Abstract: Electrochemical cell for high-voltage operation and electrode coatings for the same. The electrochemical cell and electrode coatings of the present invention can preferably withstand charging voltages to at least 5-Volts. In one embodiment, the electrochemical cell can include an anode, a cathode, a separator, and an electrolyte, wherein the anode, the cathode, and the separator are operatively associated with the electrolyte. The cathode can include, for example, a mixture of a metal oxide, an elongated carbon structure, and a conductive material. The metal oxide can be, for example, a lithium-nickel-manganese oxide, such as LiNi0.5Mn1.5O4. The elongated carbon structure can be, for example, a carbon nanotube, a carbon fibril, or a carbon fiber. The conductive material can be, for example, a conductive carbon. The metal oxide, the elongated carbon structure, and the conductive material can be bound together, for example, with a binder.

Abstract: A multi-gas microsensor assembly for simultaneously detecting carbon dioxide and oxygen in real time. According to one embodiment, the assembly comprises a non-conductive, solid substrate. A plurality of sensing electrodes, a single reference electrode, and a single counter electrode are positioned on one side of the non-conductive, solid substrate. In addition, all of the electrodes are in intimate contact with the same side of a solid-polymer electrolyte anion-exchange membrane, the solid polymer electrolyte membrane having at least one gas diffusion opening aligned with each sensing electrode. The sensor is operated in a three-electrode potentiostatic mode, in which a constant potential is maintained between the sensing and reference electrodes, and the current is measured between the sensing and counter electrodes. Control of the electrodes is achieved with a small bi-potentiostat.

Abstract: A method for the detection of carbon dioxide gas using an electrochemical sensor. The method includes exposing a gas to a sensor, which includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The method is highly sensitive and selective to carbon dioxide with a very rapid response time.

Abstract: System for modifying the chemical composition of atmosphere within an enclosed space and incubator system including such a system. The concentration of oxygen within the enclosed space may be either increased or decreased using an electrochemical device. The concentration of carbon dioxide within the enclosed space may be increased using an electrochemical or chemical device. As necessary, purging of the system with ambient air can be a part of the process of controlling the chemical composition of the atmosphere. The present invention obviates the need to use pressurized gas cylinders to supply atmospheric gases to the enclosed space.

Abstract: A method for the detection of carbon dioxide gas using an electrochemical sensor. The method includes exposing a gas to a sensor, which includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The method is highly sensitive and selective to carbon dioxide with a very rapid response time.

Abstract: An electrochemical sensor is provided for the detection of carbon dioxide gas. The sensor includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The sensor is highly sensitive and selective to carbon dioxide and has very rapid response time.

Abstract: A high-voltage electrochemical-electrolytic capacitor. The capacitor includes a cathode comprising a plurality of electrically-conductive particles in intimate electrical contact with one another and disposed in a proton-conductive, electrically-non-conductive, solid ionomer matrix. The capacitor also includes an anode comprising a plurality of electrically-conductive particles in intimate electrical contact with one another and disposed in a proton-conductive, electrically-non-conductive solid ionomer matrix, the electrically-conductive particles of the anode differing in composition from the electrically-conductive particles of said cathode. The capacitor further includes a proton-conducting dielectric positioned between and in contact with each of the cathode and the anode, the proton-conducting dielectric comprising a solid ionomer.

Abstract: An electrochemical sensor is provided for the detection of carbon dioxide gas. The sensor includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The sensor is highly sensitive and selective to carbon dioxide and has very rapid response time.

Abstract: A graphite reference electrode for use in the cathodic protection of steel embedded in concrete has been produced with a stable catalyzed structure that when equilibrated with air or oxygen and an electrolyte reaches a reproducible and reversible redox potential. This stable device is produced by exposure to hydrogen peroxide, impregnating with a metal oxide followed by a coating treatment. The embedded catalyzed graphite reference electrodes can be used in impressed cathodic protection systems or monitoring the corrosion condition of embedded steel to provide an early warning of impending damage.

Abstract: A method for continuous tracking of blood alcohol, is comprised of 1) a potential- and diffusion-controlled electrochemical solid polymer electrolyte sensor that continuously and concurrently measures very low concentrations of ethanol vapor at the surface of the skin as well as skin properties such as temperature and ionic conductivity, 2) a sensor control circuit, and 3) a data acquisition-recording device. Sensitive and reproducible measurements of ethanol over a wide population range is obtained by simultaneously maintaining the potential of the sensing electrode constant at a voltage above the rest potential of the platinum/air (O.sub.2) electrode and by use of a thin, permselective diffusion-control membrane over the sensing electrode, and in series with the human stratum corneum membrane. The electrochemical oxidation current is a direct measure of the local ethanol vapor concentration over the skin surface.

