Abstract: An intrinsically safe electrolysis system for generating hydrogen gas includes an electrolyzer containing an electrolyte and providing an outlet for generated gasses. An enclosure encloses the electrolyzer and a portion of the gas outlet. A safety interlock mounted within the enclosure and outside the electrolyzer includes a radiative element and a thermal switch, the thermal switch connected in series with a power supply for the electrolyzer and mounted in a proximity to the radiative element so that when a rated current is applied to the radiative element, the thermal switch in response to receiving heat from the radiative element changes state to provide power to the electrolyzer. The electrolyzer may generate hydrogen or oxygen gas as a fuel supplement deliverable to an internal combustion engine via the gas outlet. The electrolyzer may be mounted within a vehicle compartment that may serve as the enclosure.

Abstract: A demisting flame arrestor provides a border between an electrolytic reaction vessel and an intake manifold of an engine, and includes a composite material having hydrophilic zones and hydrophobic zones constructed to form multiple pathways for permitting gaseous flow. The hydrophilic zones promote trapping and condensation of water vapor and in the event of fire disperse flame into the multiple pathways to arrest the flame front. The hydrophobic zones repel condensed water to return the water to the reaction vessel through force of gravity.

Abstract: An intrinsically safe electrolysis system for generating hydrogen gas includes an electrolyzer containing an electrolyte and providing an outlet for generated gasses. An enclosure encloses the electrolyzer and a portion of the gas outlet. A safety interlock mounted within the enclosure and outside the electrolyzer includes a radiative element and a thermal switch, the thermal switch connected in series with a power supply for the electrolyzer and mounted in a proximity to the radiative element so that when a rated current is applied to the radiative element, the thermal switch in response to receiving heat from the radiative element changes state to provide power to the electrolyzer. The electrolyzer may generate hydrogen or oxygen gas as a fuel supplement deliverable to an internal combustion engine via the gas outlet. The electrolyzer may be mounted within a vehicle compartment that may serve as the enclosure.

Abstract: A system for controlling electrolyte level and concentration within a water electrolyzer includes an electrolysis chamber containing electrolyte for production of hydrogen and oxygen, a water reservoir containing make-up water and separated from the electrolysis chamber through a check valve that opens only when electrolyte level drops to a predetermined level, and a gas lift pump within the water reservoir connected to the electrolysis chamber through the check valve and having electrodes immersed in the make-up water. Energization of the electrodes creates bubbles that transport the make-up water to the electrolysis chamber to maintain a desired concentration of the electrolyte during the production of hydrogen and oxygen.

Abstract: A system for producing metal particles using a discrete particle electrolyzer cathode, a discrete particle electrolyzer cathode, and methods for manufacturing the cathode. The cathode has a plurality of active zones on a surface thereof at least partially immersed in a reaction solution. The active zones are spaced from one another by between about 0.1 mm and about 10 mm, and each has a surface area no less than about 0.02 square mm. The cathode is spaced from an anode also at least partially immersed in the reaction solution. A voltage potential is applied between the anode and cathode. Metal particles form on the active zones of the cathode. The particles may be dislodged from the cathode after they have achieved a desired size. The geometry and composition of the active zones are specified to promote the growth of high quality particles suitable for use in metal/air fuel cells. Cathodes may be formed from bundled wire, machined metal, chemical etching, or chemical vapor deposition techniques.

Abstract: Improved fuel cell systems comprise a fuel delivery system having a fluidization apparatus and a fluidization pump for creating an electrolyte flow suitable for fluidizing at least a portion of the fuel particles located within the fluidization apparatus. Due to the presence of the fluidization pump and the fuel delivery pump, the degree of fluidization of the fuel particles can be controlled independently of the overall electrolyte flow rate provided to the cell stacks. In other words, the mass flow rate of fuel particles through the fuel cell can be varied independently from the total flow rate through the fuel cell system. The fluidization of fuel particles can facilitate suitable mixing of fuel particles and electrolyte and can prevent fuel particle agglomeration, which can clog the fuel cell piping system.

Abstract: A method of producing metal particles through electrolysis. A cathode having a plurality of active zones on a surface thereof is at least partially immersed in a reaction solution. The cathode is spaced from an anode also at least partially immersed in the reaction solution. A voltage potential is applied between the anode and cathode. Metal particles form on the active zones of the cathode. In order to promote the formation of good quality particles, a turbulent flow of the solution is maintained past one or more the active zones, and the current density in the active zones is maintained greater than about 5 kA/m2. The particles may be dislodged from the cathode after they have achieved a desired size.

Abstract: A system for maintaining a concentration range of an electroreducible metal species undergoing electrolysis within a predetermined concentration range comprises a first container containing a body of an electrolyte solution in which a metal is partially dissolved, a second container in fluid communication with the first container, the second container containing a second body of the solution, and a means for exchanging solution between the containers. The second container is configured with a means for electrolyzing, and a means for sensing the concentration of, the dissolved metal in the second body. During electrolysis, if the sensed concentration is within a predetermined range, the second body is circulated through the electrolyzing means; if the sensed concentration is outside or nearly outside the range, the solution is exchanged to maintain the concentration within the range.

