A fuel cell system including a fuel cell, an off-gas reprocessing unit that is provided downstream of the fuel cell and that at least partially removes at least one of steam or carbon dioxide from an off-gas discharged from the fuel cell, a flow passage that is provided downstream of the off-gas reprocessing unit and that allows a reprocessed off-gas discharged from the off-gas reprocessing unit to flow therethrough, and a controlling unit that modulates the reaction constant K.sub.pa of a reaction A with respect to the reprocessed off-gas discharged from the off-gas reprocessing unit, to 1.22 or more.

A planar SOFC cell unit is formed from a plurality of planar elements (1100, 1200, 1300) stacked one above another. The cell unit encloses a cell chamber (1400) that includes a solid oxide fuel cell (2000) configured for electro-chemical generation, compliantly supported within the cell chamber. The plurality planar elements each comprise a thermally conductive material having a co-efficient of thermal conductivity that is a least 100 W/mK such as aluminum or copper. The planar elements are thermally conductively coupled to each other to provide a continuous thermally conductive pathway that extends from perimeter edges of the cell chamber to perimeter edges of the plurality of planar elements. An SOFC stack comprises a plurality of the planar SOFC cell units stacked one above another.

The present invention relates to a proton ceramic fuel cell which has a hydrogen-permeable film as an anode and in which an electrolyte material is BaZr.sub.xCe.sub.1-x-zY.sub.zO.sub.3 (x=0.1 to 0.8, z=0.1 to 0.25, x+z≤1.0) (BZCY). An electron-conducting oxide thin film having a film thickness of 1-100 nm is present between a cathode and an electrolyte comprising the material. The present invention also relates to a method for producing a proton ceramic fuel cell having a hydrogen-permeable film as an anode. The method comprises forming a thin film having a thickness of 1-100 nm between a cathode and an electrolyte comprising BZCY, the thin film comprising an electron-conducting oxide. The present invention provides a novel means for improving the output of a PCFC in which BZCY is used in an electrolyte material, and provides a PCFC having an output that exceeds a benchmark of 0.5 W cm.sup.−2 at 500° C.

Provided is a fuel cell system capable of further increasing electric power generation efficiency, compared to the current circumstances, with respect to a fuel cell SOFC that generates electric power by supplying a reformed gas obtained by steam reforming to a fuel electrode. A steam reformer that reforms a hydrocarbon fuel by a steam reforming reaction; a fuel cell that operates by introducing a reformed gas to a fuel electrode; and an anode off-gas circulation path that removes condensed water while cooling an anode off-gas, and introduces the anode off-gas to the steam reformer are provided. A condensation temperature in a condensing device is controlled by a control unit that controls a steam partial pressure of the anode off-gas circulated to the steam reformer, and S/C adjustment is adapted to high-efficiency electric power generation.

Provided is a fuel cell system capable of further increasing electric power generation efficiency, compared to the current circumstances, with respect to a fuel cell SOFC that generates electric power by supplying a reformed gas obtained by steam reforming to a fuel electrode. A steam reformer that reforms a hydrocarbon fuel by a steam reforming reaction; a fuel cell that operates by introducing a reformed gas to a fuel electrode; and an anode off-gas circulation path that removes condensed water while cooling an anode off-gas, and introduces the anode off-gas to the steam reformer are provided. A condensation temperature in a condensing device is controlled by a control unit that controls a steam partial pressure of the anode off-gas circulated to the steam reformer, and S/C adjustment is adapted to high-efficiency electric power generation.

The present invention relates to glass-ceramic/silver composite precursor compositions in the form of powders, and to glass-ceramics/silver composite materials produced therefrom. Such materials find particular use as interconnect materials for high temperature electrochemical conversion devices such as solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs).

A solid oxide fuel cell (SOFC) assembly connectable to a source of a hydrocarbon fuel; said SOFC assembly comprises at least one SOFC. Each SOFC further comprises: (a) an anode support member having a nickel felt-made anode current collector; (b) an electrolyte layer disposed on the anode support member; and a cathode having a cathode current collector; the cathode disposed on said electrolyte layer. The nickel felt-made anode current collector is doped with Scandium.

A solid oxide fuel cell (SOFC) assembly connectable to a source of a hydrocarbon fuel; said SOFC assembly comprises at least one SOFC. Each SOFC further comprises: (a) an anode support member having a nickel felt-made anode current collector; (b) an electrolyte layer disposed on the anode support member; and a cathode having a cathode current collector; the cathode disposed on said electrolyte layer. The nickel felt-made anode current collector is doped with Scandium.

A method for operating a solid oxide electrolysis cell which can suppress degradation of the hydrogen electrode, is provided. A method for operating a solid oxide electrolysis cell includes a hydrogen electrode, an oxygen electrode, and an electrolyte layer sandwiched between the hydrogen electrode and the oxygen electrode. The hydrogen electrode includes a catalyst layer structured with Ni-containing particles dispersed and supported on a porous mixed ionic and electronic conducting oxide. The method includes an alternating operation in which a water vapor electrolysis operation and a fuel cell operation are repeated alternately.

Provided is a proton conductor that achieves an improvement in transport number while suppressing a decrease in conductivity. The proton conductor contains a metal oxide having a perovskite structure and represented by formula (1): A.sub.aB.sub.1-x-yB′.sub.xM.sub.yO.sub.3-δ (1), wherein an element A is at least one element selected from the group consisting of Ba, Sr, and Ca, an element B is at least one element selected from the group consisting of Zr and Ce, an element B′ is Hf, an element M is at least one element selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency amount, and “a”, “x”, and “y” satisfy 0.9≤a≤1.0, 0.1≤y≤0.2, and 0<x(1−y)≤0.2.