On-chip interdigitated supercapacitor based on nano-porous gold/manganese oxide nanowires hybrid electrode

The rapid development of micro-sized electronics has aroused demand for on-chip energy storage devices of high reliability, stability and performance. Micro fabrication technology has now enabled planar supercapacitors (SCs), based on various electrode materials, to be prepared onto a chip for a variety of applications. Nano-porous metal/manganese oxide hybrid electrode with enhanced conductivity and capacitive performance has been proven to be a promising candidate for SCs but has not yet been utilized for interdigitated on-chip energy storage. Herein, we demonstrate a scalable preparation of nano-porous gold/manganese oxide nanowires thin film electrode material, which can be further fabricated to on-chip interdigitated all-solid-state supercapacitors on silicon wafers so that they can be integrated with MEMS or CMOS. Also the nucleation and growth mechanism of manganese oxide nanowires on nano-porous gold has been investigated. Remarkably, the miniaturized SCs based on the nano-porous gold/manganese oxide nanowires hybrid material exhibits excellent cycle stability and superior frequency response (4 ms) and demonstrates energy density of 55 μWh cm−3 and power density of 3.4 W cm−3, which is relatively high compared with other manganese oxide based supercapacitors.