Abstract: A system for filtering particles within a multiphase fluid that comprises a particulate phase is disclosed. The system comprises a first plurality of substantially parallel, substantially planar thin slabs separated by a predetermined distance to retain particles having a maximum cross-sectional dimension greater than the predetermined distance, and provides at least one flow path for at least part of the multiphase fluid. In one application, the system is used in connection with an electrochemical power source and components thereof, wherein the multiphase fluid comprises flowable fuel.

Abstract: A fuel cell system is described which comprises a power source and a fuel storage unit. A flowable fuel is contained with the fuel storage unit. A first flow path delivers fuel from the fuel storage unit to the power source. Some or all of this fuel is deposited into the individual cell cavities within the power source. A second flow path delivers fuel that is not deposited into the cell cavities to the fuel storage unit. A third flow path delivers unused and/or partially used fuel and/or reaction products and/or spent reaction solution from the cell cavities back to an optional reaction product storage unit and/or the fuel storage unit and/or to the second flow path. The system may further comprise an optional reaction product storage unit, an optional regeneration unit, an optional second reactant storage unit, an optional controller, and an optional power converter.

Abstract: A system for measuring available energy in a metal fuel cell is provided. The system comprises first componentry for measuring an electrical property of a mixture formed from one or more reaction products dissolved in a reaction medium. The electrical property may be such as to bear a known relationship with the concentration of the one or more reaction products. Using this known relationship, second componentry estimates the concentration of the one or more reaction products, and, responsive thereto, determines the available energy in the fuel cell.

Abstract: A metal-based fuel cell in which a flow path delivers a flow of reaction solution through a particulate anode and one or more particle releasers are situated along the flow path and configured to release from the cell particles which are prone to clogging due to reductions in size caused by anodic dissolution.

Abstract: Improved metal/air fuel cells comprise an anode and a cathode in which the cathode provides for gas diffusion and reduction of gaseous oxidizing agents with a catalyst and comprises an initial oxidizing agent. The initial oxidizing agent can be a non-gaseous composition present in the cathode for immediate availability. Due to the presence of the initial oxidizing agent, the metal/air fuel cells can produce current immediately after closing the circuit, regardless of the level, or concentration, of a gaseous oxidizing agent present in the catalytic layer of the cathode. Thus, the improved fuel cells can generate current without a time delay that can be associated with the flow of a gaseous oxidizing agent into the catalytic layer of the cathode.

Abstract: Improved self-contained fuel cells have a gas diffusion electrode suitable for reducing molecular oxygen and a separate gas diffusion electrode suitable for generating molecular oxygen. The fuel for the cell generally is in contact with both gas diffusion electrodes such that the fuel can be regenerated within the cell. In some embodiments, the fuel and the oxidation products of the fuel are in the form of a flowable paste that can be circulated within the cell to maintain a more uniform concentration of fuel within the cell.

Abstract: An improved electrolyte-particulate fuel cell where the fuel cell includes an anode, cathode, a bottom surface area formed by the anode and cathode where fuel flows from top to bottom, and a screen where the screen is located near the anode's bottom and has a surface area greater than the cell's bottom surface area.

Abstract: A system for producing metal particles using a discrete particle electrolyzer cathode, a discrete particle electrolyzer cathode, and methods for manufacturing the cathode. The cathode has a plurality of active zones on a surface thereof at least partially immersed in a reaction solution. The active zones are spaced from one another by between about 0.1 mm and about 10 mm, and each has a surface area no less than about 0.02 square mm. The cathode is spaced from an anode also at least partially immersed in the reaction solution. A voltage potential is applied between the anode and cathode. Metal particles form on the active zones of the cathode. The particles may be dislodged from the cathode after they have achieved a desired size. The geometry and composition of the active zones are specified to promote the growth of high quality particles suitable for use in metal/air fuel cells. Cathodes may be formed from bundled wire, machined metal, chemical etching, or chemical vapor deposition techniques.

Abstract: An improved electrode assembly for a fuel cell with a gaseous reactant comprises an active layer and a backing layer adhered to the active layer, in which the active layer comprises a catalyst, a matrix polymer and an ion-conducting polymer. The matrix polymer can form a porous polymer matrix in which the ion-conducting polymer is disposed. The backing layer comprises a hydrophobic polymer and a porous composite. A fuel cell stack can include one or more of the improved electrode assemblies.

Abstract: A method for operating an electrolyzer to produce metal particles by electrolysis of an electrolyte solution while optimizing electrolyzer service life and particle quality. An electrolyzer immersed in a body of electrolyte including dissolved metal is energized by a power supply and cell voltage across an anode and cathode is monitored. Power supply output is adjusted responsive to the monitored voltage to maintain current density within a preferred range to promote high-quality particle growth. In a growth cycle, particles fully grown are removed from the cathode, and cell voltage polarity is reversed to dissolve unremoved particles. Peak cathode current may be monitored during polarity reversal to indicate a cathode surface condition, and the surface reconditioned if peak current exceeds an operating limit.

Abstract: A method of and system for flushing one or more cells or components thereof in a particle-based electrochemical power source is provided. Reaction solution is delivered to and withdrawn from the one or more cells when the electrochemical power source is in a standby mode of operation.

Abstract: A fuel cell system for providing primary and/or auxiliary/backup power to one or more loads for which a primary and/or backup power source is desirable to enable equipment to function for its intended purpose. The system provides power to the one or more loads upon the occurrence of power outage condition, which includes a disruption in the delivery of primary power 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.