Pioneering 10 Khz+ Applications: The Promise of Asymmetrically Designed Hybrid Micro Supercapacitors

Micro supercapacitors (MSCs) are the promising substitute to bulky electrolytic capacitor due to the ultrahigh capacitance density, yet their low characteristic frequency strictly limits the potential in circuit applications. This paper presents a novel strategy for designing a hybrid electrochemical-electrolytic electrode to achieve a record-high MSCs characteristic frequency. Specifically, the cathode of hybrid MSC is based on an electrochemical effect and made of porous Au, providing large capacitance, while the anode of MSC is similar to an electrolytic capacitor electrode and made from Al
2
O
3
-covered porous Au, providing high-frequency response. Such hybrid MSC exhibits an exceptional characteristic frequency of 14,700 Hz, more than one order higher than previously reported MSCs, and five times higher than commercial electrolytic capacitors. Moreover, the hybrid MSC is fabricated by wafer-level fully CMOS-compatible processes, ensuring mass production and chip integration capabilities.