聚吡咯纳米管/碳纳米管复合材料在氧化还原电解液中的电化学性能

Electrochemical Performance of Polypyrrole Nanotubes/Carbon Nanotubes Composites in a Redox Electrolyte

用模板法制备聚吡咯纳米管(PPyNTs),然后采用乙醇混合法将其和多壁碳纳米管(MWCNTs)制备了复合电极材料(PM)。比较不同材料在传统H2SO4电解液和添加了具有氧化还原活性物质胭脂红(AR18)的电解液中的电化学性能。三电极测试结果表明,在H2SO4电解液中PPy纳米颗粒的比电容为220F/g,在氧化还原电解液中,PPyNTs的比电容为579.2F/g,高于PPy纳米颗粒(445F/g),而PM复合材料的最高比电容可达674.2F/g,既高于单一PPyNTs又高于MWCNTs的(405.8F/g)。利用性能优化的PM-3复合材料组装对称电容器,当电流密度为0.5A/g时,功率密度为300W/kg,能量密度达15.7Wh/kg,且经过5000次循环,电容保持率为90%。说明AR18和H2SO4构建的氧化还原电解液能够提供额外的氧化还原反应,使具有双电层电容和赝电容的复合材料具有更加优良的电化学性能。

Redox electrolytes benefit the improvement of electrochemical performance.After preparing polypyrrole nanotubes(PPyNTs)via template method and polypyrrole nanotubes/carbon nanotubes composites(PM)through mixing method,the electrochemical performances of various materials were tested in a H2SO4 electrolyte and a redox electrolyte fabricated by H2SO4 and carmine(AR18).In a three-electrode system,the specific capacitance of PPy nanoparticles is 220 F/g in the H2SO4 electrolyte;that of PPyNTs is 579.2 F/g in the redox electrolyte,which is higher than that of PPy nanoparticles(443.3 F/g).Also,that of PM composites is 674.2 F/g,which is the highest specific capacitance among these materials.A symmetric supercapacitor is assembled to prove the excellence of electrode material and the contribution of the redox electrolyte.The results show that an energy density of the supercapacitor is 15.7 Wh/kg at a power density of 300 W/kg with a current density of 0.5A/g.After 5000 cycles,the capacitance retention rate is 90%.Thus,with the help of redox electrolyte,PM composites owning both double-layer capacitance and pseudo-capacitance have much excellent electrochemical performance.