Supercapacitors: Size Matters

Carbon supercapacitors use ion adsorption on the surface of highly porous carbon electrodes to store charge. Studying the effect of the pore size on capacitance has the potential to improve performance by maximizing the available surface area, but until recently, the lower limit of accessible pores had been unknown. It has long been believed that pores smaller than the size of solvated electrolyte ions are incapable of contributing to charge storage.