Porous RuO_xN_yS_z Electrodes for Microsupercapacitors and Microbatteries with Enhanced Areal Performance

Three-dimensional (3D) electrodes with improved areal energy have become increasingly important for microscale energy storage at the dawn of the Internet of Things. At its heart are a plethora of microelectronic devices that require embedded energy harvesters and energy storage components to ensure autonomy. In this study, we develop porous metallic microstructures and their conformal coating with a new RuOxNySz material through a facile optimized electrodeposition process. The microporous structure with a nanodendritic network shows high areal capacitance (14.3 F cm–2 for the electrode and 714 mF cm–2 for an all-solid-state microsupercacitor) and stable performance (>80% retention after 5000 cycles) toward H+ storage. Remarkable Li+ storage capability with high areal capacity (5 mAh cm–2) and rate characteristics (1.5 mAh cm–2 at 3C) is also observed. These results coupled with a facile synthetic strategy can thus offer inspiration for large-scale production of 3D porous electrodes for microbatteries and microsupercapacitors.