Influence of oCVD Polyaniline Film Chemistry in Carbon-Based Supercapacitors

Polyaniline (PANI) is integrated into Mo₂C carbide-derived-carbon (CDC) electrodes using the single-step, solvent-free process of oxidative chemical vapor deposition (oCVD). By optimizing the oCVD processing conditions, CDC electrodes integrated with oCVD PANI exhibit more than double the gravimetric capacitance (115 F/g) vs bare CDC electrodes (52 F/g) and a 79% capacity retention after over 10 000 cycles. The oxidant flow rate, substrate temperature, and reactor pressure were varied, and their influence on film chemistry and supercapacitor performance was explored electrochemically and with FTIR and XPS. The study reveals that a higher substrate temperature, pressure, and oxidant flow rate are critical for depositing emeraldine PANI for optimal electrochemical performance. Interestingly, the optimally performing PANI-CDC devices have a porous PANI morphology as determined by SEM, which may facilitate ion transport, improve scan rate performance, and impart electric double layer capacitance in addition to the intrinsic Faradaic pseudocapacitance.