Masashi Kishimoto

Abstract Power generation performance and long‐term durability of ammonia‐fueled solid oxide fuel cell (SOFC) systems are investigated with SOFC stacks consisting of 30 planar anode‐supported cells. SOFC systems with three different operation modes are employed: direct ammonia, external decomposition and autothermal decomposition. A novel BaO/Ni/Sm 2 O 3 /MgO catalyst is newly developed for the external ammonia cracker, whereas a Co‐Ce‐Zr composite oxide catalyst is used for the autothermal ammo

Three-dimensional numerical analysis of solid oxide fuel cell (SOFC) anode polarization is conducted with a microstructure obtained by a focused ion beam and scanning electron microscope (FIB-SEM). Electronic, ionic and gaseous transports with electrochemical reaction are considered in the porous anode. A sub-grid scale (SGS) model is newly developed and effectively used to consider the structural information whose characteristic scale is smaller than calculation grid size. The proposed SGS mode

Abstract Ni‐YSZ anode of solid oxide fuel cells (SOFCs) with three different compositions are examined and compared through electrochemical measurement, microstructural analysis, and numerical simulation. Three‐dimensional (3D) microstructure of the porous anodes is directly observed using focused ion beam and scanning electron microscope (FIB‐SEM), and microstructural parameters such as phase connectivity and three‐phase boundary (TPB) density are quantified to correlate the microstructure to t

Two-dimensional numerical model of an ammonia-fueled planar solid oxide fuel cell is developed to investigate the distributions of flow, temperature, species and electrochemical quantities within the cell. The model consists of the conservation equations of mass, momentum, energy, species and charge carriers, which are coupled by the electrochemical oxidation of hydrogen and the ammonia decomposition reaction. Comparison between the direct ammonia supply and pre-decomposed ammonia supply cases g

Active thickness in SOFC anodes is investigated by using one-dimensional numerical simulation. The effects of the operating conditions and the microstructural parameters of the porous anodes on the active thickness are systematically investigated. The non-linearity of the Butler-Volmer equation used for the electrochemical reaction model is found to be the key to explain the behaviour of the active thickness. The characteristic length of oxide-ion conduction is introduced by taking the ratio bet

Microstructural properties of an SOFC anode, such as tortuosity, surface-to-volume ratio and permeability, are quantitatively evaluated using three-dimensional data obtained by a system consisting of a focused ion beam and scanning electron microscope, FIB-SEM. A method employed to evaluate these properties is based on a random walk process in which the diffusion of imaginary particles is considered. In addition, the connectivities of three phases, i.e., the Ni, YSZ and pore phases are also anal