38 results about "Metal–air electrochemical cell" patented technology

The present invention relates to a metal-air electrochemical cell with a high energy efficiency mode.

A solid-state metal-air electrochemical cell comprising: (A) a metal-containing electro-active anode; (B) an oxygen electro-active cathode; and (C) an ion-conducting glass electrolyte disposed between the metal-containing anode and the oxygen electro-active cathode. The cathode active material, which is oxygen gas, is not stored in the battery but rather fed from the environment. The oxygen cathode is preferably a composite carbon electrode which serves as the cathode current collector on which oxygen molecules are reduced during discharge of the battery to generate electric current. The glass electrolyte typically has an ion conductivity in the range of 5×10⁻⁵ to 2×10⁻³ S/cm. The electrolyte layer is preferably smaller than 10 μm in thickness and further preferably smaller than 1 μm. The anode metal is preferably lithium or lithium alloy, but may be selected from other elements such as sodium, magnesium, calcium, aluminum and zinc.

Disclosed are electrochemical cells including a composite separator capable of changing the performance of the cell by a) changing the internal electric field of the cell, b) activating lost active material, c) providing an auxiliary current collector for an electrode and/or d) limiting or preventing hot spots and/or thermal runaway upon formation of an electronic short in the system. An exemplary composite separator includes at least one electronically conducting layer and at least one electronically insulating layer. Another exemplary composite separator includes an electronically conducting layer and a solid ionic conductor. Also disclosed are methods for detecting and managing the onset of a short in an electrochemical cell and for charging an electrochemical cell.

A rechargeable metal air electrochemical cell is provided. The rechargeable metal air electrochemical cell generally includes an anode and a cathode in ionic communication via a separator and in fluid communication via one or more tubes or apertures, wherein the one or more tubes or apertures provide sufficient ionic resistance thereby preventing shorting between the electrodes while allowing liquid solvent to flow therebetween.

Methods and devices for catalyzing reactions, e.g., in a metal-air electrochemical cell, are disclosed. In some instances, a porous positive electrode of the metal-air electrochemical cell includes a metal to catalyze a reaction at the electrode (e.g., oxidation of one or more metal-oxide species). The metal can be disposed as nanoparticles, and/or be combined with a second metal. Other aspects are directed to devices and methods that can generally promote a chemical reaction (e.g., an oxidation/reduction reaction) such as the formation of platinum containing nanoparticles that can be used to catalyze electrochemical reactions.

A manganese based catalyst for use in a metal-air electrochemical cell wherein the catalyst is made by a micelle process and a method of producing the catalyst. An electrode comprising said catalyst and method of producing the electrode. The micelle encapsulation process creates catalyst particles that are submicron and easily distributed throughout the active layer of the electrode.

Protective layers in lithium-ion electrochemical cells, and associated electrodes and methods, are generally described. The protective layers may comprise lithium-ion-conductive inorganic ceramic materials, such as lithium oxide, lithium nitride, and/or lithium oxysulfide. The resulting lithium-ion electrochemical cells may exhibit enhanced performance, including reduced capacity fade rates and reduced self-discharge rates.

This invention pertains to metal-air electrochemical cells wherein one or more air entry ports is located in the bottom of the cathode can, to provide for entry of oxygen-rich air into the cathode can, where the oxygen participates in the electrochemical reaction whereby the cell produces electrical energy. In this invention, extremely small air ports are provided, along with methods of reliably fabricating such small air ports Generally, the use of an increased number of small air ports distributed over the bottom of the cathode can, opposite the reaction surface of the cathode assembly, wherein the overall open area of the ports is not increased, results in less moisture traversing the air ports, into or out of the cell. Accordingly, moisture loss, or gain, as a function of electrical energy produced, is thereby reduced.

An electrochemical cell comprising a lithium anode, a silver vanadium oxide cathode having a relatively lower basis weight, and an electrolyte activating the anode and the cathode is described. By limiting the amount of cathode active material per unit area (i.e. basis weight) facing the anode in the Li/SVO cell, the magnitude of the passivating film growth at the solid-electrolyte interphase (SEI) and its relative impermeability to lithium ion diffusion is reduced. Therefore, by using a cathode of a relatively low basis weight active material, it is possible to eliminate or significantly reduce undesirable irreversible Rdc growth and voltage delay in the cell and to extend its useful life in an implantable medical device.

The anode structure comprises a metal constituent and a base at least partially contained by a separator. Additionally, a method of manufacture of an anode structure is provided, wherein a metal constituent and a base are integrally formed into a substantially solid structure, and a separator is provided to at least partially contain the metal constituent and the base.

