菲醌修饰多孔碳纳米管复合材料的制备及其在对称超级电容器中的应用

Preparation of phenanthrenequinone modified porous carbon nanotube composite material for symmetric supercapacitor

为获得具有优异电化学性能的超级电容器电极材料,首先依次对实验合成的聚吡咯(PPy)纳米管进行碳化处理和活化处理来制备层级多孔碳纳米管(PCNTs)。然后用一步溶剂热法将9,10-菲醌(PQ)分子通过π-π堆积作用进一步修饰到PCNTs表面得到PQ分子非共价修饰的PCNTs复合材料(PQ/PCNTs)。不仅对合成的复合材料进行了形貌表征,而且还通过循环伏安法(CV)、恒电流充放电(GCD)和电化学阻抗谱(EIS)研究了具有不同PQ分子负载率的复合材料(PQ/PCNTs)的超级电容性能。实验结果表明:PQ分子与PCNTs质量比为5∶5的复合材料的电化学性能最好,在1 A·g^(-1)的电流密度下的比容量可以达到407.7 C·g^(-1)。同时复合材料表现出优异的倍率性能(电流密度为50 A·g^(-1)时的比容量为307.3 C·g^(-1))和循环稳定性能(在10 A·g^(-1)电流密度下循环10,000次后电容保持率为91.4%)。为了进一步研究复合材料的实际应用性能,以PQ与PCNTs质量比为5∶5作为电极材料组装了对称超级电容器,组装后的对称超级电容器可提供高达21.5 W·h·kg^(-1)的能量密度和0.8 kW·kg^(-1)的功率密度。

In purpose of obtaining electrode materials with superior electrochemical properties for supercapacitor,porous carbon nanotubes(PCNTs) were firstly prepared by the carbonization and activation of polypyrrole(PPy)nanotubes. The obtained PCNTs were further modified with 9,10-phenanthrenequinone(PQ) molecules via π-πstacking interaction through one-step solvothermal method. The electrochemical performance of the obtained composites(PQ/PCNTs) with different mass ratios of PQ to PCNTs as the electrode materials for supercapacitors were investigated by cyclic voltammetry(CV), galvonostantic charging-discharging(GCD) and electrochemical impedance spectroscopy(EIS). The experimental results show that the composites with the mass ratio of PQ molecule to PCNTs of 5∶5 achieves the largest specific capacity of 407.7 C·gat a current density of 1 A·g^(-1). The resultant composite also exhibits excellent rate capability(the specific capacity at a current density of 50 A·g^(-1)is equal to 307.3 C·g^(-1))and cycling stability(capacitance retention of 91.4% after 10,000 cycles at the current density of 10 A·g^(-1)). Furthermore, a symmetric supercapacitor was assembled with the mass ratio of PQ molecule to PCNTs of 5∶5 as electrode materials to investigate the practical applications of the composites. And the assembled symmetric supercapacitor delivers an energy density as high as 21.5 W·h·kg^(-1)and a power density of 0.8 kW·kg^(-1).