Electrochemical and Microwave Absorbing Properties of Polypyrrole Coated Silicon Carbide Aerogel Composites
Polypyrrole(PPy)is used as an electrode material for supercapacitors due to its high specific capacitance,high conductivity,high flexibility and structural diversity.It can be compounded with other materials to improve dielectric loss and absorption performance.PPy-coated silicon carbide(SiC)aerogel composites were synthesized by chemical in-situ polymerization,which effectively solved the problems of the decline of cycle stability of PPy-based supercapacitors induced by the ion doping/dedoping during the charging/discharging process.The electrochemical performance of the composite material was measured by the three-electrode system,and the electromagnetic parameters were tested with the vector network analyzer.The results show that the specific capacitance reaches 309.65 F·g-1 at a current density of 0.5 A g-1,and the specific capacitance retention rate is 94.2％after 1000 cycles,indicating good cycle stability.The aerogel can maintain a height of 95％subjected to 100 repeated pressure.The compressive strength is 105 kPa.The effective absorption intensity at 2.2 GHz is 22.32 dB,while the value for PPy is only 8.99 dB,which effectively improve absorption intensity.Therefore,SiC/PPy composites are promising electrode materials for supercapacitors and electromagnetic wave absorbing materials.
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