Morphology-Dependent Enhancement of Pseudocapacitance of Tunable Template-Guided Polyaniline Nanostructures

Wei Chen, R.B. Rakhi, and H.N. Alshareef, “Morphology-Dependent Enhancement of Pseudocapacitance of Tunable Template-Guided Polyaniline Nanostructures”
J. Phys. Chem. C, 2013117 (29), pp 15009–15019
Wei Chen, R.B. Rakhi, and H.N. Alshareef
Morphology-Dependent, Polyaniline
Polyaniline is one of the most investigated conducting polymers as supercapacitor material for energy storage applications. The preparation of nanostructured polyaniline with well-controlled morphology is crucial to obtaining good supercapacitor performance. We present here a facile chemical process to produce polyaniline nanostructures with three different morphologies (i.e., nanofibers, nanospheres, and nanotubes) by utilizing the corresponding tunable morphology of MnO2 reactive templates. A growth mechanism is proposed to explain the evolution of polyaniline morphology based on the reactive templates. The morphology-induced improvement in the electrochemical performance of polyaniline pseudocapacitors is as large as 51% due to the much enhanced surface area and the porous nature of the template-guided polyaniline nanostructures. In addition, and for the first time, a redox-active electrolyte is applied to the polyaniline pseudocapacitors to achieve significant enhancement of pseudocapacitance. Compared to the conventional electrolyte, the enhancement of pseudocapacitance in the redox-active electrolyte is 49%–78%, depending on the specific polyaniline morphology, reaching the highest reported capacitance of 896 F/g for polyaniline full cells so far.