PbO 2 /activated carbon (AC) hybrid supercapacitor in H 2 SO 4 with a carbon foam current collector is studied. The PbO 2 /AC hybrid is designed with electrodeposited PbO 2 thin film as positive electrode to match with AC negative electrode. The discharge curve shows capacitive characteristics between 1.88V and 0.65V. The hybrid system exhibits excellent energy and power performance, with specific energy of 43.6Wh/kg at a power density of 654.2W/kg. The use of carbon foam current collector ensures stability of the PbO 2 electrode in H 2 SO 4 environment. After 2600 deep cycles at 15C high rate of charge/discharge, the capacity remains nearly unchanged from its initial value.