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

Abstract

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 (similar to 100 times) and double layer capacitance (similar to 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. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.