This disclosure relates to polymer electrolyte membranes, and in particular, to a composite membrane having at least two reinforcing layers comprising a microporous polymer structure and a surprisingly high resistance to piercing. This disclosure also relates to composite membrane-assemblies and electrochemical devices comprising the composite membranes of the disclosure, and to methods of manufacture of the composite membranes.

This disclosure relates to polymer electrolyte membranes, and in particular, to a composite membrane having at least two reinforcing layers comprising a microporous polymer structure and a surprisingly high resistance to piercing. This disclosure also relates to composite membrane-assemblies and electrochemical devices comprising the composite membranes of the disclosure, and to methods of manufacture of the composite membranes.

Membrane assemblies and separation layer(s) for electrochemical devices such as fuel cells and/or electrolyzers are provided, as well as their production methods. The separation layer(s) include surface-charged particles such as LDH particles to strengthen the membranes, enhance their ionic conductivity and prevent or reduce membrane dehydration and/or chemical degradation. In various configurations a single or few, relatively thick separation layer(s) with surface-charged particles may be used, while in other configurations alternating layers of ionomeric material and layers with surface-charged particles may be used, optimizing ionic conductivity with mechanical strength. Thin protective layers with solids content up to 100% may be set adjacent to the electrodes, and the orientation of the surface-charged particles may be set to enhance the ion conductivity of the respective layer.

A membrane electrode assembly and a polymer electrolyte fuel cell that are capable of improving water release in a high current region, where a large amount of water is generated, without impairing water retention under low humidity conditions, and also capable of exhibiting high power generation performance and durability under high humidity conditions, and also reducing the production cost of the electrode catalyst layer. A membrane electrode assembly of the present embodiment includes a polymer electrolyte membrane, and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane. At least one of the pair of electrode catalyst layers contains catalyst-supporting particles having a hydrophobic coating, hydrophobic polymer fibers, and a polymer electrolyte.

A membrane electrode assembly and a polymer electrolyte fuel cell that are capable of improving water release in a high current region, where a large amount of water is generated, without impairing water retention under low humidity conditions, and also capable of exhibiting high power generation performance and durability under high humidity conditions, and also reducing the production cost of the electrode catalyst layer. A membrane electrode assembly of the present embodiment includes a polymer electrolyte membrane, and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane. At least one of the pair of electrode catalyst layers contains catalyst-supporting particles having a hydrophobic coating, hydrophobic polymer fibers, and a polymer electrolyte.

Disclosed are an additive for a polymer electrolyte membrane fuel cell and a polymer electrolyte membrane fuel cell including the additive. The additive may include a carbon material having a predetermined shape and a perovskite compound having the formula Ce(Zr.sub.xTi.sub.1-x)O.sub.3, wherein x satisfies 0<x<1, and wherein the perovskite compound is deposited on the carbon material.

A separator plate is produced by hot compacting a pliable and malleable material made from a blend of powder containing at least 70% carbon powder, 10-20% of poly-phenylene sulfide, PPS, and 0.005-10% PolyTetraFluoroEthylene, PTFE. Advantageously, the powder is suspended in water without using isopropanol. A method of producing a separator plate is also disclosed.

A separator plate is produced by hot compacting a pliable and malleable material made from a blend of powder containing at least 70% carbon powder, 10-20% of poly-phenylene sulfide, PPS, and 0.005-10% PolyTetraFluoroEthylene, PTFE. Advantageously, the powder is suspended in water without using isopropanol. A method of producing a separator plate is also disclosed.

Proton conducting materials and membranes and electrochemical devices incorporating the materials and membranes are provided. Also provided are methods of making the materials and membranes and methods of operating the electrochemical devices. The proton conducting materials are solid acids that form superprotonic phases at elevated temperatures. The superprotonic phases have a cubic structure and the general formula: M.sub.(1−x)H.sub.y]H.sub.2PO.sub.4, where M represents one or more monovalent cations or a combination of monovalent cations and divalent cations, 0<x≤2/9, and y is a number that provides charge balancing.

Proton conducting materials and membranes and electrochemical devices incorporating the materials and membranes are provided. Also provided are methods of making the materials and membranes and methods of operating the electrochemical devices. The proton conducting materials are solid acids that form superprotonic phases at elevated temperatures. The superprotonic phases have a cubic structure and the general formula: M.sub.(1−x)H.sub.y]H.sub.2PO.sub.4, where M represents one or more monovalent cations or a combination of monovalent cations and divalent cations, 0<x≤2/9, and y is a number that provides charge balancing.