Study On Supercapacitor Electrode Materials And Porous Carbon-based Oxygen Reduction Electrocatalysts

The potential exhaustion of fossil fuels and the environmental impacts associated with greenhouse gas emissions have led to increasing global demands sustainable energy.Renewable energy sources such as solar energy,water energy and wind energy are the main ways to solve these problems.However,the instability and unsuitable storage of these energies inevitably require the first energy storage system with high power and high energy density.Fuel cells and supercapacitors are one of the most efficient and reliable technologies for electrochemical energy conversion and storage.Therefore,research and development of new energy storage devices are of great significance for solve the current energy crisis.This paper mainly studies supercapacitors with good electrochemical performance and electrocatalysts with excellent oxygen reduction reaction performance for the assembly of zinc-air batteries.The content includes the following:1 A series of NaNixCo1-xPO4 electrode materials were prepared by microwave-assisted method and used as electrode materials for supercapacitors.NaNi0.33Co0.67PO4·H2O electrode material has good electrochemical performance.The specific capacity can reach 828 F g-1 when the current density is 1 A g-1.When the current density is increased by 10 times,the capacitance is still maintained at 88.7%,it has non-high rate performance.Use it to assemble asymmetric supercapacitors,the energy density of the supercapacitor can reach 29.85 Wh kg-1 at a power density of 374.95 W kg-1,and at high power density of 24.37 Wh kg-1 the energy density 7500 W kg-1.The capacitor also has long-term cycle stability.After 10,000 cycles,the capacitor value remains 76.9%.2 A nitrogen-rich-supercrosslinked polymer synthesized with 2,2'-bipyridine and p-dichlorobenzyl as monomers was activated by adding alkali at high temperature to obtain nitrogen-doped porous carbon with high specific surface and multi-level pore structure.Nitrogen-doped graded porous carbon material.The optimal electrode material N-HPC-8-2 was obtained by adjusting the calcination temperature and alkali content,and its specific capacity could reach 302 F g-1 at 0.5 A g-1.After 5000 cycles,the specific capacity is still 96.2%.When forming a symmetrical capacitor,when the power density is 151.7 W kg-1,the energy density of the electric double layer capacitor can reach 12.61 Wh kg-1.After 10,000 cycles,the capacitance value remains at 80%.This catalyst has good cycle life and electrochemical performance.3 N,S double-doped lamellar porous carbon containing iron was prepared by the self-sacrifice template method.Tests have shown that Fe@S,N/C-800 catalyst has has high catalytic activity,good methanol tolerance and excellent cycle stability in alkaline environment.At the same time,the electrocatalyst has a high specific surface area,which allows the active sites to be fully exposed,thereby accelerating the transfer of electrolyte ions.The liquid zinc-air battery prepared using Fe@S,N/C-800 as the cathode has a high energy density(130.2 mW cm-2),high open circuit potential(1.44 V),and excellent stability.