108 results about "Over potential" patented technology

The invention is a fuel cell (20) having a corrosion resistant and protected cathode catalyst layer (24). The cathode catalyst layer (24) includes a platinum oxygen reduction catalyst and an oxygen evolution catalyst selected from the group consisting of catalysts that are more active than platinum for oxygen evolution. The oxygen evolution catalyst may be uniformly applied within the cathode catalyst layer, or non-uniformly applied to identified high corrosion areas (82) (84) of the cathode catalyst layer (24). The cathode catalyst layer (24) may include heat-treated carbon support material, and/or a heat-treated carbon black within a diffusion layer (40) supporting the cathode catalyst layer (24). The fuel cell (20) may also include an anode catalyst layer (22) having a poor oxygen reduction catalyst having a greater oxygen reduction over potential than platinum.

An alkaline battery constructed of a cathode can and an anode cup in such a way that an open end of the cathode can is sealed by the anode cup, with a gasket interposed between them, characterized in that the open end of the anode cup is folded back in U-shape along its periphery and the fold is tightened for hermetic sealing by the internal periphery of the open end of the cathode can, with the gasket interposed between them, the anode cup has a higher hydrogen over potential material coating layer formed in a limited region on the inside thereof excluding the bottom of the U-shaped fold and the outer periphery of the fold, the cathode can contains the cathode active material and silver-nickelite (AgNiO.sub.2), the anode cup contains the anode mix which is mercury-free zinc or zinc alloy powder as the anode active material.

The invention discloses a preparation method of a Keggin type heteropoly acid-polypyrrole-graphene composite material modified electrode. The preparation method comprises the following steps: selecting a glassy carbon electrode and carrying out surface treatment on the glassy carbon electrode; dropping graphene dispersion liquid on the surface of the glassy carbon electrode and putting the glassy carbon electrode under an infrared lamp to be dried to prepare a graphene modified electrode; immersing the prepared graphene modified electrode into a sulfuric acid solution containing polypyrrole and Keggin type heteropoly acid; scanning by using a cyclic voltammetry; after scanning, taking out the graphene modified electrode and eluting with water for the second time; drying at room temperature to obtain the Keggin type heteropoly acid-polypyrrole-graphene composite material modified electrode. The Keggin type heteropoly acid-polypyrrole-graphene composite material modified electrode prepared by the preparation method has a sensitive inhibition effect based on an oxidization reduction reaction of folic acid on the Keggin type heteropoly acid and can be used for determining the folic acid; compared with a common electrode, the Keggin type heteropoly acid-polypyrrole-graphene composite material modified electrode has the advantages of small over-potential, high sensitivity, good stability, high reproducibility and the like; a preparation process is simple, raw materials are easy to obtain and the cost is low.

The invention provides negative lead plaster of a lead-carbon battery and a preparation method thereof, a negative polar plate and a lead-carbon battery, which belongs to the field of the preparation of a lead-acid battery, and aims at solving the problems of the existing lead-carbon battery that the hydrogen evolution over-potential is low and the dehydration of the battery is severe in the circulating process. A hydrogen evolution inhibitor is added into the negative lead plaster of the lead-carbon battery, and the lead-carbon battery adopting the negative lead plaster as a raw material solves the problems of the short cycle life caused by low hydrogen evolution over-potential of the lead-carbon battery and the severe dehydration of the battery in the circulating process.

The invention provides a cathode for hydrogen production by alkaline water electrolysis or a cathode for chlor-alkali industry and a preparation method thereof. The method is characterized by using a three-dimensional nickel net as a matrix, conducting electrochemical deposition by controlling electrodeposition potential and the concentration of Ni and Mo in the electrolyte to form a Ni-Mo alloy coating to gradually reduce the concentration of Ni near the side of the matrix in the coating and gradually increase the concentration of Mo near the side of the matrix in the coating; and then, conducting anodic etching in an ammonia solution, wherein because the dissolution and solution of Ni are generated in the coating and the matrix and Mo is kept, the electrode specific surface is increased, and hydrogen evolution over potential is reduced. According to the gradient deposition and anodic etching method of the invention, the catalyst coating and Ni matrix form integrated alloy, delamination and detachment between the catalyst and the matrix can be prevented, and simultaneously good hydrogen evolution performance is achieved.

