Provided is a polymer electrolyte membrane comprising: (a) a polyelectrolyte having an ion exchange capacity of from 0.5 to 3.0 meq/g; and (b) at least one scandium compound selected from the group consisting of scandium oxide, scandium acetate, scandium sulfate, scandium nitrate, and scandium carbonate, wherein a polyethylene glycol (PEG)-derived compound in the polymer electrolyte membrane has a total content of 10 ppm or less.

Provided is a polymer electrolyte membrane comprising: (a) a polyelectrolyte having an ion exchange capacity of from 0.5 to 3.0 meq/g; and (b) at least one scandium compound selected from the group consisting of scandium oxide, scandium acetate, scandium sulfate, scandium nitrate, and scandium carbonate, wherein a polyethylene glycol (PEG)-derived compound in the polymer electrolyte membrane has a total content of 10 ppm or less.

Provided is an LDH separator including a porous substrate and a layered double hydroxide (LDH) that fills up pores of the porous substrate. The LDH is composed of a plurality of hydroxide base layers containing Mg, Al, Ti, and OH group; and interlayers which are interposed between the plurality of hydroxide base layers and composed of anions and H.sub.2O.

Disclosed are a highly durable electrolyte membrane having improved ion conductivity and a method of producing the same. The electrolyte membrane may include an ionomer having hydrogen ion conductivity and a complex dispersed in the ionomer. The complex may include: a support; a primary antioxidant loaded on the support and having radical scavenging ability; and a secondary antioxidant loaded on the support and having peroxide decomposition activity.

Disclosed are porous multi-metal oxide nanotubes and a production method therefor. In one aspect, methods for producing porous multi-metal oxide nanotubes are provided comprising: (a) preparing an admixture comprising metal-acetylacetonate precursors, polyacrylonitrile (PAN) and a solvent component; and (b) producing a nanocomposite from the admixture, wherein metals of the metal-acetylacetonate precursors comprise a non-radioactive alkali metal stable isotope and a non-radioactive alkaline earth metal stable isotope. As such, porous multi-metal oxide nanotubes having a single-phase multivalence may be obtained in high yield without using harmful chemical substances. In addition, the polymer electrolyte membrane including the porous multi-metal oxide nanotubes may have maintained and improved mechanical strength, and thus may have maintained durability even during cell operation and may also have improved proton conductivity even at low humidity. The fuel cell including the polymer electrolyte membrane may have improved performance.

Disclosed are an electrolyte membrane for fuel cells that can prevent poisoning of catalysts and a method of producing the same. The electrolyte membrane for fuel cells includes an ion transport layer including an ionomer having proton conductivity, and a catalytic composite dispersed in the ion transport layer, wherein the catalytic composite includes a catalytic particle including a catalytic metal component having an activity of decomposing hydrogen peroxide, and a protective layer formed on at least a part of a surface of the catalytic particle to prevent the ionomer from contacting the catalytic metal component.

Chemically inert, mechanically tough, cationic metallo-polyelectrolytes designed as durable anion-exchange membranes (AEMs) via ring-opening metathesis polymerization (ROMP) of cobaltocenium-containing cyclooctene with triazole as the only linker group, followed by backbone hydrogenation to provide a new class of AEMs with a polyethylene-like framework and alkaline-stable cobaltocenium cation for ion transport, which exhibit excellent thermal, chemical and mechanical stability, as well as high ion conductivity.

Chemically inert, mechanically tough, cationic metallo-polyelectrolytes designed as durable anion-exchange membranes (AEMs) via ring-opening metathesis polymerization (ROMP) of cobaltocenium-containing cyclooctene with triazole as the only linker group, followed by backbone hydrogenation to provide a new class of AEMs with a polyethylene-like framework and alkaline-stable cobaltocenium cation for ion transport, which exhibit excellent thermal, chemical and mechanical stability, as well as high ion conductivity.

Provided is a polymer electrolyte membrane comprising: (a) a polyelectrolyte having an ion exchange capacity of from 0.5 to 3.0 meq/g; and (b) at least one scandium compound selected from the group consisting of scandium oxide, scandium acetate, scandium sulfate, scandium nitrate, and scandium carbonate, wherein a polyethylene glycol (PEG)-derived compound in the polymer electrolyte membrane has a total content of 10 ppm or less.

Provided is a polymer electrolyte membrane comprising: (a) a polyelectrolyte having an ion exchange capacity of from 0.5 to 3.0 meq/g; and (b) at least one scandium compound selected from the group consisting of scandium oxide, scandium acetate, scandium sulfate, scandium nitrate, and scandium carbonate, wherein a polyethylene glycol (PEG)-derived compound in the polymer electrolyte membrane has a total content of 10 ppm or less.