Abstract: Separators, electrochemical cells and methods are provided, to improve operation of cells such as metal-ion batteries and fuel cells. Separators comprise a porous, ionically conductive film including layered double hydroxide(s) (LDHs), which are functional ceramic additives, removing potentially harmful anions from the electrolyte by incorporating them into the LDH structure of positively-charged sheets with intermediary anions. For example, anions which are electrolyte decomposition products or cathode dissolution products may be absorbed into the LDH to prevent them from causing damage to the cell and shortening the cell's life. LDHs may be incorporated in the separator structure, coated thereupon or otherwise associated therewith. Additional benefits include dimensional stability during thermal excursions, fire retardancy and impurity scavenging.

Abstract: Rechargeable batteries and corresponding methods are provided, in which zinc dendrite growth to a compartment between a zinc-based anode and a separator of a rechargeable battery is limited, by preventing zincate anions from diffusing outside of the compartment. Separators limiting dendrite growth may comprise ion-selective membrane(s) configured to be permeable to charge transfer cations of the alkaline electrolyte and impermeable to hydrated zincate anions. The membrane(s) may be reinforced and/or support internal compartment(s) with electrolyte lacking zincate ions. More generally, separators are provided, which are permeable to charge transfer ions but impermeable to metal ions, and limit the latter to the anode compartment in which the metal ions may be deposited in a manner that does not form dendrites which can compromise the structural and functional integrity of the battery cell.

Abstract: A method for renovation of a consumed anode in a metal-air cell without dismantling the cell according to embodiments of the present invention comprising circulating electrolyte through the cell to evacuate used slurry from the cell, circulating electrolyte with fresh slurry into the cell and allowing sedimentation of the fresh slurry inside the cell to form an anode and compacting the slurry to reduce the gaps between its particles.

Abstract: Powders, electrodes, zinc-air batteries and corresponding methods are provided. Powders comprise perforated shells having a size of at least 100 nm and comprising openings smaller than 10 nm. The shells are electrically conductive and/or comprise an electrically conductive coating. Powders further comprise zinc and/or zinc oxide which resides at least partially within the shells. Methods comprise wetting the shells with a zinc solution to yield at least partial penetration of the zinc solution through the openings, and coating zinc internally in the shells by application of electric current to the shells. Upon electrode preparation from the powder, cell construction and cell operation, zinc is oxidized to provide energy and the shells retain formed Zn O therewith, providing sufficient volume for the associated expansion and maintaining thereby the mechanical stability and structure of the electrode—to enable many operation cycles of the rechargeable zinc-air batteries.

Abstract: A method and system for creating low corrosion passivation layer on an anode in a metal-air cell comprise asserting high negative potential and low drawn current density on the cell after its operational parameters have stabilized after the cell has been powered-on. As a result the H2 evolution rate momentarily raises and then drops sharply, thereby causing the creation of a passivation layer on the face of the anode.

Abstract: This invention provides a system and a method for safe production of electrolyte at required concentration on site on demand where occasionally only water is needed to be filled up. The system includes two main units: a saturated electrolyte unit and a diluted electrolyte unit.

Abstract: Aluminum-air battery units and stacks are provided with frames configured to mechanically support the anode of each unit, within a housing configured to support the frame and the air cathode(s) mechanically, sealably hold the electrolyte within the housing and in fluid communication with openings in the housing—forming one or two sided electrochemical cell in each unit. The frame comprises a protective strap configured to protect edges of the rectangular anode against corrosion by the electrolyte during operation, and also an external trapezoid shape that is configured to press the protective strap against the edges of the rectangular anode upon insertion of the frame with the anode into the housing. Various embodiments comprise, spacers between the anode and cathodes and grids supporting airways to the cathodes. In disclosed configurations, anode may be replaced after electrolyte evacuation while maintaining the stack sealed and quickly ready for renewed operation.

Abstract: Methods and systems are provided, which convert spent electrolyte from aluminum-air batteries into high purity alumina (HPA) and useful co-products such as fertilizer(s) and/or feed supplement(s). Aluminum tri-hydroxide (ATH) having potassium (K) and/or sodium (Na) impurities, e.g., from spent electrolyte, may be dissolved in strong acid to form an acidic ATH solution having pH<4. Consecutively, the acidic ATH solution may be neutralized to pH>4 to precipitate ATH while retaining dissolved K/Na in the neutralized solution. The dissolving and the neutralizing may then be repeated with the precipitated ATH until a specified purity level of the precipitated ATH is reached. Using appropriate bases to neutralize the acidic ATH solution, e.g., ammonia and/or choline, yields useful co-products such as ammonium nitrate (with nitric acid as the strong acid) and choline chloride (with hydrochloric acid as the strong acid), respectively.

Abstract: Methods and systems for electrolyte regeneration are provided, which regenerate a spent alkaline electrolyte (SE) comprising dissolved aluminum hydrates from an aluminum-air battery, by electrolysis, to precipitate aluminum tri-hydroxide (ATH) and form regenerated alkaline electrolyte, and adding a same-cation salt to an anolyte used in the electrolysis to supplant a corresponding electrolyte cation. The regeneration may be carried out continuously and further comprise mixing the SE and the same-cation salt in a salt tank configured to deliver the anolyte, removing the regenerated alkaline electrolyte from a catholyte tank configured to deliver the catholyte, and filtering the ATH from a solution delivered from the salt tank to the anolyte. Optionally, the salt may be a buffering salt, and in some cases chemical reactions may be used to enhance the regeneration by electrolysis.