A method for improving recognition results of a speech recognizer uses supplementary information to confirm recognition results. A user inputs speech to a speech recognizer. The speech recognizer resides on a mobile device or on a server at a remote location. The speech recognizer determines a recognition result based on the input speech. A confidence measure is calculated for the recognition result. If the confidence measure is below a threshold, the user is prompted for supplementary data. The supplementary data is determined dynamically based on ambiguities between the input speech and the recognition result, wherein the supplementary data will distinguish the input speech over potential incorrect results. The supplementary data may be a subset of alphanumeric characters that comprise the input speech, or other data associated with a desired result, such as an area code or location. The user may provide the supplementary data verbally, or manually using a keypad, touchpad, touchscreen, or stylus pen.

The invention relates to a formation method of a battery, in particular to an opening formation method of a lithium ion secondary battery using lithium titanate as a cathode, and the method comprises the following steps: at a formation temperature of the lithium ion secondary battery using lithium titanate as the cathode, the charging process comprises large current constant-current charge to a charge cutoff voltage and a constant-voltage charge to a cutoff current, and a solid electrolyte interfacial film is formed on the surface of the cathode material, wherein the large current is 0.2 C to 3C; the charge cutoff voltage is 1.8V to 2.8V, the cutoff current is less than or equal to 0.05C, and the formation temperature of the lithium ion secondary battery is 15 DEG C to 60 DEG C. Aiming at the characters of the lithium ion secondary battery using lithium titanate as the cathode, the large current is adopted to charge in the formation process, thus forcing to form an SEI film on the surface of the lithium titanate cathode, and the generated gas is pumped, thus avoiding the gas bulging problem owning to reaction of the lithium titanate active material and electrolyte caused by over-potential in the using process of the lithium battery and ensuring the capacity and the cyclicity of the battery simultaneously.

A method for improving the efficiency and durability of reversible solid oxide cells during electrical energy storage is disclosed. The method utilizes a specific set of operating conditions that produces a storage chemistry where approximately thermal-neutral operation can be achieved at low cell over-potentials. Also disclosed are reversible solid oxide cell energy storage system configurations, including one that utilizes storage in natural gas and water storage/distribution networks, thereby reducing storage cost.

The invention provides a transition metal phosphide/g-C3N4 composite material as well as a preparation method and application thereof. According to the transition metal phosphide/g-C3N4 composite material, transition metal phosphide is loaded on g-C3N4, the compounding of photoelectrons and holes can be remarkably reduced and hydrogen evolution over-potential is reduced, so that the photo-catalytic reaction activity of the g-C3N4 is improved; the transition metal phosphide/g-C3N4 composite material can be applied to a photo-catalytic reaction system and especially can be used in a photo-catalytic water decomposition and hydrogen production system. According to the preparation method provided by the invention, the interface bonding performance of the transition metal phosphide and the g-C3N4 can be improved so that the catalytic activity is improved; furthermore, the preparation method is simple to operate, wide in applicability, good in repeatability and wide applicable range; a reliable scheme is provided for reduction of the photo-catalytic cost and photo-catalytic hydrogen production.

The invention relates to a MoS2/Ni3S2 electrode material as well as a preparation method and application thereof, which belongs to the technical field of environmental protection and energy of hydrogen production by virtue of electric decomposition of water. The application of different sulfur sources is verified to have great influence for the morphology and performance of a catalyst; and by virtue of comparison, the MoS2/Ni3S2 electrode synthesized by using thioacetamide as a sulfur source has optimum morphology, performance and reaction active site, the over-potential for the reaction can be greatly reduced, and the energy loss in the electrochemical hydrogen production process can be reduced. Meanwhile, the synthetic method is simple, and the foam nickel self-supported MoS2/Ni3S2 electrode can be synthesized by adopting a one-step hydrothermal method, so that the industrialized production and actual application value is high.

