis and activation methods and tested their corresponding characterization and electrochemical performance.The main work is as follows:（1）Using lettuce leaf as raw material,porous carbon electrode material was prepared by two-step carbonization method.The electrochemical test revealed that the material’s specific capacitance could reach 196.5 F g^-1 at a current density of 0.5 A g^-1.After 5000cycles,the material’s cyclic stability is demonstrated,with its current density of 20 A g^-1allowing it to reach a capacity of 94.8%of its original capacity.（2）The porous carbon material with high voltage and large capacity was prepared from celery leaves by simple method.Layered porous carbon materials can achieve both high capacity and long cycle durability due to their high surface.The specific capacitance is up to 753.7 F g^-1 at 0.5 A g^-1,and the capacity retention rate is remarkable,reaching a remarkable 96.7%even after 5000 cycles.The supercapacitors,symmetrical and assembled,offers a remarkable energy density of 17.36 Wh kg^-1 at 250 W kg^-1.The effects of yellow,green and different activation temperatures on the properties of electrode materials were also systematically studied.Results demonstrate that the electrochemical performance of the biomass carbon electrode material is remarkable,making it ideal for the production of high-grade energy systems and green supercapacitors.