Facile synthesis of highly processable and water dispersible polypyrrole and poly(3,4-ethylenedioxythiophene) microspheres for enhanced supercapacitive performance

Much recent work has focused on improving the processibility and electrocapacitive performance of conducting polymer-based materials for energy related applications. The key mechanism of conducting polymers as supercapacitor materials is driven by the rapid charging and discharging processes that involve mass transport of the counter ions insertion/ejection within the polymer structure, where ion diffusion is usually the limiting step on the efficiency of the conducting polymer capacitor. Here, we report a facile method for the green fabrication of polypyrrole microspheres (PPy-MSs) and poly (3, 4-ethylenedioxythiophene) microspheres (PEDOT-MSs) with good processability, intact morphology and large active surface for enhanced ion interchange processes, without using surfactant and highly irritant or toxic organic solvents during the synthetic process. The structure and morphology of the PPy-MSs and PEDOT-MSs were characterized by means of SEM, EDX, TEM and FTIR. Both PPy-MSs and PEDOT-MSs showed intact microsphere structures with greatly improved water dispersity and processability. More importantly, facilated by the large active surface and inter-microsphere space for ions diffusion, both the PPy-MSs and PEDOT-MSs showed a signiciantly enhanced electrical capacitive performance of 242 F g(-1) and 91.2 F g(-1), repsectively (i.e. 10 and 1.51 times in specific capacitance than the randomly structured PPy and PEDOT). This innovative approach not only addresses fundamental issues in fabrication of high performance processable microstructured conducting polymers, but also makes progress in delivering water processable conducting polymers that could be potentially used for fabrication of printed electronic devices.