Low cost membrane electrode assemblies (MEA) with improved coulombic efficiency (CE), reduced maintenance cost, and improved deliverable capacity have been developed for redox flow batteries and other electrochemical reaction applications. The MEA comprises: a microporous substrate membrane, first and second hydrophilic ionomeric polymer coating layers on surfaces of the microporous substrate membrane, and an electrode adhered to a second surface of the second hydrophilic ionomeric polymer coating layer. Methods of preparing the MEA and a redox flow battery system incorporating the MEA are also described.

Improved membrane electrode assemblies, cation-associating components thereof, and methods of making and treating the same are provided. Membrane electrode assemblies may include an ionomer having a first pKa value, and a water-insoluble net polymer having a weakly-acidic functional group, wherein the weakly-acidic functional group has a second pKa value greater than the first pKa value.

Improved membrane electrode assemblies, cation-associating components thereof, and methods of making and treating the same are provided. Membrane electrode assemblies may include an ionomer having a first pKa value, and a water-insoluble net polymer having a weakly-acidic functional group, wherein the weakly-acidic functional group has a second pKa value greater than the first pKa value.

Disclosed is a method of manufacturing an electrolyte membrane for fuel cells. The method includes preparing an electrolyte layer including one or more ion conductive polymers that form a proton movement channel, and permeating a gas from a first surface of the electrolyte layer to a second surface of the electrolyte layer.

Disclosed is a method of manufacturing an electrolyte membrane for fuel cells. The method includes preparing an electrolyte layer including one or more ion conductive polymers that form a proton movement channel, and permeating a gas from a first surface of the electrolyte layer to a second surface of the electrolyte layer.

A composite membrane and moisture adjustment module using the same is disclosed. The composite membrane includes a moisture-permeable resin layer interposed between porous membranes that constitute a pair; and the mean thickness of the moisture-permeable resin layer is 5 μm or less.

A composite membrane and moisture adjustment module using the same is disclosed. The composite membrane includes a moisture-permeable resin layer interposed between porous membranes that constitute a pair; and the mean thickness of the moisture-permeable resin layer is 5 μm or less.

A reinforced proton-exchange membrane is provided that includes a first layer including a first ionomer, where the first layer has a first side and a second side. A second layer includes a graphene oxide, where the second layer has a first side and a second side, the first side of the second layer adjacent the second side of the first layer. A third layer includes a second ionomer, where the third layer has a first side and a second side, the first side of the third layer adjacent the second side of the second layer. The proton-exchange membrane can include or be formed upon a support layer, where the support layer is adjacent the first side of the first layer.

A reinforced proton-exchange membrane is provided that includes a first layer including a first ionomer, where the first layer has a first side and a second side. A second layer includes a graphene oxide, where the second layer has a first side and a second side, the first side of the second layer adjacent the second side of the first layer. A third layer includes a second ionomer, where the third layer has a first side and a second side, the first side of the third layer adjacent the second side of the second layer. The proton-exchange membrane can include or be formed upon a support layer, where the support layer is adjacent the first side of the first layer.

The redox flow secondary battery includes an electrolytic cell including a positive electrode cell, a negative electrode cell, and a separation membrane that separates the positive electrode cell and the negative electrode cell. Moreover, the above described redox flow secondary battery is configured as follows. That is, the separation membrane has a microporous membrane and an ion-exchange resin layer contacting the microporous membrane, and the air resistance of the separation membrane per thickness of 200 μm is 10000 sec/100 cc or more. Furthermore, the microporous membrane includes a polyolefin resin or a vinylidene fluoride resin and an inorganic filler. Further, the smoothness of at least a surface of the microporous membrane contacting the ion-exchange resin layer is 16000 seconds or less.