Various designs and configurations of and methods of operating fuel cell units, fuel cell systems and combined heat and power systems are provided that permit efficient thermal management of such units and systems to improve their operation.

Various designs and configurations of and methods of operating fuel cell units, fuel cell systems and combined heat and power systems are provided that permit efficient thermal management of such units and systems to improve their operation.

A cell according to the present disclosure includes: a solid electrolyte layer including a first surface and a second surface opposite to the first surface; a fuel electrode on the first surface; an air electrode on the second surface; and a middle layer between the second surface and the air electrode. The middle layer=is a CeO.sub.2-type sintered body containing Si, the content of Si equivalent to or less than 150 ppm in terms of SiO.sub.2. A cell stack device includes a cell stack in which the plurality of cells is aligned. A module includes: a storage container; and the cell stack device that is housed in the storage container. A module housing device includes: an external case; the module and an auxiliary equipment that drives the module, which are housed in the external case.

A cell according to the present disclosure includes: a solid electrolyte layer including a first surface and a second surface opposite to the first surface; a fuel electrode on the first surface; an air electrode on the second surface; and a middle layer between the second surface and the air electrode. The middle layer=is a CeO.sub.2-type sintered body containing Si, the content of Si equivalent to or less than 150 ppm in terms of SiO.sub.2. A cell stack device includes a cell stack in which the plurality of cells is aligned. A module includes: a storage container; and the cell stack device that is housed in the storage container. A module housing device includes: an external case; the module and an auxiliary equipment that drives the module, which are housed in the external case.

A vehicular power system, a vehicle and a method of providing auxiliary power to a vehicle using an auxiliary power unit that uses a molten metal anode solid oxide fuel cell rather than an internal combustion engine. The auxiliary power unit includes a container with numerous fuel cells disposed within it such that when the metal anode is heated, the metal converts to a molten state that can be electrochemically cycled between oxidized and reduced states by oxygen and a fuel present in the molten metal, respectively. The auxiliary power unit further includes a furnace that selectively provides heat to the fuel cells in order to place the anode into its molten metal state. Seals may provide fluid isolation between the molten metal within the container and the ambient environment.

A redox flow battery. The redox flow battery has a plurality of cells stacked on each other and three or more conductive terminals. The redox flow battery is able to vary a charge voltage and a discharge voltage by switching control.

Flow batteries can be constructed by combining multiple electrochemical unit cells together with one another in a cell stack. High-throughput processes for fabricating electrochemical unit cells can include providing materials from rolled sources for forming a soft goods assembly and a hard goods assembly, supplying the materials to a production line, and forming an electrochemical unit cell having a bipolar plate disposed on opposite sides of a separator. The electrochemical unit cells can have configurations such that bipolar plates are shared between adjacent electrochemical unit cells in a cell stack, or such that bipolar plates between adjacent electrochemical unit cells are abutted together with one another in a cell stack.

Electrochemical cells can include flow channels designed to provide an electrolyte solution more efficiently to an electrode or ionically conductive separator. Such electrochemical cells can include an ionically conductive separator disposed between a first half-cell and a second half-cell, a first bipolar plate in the first half-cell, and a second bipolar plate in the second half-cell. At least one of the first bipolar plate and the second bipolar plate are a composite containing a conductive material and a blocking material. The blocking material defines a plurality of flow channels that are spaced apart from one another and extend laterally through the composite with respect to the ionically conductive separator. The plurality of flow channels are also in fluid communication with one another in the composite. Such electrochemical cells can be incorporated in electrochemical stacks and/or be fluidly connected to a fluid inlet manifold and a fluid outlet manifold.

Electrochemical cells can include flow channels designed to provide an electrolyte solution more efficiently to an electrode or ionically conductive separator. Such electrochemical cells can include an ionically conductive separator disposed between a first half-cell and a second half-cell, a first bipolar plate in the first half-cell, and a second bipolar plate in the second half-cell. At least one of the first bipolar plate and the second bipolar plate are a composite containing a conductive material and a blocking material. The blocking material defines a plurality of flow channels that are spaced apart from one another and extend laterally through the composite with respect to the ionically conductive separator. The plurality of flow channels are also in fluid communication with one another in the composite. Such electrochemical cells can be incorporated in electrochemical stacks and/or be fluidly connected to a fluid inlet manifold and a fluid outlet manifold.

Systems and methods for operating a redox flow battery system may include switching the redox flow battery system to an idle mode, wherein the idle mode includes operation of the redox flow battery system outside of a charging mode and outside of a discharge mode; in response to switching to the idle mode, repeatedly cycling operation of an electrolyte pump between an idling threshold flow rate less than a charging threshold flow rate and a deactivation threshold flow rate; and in response to switching to the charging mode, maintaining operation of the electrolyte pump at the charging threshold flow rate greater than the idling threshold flow rate. In this way, a responsiveness of the redox flow battery system to charging and discharging commands can be maintained while in idle, while reducing parasitic pumping losses due to pumping and heating, and reducing shunt current losses.