Abstract: A direct methanol fuel cell (DMFC) contains a membrane electrode assembly (MEA) including an anode porous electrode structure which can operate on a liquid or vapor methanol/water feed in the absence of a liquid electrolyte such as sulfuric acid, a proton-exchange membrane electrolyte, and a porous gas-diffusion cathode. The anode porous electrode structure includes a three-dimensional reduced (Pt--Ru)O.sub.x catalyst particle-ionomer composite structure, whereby the ionomer coats the individual particles and provides a mechanism for continuous proton transport throughout the composite structure, eliminating the need for a liquid acidic electrolyte. The partially reduced (Pt--Ru)O.sub.x particles are individually ionomer coated prior to anode fabrication. The anode porous electrode structure is subsequently bonded to one side of a thin sheet of a solid proton-conducting ionomer membrane and a cathode structure bonded to the opposite side of the membrane, to form a MEA.

Abstract: A method of in situ protection against corrosion of steel reinforcing bars in freshly poured concrete by application of a potential (anodic or cathodic), thereby enhancing the corrosion resistance of the steel for the life of the reinforced concrete structure.

Abstract: Disclosed is a high-energy-density all-solid ionomer electrochemical capacitor, completely free of liquid electrolyte. The capacitor includes 1) a three-dimensional metal oxide-particulate-ionomer composite electrode structure, whereby the ionomer coats the individual particles and provides a mechanism for continuous proton transport throughout the composite structure and 2) a unitized repeating cell element that includes this three-dimensional composite electrode structure. The composite electrode structures are bonded to opposite sides of a thin sheet of a solid proton-conducting ionomer membrane and form an integrally bonded membrane and electrode assembly (MEA). The composite electrodes of the MEA are pressed against thin electrically conductive current collectors to form a repeating element in a bipolar cell capacitor arrangement. Energy storage and discharge are achieved by utilizing double-layer and reversible redox processes.

Abstract: Ternary alloy electrocatalysts comprising platinum and at least two less noble elements are described. The ternary alloy electrocatalysts when employed in the cathode of a fuel cell utilizing a phosphoric acid electrolyte provide improved oxygen activity and stability in comparison to unalloyed platinum. The cost of the electrocatalysts is also reduced in comparison to an unalloyed platinum electrocatalyst.

Abstract: A fast response diffusion-type sensor cell for the detection of carbon monoxide and other oxidizable or reducible gases comprising a three-electrode hydrated proton-conducting membrane cell configuration, with all electrodes in intimate contact with the same proton-conducting membrane is described. The liquid electrolyte-free system has a porous gas-diffusion sensing electrode and a counter electrode located on the same side of and in intimate contact with the proton-conducting membrane. The reference electrode is spatially located on the same or opposite side of the membrane as are the sensing and counter electrodes.

Abstract: A fuel cell comprising an anode, a cathode and an aqueous carbonate electrolyte, and including means for feeding carbon dioxide to at least one of the anode and cathode during operation of the cell. The addition of carbon dioxide provides a higher current density at a working potential.

Abstract: An electrochemical sensor capable of determining the partial pressure of various gases (e.g., CO, CO.sub.2, H.sub.2 S, alcohol vapors, hydrocarbons, NO.sub.x, etc.) and, optionally, substantially concurrently, but independently, oxygen content in gases and liquids. The sensor measures the amount of chemisorbent species formed either electrochemically by partial reduction (such as "Reduced-CO.sub.2 " in the case of CO.sub.2) or partial oxidation (in the case of alcohol) or non-electrochemically via specific adsorption (in the case of CO and hydrocarbons) on platinum or other metals. The charge required to oxidize this chemisorbed species is proportional to the amount of adsorbate on the electrode surface which is made a reproducible and reliable function of the partial pressure of the gas to be measured. By the proper selection of the sensor construction and electrical parameters, high sensitivity, fast response time, and high selectivity can be obtained.

Abstract: An electrochemical sensor capable of determining the partial pressure of various gases (e.g., CO, CO.sub.2, H.sub.2 S, alcohol vapors, hydrocarbons, NO.sub.x, etc.) and, optionally, substantially concurrently, but independently, oxygen content in gases and liquids. The sensor measures the amount of chemisorbent species formed either electrochemically by partial reduction (such as "Reduced-CO.sub.2 " in the case of CO.sub.2) or partial oxidation (in the case of alcohol) or non-electrochemically via specific adsorption (in the case of CO and hydrocarbons) on platinum or other metals. The charge required to oxidize this chemisorbed species is proportional to the amount of adsorbate on the electrode surface which is made a reproducible and reliable function of the partial pressure of the gas to be measured. By the proper selection of the sensor construction and electrical parameters, high sensitivity, fast response time, and high selectivity can be obtained.

Abstract: A device for the passive electrolytic separation of the components of a gas mixture comprising an ion-transfer medium with an anodic and cathodic surface, means for electronically short-circuiting the anodic and cathodic surfaces, and means for controlling and stabilizing the partial pressure of a gas to the anode and cathode. In operation, a gaseous mixture containing a gas which participates in a reversible electrochemical reaction at the anodic and cathodic surfaces of an electrolytic cell and inert gases are fed to the anode of the separator while the anodic and cathodic surfaces are short-circuited. The pressure of the gaseous mixture is controlled in order that the partial pressure of the gas to be separated from the mixture of gases is maintained at a higher partial pressure at the anode than at the cathode.