Methods and systems are provided for a redox flow battery system. In one example, the redox flow battery system has a first redox flow battery and a second redox flow battery, stacked above and in contact with the first redox flow battery along a vertical axis of the redox flow battery system. The second redox flow battery may be coupled to the first redox flow battery via nesting detents. Furthermore, operation of the first redox flow battery and the second redox flow battery may be adjustable according to a power demand.

The fuel cell of the present disclosure includes: a fuel single cell comprising a fuel electrode, an air electrode, and an electrolyte disposed between the electrodes; a separator for separating a fuel gas flowing through the fuel electrode and air flowing through the air electrode; and a sealing portion for hermetically bonding between the separator and the electrolyte, wherein the sealing portion is constituted of a glass composition containing at least two of metallic or metalloid elements contained in the electrolyte and at least two of metallic or metalloid elements contained in the separator; the electrolyte includes a proton conductor; and the proton conductor is represented by a compositional formula: BaZr.sub.1-xM.sub.xO.sub.3, where 0.05≤x≤0.5; and M is at least one selected from the group consisting of Sc, In, Lu, Yb, Tm, Er, Y, Ho, Dy, and/or Gd.

The fuel cell of the present disclosure includes: a fuel single cell comprising a fuel electrode, an air electrode, and an electrolyte disposed between the electrodes; a separator for separating a fuel gas flowing through the fuel electrode and air flowing through the air electrode; and a sealing portion for hermetically bonding between the separator and the electrolyte, wherein the sealing portion is constituted of a glass composition containing at least two of metallic or metalloid elements contained in the electrolyte and at least two of metallic or metalloid elements contained in the separator; the electrolyte includes a proton conductor; and the proton conductor is represented by a compositional formula: BaZr.sub.1-xM.sub.xO.sub.3, where 0.05≤x≤0.5; and M is at least one selected from the group consisting of Sc, In, Lu, Yb, Tm, Er, Y, Ho, Dy, and/or Gd.

A fuel cell is provided that includes a cell stack having a plurality of unit cells stacked in a first direction. An enclosure is disposed to surround the cell stack and includes an inlet that suctions external air and an outlet that discharges air that has been suctioned through the inlet and has circulated in the space between the cell stack and the enclosure. An insulating member is disposed to extend in the first direction in the space between an outer surface of the cell stack and an inner surface of the enclosure. The insulating member divides the space into a plurality of spaces and has an aperture formed therein to provide communication between the divided plurality of spaces, and an air intake member configured to suction air discharged from the outlet.

A fuel cell is provided that includes a cell stack having a plurality of unit cells stacked in a first direction. An enclosure is disposed to surround the cell stack and includes an inlet that suctions external air and an outlet that discharges air that has been suctioned through the inlet and has circulated in the space between the cell stack and the enclosure. An insulating member is disposed to extend in the first direction in the space between an outer surface of the cell stack and an inner surface of the enclosure. The insulating member divides the space into a plurality of spaces and has an aperture formed therein to provide communication between the divided plurality of spaces, and an air intake member configured to suction air discharged from the outlet.

A fuel cell stack includes a first power output unit connected to a first terminal plate, the first power output unit including a first conductor, and a second conductor extending from the first conductor to the outside of an outer peripheral end of a first inner insulator in the state where the second conductor is placed between the first inner insulator and a first end plate. The second conductor is positioned inside of the first end plate in a stacking direction of a cell stack body.

A fuel cell stack includes a first power output unit connected to a first terminal plate, the first power output unit including a first conductor, and a second conductor extending from the first conductor to the outside of an outer peripheral end of a first inner insulator in the state where the second conductor is placed between the first inner insulator and a first end plate. The second conductor is positioned inside of the first end plate in a stacking direction of a cell stack body.

Disclosed herein is a fuel-cell unit cell, at a first part of which: the fuel-cell unit cell has a bonding layer; between a first separator and an outer peripheral edge portion of a first gas diffusion layer, the bonding layer bonds the first separator and the outer peripheral edge portion together; between the first separator and an outer peripheral edge portion of a membrane-electrode assembly, the bonding layer is bonded to the outer peripheral edge portion of the membrane-electrode assembly; and between the first separator and a support frame and/or between a second separator and the support frame, the bonding layer bonds the support frame and the separator together.

A fuel cell system includes a stack case and an auxiliary device case. The stack case stores a stack including a power generation cell stack body including a plurality of power generation cells stacked horizontally in a stacking direction, and an insulating plate stacked at an end of the power generation cell stack body in the stacking direction. The auxiliary device case stores a fuel cell auxiliary device. The inside of the stack case and the inside of the auxiliary device case that are adjacent to each other in the stacking direction are separated by a partition wall. The partition wall has ventilation connection ports. The ventilation connection ports connect the inside of the stack case with the inside of the auxiliary device case. The insulating plate provided closer to the partition wall, than the power generation cell stack body, inside the stack case faces the ventilation connection ports.

A stack (1) of intermediate temperature, metal-supported, solid oxide fuel cell units (10), each unit comprising a metal support substrate (12), a spacer (22) and an interconnect (30) that each have compression bolt holes (34), fuel inlet port (33), fuel outlet port (32) and air outlet (17) therein, wherein bolt voids (34) are formed by aligning the bolt holes and a further void (17) by aligning the air outlets, and the voids are vented, for example, to the environment or further void to prevent the build-up of fuel, moisture or ions.