The invention provides an fct-phase FePtCu ternary alloy nano particle catalyst and a synthesis method thereof. A polyalcohol reduction method is adopted, and metal precursors (including anhydrous FeCl2, platinum acetylacetonate and copper acetylacetonate), 1,2-hexadecanediol, oleic acid and oleylamine are heated to react in an organic solvent hexadecylamine, and are stirred in an N2 protection atmosphere; after heating and cooling, n-hexane and ethanol are added, and then the mixture is centrifuged and separated; supernatant is removed and sediment is dried to obtain a nano particle product; the structure, magnetism and catalytic activity of the nano particle product are determined; and the diameter of fct-phase FePtCu ternary alloy nano particles is 9-15 nanometers, the coercive force reaches 900Oe-4800Oe, an HER (Hydrogen Evolution Reaction) electro-catalytic property is characterized under the condition of 10mA/cm<2> and the over-potential eta=34-44mV Tafel slope b is equal to 23.6mV/dec-28.2mV/dec, and the ORR (Oxygen Reduction Reaction) electro-catalytic performance is excellent. The invention further synthesizes the fct-phase FePtCu ternary alloy nano particle catalyst with excellent performance. The fct-phase FePtCu ternary alloy nano particle catalyst does not need to be subjected to high-temperature annealing treatment, has the advantages of simplicity in preparation, low cost, high catalytic activity and good catalyst stability, and has very great application potential by being used as the HER and OOR electro-catalyst.

The invention provides a catalyst for electrochemically reducing carbon dioxide into carbon monoxide and a preparation method of the catalyst. The catalyst is a carbon-support nano copper-silver alloy. According to the catalyst provided by the invention, an over-potential for electrocatalytic reduction of the carbon dioxide can be effectively reduced, and the production efficiency is improved; in addition, the catalyst has more excellent catalytic activity; the cost of the catalyst in scale production is favorably reduced. The invention also provides a preparation method of the catalyst.

The invention discloses application of a functional carbon material and a high-hydrogen-evolution substance doped functional carbon material. The functional carbon material or the high-hydrogen-evolution substance doped state functional carbon material is taken as a repressed hydrogen cathode carbon material applied in a cathode lead paste additive for preparing a carbon negative electrode or a lead carbon battery of a super battery. The hydrogen evolution impedance on the surface of the functional carbon material or the high-hydrogen-evolution substance doped functional carbon material is increased, so as to increase the hydrogen evolution over-potential and reduce hydrogen evolution. The functional carbon material and the high-hydrogen-evolution substance doped functional carbon material can fully exert the advantages of a C material, the cycle life of the super battery or the lead carbon battery is prolonged and the charge capacity and the discharge capacity caused by over-large current are improved, and simultaneously negative effects caused by overlarge hydrogen evolution current of the C material are avoided when.

The invention discloses a preparation method for a bifunctional catalyst material for a lithium air battery. A cobalt nitride nanometer cubic-nitrogen doped carbon composite material is taken as an air electrode catalyst material. The preparation method comprises the following steps: dispersing cobalt salt and polyvinylpyrrolidone in methyl alcohol, thereby acquiring a dispersion solution; dissolving 2-methylimidazole in methyl alcohol, thereby acquiring another dispersion solution; mixing the two dispersion solutions, fully stirring for reacting, and then standing, purifying and washing, thereby acquiring a nanometer-scale metallic organic frame complex; performing fractional heat treatment on the complex at 300-400 DEG C, wherein the front fractional heat treatment is performed under inert atmosphere and the posterior fractional heat treatment is performed under the condition of introducing ammonia gas; and finally, acquiring the cobalt nitride nanometer cubic-nitrogen doped carbon composite material. When the material is applied to the catalyst for the lithium air battery, under the effects of high electronic transmission performance and stable catalytic performance of nitrides, the charging/discharging over-potential of the lithium air battery can be effectively reduced, the double-trip efficiency of the battery can be increased, and the circulating service life of the battery can be prolonged. The invention has the advantages of excellent catalytic performance of the catalyst material, simple and controllable preparation method, high operability and low production cost.

