A pH‐Tailored Anodic Deposition of Hydrous RuO₂ for Supercapacitors

Abstract

A pH‐tailored anodic deposition strategy is reported in this work, by which the hydrous ruthenium oxide (RuO2) can be directly deposited on titanium (Ti) substrates. The prepared RuO2 electrode exhibits a well kinetic performance (the remarkably low equivalent series resistance of Res∼2 mΩ and charge transfer resistance of Rct∼0.11Ω) and a high specific capacitance of 756 F g‐1 at 0.6 A g‐1. More importantly, a symmetric supercapacitor based on the RuO2 electrode delivers a high specific energy of 24 Wh kg‐1 at 150 W kg‐1. Even at a large specific power of 26.25 kW kg‐1, specific energy is still as high as 8.6 Wh kg‐1, meanwhile achieving a long lifespan of 98% retention over 100,000 cycles. All of these distinguishing properties not only enable the prepared RuO2 to be an excellent electrode material for high‐power output and long life supercapacitors, but also indicates that the pH‐tailored anodic deposition strategy reported in this work is effective to prepare high‐performance RuO2 electrode.

Composite g‐C3N4/NiCo2O4 with Excellent Electrochemical Impedance as an Electrode for Supercapacitors

“…The supercapacitor electrode is the most crucial part of the storage capacity of the supercapacitor. In previous studies, pseudo-capacitance electrodes are mainly composed of oxides of elements such as Co [7][8][9], Fe [10,11], Ru [12][13][14], Mn [15,16], Ni [17,18], W [19,20], and Zn [21,22]. These metal oxides have relatively high theoretical capacitance values [23,24], and the synthesis method is simple.…”