NOVELTY - An alkali metal/oxygen electrochemical energy storage cell comprises an anode (1) comprising alkali metal electroactive component material; a cathode (4) on or at which molecular oxygen is electro-reduced during cell discharge; a catholyte (6), in contact with cathode, comprising water and at least one evaporative-loss resistant and/or polyprotic active compound dissolved in water that partake in a cell discharge reaction and effectuate cathode capacity for discharge in acidic region; and protective membrane architecture (2).    USE - As alkali metal/oxygen electrochemical energy storage cell (claimed) e.g. lithium/air secondary battery cell.    ADVANTAGE - The aqueous catholyte in the cell provides improved performance including increased specific energy, improved stability on open circuit, and prolonged cycle life for alkali metal/oxygen electrochemical energy storage cell. The cell exhibits high energy density and prolonged cycle life. The chemically active species added to the catholyte enhances or improves any number of cell characteristics including cathode capacity, reversibility, discharge/charge cycling stability, stability of the solid electrolyte membrane in contact with the catholyte, water management (especially to prevent catholyte dry out in an open to air cell) and/or improves overall cell performance or improves a particular performance parameter during active operation (i.e. during actual discharge and charge) and/or at open circuit during storage prior to initial discharge or at intermittent rest periods over the course of operation. The catholyte does not contain any chloride containing salts or free chlorine ions.    DETAILED DESCRIPTION - An alkali metal/oxygen electrochemical energy storage cell comprises an anode (A1) (1) comprising an alkali metal electroactive component material; a cathode (A2) (4) on or at which molecular oxygen is electro-reduced during cell discharge, where the cathode is in alkali metal ion communication with the anode; a catholyte (A3) (6) comprising water and at least one evaporative-loss resistant and/or polyprotic active compound dissolved in water that partake in a cell discharge reaction and effectuate cathode capacity for discharge in the acidic region, where the catholyte is in contact with cathode; and a protective membrane architecture (A4) (2) interposed between the cathode and the anode, where the protective membrane architecture having a first and second major surface, the first surface adjacent to the cathode and in contact with the catholyte and the second surface adjacent to the anode; and the protective membrane architecture solely allows through transport of the alkali metal ion and prevents liquids from contacting the alkali metal anode. INDEPENDENT CLAIMS are included for the following:    (1) making or using an alkali metal/oxygen electrochemical energy storage cell involving providing the anode (A1), cathode (A2), and protective membrane architecture (A4), and dispensing or flowing the catholyte (A3) into contact with the cathode; and    (2) making an initial catholyte for use in an alkali metal oxygen electrochemical energy storage cell involving providing water, dissolving a polycarboxylic acid in water, and dissolving a chemical species in water that undergoes an electron donor-acceptor reaction with the polycarboxylic acid.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the lithium/air battery cell.    Lithium anode (1)    Solid electrolyte protective membrane (2)    Interlayer (3)    Cathode compartment (4)    Air cathode (5)    Aqueous catholyte (7) Porous solid reservoir (6)