The invention relates to a photo-cured solid state composite electrolyte and a preparation method thereof, and belongs to the technical field of alkali metal batteries. The electrolyte is prepared byuniformly mixing a polymer prepolymer, a photoinitiator, an inorganic solid electrolyte, a salt and an ionic liquid in a light shielding condition, and then carrying out ultraviolet curing under an inert atmosphere. The electrolyte has gradient distribution characteristics due to the gravity sedimentation effect of the inorganic solid state electrolyte in the preparation process, so that the defect that the PEO is directly contacted with the positive electrode and is easy to oxidize can be solved; meanwhile, the metal ion distribution of the surface of the battery electrolyte and the surface of the metal negative electrode can be adjusted, high compatibility of the alkali metal negative electrode and the positive electrode is achieved, and relatively low over-potential and long-term cycling stability in the constant-current polarization can be shown; the impedance of the electrolyte and the electrode interface is relatively small, and the impedance is almost not increased along with the increase of the storage time of the battery; and the method has the advantages that the preparation process is simple, the conventional equipment is used, the raw materials are easy to obtain, the method is safe and pollution-free, and the method is suitable for large-scale batch production.

The invention relates to a method for preparing alkaline hydrogen peroxide in situ, which is used for taking hydrogen, oxygen and an alkaline solution as raw materials to prepare an alkaline hydrogen peroxide water solution by direct electrocatalysis in situ. The preparing method adopts a membrane reactor, the oxygen and the hydrogen enter cathode and anode by the air inlets of a cathode end plate and an anode end plate and generate electrochemical reaction on the gas diffusion electrode loading with nano electro-catalyst, and the obtained product rapidly enters an electrolyte solution to be beneficial to the enrichment of the hydrogen peroxide. The middle adopts a cation-exchange membrane, so the explosion hazard of direct reaction of the hydrogen and the oxygen is avoided, and the safety is high. The volume of the reactor is small, and the product can be simply separated from reactants. Adopting the gas diffusion electrode loading with the nano electro-catalyst, the preparing method effectively increases the three-phase reaction interface, improves the utilization ratio of the catalyst, and increases the reaction rate. The use of the nano electro-catalyst can effectively reduce the over potential of reaction and energy consumption.

The invention relates to a Mo2C/C nano composite material as well as a preparation method thereof and a lithium carbon dioxide battery cathode comprising the Mo2C/C nano composite material as well asa preparation method thereof, and belongs to the technical field of electrochemical energy. Ammonium molybdate is taken as a molybdenum source, and citric acid is taken as a carbon source to prepare the Mo2C/C nano composite material by utilizing reducing characteristics of hydrogen gas. A lithium carbon dioxide battery cathode plate is prepared through a coating method, the Mo2C/C nano compositematerial and PVDF are mixed as coating slurry for being coated on a current collector, so as to obtain the lithium carbon dioxide battery cathode containing the Mo2C/C nano composite material. The lithium carbon dioxide battery cathode containing the Mo2C/C nano composite material effectively relieves the battery cathode polarization problem, and reduces the charging over-potential of a lithium carbon dioxide battery, so that the lithium carbon dioxide battery can stably and efficiently operate.

An aftertreatment module includes a catalytic brick having upstream and downstream flanges sized to extend over potential leak flow paths between bricks. Additionally, an aftertreatment module has an array of similarly flanged bricks to reduce leakage through all interfaces between adjacent bricks. A frame for holding the array of bricks includes flow modulators to restrict leakage through an interface between the frame and at least one side surface defined by the array of bricks.

The invention is a device for electrical load-leveling and/or electrolysis. A housing contains pairs of electrodes made from or containing a porous material. The electrodes are filled respectively with an anolyte and a catholyte, which is an ionic couple such as Vanadium +2/+3. A non-permi-selective barrier membrane with openings may be included to substantially separate the electrode pair. The device results in reduced resistive, over-potentials and polarization losses, and may be scaled-up for integration into an electric utility.

