NOVELTY - Avoiding (M1) the formation of or removing or of reducing the concentration of metal-hydroxide precipitate formed in an alkaline electrolyte solution of a metal-air electrochemical cell (1) during an electrochemical reaction, involves adding submicron particles to the solution or applying ultrasonic vibration to the solution.    USE - For avoiding the formation of or removing or of reducing the concentration of metal-hydroxide precipitate formed in an alkaline electrolyte solution of a metal-air electrochemical cell during an electrochemical reaction (claimed), for electric vehicles, unmanned aerial vehicles (UAV), reserve and emergency power supply and other applications.    ADVANTAGE - The nanoparticles prevent or avoid agglomeration of metal hydroxide particles. The presence of the nanoparticles of in the electrolyte prior to discharge, prevents the formation of large species/agglomerates of metal hydroxide (e.g. aluminum hydroxide). In contrast to precipitation of an already formed aluminum hydroxide using seeds, the method prevents, eliminates, avoids or reduces the formation of aluminum oxide in advance. The kinetic energy of the moving submicron or nano-sized inert particles enables to reduce the formation of aluminum hydroxide particles. The kinetic energy of the moving submicron or nano-sized inert particles enable to prevent the formation of metal hydroxides such as aluminum hydroxide particles or to prevent or avoid the formation of other metal hydroxide/aluminum hydroxide species (e.g. gels agglomerates, porous structures, fibers). In present method, there is no need for filtration or separation of the aluminum hydroxide precipitate, avoids, removes, and/or reduces the formation of such precipitate.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) increasing (M2) the electrolyte utilization coefficient of an alkaline electrolyte in a metal-air electrochemical cell, involving adding submicron particles to the electrolyte or applying ultrasonic vibration to the electrolyte;    (2) metal-air cell comprising an electrolyte chamber comprising alkaline electrolyte, an inlet for introducing the electrolyte into the electrolyte chamber, an outlet for removing the electrolyte from the electrolyte chamber, and optionally an ultrasonic source, where submicron particles are added to the electrolyte prior to cell discharge and/or during cell discharge through the inlet; and    (3) composition comprising an alkaline aqueous solution, and submicron particles, where the composition is used as the alkaline electrolyte solution in the cell.    DESCRIPTION OF DRAWING(S) - The figure shows cross-sectional view of electrochemical metal-air cell.    Metal-air electrochemical cell (1)    Aluminum electrode (2)    Electrolyte chamber (3)    Air cathodes (4)    Inlets (5)    Outlets (6)