The physics of supercapacitors

Supercapacitors are electrical energy storage devices that are quickly replacing conventional batteries in high-power applications. A number of these devices exhibit dramatically large capacitance, but the microscopic mechanisms that underlie their operation remain largely mysterious. In this talk I discuss microscopic-level theories of charge storage in supercapacitors. In particular, I show how greatly enhanced capacitance arises from a combination of charge ordering at the electrode surface and strong screening of the Coulomb interaction. In this way the physics of supercapacitors has deep analogies with the physics of correlated states in electron gases and quantum Hall systems.