Abstract: A method for renovation of a consumed anode in a metal-air cell without dismantling the cell according to embodiments of the present invention comprising circulating electrolyte through the cell to evacuate used slurry from the cell, circulating electrolyte with fresh slurry into the cell and allowing sedimentation of the fresh slurry inside the cell to form an anode and compacting the slurry to reduce the gaps between its particles.

Abstract: Rechargeable batteries and corresponding methods are provided, in which zinc dendrite growth to a compartment between a zinc-based anode and a separator of a rechargeable battery is limited, by preventing zincate anions from diffusing outside of the compartment. Separators limiting dendrite growth may comprise ion-selective membrane(s) configured to be permeable to charge transfer cations of the alkaline electrolyte and impermeable to hydrated zincate anions. The membrane(s) may be reinforced and/or support internal compartment(s) with electrolyte lacking zincate ions. More generally, separators are provided, which are permeable to charge transfer ions but impermeable to metal ions, and limit the latter to the anode compartment in which the metal ions may be deposited in a manner that does not form dendrites which can compromise the structural and functional integrity of the battery cell.

Abstract: A method and system for creating low corrosion passivation layer on an anode in a metal-air cell comprise asserting high negative potential and low drawn current density on the cell after its operational parameters have stabilized after the cell has been powered-on. As a result the H2 evolution rate momentarily raises and then drops sharply, thereby causing the creation of a passivation layer on the face of the anode.

Abstract: Separators, electrochemical cells and methods are provided, to improve operation of cells such as metal-ion batteries and fuel cells. Separators comprise a porous, ionically conductive film including layered double hydroxide(s) (LDHs), which are functional ceramic additives, removing potentially harmful anions from the electrolyte by incorporating them into the LDH structure of positively-charged sheets with intermediary anions. For example, anions which are electrolyte decomposition products or cathode dissolution products may be absorbed into the LDH to prevent them from causing damage to the cell and shortening the cell's life. LDHs may be incorporated in the separator structure, coated thereupon or otherwise associated therewith. Additional benefits include dimensional stability during thermal excursions, fire retardancy and impurity scavenging.

Abstract: A method and system for creating low corrosion passivation layer on an anode in a metal-air cell comprise asserting high negative potential and low drawn current density on the cell after its operational parameters have stabilized after the cell has been powered-on. As a result the H2 evolution rate momentarily raises and then drops sharply, thereby causing the creation of a passivation layer on the face of the anode.

Abstract: A method for renovation of a consumed anode in a metal-air cell without dismantling the cell according to embodiments of the present invention comprising circulating electrolyte through the cell to evacuate used slurry from the cell, circulating electrolyte with fresh slurry into the cell and allowing sedimentation of the fresh slurry inside the cell to form an anode and compacting the slurry to reduce the gaps between its particles.

Abstract: The present invention relates to zinc electrode and to methods of producing zinc electrode and particularly to a method of producing zinc electrode providing dimensional/geometrical stability during a battery charge/discharge operation. The invention provides methods of use of batteries comprising the zinc electrode of this invention. Applications of batteries of this invention include electric vehicles, portable electronics and drones.

Abstract: Methods of producing high purity powders of submicron particles of metal oxides are presented. The methods comprise providing or forming an alloy of a first metal with a second metal, optionally heating the alloy, subjecting the alloy to a leaching agent to remove the second metal from the alloy and to oxidize the first metal, thus forming submicron oxide particles of the first metal. Collections of high purity, high surface area, submicron particles are presented as well.

Abstract: Aluminum-air battery units and stacks are provided with frames configured to mechanically support the anode of each unit, within a housing configured to support the frame and the air cathode(s) mechanically, sealably hold the electrolyte within the housing and in fluid communication with openings in the housing—forming one or two sided electrochemical cell in each unit. The frame comprises a protective strap configured to protect edges of the rectangular anode against corrosion by the electrolyte during operation, and also an external trapezoid shape that is configured to press the protective strap against the edges of the rectangular anode upon insertion of the frame with the anode into the housing. Various embodiments comprise, spacers between the anode and cathodes and grids supporting airways to the cathodes. In disclosed configurations, anode may be replaced after electrolyte evacuation while maintaining the stack sealed and quickly ready for renewed operation.

Abstract: Powders, electrodes, zinc-air batteries and corresponding methods are provided. Powders comprise perforated shells having a size of at least 100 nm and comprising openings smaller than 10 nm. The shells are electrically conductive and/or comprise an electrically conductive coating. Powders further comprise zinc and/or zinc oxide which resides at least partially within the shells. Methods comprise wetting the shells with a zinc solution to yield at least partial penetration of the zinc solution through the openings, and coating zinc internally in the shells by application of electric current to the shells. Upon electrode preparation from the powder, cell construction and cell operation, zinc is oxidized to provide energy and the shells retain formed Zn O therewith, providing sufficient volume for the associated expansion and maintaining thereby the mechanical stability and structure of the electrode—to enable many operation cycles of the rechargeable zinc-air batteries.

Abstract: A method for renovation of a consumed anode in a metal-air cell without dismantling the cell according to embodiments of the present invention comprising circulating electrolyte through the cell to evacuate used slurry from the cell, circulating electrolyte with fresh slurry into the cell and allowing sedimentation of the fresh slurry inside the cell to form an anode and compacting the slurry to reduce the gaps between its particles.