6768results about "Fuel cell details" patented technology

A bipolar separator plate for fuel cells consists of a molded mixture of a vinyl ester resin and graphite powder. The plate serves as a current collector and may contain fluid flow fields for the distribution of reactant gases. The material is inexpensive, electrically conductive, lightweight, strong, corrosion resistant, easily mass produced, and relatively impermeable to hydrogen gas. The addition of certain fiber reinforcements and other additives can improve the properties of the composite material without significantly increasing its overall cost.

A fuel cell system includes a fuel cell constructed by plural stacked cells, a circulation path through which a thermal medium is circulated into each cell, a heater for heating the thermal medium, a bypass path through which the thermal medium is circulated into a part of each cell while bypassing the other part thereof, and a flow control valve for controlling a flow amount of the thermal medium circulated in the bypass path. The thermal medium can be circulated into only the part of each cell in a warm-up operation, so that the part of each cell is collectively heated. An amount of the thermal medium circulated into the other part of each cell is controlled, so that all of each cell is finally warmed up in the warm-up operation.

A fuel cell stack comprises a plurality of modules and each module comprises an elongate hollow member and one passage extending through the hollow member for the flow of a reactant. Each hollow member has a first flat surface and a second flat surface. At least one of the modules includes a plurality of fuel cells arranged on at least one of the first and second flat surfaces. Each module has a first and second integral feature to provide a spacer and a connection with its adjacent modules. The first integral feature comprises a third flat surface and the second integral feature comprises a fourth flat surface. The third flat surface is arranged at an intersecting angle to the first flat surface and the fourth flat surface is arranged at an intersecting angle to the second flat surface.

A fuel cell system is described for providing primary and/or auxiliary/backup power to one or more loads selected from the group comprising: lawn & garden equipment; radios; telephone; targeting equipment; battery rechargers; laptops; communications devices; sensors; night vision equipment; camping equipment; stoves; lanterns; lights; vehicles; cars; recreational vehicles; trucks; boats; ferries; motorcycles; motorized scooters; forklifts; golf carts; lawnmowers; industrial carts; passenger carts (airport); luggage handling equipment (airports); airplanes; lighter than air crafts; blimps; dirigibles; hovercrafts; trains; locomotives; submarines (manned and unmanned); torpedoes; security systems; electrical energy storage devices for solar-based, tidal-based, hydro-based, wind-based, and other renewable energy source; equipment for which a primary and/or backup power source is necessary or desirable to enable the equipment to function for its intended purpose, military-usable variants of above, and suitable combinations of any two or more thereof. The system provides power to the one or more loads upon the occurrence of a power outage condition, which includes a disruption or discontinuation in the delivery of primary power (i.e., power from a system-external primary source, namely, a source other than the fuel cell system) to, or power demand condition by, the one or more loads. A controller senses outage of primary power to, or demand for primary power by, the one or more loads, and, responsive thereto, operatively engages one or more fuel cells to provide power to the one or more loads.

Improved compositions comprise a polymer and carbon fibers, such as nanotubes. In some embodiments, the carbon fibers, e.g., nanotubes, can be mechanically blended or incorporated into the polymer, while in some embodiments carbon nanotubes also may be covalently bonded to the polymer to form corresponding covalent materials. In particular, the polymer can be covalently bonded to the side walls of the carbon nanotubes to form a composite with particularly desirable mechanical properties. Specifically, the bonding of the polymer to the nanotube sidewall can provide desirable mechanical properties of the composite due to the orientation relative to other types of association between the nanotubes and the polymer. The processing of the nanotubes can be facilitated by the dispersion of the nanotubes in an aqueous solution comprising a hydrophylic polymer, such as ethyl vinyl acetate. A dispersion of nanotubes can be combined with a polymer in an extrusion process to blend the materials under high shear, such as in an extruder. In general, various articles can be formed that take advantage of the properties of the composite materials incorporating a polymer and carbon fibers, such as carbon nanotubes.

In a solid polymer fuel cell series, various circumstances can result in the fuel cell being driven into voltage reversal. For instance, cell voltage reversal can occur if that cell receives an inadequate supply of fuel (for example, fuel starvation). In order to pass current during fuel starvation, reactions other than fuel oxidation may take place at the fuel cell anode, including water electrolysis and oxidation of anode components. The latter may result in significant degradation of the anode. Such fuel cells can be made more tolerant to cell reversal by promoting water electrolysis over anode component oxidation at the anode. This can be accomplished by incorporating a catalyst composition at the anode to promote the water electrolysis reaction, in addition to the typical anode electrocatalyst for promoting fuel oxidation.

A disclosed apparatus for generating electrical power has, according to one embodiment of the invention, a plurality of tubular solid oxide fuel cells contained in a reaction chamber. The fuel cells are secured at one end thereof in a manifold block, the other ends thereof passing freely through apertures in a baffle plate to reside in a combustion chamber. Reaction gases are supplied to the insides of the tubular fuel cells from a plenum chamber below the manifold block and to the reaction chamber surrounding the outsides of the fuel cells through an annular inlet path, which may include a reformation catalyst. The gases inlet path to the plenum chamber, and the annular inlet path surround the reaction chamber, are both in heat conductive relation with the reaction chamber and the combustion chamber, and raise the gases to formation and reaction temperatures as appropriate.

Between adjacent MEA's is a bipolar plate assembly having a first sub-plate with a flow channel which is open to the anode side of the one of the MEA's. A second sub-plate has a flow channel which is open to the cathode side of the adjacent MEA. The sub-plates are nested together to form a coolant flow channel between the sub-plates. The coolant flow path has a height dimension wherein the distance between the adjacent MEA's is substantially unaffected by the height dimension of the coolant flow path. A method of manufacturing a bi-polar plate assembly includes forming a closed coolant flow channel between the sub-plates by nesting the sub-plates together. A method of operating a fuel cell includes passing the coolant through a flow path having a height dimension which is substantially aligned with the height dimension of the hydrogen flow path, the oxygen flow path, or both.

