Development of Segmented-in-series Cell-stacks with Flat-tubular Substrates

Abstract

The SOFC cell-stacks called flat-tube segmented-in-series cell-stacks have been developed by a joint work of Tokyo Gas and Kyocera. The cell-stacks were composed of multiple single- cells (8YSZ electrolyte, Ni/8YSZ anode, and LaSrCoFe cathode) and current-collectors, placed on both sides of the flat- tubular substrate. The fuel to electric power-generation efficiency of the latest cell-stack converted as the methane fuel was estimated more than 53% HHV-DC at 1023K at the current density, 0.2A/cm2. The complex impedance spectra of the cell- stacks were measured under the operating conditions, for investigations of the relation between the performance and components design. By the measurements under several conditions, we identified the relationship between the impedance spectra and the fuel usage dependence and degradation of the segmented-in-series type cell-stack performance. Based on these results, we continue further studies of the component design (especially anode), for higher efficiency and long-term durability of the cell-stacks.