The invention belongs to the technical field of electrochemistry, and relates to a preparation method of an impregnation type mono-atomic iron-carbon layer modified nickel based or cobalt based composite material electrode. The preparation method comprises following steps: preparing an ethanol solution of tannic acid and an ethanol solution of ferric nitrate; slowly and dropwise adding the ferricnitrate solution into the tannic acid solution to form a colloidal solution; soaking a substrate material into the colloidal solution, wherein the substrate material is nickel based or cobalt based carbon paper, carbon cloth, electroconductive glass or a stainless steel net; taking out the substrate material, mixing the substrate material with a sulfur source, a phosphor source, or a nitrogen source, (or no other raw material is added), burning the substrate material for 0.5 to 4 hours under the protection of inert gas, and cooling. The raw materials are cheap, nontoxic and easily available, the operation is easy and simple, multiple substrates can be painted and impregnated, the reaction time is short, and industrialization is easy. The prepared composite material electrode has a good morphology maintaining performance, good electrochemical properties, and high stability, and can be applied to electrocatalytic decomposition of water to prepare oxygen. The prepared composite material can be used as the positive pole for electrocatalytic decomposition of water; and the over-potential is 280 mV, when the current density is 40 mA/cm<-2>.

The invention relates to a preparation method of a ternary composite material for a lead-carbon battery. The preparation method comprises the following steps: performing purification treatment on biomass fibers and graphene oxide by using a NaOH solution to ensure that sufficient graphene oxide is loaded on surfaces of the biomass fibers; and then performing high-temperature carbonization after chemical adsorption of Pb ions to obtain a lead/graphene/activated carbon fiber ternary composite material. According to the method provided by the invention, the adopted biomass fibers are wide in source, the preparation process is economical and environment-friendly, the prepared lead/graphene/activated carbon fiber ternary composite material not only can solve the problem of low electric conductivity of activated carbon by virtue of graphene, but also effectively solves the problem of serious agglomeration of graphene. Meanwhile, a layer of nano-scale lead oxide covers uniformly on the surface of a carbon material, so that on one hand, the over-potential of hydrogen evolution of the carbon material is improved, and on the other hand, the compatibility between the carbon material and lead powder is improved, and the interface resistance is reduced. The ternary composite material is used for making the lead-carbon battery, and the cycle life of the battery is prolonged.

The invention discloses a preparation method of a nickel-based alloy electrolysis hydrogen evolution cathode porous material. According to the preparation method, a Ni-W-Al-LaNi5 porous material is synthesized by uniformly mixing and drying four types of high-purity element powder, namely, Ni, W, Al and LaNi5, in the following percentage by mass: 15 to 32 percent of the W, 5 to 18 percent of the Al, 2 to 7 percent of the LaNi5, and the balance of Ni, pressing and forming to obtain a green body, and performing a vacuum sintering reaction on the green body by utilizing a solid phase partial diffusion principle. The porous material prepared by the preparation method has the advantages of abundant pores, large specific surface area, concerted catalysis, low hydrogen evolution over-potential, stable hydrogen evolution, good corrosion resistance, easiness, environment-friendliness, capacity of batch production and the like, and has important significance to production and application of hydrogen energy.

The invention discloses a method for coating the surface of nano-alpha-phase nickel hydroxide with CoOOH. The method is mainly characterized in that a precipitation conversion process is adopted to coat the surface of alpha-phase nickel hydroxide with a layer of CoOOH. The method obviously improves the conductive performance of the alpha-phase nickel hydroxide, and improves the electrode performance of nickel hydroxide, so the cell performances are obviously improved, for example, the specific capacity and the output power are improved, the large-rate discharge capability and the charge and discharge cycle performance are improved, and the oxygen evolution over-potential and the discharge plateau are improved. The discharge capacity of the cobalt coated nickel hydroxide prepared in the invention is high to 386mAh/g.