[News] Tsinghua University Research Team Made New Progress in High-Frequency Supercapacitor Research

Recently, the research team led by Professor Wang Xiaohong from the School of Integrated Circuits at Tsinghua University has made a breakthrough in the study of the dynamic response limits of high-frequency supercapacitors. For the first time, they experimentally quantified the upper limit of the dynamic response frequency of supercapacitors.

The team constructed ideal electrodes with absolutely flat, pore-free surfaces using micro-nano fabrication techniques, and precisely determined the upper bound of the dynamic response frequency of supercapacitors for the first time by introducing parasitic capacitance shielding structures and external phase-locked loop amplification to eliminate interference.

Building on this, the team innovatively proposed the concept of a “dielectric-electrochemical” asymmetric capacitor — a device dominated by electrochemical effects at low frequencies and by dielectric effects at high frequencies, which achieves a dual breakthrough in both frequency response and capacitance density. The micro supercapacitor chip developed based on this concept has a characteristic frequency exceeding 1 MHz, which is six orders of magnitude higher than that of commercial supercapacitors and covers the operating frequency range of mainstream power circuits.

In recent years, Professor Wang’s team has systematically conducted researches on the dynamic mechanisms, wafer processing methods, and chip integration technologies of high-frequency supercapacitors. Previously, the team successfully overcame the challenge of process incompatibility between electrochemical and semiconductor devices, proposed a cross-energy-domain heterogeneous integration theory and a three-dimensional architecture, established a CMOS-compatible wafer-level full-process fabrication system, and developed the world’s first integrated electrochemical power rectification and filtering chip.