Lithium-ion supercapacitors for pulsed power applications

A new class of supercapacitors has the potential to supplement or replace mechanical flywheels for energy storage and pulsed energy in some high power applications. These Lithium Ion Capacitors have three times the gravimetric energy density, and five times the volumetric energy density of standard electric double layer supercapacitors. In this work, we utilize two experimental test bench systems; one constructed with a motor/generator/flywheel combination, and the other with a purely solid-state solution using Lithium Ion Capacitors. This is done to facilitate a comparison that demonstrates the potential of this new device for solid-state energy storage. Of particular interest is the fact that Li-ion capacitors, as an energy storage component, offer gravimetric energy density (50-60 J/g) comparable to state-of-the-art flywheels, thus making them a possible replacement as the energy-storage media in some applications utilizing flywheel technology as the most cost effective solution. Also discussed are other unique capabilities of Li-ion capacitors, including long lifetime, high reliability, zero maintenance, and very low energy leakage, which allow energy storage for many years without power input.