Masahiro Kato

Nickel Substrate Having Three-Dimensional Micronetwork Structure for High-Power Nickel/Metal-Hydride Battery

A low-cost substrate for the positive electrode of nickel/metal-hydride battery was developed by using a nonwoven cloth with a three-dimensional micronetwork structure, in which the amount of plated nickel was less than half compared with the conventional foam-type substrate. The substrate was designed to have a finer structure than the foam-type substrate. The cylindrical sealed cell using the substrate exhibited superior high-rate discharging capability to the cell using the foam-type substrate, despite the reduction of plated nickel. The characteristic microporous structure of the substrate presumably contributes to the improvement of high-rate discharge performance.

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.