Methods for forming a metal oxide electrolyte improve ionic conductivity. Some of those methods involve applying a first metal compound to a substrate, converting that metal compound to a metal oxide, applying a different metal compound to the metal oxide, and converting the different metal compound to form a second metal oxide. That substrate may be in nanobar form that conforms to an orientation imparted by a magnetic field or an electric field applied before or during the converting. Electrolytes so formed can be used in solid oxide fuel cells, electrolyzers, and sensors, among other applications.

A membrane electrode assembly includes a polymer electrolyte membrane; a first electrode layer disposed on an upper surface of the polymer electrolyte membrane; and a second electrode layer disposed on a lower surface of the polymer electrolyte membrane. At least one end of the polymer electrolyte membrane is bent upward along a side of the first electrode layer and extends to an upper surface of the first electrode layer or is bent downward along a side of the second electrode layer and extends to a lower surface of the second electrode layer.

A membrane electrode assembly includes a polymer electrolyte membrane; a first electrode layer disposed on an upper surface of the polymer electrolyte membrane; and a second electrode layer disposed on a lower surface of the polymer electrolyte membrane. At least one end of the polymer electrolyte membrane is bent upward along a side of the first electrode layer and extends to an upper surface of the first electrode layer or is bent downward along a side of the second electrode layer and extends to a lower surface of the second electrode layer.

A bipolar plate assembly includes a first frame member, a second frame member, and a membrane electrode assembly. The first frame member has a first side and a second side. The first side has a first side protuberance. The second frame member includes a first side and a second side. The second side has a second side recess. The membrane electrode assembly has an anode plate and a cathode plate. A portion of the membrane electrode assembly is disposed between the first frame member and the second frame member. The portion of the membrane electrode assembly has a juxtaposition of the anode plate and the cathode plate. The first side protuberance of the first frame member deforms the portion of the membrane electrode assembly into the second side recess of the second frame member.

A bipolar plate assembly includes a first frame member, a second frame member, and a membrane electrode assembly. The first frame member has a first side and a second side. The first side has a first side protuberance. The second frame member includes a first side and a second side. The second side has a second side recess. The membrane electrode assembly has an anode plate and a cathode plate. A portion of the membrane electrode assembly is disposed between the first frame member and the second frame member. The portion of the membrane electrode assembly has a juxtaposition of the anode plate and the cathode plate. The first side protuberance of the first frame member deforms the portion of the membrane electrode assembly into the second side recess of the second frame member.

A stainless steel sheet for fuel cell separators comprises: a predetermined chemical composition; and fine precipitates containing Cr and Ti at a steel sheet surface, wherein an average equivalent circular diameter of the fine precipitates is 20 nm or more and 500 nm or less, and a number of the fine precipitates existing per 1 m.sup.2 at the steel sheet surface is three or more.

A stainless steel sheet for fuel cell separators comprises: a predetermined chemical composition; and fine precipitates containing Cr and Ti at a steel sheet surface, wherein an average equivalent circular diameter of the fine precipitates is 20 nm or more and 500 nm or less, and a number of the fine precipitates existing per 1 m.sup.2 at the steel sheet surface is three or more.

The fuel cell single cell of the present invention includes: a membrane electrode assembly; a low-rigidity frame that supports the membrane electrode assembly; a pair of separators that holds the low-rigidity frame and the membrane electrode assembly therebetween; a gas channel for supplying gas to the membrane electrode assembly between the pair of separators; manifold parts that are formed in the low-rigidity frame and the pair of separators to supply the gas to the gas channel; restraining ribs that restrain the low-rigidity frame near the manifold parts; a projected part of the low-rigidity frame that projects toward the manifold parts beyond the restraining ribs; and a gas flow part that is formed in the projected part to supply the gas from the manifold part to the gas channel.

The fuel cell single cell of the present invention includes: a membrane electrode assembly; a low-rigidity frame that supports the membrane electrode assembly; a pair of separators that holds the low-rigidity frame and the membrane electrode assembly therebetween; a gas channel for supplying gas to the membrane electrode assembly between the pair of separators; manifold parts that are formed in the low-rigidity frame and the pair of separators to supply the gas to the gas channel; restraining ribs that restrain the low-rigidity frame near the manifold parts; a projected part of the low-rigidity frame that projects toward the manifold parts beyond the restraining ribs; and a gas flow part that is formed in the projected part to supply the gas from the manifold part to the gas channel.

A fuel cell includes a reaction layer including: a membrane electrode assembly (MEA); and gas diffusion layers (GDLs) each of which is disposed at both side surfaces of the MEA. A porous separation layer has one surface adhered to one surface of the reaction layer and supplied with reaction gas, and a cathode bipolar plate has a panel shape and adhered to another surface of the porous separation layer. A front end part of the cathode bipolar plate having a manifold that is supplied with the reaction gas and having a plurality of diffusion channels through which the reaction gas directs from the manifold toward the porous separation layer. The cathode bipolar plate has a partition wall channel which separates the porous separation layer, which extends in a direction in which the reaction gas flows, and which extends from the manifold in a diagonal direction.