An electrolyte sheet for solid oxide fuel cells that includes a ceramic plate body having a warpage height of not more than 300 μm, wherein a maximum value among values of 100×Q/L.sub.X, 100×R/L.sub.Y, and 100×S/L.sub.X is not greater than 1, where Q is a maximum difference between a second side D.sub.2 and a second virtual straight line V.sub.2 in an X coordinate, R is a maximum difference between a third side D.sub.3 and a third virtual straight line V.sub.3 in a Y coordinate, S is a maximum difference between a fourth side D.sub.4 and a fourth virtual straight line V.sub.4 in the X coordinate, L.sub.X is a length of a virtual rectangle in an X-axis direction, and Ly is a length of the virtual rectangle in a Y-axis direction.

A solid oxide electrochemical cell includes a solid oxide electrolyte, an anode located on a first side of the solid oxide electrolyte, and a cathode located on a second side of the solid oxide electrolyte. The cathode includes lanthanum nickel ferrite.

A solid oxide electrochemical cell includes a solid oxide electrolyte, an anode located on a first side of the solid oxide electrolyte, and a cathode located on a second side of the solid oxide electrolyte. The cathode includes lanthanum nickel ferrite.

A bipolar membrane comprising a first member comprising at least one anion exchange material; a second member comprising at least one cation exchange material, wherein the first member and the second member together form an interface junction; and disposed within the interface junction a solitary layer comprising a composite water dissociation catalyst or a composite water recombination catalyst.

Disclosed herein are barium hafnate comprising proton-conducting electrolytes for use in solid oxide fuel cells. The disclosed electrolytes are also useful for electrolysis operations and for carbon dioxide tolerance.

An anion exchange membrane includes a porous structural framework and bismuth atoms bonded to pore surfaces of the porous structural framework. Each bismuth atom is bonded to a pore surface by way of one or two oxygen atoms.

An anion exchange membrane includes a porous structural framework and bismuth atoms bonded to pore surfaces of the porous structural framework. Each bismuth atom is bonded to a pore surface by way of one or two oxygen atoms.

A flow battery includes a negative electrode, a positive electrode, a first liquid including first redox species, a second liquid, and a lithium ion conductive membrane. At least one selected from the group consisting of the first liquid and the second liquid includes a supporting electrolyte including lithium. The total of the number of moles of lithium dissolved in the first liquid and the number of moles of lithium dissolved in the second liquid is larger than the number of moles of lithium present in the supporting electrolyte. 0.2≤(M1+M2−M3)/M4≤1.5 wherein M1 is the number of moles of lithium dissolved in the first liquid, M2 is the number of moles of lithium dissolved in the second liquid, M3 is the number of moles of lithium present in the supporting electrolyte, and M4 is the number of moles of the first redox species.

A flow battery includes a negative electrode, a positive electrode, a first liquid including first redox species, a second liquid, and a lithium ion conductive membrane. At least one selected from the group consisting of the first liquid and the second liquid includes a supporting electrolyte including lithium. The total of the number of moles of lithium dissolved in the first liquid and the number of moles of lithium dissolved in the second liquid is larger than the number of moles of lithium present in the supporting electrolyte. 0.2≤(M1+M2−M3)/M4≤1.5 wherein M1 is the number of moles of lithium dissolved in the first liquid, M2 is the number of moles of lithium dissolved in the second liquid, M3 is the number of moles of lithium present in the supporting electrolyte, and M4 is the number of moles of the first redox species.

A redox flow battery includes a positive terminal, a negative terminal, and a solid state ionic conductive membrane on a macro porous support scaffold between the positive terminal and the negative terminal.