In recent years metal ion capacitors (MICs) and supercapacitors devices have been reported as promising alternatives for energy storage on a large scale. MICs are characterized by superior power density and energy density, combining advantages of metal-ion batteries such as lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, zinc-ion batteries, etc., and those of supercapacitors. Herein we provide a review of recent progress on MICs, focusing on the sodium-ion capacitor (SICs), potassium-ion capacitors (PICs), and zinc-ion capacitors (ZICs); starting from the basic concepts (...
