Origination of forced particle-void networks for superior electron and mass transfer in binder-free supercapacitors

Recent developments in the field of energy storage systems have led to the need for a process that can synthesize an electrode in a cost-effective and environmentally friend manner with excellent performance. In this study, we developed a noble electrode structure by direct powder deposition process of MnO₂ powder for a pseudo-capacitor configuration. This homogeneous electrode has uniformly distributed pores and direct contact between MnO₂ particles, which helps improve ionic transport in an aqueous electrolyte and electron transport between MnO₂ particles. In addition, electrochemical impedance analysis confirms that the homogeneous MnO₂ electrode structure by powder deposition has a considerably lower value of charge transfer resistance (∼ 100 times) and double layer capacitance (∼10 times) compared to those for paste-type electrodes. Furthermore, our electrodes maintain a high specific capacitance of 383.4 F g⁻¹ at more than 2 mg cm⁻² of mass loading, whereas the capacitance of the paste-type electrode decreases considerable.