Along with fundamental principles, this article covers various types of supercapacitors, such as hybrid, electric double-layer, and pseudocapacitors. Further, comprehensive electrochemical characterization methods, including galvanostatic charge–discharge, electrochemical impedance spectroscopy. . Supercapacitors (SCs) are an emerging energy storage technology with the ability to deliver sudden bursts of energy, leading to their growing adoption in various fields. This paper conducts a comprehensive review of SCs, focusing on their classification, energy storage mechanism, and distinctions. . The findings in this report primarily come from two pillars of SI 2030—the SI Framework and the SI Flight Paths. For more information about the methodologies of each pillar, please reference the SI 2030 Methodology Report, released alongside the ten technology reports. 2F, with an ultra-thin and compact. nt cycling and power capabilities, it is ideal as a short-term energy storage component for energy. It typically stores 10 to 100 times more. .