Abstract: A protective system for multi-part connections that prevents unintended disconnection, is inexpensive, and can be used regardless of the shape of the connectors which form the connection. The protective system allows interchanging of component connectors without compromising the protective function. The secured connection includes a first connector, a second connector shaped to engage the first connector and including a catch positioned to be accessible when the connectors are engaged, and a securing line shaped at a first end thereof to engage the first connector and at a second end thereof to be secured in the catch.

Abstract: A rechargeable metal-air electrochemical cell comprising a hydrogen-oxygen recombination electrode recombines hydrogen produced at the anode with oxygen to replenish the supply of water in the cell. The cell comprises an oxygen gas-permeable, liquid water-impermeable air cathode disposed in the cell case such that the cell is substantially impermeable to liquid water and the cell can receive and discharge oxygen gas through an opening in the cell case. During the discharge mode of the cell, the recombination electrode is inactive, and during the recharge mode, the recombination electrode catalyzes the electrochemical recombination of hydrogen and oxygen in the cell to form water. According to another aspect, the cell can comprise a device for indicating the end of the charge mode by sensing the level of current between the cathode and the recombination electrode and comparing that current level to a predetermined current level.

Abstract: An air manager is disclosed which recirculates reactant air in a battery and exchanges only a minimal amount of recirculated air for ambient air that is necessary to maintain a sufficient oxygen concentration in the battery. In the air manager, the reactant air is recirculated in a defined air pathway that provides reactant air to the entire area of all the air cathodes. A catalyst element is also provided in the air manager to convert the hydrogen gas that is generated during the recharge of a metal-air battery to water vapor. The air manager is nevertheless compact and lightweight so that the resulting battery is portable.

Abstract: An anode for use in an electrochemical cell comprising a current collector layer having a thickness less than about 10 mils, and desirably less than about 4 mils, and a rigid support extending adjacent one side of the current collector layer so that the current collector layer is sandwiched between the anodic layer of the anode and the rigid support. The rigid support maintains the current collector layer in the original configuration of the current collector layer during discharge and recharge cycles of the cell. A cell containing the anode is also disclosed. The rigid support for the anode current collector can be mounted in the electrochemical cell case so as to allow for the release from the cell of gas produced at the anode.

Abstract: A case for a rechargeable electrochemical cell comprises a vent disposed in the case interior, the vent including an oxygen/hydrogen recombination catalyst for catalyzing the recombination of the hydrogen produced by the cell during the recharge mode with oxygen in the case interior to form water in the case interior. The vent comprises a vent support extending inwardly from the cell case shell, a gas permeable, electrolyte impermeable vent cover membrane adjacent the interior surface of the vent support, and a foraminous catalyst support disposed in the case adjacent the interior surface of the vent cover membrane so that the vent cover membrane is sandwiched between the catalyst support and the vent support. Oxygen from the ambient air permeates the vent cover membrane and recombines with the hydrogen in the cell case interior. A rechargeable electrochemical cell comprising the cell case is encompassed and the cell is desirably a metal-air cell.

Abstract: The present invention provides a system for venting gas from within a case housing a metal-air cell having a cathode and an anode with a separator positioned therebetween. The cell has at least one gas vent on the anode side of the separator that extends from the interior surface of the case to the exterior surface. Each gas vent has a gas vent cap thereon on the interior surface of the case. A gas permeable, hydrophobic membrane is positioned between each gas vent and gas vent cap. The gas vent, with the gas vent cap positioned thereon, prevents the anode from blocking the venting of gas through the membrane.

Abstract: A vent system for exhausting gas generated within a battery case is provided. The vent system exhausts gas from the battery case while maintaining the hermetic seal of the case. The vent system provides a small gas exit hole that is sufficiently small to prevent electrolyte leakage and also intake of excess carbon dioxide or excess water vapor from the atmosphere. Also, various combinations of gas-permeable, hydrophobic membranes and diffuser material may cover the gas exit hole to provide humidity control for the battery while exhausting gases from the battery. A recess may be provided within the case such that the gas exit hole communicates between the atmosphere and the recess. Also, various combinations of gas-permeable, hydrophobic membranes and diffuser material may cover the recess and gas exit hole to provide humidity control for the battery while exhausting gases from the battery case.

Abstract: An air manager system is disclosed which maintains a more stable water vapor and carbon dioxide equilibrium across the air cathode of a metal-air cell while still providing new oxygen needed for operation of the cell at desired power levels. Oxygen is preferentially drawn in through one or more ventilation openings in a housing, so that the concentrations of water vapor and carbon dioxide in the battery housing remain more stable, resulting in less transfer across the cathode. A fan circulates the gases within the battery housing, keeping the oxygen needed for operation of the cell in contact with the air cathode even though the oxygen concentration within the housing is reduced compared to the ambient air outside the housing. Therefore, the cell is less susceptible to drying out or flooding, and less carbon dioxide intrudes into the cell.

Abstract: A metal-air power supply which provides improved control over air flow is provided. The reactant air and cooling air inlets are separate from one another and isolated from the exhausted reactant and cooling portions of the air flow. The reactant air flow is limited to a volumetric flow rate sufficient to provide from about 3 to about 10 times the stoichiometric amount of oxygen necessary to produce a predetermined level of current from the cell, and a total volumetric flow rate of air sufficient so that the cooling portion of the air flow has a volumetric flow rate from about 10 to about 1000 times the volumetric flow rate of the reactant portion of the air flow is provided.

Abstract: A cathode cover for a metal-air cell of the type having an air cathode positioned along an external surface of a cell case provides for improved control over exposure of the air cathode to air. The cathode cover allows a sufficient amount of air to the air cathode for an adequate production of power from the cell but limits the amount of air to which the air cathode is exposed so as to prevent premature failure of the cell from flooding, drying out, or contamination. In addition, the cathode cover avoids the problems of point diffusion of oxygen through the air cathode and localized electrolytic reactions. The cathode cover includes a mask member defining a plurality of openings therethrough and forming at least one substantially unobstructed air chamber between the mask member and the air cathode. The mask member includes at least about three of the openings per square inch of the air cathode and the openings provide between about 0.001 and about 0.

Abstract: A bifunctional air-electrode for use in electrochemical energy cells discharges a satisfactory current on the first discharge cycle and operates for a relatively large number of charge-discharge cycles without gas forming between the electrolyte side of the air electrode and the electrolyte. The active layer of the electrode includes an oxygen reduction catalyst having a first oxygen evolution potential and an oxygen evolution catalyst having a second oxygen evolution potential less than the first oxygen evolution potential, the oxygen reduction catalyst being present in a greater concentration proximate the electrolyte side than proximate the air side and the oxygen evolution catalyst being present in a greater concentration proximate the air side than proximate the electrolyte side.