152 results about "Nafion membrane" patented technology

A proton exchange membrane is provided which includes a proton exchange polymer, such as Nafion®, and agglomerates of metal oxide or metal phosphate particles. The particles and agglomerates are characterized in specific embodiments in having a high specific surface area. In one configuration an included particle includes a metal oxide or metal phosphate such as SiO₂, ZrO₂, GeO₂, SnO₂, TiO₂ or a zirconium phosphate. A further detailed proton exchange membrane provided according to an embodiment of the invention is a membrane in which one surface is enriched in agglomerates of group IV metal oxide or phosphate particles. Inventive membranes demonstrate improvement in performance under dehydrating conditions compared to unmodified Nafion membranes.

The invention discloses a preparation process of a palladium electrode ion polymer and metal composite, which is used for preparing a palladium metal electrode IPMC (Ion Polymer Metal Composite) by using immersion reduction plating and chemical plating methods in which an ion exchange membrane is used as a matrix material and [Pd (NH3)4] C12 is used as a main salt. The preparation process comprises the following four main steps of: (1) pretreatment of the matrix membrane: carrying out roughening, surface cleaning, foreign ion removal and full swelling on the matrix membrane; (2) immersion reduction plating including two processes, i.e., ion exchange and ion reduction: subjecting a pretreated Nafion membrane to repeated palladium ion immersion and exchange, and reducing the pretreated Nafion membrane with NaBH4 by adopting ultrasonic waves to form palladium metals on the surface and the internal surface of the ion exchange membrane; (3) chemical plating: wherein the thickening electrodes on the outer surface of a core material to compact internal surface electrodes by using an improved chemical plating method; and (4) postprocessing of the composite. The preparation process has a higher popularization value due to relatively improved efficiency, relatively lower cost and excellent actuation response.

The invention provides a preparation method of a polyvinylidene fluoride grafted p-styrenesulfonic acid proton exchange membrane. The method comprises the following steps of: firstly, adding a phase transfer catalyst into a prepared alkaline alcohol solution to obtain an alkaline alcohol solution containing the phase transfer catalyst; adding polyvinylidene fluoride into the solution and processing to obtain alkaline-treatment polyvinylidene fluoride powder; adding the obtained powder into an organic solvent to obtain an alkaline-treatment polyvinylidene fluoride powder solution; adding a p-styrene sulfonate monomer and an initiator, and reacting in a nitrogen atmosphere; performing ultrasonic oscillation, and putting the product in a polytetrafluoroethylene membrane frame; drying and stripping the membrane; replacing the monovalent cations in the membrane; removing the residual sulfuric acid; and storing the product in the deionized water to obtain the polyvinylidene fluoride grafted p-styrenesulfonic acid proton exchange membrane. Through the method, a proton exchange membrane with high electric conductivity can be prepared, and the electric conductivity is relatively approximate to that of a Nafion membrane; and the preparation method is simple and easy to implement, has relatively low cost and can be applied to large-scale production.

The invention relates to a preparation method of the membrane electrode of a direct methanol fuel cell. The method comprises the following steps: an electrostatic spinning technology is adopted to construct a nano-fiber network structure thin membrane mixed by active carbon powder and Nafion resin; a precious metal nano-catalyst is deposited on the surface of the manufactured nano-fiber network structure thin membrane, so that a cathode catalyst layer thin membrane and an anode catalyst layer thin membrane are manufactured respectively; or the mixture of the precious metal nano-catalyst and the Nafion resin is taken as raw materials to directly construct the cathode catalyst layer thin membrane and the anode catalyst layer thin membrane through the electrostatic spinning technology; a cathode gas diffusion layer, the anode catalyst layer thin membrane, a Nafion membrane, the cathode catalyst layer thin membrane and a cathode gas diffusion layer are hot-pressed finally, so that the aggregation of the membrane electrode of the direct methanol fuel cell is manufactured; the membrane electrode with a nano-fiber three-dimensional network structure is constructed through the electrostatic spinning technology, so that the maximization of the three-phase reaction interface of the membrane electrode is achieved, and the improvement of electrocatalytic activity, mass-transfer efficiency and utilization efficiency of the catalyst is achieved.

