In response to the growing demand for efficient energy storage systems, particularly in portable electronics and electric vehicles, this study explores the development of novel 3D-printed reduced graphene oxide (rGO) electrodes coated with polyaniline (PANI). These composite electrodes aim to enhance electrochemical properties while addressing the challenge of improving energy density without compromising performance.

The rGO electrodes were fabricated using direct ink writing (DIW), enabling precise control over thickness, ranging from 4 to 24 layers. An optimized ink formulation, consisting of rGO, cellulose acetate (CA) as a binder, and acetone as a solvent, was utilized for the printing process. PANI coatings were applied via chemical oxidative polymerization (COP) with up to five deposition cycles.

Electrochemical testing techniques, including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS), demonstrated that 12-layer electrodes with three PANI deposition cycles achieved the highest areal capacitance of 84.32 mF/cm². Thicker electrodes (16 layers and beyond) showed decreased performance due to ion diffusion limitations, yet the composite electrodes exhibited excellent cycling stability, retaining over 80% of their initial capacitance after 1500 cycles.

This work highlights the potential of 3D-printed PANI/rGO electrodes for scalable, high-performance supercapacitors with customizable architectures, contributing to advancements in energy storage solutions.