The invention concerns redox flow batteries comprising one or more electrochemical cells in fluid contact with an electrochemical balancing cell, the balancing cell comprising: (i) a first electrode comprising a gas diffusion electrode and the first electrode comprising a hydrogen oxidation catalyst, wherein the first electrode being maintained at a potential more positive than the thermodynamic potential for hydrogen evolution; (ii) a second electrode, the second electrode contacting negative electrolyte, and the second electrode being maintained at a potential sufficiently negative to reduce the negative electrolyte; (iii) a membrane disposed between the positive electrode and the negative electrode, the membrane being suitable to allow hydrogen cations to flow from the membrane to the negative electrolyte; and (iv) a means for contacting hydrogen with the first electrode.

A metal-air electrochemical cell that includes spun mercury-amalgamated zinc powder particles is disclosed. The mercury-amalgamated zinc powder particles have advantageous physical properties that improve the performance characteristics of the cell including increasing the rate capability while decreasing the failure rate of the cell from buildup of hydrogen gas in the cell.

A metal-air electrochemical cell that includes spun mercury-amalgamated zinc powder particles is disclosed. The mercury-amalgamated zinc powder particles have advantageous physical properties that improve the performance characteristics of the cell including increasing the rate capability while decreasing the failure rate of the cell from buildup of hydrogen gas in the cell.

This invention pertains to metal-air electrochemical cells wherein one or more air entry ports is located in the bottom of the cathode can, to provide for entry of oxygen-rich air into the cathode can, where the oxygen partcicpates in the chemical reaction whereby the cell produces electrical energy. In this invention, multiple small air entry ports are provided. Generally, the use of multiple ports distributed over the bottom of the cathode can, opposite the reaction surface of the cathode assembly, while not increasing the overall open area of the ports, results in an increase in the ratio of the cell limiting current to the rate at which moisture is lost from the cell. Accordingly, moisture loss as a function of electrical energy produced, is less.

Methods and devices for enhanced energy storage in an electrochemical cell are provided. In some embodiments, an electrode for use in a metal-air electrochemical cell can include a plurality of nanofiber (NF) structures having high porosity, tunable mass, and tunable thickness. The NF structures are particularly suited for energy storage and can provide the electrode with exceptionally high gravimetric capacity and energy density when used in an electrochemical cell.

An anode material for a metal air electrochemical cell is provided. The anode material comprises metal and/or metal oxide particles and a polymer electrolyte, particularly a polymer matrix material including electrolyte supported within the molecular structure of the polymer matrix material. Additionally, a metal air electrochemical cell is provided, using the anode material an air cathode, and a separator between the anode material and the air cathode.

An exemplary electrochemical cell incorporates at least a first battery electrode, such as a zinc electrode, at least a second battery electrode, such as a reversible metal electrode such as nickel, and at least an oxidant reduction electrode, such as an air cathode. The oxidant reduction electrode(s) is configured in a cell housing such that it is essentially orthogonal to the first and second electrodes. The cell housing contains electrolyte therein and the electrodes are immersed, at least partially, in the electrolyte. The positioning of the oxidant reduction electrode(s) on the side of the cell and relatively perpendicular to the first and second (metal) electrodes, allows for more consistent ionic resistance across all the metal electrodes. Optionally, a fourth or oxygen evolving electrode may be provided in the cell housing, horizontal, orthogonal, and below the first and second electrodes to provide oxygen bubbles for mixing the electrolyte.

Systems and methods of the various embodiments may provide metal air electrochemical cell architectures. Various embodiments may provide a battery, such as an unsealed battery or sealed battery, with an open cell arrangement configured such that a liquid electrolyte layer separates a metal electrode from an air electrode. In various embodiments, the electrolyte may be disposed within one or more vessel of the battery such that electrolyte serves as a barrier between a metal electrode and gaseous oxygen. Systems and methods of the various embodiments may provide for removing a metal electrode from electrolyte to prevent self-discharge of the metal electrode. Systems and methods of the various embodiments may provide a three electrode battery configured to operate each in a discharge mode, but with two distinct electrochemical reactions occurring at each electrode.

Various embodiments of a metal-air cell having a tab system that covers an air entry port of the metal-air cell are provided. In one representative embodiment the tab system includes polymer layer and an adhesive layer between the metal-air cell and the polymer layer. The tab system has a loss stiffness of less than 55,000 N/m at 20° C. to 25° C.