The invention provides a preparation method of a sulfonated graphene modified perfluorosulfonate ion composite membrane. According to the ion composite membrane, an expanded PTFE microporous membrane serves as a base membrane. The method comprises the step that the base membrane is soaked in a sulfonated graphene perfluorosulfonate resin solution. Compared with the prior art, through doping of sulfonated graphene, self-discharge caused by permeation of vanadium ions is effectively prevented; meanwhile, the conductivity of the composite membrane is greatly improved compared with a Nafion membrane, and the improvement effect is more remarkable along with raise of temperature. Compared with a proton exchange membrane before sulfonated graphene modification, the maximum power of the composite membrane is increased by 80%.

The invention relates to a preparation method of a perfluorinated high-temperature proton-conductor composite membrane, belonging to the technical field of a fuel cell. A Nafion membrane is soaked in H2O2 water solution, deionized water and H2SO4 water solution sequentially and then is flushed and dried, and then the Nafion membrane is placed into BMIMOH ionic liquid for closed reaction at the temperature of 60-120 DEG C for 1-10h to obtain a Nafion-BMIM composite membrane. The ionic liquid at the surface of the Nafion-BMIM composite membrane is flushed by water and then placed into a vacuum drying chamber for drying. At the room temperature, the Nafion-BMIM composite membrane is completely soaked in phosphoric acid water solution for 12-48h for acid doping, so as to obtain the perfluorinated high-temperature proton-conductor composite membrane doped with phosphoric acid. The perfluorinated high-temperature proton-conductor composite membrane has good conductivity under the condition of no humidification at the temperature of 80-160 DEG C.

The invention relates to a bacterial cellulose-Nafion sandwich proton exchange membrane. The sandwich proton exchange membrane is in a BC-Nafion-BC or Nafion-BC-Nafion structure. The preparation comprises the following steps: soda boiling and washing the bacterial cellulose membrane to acquire a gel-like bacterial cellulose membrane; stacking the gel-like bacterial cellulose membrane, the treated Nafion membrane and the gel-like bacterial cellulose membrane in sequence, or stacking the treated Nafion membrane, the gel-like bacterial cellulose membrane and the treated Nafion membrane in sequence, or drying and soaking the gel-like bacterial cellulose membrane in a Nafion solution, drying the soaked bacterial cellulose membrane; and finally toughening the dried bacterial cellulose membrane. According to the invention, the sandwich proton exchange membrane has lower methanol permeability, higher proton conductivity and high thermal stability, and a good application prospect in a methanol fuel cell. The preparation process is simple and easy, and has little pollution to the environment.

The invention discloses preparation of an electrochemical biosensor device based on Hb-Pd-GR (hemoglobin-nano-palladium-graphene) composite materials and applied research of the electrochemical biosensor device. A preparation method of the electrochemical biosensor device includes the steps: taking ionic liquid 1-hexylpyridine hexafluorophosphate as modifying agents to prepare a CILE (carbon ionic liquid electrode); mixing Pd-GR and Hb, coating the surface of the electrode with mixture of the Hb-Pd and the GR, and drying the coated electrode; curing the dried electrode by the aid of a Nafion membrane to prepare a modified electrode Nafion/Hb-Pd-GR/CILE. Spectrum research shows that Hb in a composite membrane keeps that structures of the Hb cannot be denaturized, electrochemical behaviors of the Hb are researched by the aid of cyclic voltammetry, a pair of quasi-reversible reduction and oxidation peaks with good peak shapes are acquired in phosphate buffer solution, and pH (potential of hydrogen) of phosphate buffer solution is 3.0. The Pd-GR exists, so that electron transport rate between the Hb and a substrate electrode is accelerated, and the Hb can be directly electrochemically formed on the modified electrode. The Nafion/Hb-Pd-GR/CILE has good electro-catalytic performance for TCA (trichloroacetic acid) and NaNO2 (sodium nitrite) and can be applied to electrochemical sensing analysis of the TCA and the NaNO2.

The invention provides a cathode structure of a membrane electrode assembly (MEA) of a direct alcohol fuel cell and a manufacturing method. The cathode is in a double-micropore layer structure which obviously improves the performance and the stability of the MEA. The manufacturing process is characterized by comprising the following steps: (1) dispersing carbon powder and polytetrafluoroethylene (PTFE) emulsion in an isopropyl alcohol solution to form uniform slurry, changing the type of the carbon powder and the content of the PTFE in the slurry, and obtaining the slurry of different component proportions; (2) coating the slurry on a supporting layer by a spraying way, and the like, to form an anode micropore layer, and sequentially coating the two kinds of slurry of different component proportions on the same supporting layer by the same way to form a cathode double-micropore layer; (3) coating the ink which comprises catalysts and Nafion on the anode micropore layer or the cathode double-micropore layer by the spraying way, and the like, to form a cathode or an anode; and (4) hot-pressing the anode, the Nafion membrane and the cathode to obtain the MEA. The structure increases the oxygen transmission of the cathode and the inverse diffusion of water, and obviously improves the power density and the stability of the cell.

