Effects of three-dimensional current collectors on supercapacitorsʹ characteristics

Supercapacitors made of high-area electrode materials are complementary to batteries as far as electrical energy storage is concerned. Indeed, supercapacitors show low energy-density but high power-density. To achieve this, the time constant RC must be as low as possible, so the internal resistance R must be low. Apart from the effect of electrolyte resistivity and electrode thickness on the internal resistance, we show that the structure of the current collector acts on this parameter; the use of a three-dimensional current collector, such as metallic foam, results in an important decrease of the internal resistance of the cell.