Disclosed are a polymer electrolyte membrane for fuel cells which has improved handling properties and mechanical strength by employing symmetric-type laminated composite films and a method for manufacturing the same.

A composition for manufacturing an electrode, the composition including an electrically conductive carbon-based compound, at least one species able to form a catalyst, and cellulose microfibrils encapsulating chitosan. The cellulose microfibrils create a fibrous mesh binding the composition while limiting coating of the catalyst. Thus, the catalyst remains accessible to the surrounding environment, to allow the redox reactions at the electrode. The electrochemical performances of the electrode are consequently improved. The composition is furthermore particularly adapted for shaping an electrode by 3D printing.

A catalytic composition in particle form for making a gas diffusion electrode for an oxygen reduction reaction (ORR) has at least iron (Fe) in at least two different degrees of oxidation, optionally the at least two different degrees of oxidation being Fe and Fe.sub.2O.sub.3, and carbon (C). A gas diffusion electrode having the catalytic composition and a membrane-electrode assembly having the gas diffusion electrode are provided.

An electrode for a fuel cell system is provided. The electrode includes a carbon support. Platinum-based catalyst nanoparticles are dispersed on the carbon support. Zirconium-based dopants are disposed on the carbon support. In one example, a fuel cell system includes the electrode as a first electrode and further includes a second electrode and a fuel cell membrane. The fuel cell membrane is disposed between the first and second electrodes.

The present invention relates to a method for preparing a fuel cell catalyst. The method includes: preparing a core-carrier particle dispersion solution by dispersing, in an organic solvent, core-carrier particles in which a core containing platinum and a transition metal is supported on a conductive carrier and stirring the dispersed solution under a reducing gas atmosphere (S1); creating a mixture by performing a galvanic replacement reaction by mixing the core-carrier particle dispersion solution with a secondary metal precursor solution (S2); and washing and drying the mixture and then heat-treating under a reducing gas atmosphere (S3), wherein performing the galvanic replacement reaction includes: preparing the core-carrier particle dispersion solution into an acidic dispersion solution having a pH of 2 to 5 and then stirring and mixing the solution with a platinum-excluded precious metal precursor solution (S2-1); or preparing a core-shell nanoparticle-containing dispersion solution by stirring and mixing the core-carrier particle dispersion solution with the platinum-excluded precious metal precursor solution and then washing and drying the core-shell nanoparticle-containing dispersion solution and then heat-treating to prepare primary core-shell nanoparticles, and then dispersing the primary core-shell nanoparticles in an acidic solution having a pH of 2 to 5 (S2-2).

An electrode for a redox-flow battery, the electrode comprising a base material having a sheet form and a catalyst supported on the base material, wherein the base material is composed of a sintered body formed of a plurality of particles bonded to each other, the plurality of particles include titanium, the catalyst includes a first oxide provided to cover at least some of the plurality of particles, the first oxide is an oxide including ruthenium and at least one type of first element selected from the group consisting of tungsten, molybdenum, cerium, neodymium, and vanadium, and each of a content of iridium and a content of palladium included in the catalyst per 1 m.sup.2 of an area of the electrode is 1 g or less.

An embodiment method of manufacturing a membrane-electrode assembly includes feeding an electrolyte membrane by a feeding device, applying a catalyst slurry to manufacture a first electrode onto a surface of the electrolyte membrane by an applicator, while feeding the electrolyte membrane by the feeding device, performing drying of the catalyst slurry and heat treatment of the first electrode by applying heat to the electrolyte membrane by temperature control devices, while feeding the electrolyte membrane by the feeding device, and transferring a second electrode to a remaining surface of the electrolyte membrane discharged from the feeding device, opposite to the surface of the electrolyte membrane having the first electrode bonded thereto, by a transfer device.

Provided is a method for manufacturing a membrane-electrode assembly (MEA) with a shortened initial activation time that involves preparing an assembly with cathode and anode layers on opposite sides of an electrolyte membrane, and applying specific pressure and temperature conditions. The electrolyte membrane includes a hydrocarbon-based ionomer with an ion pair comprising a cation and an activator anion. The cathode and anode layers each contain a fluorine-based ionomer with a functional group derived from the activator. This process results in a unit cell that achieves 95% of its maximum current density in about 10 hours or less under specified conditions. The MEA itself features the hydrocarbon-based ionomer and the fluorine-based ionomer, with an activator or phosphoric acid present throughout, achieving the same rapid activation time.

A method for preparing a transition metal electrochemical catalyst according to an embodiment of the present disclosure includes dissolving a nitrogen precursor and a transition metal precursor in a polyol-based solvent so as to prepare a solution in which transition metal ions and free anions are coordinated, and mixing same with a support so as to prepare a mixture, igniting the mixture so as to carbonize the polyol-based solvent, thereby forming transition metal nanoparticles encompassed by carbon, performing heat treatment in order to carbonize remaining organic matter contained in the mixture, and removing, through acid treatment, impurities and transition metal nanoparticles not encompassed by carbon, and then removing remaining acid through washing and additional heat treatment, thereby a nanocatalyst having a structure in which a single-atom transition metal-nitrogen bonding structure and/or transition metal nanoparticles encompassed by carbon exist is synthesized.

The present disclosure includes a system, method, and device related to controlling brakes of a towed vehicle. A brake controller system includes a brake controller that controls the brakes of a towed vehicle based on acceleration. The brake controller is in communication with a speed sensor. The speed sensor determines the speed of a towing vehicle or a towed vehicle. The brake controller automatically sets a gain or boost based on the speed and acceleration.