The invention, relating to the field of cell manufacturing and energy storage, discloses an enhanced ion-exchange membrane for a vanadium cell, solving the problems that Nafion membranes have low vanadium resistance and have influence on vanadium cell performances in the prior art. The preparation method is characterized by carrying out ultrasonic dispersion on the prepared nano carbon particles containing functional groups in a Nafion resin solution, and then conducting cast molding to obtain the enhanced membrane material. According to the method, by doping the nano carbon material whose surface contains functional groups (carboxyl or hydroxyl, etc.) in a matrix membrane material to enhance the vanadium resistance and ion exchange rate of the membrane material, thus the energy storage efficiency of the cell can be raised. The prepared ion-exchange membrane has outstanding stability. The cell performance is tested by using the prepared membrane material as a cell membrane and using 1.5M vanadyl sulfate and 2M sulfuric acid as an electrolyte, and the cell performance is obviously raised. The result of the test by vanadium resistance experiments shows that the vanadium resistance of the membrane is obviously raised.

The invention provides a composite anode of a direct-methanol fuel cell and a manufacturing method thereof. The invention is characterized in that the composite anode is composed of a supporting layer, a diffusion layer and a catalyzing layer, wherein, the diffusion layer is the structure of a network channel which is composed of carbon nano-tubes. The typical characteristics of the preparation process are that: (1) a certain amount of the carbon nano-tubes or the carbon nano-tubes added with a certain amount of other carbon materials are dispersed in isopropanol aqueous solution to obtain a sizing agent (A); (2) a certain amount of polyfluortetraethylene latex is added into the (A) and evenly dispersed to form serosity (B); (3) the (B) is evenly coated on the supporting layer, and the diffusion layer (C) loaded by the supporting layer is formed after 300-350 DEG C high-temperature roasting; (4) the (C) is coated with a layer of PtRu catalyst and then heat pressed with a cathode and a Nafion membrane to obtain a membrane electrode aggregation (MEA). Therefore, the transmission efficiency of the fuel at the anode is improved and the internal resistance of the battery is reduced so as to enhance the power density and service life of the battery.

Provided are a fuel cell system using waste hydrogen from a seawater electrolyzer, a method for producing caustic soda using the fuel cell system and the seawater electrolyzer, a method for producing PVC using chlorine from the seawater electrolyzer, methods for producing ammonia and urea using hydrogen from the seawater electrolyzer, and an integrated system thereof. According to the integrated system, power generation by the fuel cell is combined with a seawater electrolysis process using a membrane, such as a Nafion membrane.

The invention relates to a recovery method of a proton exchange membrane fuel cell, belonging to the field of resource recycling. The method comprises disassembly of a proton exchange membrane fuel cell, dissolution of a perfluorosulfonic acid (Nafion) membrane and regeneration of a cast membrane, oxidative complexation and purification of platinum, finally obtaining a bipolar plate, regeneratingthe Nafion membrane and the platinum ingot. The invention adopts organic solvent to dissolve and recover high-value Nafion membrane, avoids fluoride pollution caused by traditional direct incineration, and has remarkable economic benefit; Platinum ingots with purity over 99.99% are obtained by cationic resin adsorption and pyrometallurgical refining. The process is short and no pollutant is discharged, so it is suitable for industrial application.

The invention discloses a direct methanol fuel cell with alloy-TiO2 nanotube/Ti anode and a preparation method thereof. The direct methanol fuel cell comprises a cell housing, the cell housing is inside provided with a membrane electrode, an air chamber is arranged between the housing and the membrane electrode, the membrane electrode is inside provided with an electrolyte chamber, and the membrane electrode successively comprises a cathode diffusion layer, a cathode catalyst layer, a Nafion membrane, a porous titanium pipe, a TiO2 nanotube and a nanometer alloy layer formed through electroplating deposition; the cathode diffusion layer is connected with the cell housing via welding points and is arranged as a cathode output terminal, and an anode diffusion layer is connected with the cell housing via welding points and is arranged as an anode output terminal; a position, close to the electrolyte chamber, on the housing is provided with a feeding hole and a feeding sealing cover; a position, close to the air chamber, of the housing is provided with an air circulation hole; a position, close to the air chamber, at the bottom of the housing is provided with a water discharging hole; and a position, close to the anode diffusion layer, at the bottom of the housing is provided with a CO2 discharging hole. According to the direct methanol fuel cell, the catalytic oxidation performance and the CO-poisoning resistance of a TiO2 composite catalyst on methanol are improved, and alloy-TiO2 nanotube/Ti can be directly used as the anode of a direct methanol fuel cell and helps to improve the cell performances.

