The currently growing request for a continuous connectivity between people and things has increased exponentially the demand for portable and/or wearable electronics. Thus, high performance components with more compact size, lower power consumption, and increased energy storage capability are needed. Although electronic active components have downscaled and and their performance optimized over the years, passive elements (e.g., resistors, capacitors, and inductors) have made only little progress.Supercapacitors (SCs) are electrochemical capacitors that can achieve very high capacitance density, in the order of 0.1–1 mF/mm2. Nonetheless, SC intrinsic low operation voltage (a few Volts) and reduced frequency range (up to a few hundreds of Hertz), together with their poor compatibility with integrated circuit (IC) processes have inhibited their electronic applications to date1. Dielectric …