NOVELTY - An electrochemical cell (300) comprises a negative electrode (304) including a form of lithium; a positive electrode (308) spaced apart from the negative electrode and configured to use a form of oxygen as a reagent; a separator (312) positioned between the negative electrode and the thick positive electrode; and an electrolyte (324) including a salt concentration of less than 1 molar filling or nearly filling the positive electrode.    USE - As electrochemical cell with an improved impedance balance; for producing a uniform deposition of a reaction product in a metal/air cell having composition and potential that do not change significantly with the degree of discharge in the cell (claimed); in portable electronics and electric and hybrid-electric vehicles.    ADVANTAGE - The electrochemical cell exhibits improved impedance balance and high specific energy; exhibits high capacity, energy, and power and improved safety; allows oxygen and lithium to combine more uniformly throughout the positive electrode; and has uniform product distribution that avoids pore clogging.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a method of forming electrochemical cell with an improved impedance balance, involving: forming a negative electrode including a form of lithium; forming a thick positive electrode configured to use a form of oxygen as a reagent; forming a separator such that when assembled, the separator is positioned between the negative electrode and the thick positive electrode; and inserting an electrolyte including a salt concentration of less than 1 molar in the thick positive electrode. The method further involves: determining desired ionic impedance; and selecting the salt concentration based on the desired ionic impedance. The step of forming the thick positive electrode involves: forming a porous electrode including carbon particles (316) covered by an oxidation-resistance coating; and forming a barrier (328) configured to permit exchange of diatomic oxygen between the porous positive electrode and an external oxygen source (332). The step of inserting the electrolyte involves inserting an electrolyte with a lithium salt. The step of inserting the electrolyte with the lithium salt involves inserting an electrolyte with a lithium salt primarily composed of LiPF6 (lithium hexafluorophosphate); and    (2) a method for producing a uniform deposition of a reaction product in a metal/air cell having composition and potential that do not change significantly with the degree of discharge in the cell involving at least one of: controlling of the electrolyte ionic impedance; adjusting the oxygen concentration and pressure, and the overall gas flow rate; forming a porosity gradient in an electrode structure; forming an electrical conductivity gradient in an electrode; adjusting an ionic conductivity of an electrolyte; and controlling an electric current level during a charge and discharge cycle of the cell.    DESCRIPTION OF DRAWING(S) - The figure shows schematic view of a metal-oxygen cell with two electrodes and a separator, with the positive electrode being flooded and containing an electrolyte having a concentration of a salt of less than one molar, to increase the uniformity of distribution and removal of a discharge product during operation of the cell.    Electrochemical cell (300)    Negative electrode (304)    Thick positive electrode (308)    Separator/positive electrode interface (310)    Selectively permeable separator (312)    Carbon particles (316)    Porous matrix (320)    Electrolyte solution (324)    Barrier (328)    External oxygen source (332)