The invention discloses a preparation method of a phosphotungstic acid-polyimide composite proton exchange membrane. Diphenyl ether diamine and benzenetetracarboxylic anhydride with equal molar weight are added in dimethyl sulfoxide solvent to synthesize polyamide acid solution, deionized water, sodium tungstate and concentrated phosphoric acid are then added for heating and stirring to form a solution, the solution is poured on a glass plate, the glass plate is flatly placed in an oven in a stepped temperature rise mode for imidization, and the phosphotungstic acid-polyimide composite proton exchange membrane is obtained. The preparation method is simple in method, the cost of prepared membrane is low, and the membrane is even in distribution, and conductivity and alcohol blocking performance are obviously improved. Compared with a Nafion membrane, the phosphotungstic acid-polyimide composite proton exchange membrane prepared by the method obviously improves proton conduction performance at high temperature (lower than 100 DEG C), carbinol permeability is reduced, swelling degree is reduced, cost is lowered, and the preparation method brings convenience to mass production.

Disclosed are an ionic polymer metal composite electrolyte for a fuel cell and a method of preparing the same. In detail, the invention provides an ionic polymer metal composite electrolyte for a fuel cell, in which an ionic polymer metal composite, in which platinum nanoparticles are dispersed in a Nafion membrane, is used as an electrolyte, in place of the Nafion membrane alone, upon the fabrication of a fuel cell having a polymer electrolyte, and also provides a method of preparing the same. The ionic polymer metal composite electrolyte of the invention can solve problems related to the cross-over of a conventional Nafion membrane, and thereby can be used as the polymer membrane of a methanol direct fuel cell, having improved open-circuit voltage.

A sellf-humidified proton exchange membrane fuel cell membrane electrode with water dispersion area and its preparation, which solves the problem that water produce by existing cathode can not be dispatched timely which may result in cathode water- logged. The said water dispersion area is set at external edge of catalyst layer and placed in the same plane with the catalyst layer, the water dispersion area contacts Nafion membrane. The preparation is that : (1) prepare gas dispersion layer; (2) prepare water dispersion area and cathode catalytic layer; (3) prepare water dispersion area and anod catalytic layer. Because of the water dispersion area structure, the water produced at cathode is easy disperse to external area and move to anod to make the water distribution of the fuel cell more evenly, so that the performance of fuel cell is raised without increasing catalyst loading.

The invention discloses an inorganic/organic composite proton exchange membrane and a production method thereof. The method comprises the following steps: introducing and fixing a perfluorosulfonic acid polymer to SiO2 skeleton to obtain proton conduction glass containing the perfluorosulfonic acid polymer, and compounding the proton conduction glass containing the perfluorosulfonic acid polymer with low-cost sulfonated polycyclic aromatic hydrocarbon polymer to obtain the inorganic/organic composite proton exchange membrane. Compared with perfluorosulfonic acid polymer proton exchange membranes (such as Nafion membrane), the composite proton exchange membrane has greatly reduced total cost due to low content of the high-cost perfluorosulfonic acid polymer; and compared with sulfonated polycyclic aromatic hydrocarbon polymers (such as sulfonated polyester ether ketone), the composite membrane has improved proton conductivity and improved durability due to the introduction of a small amount of the perfluosulfonic acid polymer in the SiO2 glass skeleton. The composite proton exchange membrane produced in the invention has the advantages of reduced cost, high proton conductivity and good durability.

The invention discloses a preparation method of a high-performance composite proton exchange membrane of a fuel cell. The proton exchange membrane prepared through adding modified bentonite, sulfonated polybenzimidazole and sulfonated phenyl sodium phosphate to a Nafion membrane and spraying platinum ruthenium (PtRu)/carbon nanofiber to the Nafiton membrane has obvious advantages in the aspects of electrical conductivity under normal temperature or high temperature, alcohol-rejecting ability and mechanical strength, thereby guaranteeing steady electrochemical performance and a good electrochemical effect of the fuel cell. The preparation method is simple to operate, facilitates the preparation and has a good application prospect.