A multicell assembly is constituted by alternately stacking two types of pre-assembled elements: a bipolar electrode holding subassembly and a membrane holding subassembly. The alternate stack of elements is piled over a bottom end element and the stack is terminated by placing over the last membrane holding element a top end electrode element. Each bipolar plate electrode holding element and each ion exchange membrane separator holding element includes a substantially similar rectangular frame piece, made of an electrically nonconductive and chemically resistant material, typically of molded plastic material, having on its upper (assembly) face grooves for receiving O-ring type gasket means, and having through holes and recesses in coordinated locations disposed along two opposite sides of the rectangular frame forming, upon completion of the assembling, ducts for the separate circulation of the negative electrolyte and of the positive electrolyte through all the negative electrolyte flow chambers and all positive electrolyte flow chambers, respectively, in cascade.

The application relates to a method of fabricating micro fuel cells and membrane electrode assemblies by thin film deposition techniques using a dimensionally stable proton exchange membrane as a substrate. The application also relates to membrane electrode assemblies and fuel cells fabricated in accordance with the method. The method includes the steps of successively depositing catalyst, current collector and flow management layers on the membrane substrate in predetermined patterns. Since the fuel cell is formed layer by layer, the need for assembly and sealing of discrete components is avoided. The method improves the contact resistance between the current collectors and catalyst layers and reduce ohmic losses, thereby avoiding the need for end plates or other compressive elements. This in turn reduces the overall thickness of the manufactured fuel cell. Since the fuel cell layers are optionally flexible, the devices may be fabricated using a continuous roller process or other automated means. The method minimizes production costs and costs of non-essential materials and is particularly suitable for low power battery replacement applications.

A single chamber fuel cell comprised of a cell arranged in a mixed fuel gas comprised of hydrogen or another fuel gas and oxygen, wherein the cell used is a pn junction type semiconductor having electrodes of a p-type semiconductor with carriers of holes and an n-type semiconductor with carriers of electrons connected to ends of electrical takeout wires, and each of the p-type semiconductor and n-type semiconductor is formed porous to an extent enabling the mixed fuel gas to pass.

The present invention provides a electrochemical element, wherein a multi-component composite film comprising a) polymer support layer film and b) a porous gellable polymer layer which is formed on either or both sides of the support layer film of a), wherein the support layer film of a) and the gellable polymer layer of b) are unified with each other without an interface between them.

The invention relates to electrolyte salts for electrochemical devices of improved physical, chemical and electrochemical stability.

• • The improvement resides in the use of anions of salts of the formula comprising: i) (B₁₂F_xZ_12-x)²⁻ wherein Z comprises at least one of H, Cl, Br or OR; R comprises at least one of H, alkyl or fluoroalkyl, or at least one polymer and x is at least 3 on an average basis but not more than 12;
  • ii) ((R′R″R′″)NB₁₂F_xZ_(11-x))⁻, wherein N is bonded to B and each of R′, R″, R′″ comprise a member independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl and a polymer; Z comprises H, Cl, Br, or OR, where R comprises H, alkyl or perfluoroalkyl or a polymer, and x is an integer from 0 to 11; or
  • iii) (R″″CB₁₁F_xZ_(11-x))⁻, wherein R″″ is bonded to C and comprises a member selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, and a polymer, Z comprises H, Cl, Br, or OR, wherein R comprises H, alkyl or perfluoroalkyl or a polymer, and x is an integer from 0 to 11.

The invention is to a dual beam process for providing an ion-conducting membrane with a thin metal or metal-oxide film. The process includes the cleaning of a membrane surface with a low energy electron beam followed by the deposition of the metal or metal-oxide film by a high energy electron beam of ions.

A stack for use in a flow battery, the stack comprising an odd number of interior elements positioned between two end elements, the two end elements each including an electrode, and the odd number of interior elements including membrane elements alternating with electrode elements, wherein the membrane elements include an interior frame and a membrane, the electrode elements include the interior frame and an electrode, wherein the interior frame is rotated by 180° from the frame of the membrane elements.

Fuel cells are described and contain a gas diffusion electrode, a gas diffusion counter-electrode, an electrolyte membrane located between the electrode and counter-electrode. The electrode or counter-electrode or both contain at least one modified carbon product. The electrolyte membrane can also or alternatively contain modified carbon products as well. The modified carbon product is a carbon product having attached at least one organic group. Preferably the organic group is a proton conducting group and/or an electron conducting group. The present invention preferably permits the elimination of fluoropolymer binder in the active or catalyst layer and further preferably leads to a thinner active layer and/or a thinner electrolyte membrane. Other uses and advantages are also described.

Systems and methods drawn to an electrochemical cell comprising a low temperature ionic liquid comprising positive ions and negative ions and a performance enhancing additive added to the low temperature ionic liquid. The additive dissolves in the ionic liquid to form cations, which are coordinated with one or more negative ions forming ion complexes. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. The ion complexes improve oxygen reduction thermodynamics and/or kinetics relative to the ionic liquid without the additive.

One embodiment of the present invention provides a solid oxide fuel cell, which includes: an anode; a cathode; and an ionically conducting solid oxide electrolyte disposed between the anode and the cathode; wherein the solid oxide electrolyte includes at least one first region having a relatively high operating temperature and at least one second region having a relatively low operating temperature; and wherein the composition of the solid oxide electrolyte is different in the first and second regions. Other embodiments of the invention provide methods for making and using the fuel cell, and also the solid oxide electrolyte.