A metal-air battery may include a housing, at least one cathode disposed in the housing between an air space and an electrolyte space, and at least one metal anode disposed in the electrolyte space. The battery may also include an air path leading through the housing from an air inlet to an air outlet of the housing, both of which may be fluidically connected to the air space, and an air supply device for generating an air flow which may follow the air path and act upon the cathode. The battery may further include an electrolyte path leading through the housing from an electrolyte inlet to an electrolyte outlet of the housing, both of which may be fluidically connected to the electrolyte space, and an electrolyte supply device for producing an electrolyte flow which may follow the electrolyte path and act upon the anode and the cathode.

An anode for an aluminium-air battery may include an anode body, which may contain particles of an aluminium alloy in a sodium matrix. An electrolyte for an aluminium-air battery may consist of one of an aqueous acid and an aqueous lye containing at least one halogen and at least one surfactant.

Systems and methods of the various embodiments may provide a refuelable battery for the power grid to provide a sustainable, cost-effective, and/or operationally efficient solution to energy source variability and/or energy demand variability. In particular, the systems and methods of the various embodiments may provide a refuelable primary battery solution that addresses bulk seasonal energy storage needs, variable demand needs, and other challenges.

This invention relates to the regeneration of spent alkaline solutions, for example, alkaline electrolyte solutions used in metal/air batteries, specifically in aluminum/air batteries. The invention provides methods and systems to regenerate alkaline electrolyte solutions by adding water and optionally other solvents to spent electrolyte solutions, thus precipitating metal hydroxides from the spent electrolyte solution.

Methods and systems for electrolyte regeneration are provided, which regenerate a spent alkaline electrolyte (SE) comprising dissolved aluminum oxide hydrates from an aluminum-air battery, by electrolysis, to precipitate aluminum tri-hydroxide (ATH) and form regenerated alkaline electrolyte. A same-cation salt is added to an anolyte solution used in the electrolysis (and devoid of aluminates) to replenish a corresponding electrolyte cation and maintain the conditions for ATH precipitation. The regeneration may be carried out continuously, e.g., mixing the SE and the same-cation salt in a salt tank that delivers the anolyte solution, removing a portion of the regenerated alkaline electrolyte from a catholyte tank delivering the catholyte solution, and filtering the ATH from a solution delivered from the salt tank to the anolyte tank. Optionally, the salt may be a buffering salt, and in some cases chemical reactions may be used to enhance the regeneration by electrolysis.