Study On Electrochemical Behavior And Preparation Of High-temperature Derivatives Of Solid Carbon Sources In Nature

The development of energy storage highlights the research works of preparation of porous carbon electrode materials and their electrochemical performance.It is important part that using solid-state carbonaceous feedstocks generates porous carbon materials as well their electrochemical performance.Therefore,we study the production of porous carbon from natural precursors through high-temperature conditions,and the electrochemical properties is analyzed.The paper includes biomass derived porous carbon and graphite derived exfolation graphene.(1)Combining hydrothermal and high-temperature treatment ultimately synthesizes the 3D laminated porous carbon networks structure,which is composed of short nano-chains and bridged nanospheres.The porous carbon is used as the anode of lithium-ion batteries and supercapacitor electrodes.The carbon material obtained at 800 °C exhibits a high lithium storage capacity(504.8 m Ah g-1 at 100 m A g-1)and specific capacitance(337.4 F g-1 in the three-electrode electrochemical configuration and 322.9 F g-1 in a symmetrical two-electrode supercapacitor cell at a current density of 0.5 A g-1).(2)Based on the cell structure,a pickle method effectively introduces the activation agent into tomato,and subsequently the hierarchical porous carbon is fabricated by the high-temperature process.The obtained materials have the high carbon content(97.7%),high specifc surface area(863.6 m2 g-1)and good conductivity(195 S m-1).It shows a specific capacitance of 347.4 F g-1 at the current density of 0.5 A g-1 when the porous carbon is used as electrode of the supercapacitros.Furthermore,flexible supercapacitor was fabricated,and the drop,bending and nondestructive temperature tests demonstrate the stable and safe capacitive performance.(3)The lignin aerogel constructed by two kinds of micro-nano units of biomass(lignin and cellulose)using “bottom-up” method.Subsequently,the lignin aerogel is subjected to high-temperature carbonization to generate the porous carbon material,which is used as the electrode of supercapacitor.It exhibits excellent capacitance performance with a specific capacitance of 221.9 F g-1 at 1A g-1.(4)An available KOH thermal method generates ultralow-defect graphene in a greener and safer approach.The ab initio molecular dynamics simulations demonstrate that the alkali metal ions cleave the natural graphite at high temperatures.Furthermore,the graphene has well application in miro-electronics and epidermal sensors.