A single fuel cell according to the present disclosure includes a power generation section, a power non-generation section which does not include the power generation section, and an oxygen-ion-insulating gas seal film arranged so as to cover the surface of the power non-generation section, and the gas seal film is configured by a structure formed by firing a material containing MTiO.sub.3 (M: alkaline earth metal element) and metal oxide. The structure may include a first structure and a second structure which are different in composition, the first structure may include components derived from MTiO.sub.3 in larger amounts than the second structure, the second structure may include a metal element contained in the metal oxide in a larger amount than the first structure, and the area ratio of the second structure in the structure may be not less than 1% and not more than 50%.

An electrochemical cell includes a porous support substrate and a power generation element portion. The support substrate includes at least one first gas channel and at least one second gas channel. The first gas channel extends from a first end portion toward a second end portion and is connected to a gas supply chamber. The second gas channel is connected to the first gas channel on the second end portion side. The second gas channel extends from the second end portion toward the first end portion and is connected to a gas collection chamber. A ratio (p0/L) of a pitch p0 of a first gas channel and a second gas channel that are adjacent to each other to a distance L between the power generation element portion and a first end surface of the support substrate located on the first end portion side is 3.3 or less.

A coupling system for high-temperature tight coupling of a stack having SOEC/SOFC-type solid oxides is described. The system includes a threaded hollow connector, a smooth hollow connector, and a threaded nut. The threaded hollow connector includes an opening for establishing fluid communication with a gas inlet/outlet pipe and is intended to be attached to the gas inlet/outlet pipe. The smooth hollow connector includes an opening for establishing fluid communication with a gas inlet/outlet pipe of the stack and is intended to be attached to the inlet/outlet pipe. The threaded nut engages with the threaded hollow connector to form a screw/nut system, slides relative to the smooth hollow connector, and includes a first threaded portion and a second smooth portion in sliding contact with the smooth hollow connector.

A coupling system for high-temperature tight coupling of a stack having SOEC/SOFC-type solid oxides is described. The system includes a threaded hollow connector, a smooth hollow connector, and a threaded nut. The threaded hollow connector includes an opening for establishing fluid communication with a gas inlet/outlet pipe and is intended to be attached to the gas inlet/outlet pipe. The smooth hollow connector includes an opening for establishing fluid communication with a gas inlet/outlet pipe of the stack and is intended to be attached to the inlet/outlet pipe. The threaded nut engages with the threaded hollow connector to form a screw/nut system, slides relative to the smooth hollow connector, and includes a first threaded portion and a second smooth portion in sliding contact with the smooth hollow connector.

A cell stack device including: a cell stack comprising a plurality of cells; a support member; and a fixing part between the support member and the at least one cell of the plurality of cells, wherein in a cross section including the support member, the fixing part, and the at least one cell, the fixing part includes: a first region arranged close to the support member; a second region closer to the at least one cell than the first region; and a third region between the first region and the second region, and at least one of the first region and the second region includes a porous region having a porosity that is higher than a porosity of the third region.

A cell stack device including: a cell stack comprising a plurality of cells; a support member; and a fixing part between the support member and the at least one cell of the plurality of cells, wherein in a cross section including the support member, the fixing part, and the at least one cell, the fixing part includes: a first region arranged close to the support member; a second region closer to the at least one cell than the first region; and a third region between the first region and the second region, and at least one of the first region and the second region includes a porous region having a porosity that is higher than a porosity of the third region.

A cell stack device includes a plurality of electrochemical cells, a manifold, a gas supply portion, and a gas collection portion. The manifold includes a gas supply chamber and a gas collection chamber that extend in a direction in which the electrochemical cells are arranged. A support substrate of an electrochemical cell includes a first gas channel and a second gas channel. The first gas channel is connected to the gas supply chamber, and the second gas channel is connected to the gas collection chamber.

An auxiliary power system for an airplane includes at least one fuel cell unit each with at least one fuel cell, a voltage output, a fuel intake and an outlet for reaction products, a fuel tank that is couplable with the fuel intake of the fuel cell unit, at least one compressor unit with an air intake and air outlet and an electric motor, which is couplable with a voltage output of the at least one fuel cell unit and, by way of a shaft, with the at least one compressor unit. At least the at least one fuel cell unit, the compressor unit and the electric motor are interconnected to yield a coherent unit, which continuously provides electrical power and pressurized air.

An electrochemical element (Q) has a metal substrate (1) and multiple electrochemical reaction portions. The metal substrate (1) has gas flow allowing regions that allow the flowing of a gas between the upper side (4) and the lower side (5) of the metal substrate (1). The electrochemical reaction portions each have at least an electrode layer (A), an electrolyte layer (B), and a counter electrode layer (C), and are arranged on the upper side (4) of the metal substrate (1). The electrolyte layer (B) is arranged between the electrode layer (A) and the counter electrode layer (C), and the gas flowing through the gas flow allowing regions is supplied to the electrode layer (A).

A clamping chamber in a reactor or fuel cell architecture having a stack of elementary units is above the clamping fittings. The clamping chamber, in which a gas other than the reactive gases will flow, is substantially at the same pressure as the reactive gases in the stack. The pressure of the gas flowing in the clamping chamber above the stack of elementary units will then balance the pressure created by the reactive gases and the gases produced within the stack.