Fuel cell structures and assemblies

A fuel cell sub-bundle comprising multiple microfibrous fuel cell elements and a common heat-exchanging and/or humidifying element, wherein each microfibrous fuel cell element comprises (a) an inner current collector;

• (b) a hollow fibrous membrane separator comprising an electrolyte medium;
• (c) an inner electrocatalyst layer;
• (d) an outer electrocatalyst layer, and (e) an outer current collector.

A fuel cell structure comprising multiple fuel cell elements and a common current collector, wherein each fuel cell element comprises (1) a membrane separator having an electrolyte medium, (2) a first electrocatalyst layer in electrical contact with a first surface of said membrane separator, (3) a second electrocatalyst layer in electrical contact with a second, opposite surface of said membrane separator, and (4) an individual current collector in electrical contact with the first surface of said membrane separator, wherein each fuel cell element is in electrical contact with the common current collector at the second, opposite surface of its membrane separator.

A fuel cell bundle comprising a thermally conductive tubular element and one or more fuel cell sub-bundles positioned therein, wherein each fuel cell sub-bundle comprises multiple microfibrous fuel cells all in electrical contact with a common current collector, wherein each microfibrous fuel cell comprises:

• (a) a hollow microfibrous membrane separator comprising an electrolyte medium, (b) an inner electrocatalyst layer in contact with an inner surface of said membrane separator, (c) an outer electrocatalyst layer in contact with an outer surface of said membrane separator, and (d) an individual current collector in electrical contact with the inner surface of said membrane separator.

A fuel cell assembly, comprising an assembly of fuel cell bundles positioned in a housing, wherein each fuel cell bundle comprises a thermally conductive tubular element and one or more fuel cell sub-bundles positioned therein, wherein each fuel cell sub-bundle comprises multiple microfibrous fuel cells all in electrical contact with a common current collector, wherein each microfibrous fuel cell comprises:

• (a) a hollow microfibrous membrane separator comprising an electrolyte medium, (b) an inner electrocatalyst layer in contact with an inner surface of said membrane separator, (c) an outer electrocatalyst layer in contact with an outer surface of said membrane separator, and (d) an individual current collector in electrical contact with the inner surface of said membrane separator, wherein said housing comprises multiple leak-tightly separated compartments and multiple fluid inlets and outlets arranged and constructed for separately passing a fuel-containing fluid, an oxidant-containing fluid, and a heat-exchanging fluid through the fuel cell bundles for generation of electrical and thermal energy.

A fuel cell assembly comprising an elongated housing structure have a longitudinal axis with one or more one or more fuel cell elements placed therein, wherein said elongated housing structure comprises multiple fluid inlets and outlets for separately passing two or more fluids through the fuel cell elements, and wherein all the fluid inlets and outlets of said elongated housing structure are substantially parallel to the longitudinal axis of said elongated housing.