High-Capacity Electric Double Layer Capacitor Using Three-Dimensional Porous Current Collector

A three-dimensional porous current collector made of a nickel-chromium alloy was developed based on foamed polyurethane. The foam-type substrate exhibited a high tolerance at high voltages in nonaqueous electrochemical systems. The electric double layer capacitor (EDLC) using the foam-type substrate exhibited stable charge/discharge behavior and showed a superior high-rate discharge capability as compared to an EDLC using the conventional aluminum foil. Furthermore, impedance analysis revealed an improved current collecting ability for the foam-type substrate. To improve the performance of EDLCs, a methodology that uses a three-dimensional current collector was described.