Does Oxygen Transport Affect the Cell Voltages of Metal/Air Batteries?

Simultaneous transport of an electrolyte and dissolved oxygen is analyzed with Newman'sconcentrated-solution theory to assess how nonuniform oxygen distributions might impact the volt-ages of metal/air batteries. For a solution comprising a neutral solvent, a simple salt, and oxygen,the Onsager-Stefan-Maxwell transport equations are inverted, yielding ux-explicit laws for oxygen,anion, and cation transport that distinguish the effects of individual diffusion and migration driv-ing forces. Along with the ionic conductivity, electrolyte diffusivity, oxygen diffusivity, and cationtransference number, a migration coefficient and a cross-diffusion coefficient are identified, whichrespectively account for the effects of electro-osmotic drag on oxygen and diffusional drag betweensalt and oxygen. A derived current/voltage relation reveals how oxygen gradients can in princi-ple affect the cell potential; significant diffusion potential can arise from oxygen if it experienceselectro-osmotic drag. Prior models are proven to follow from an assumption that cross-diffusion andelectro-osmosis are both negligible, or, equivalently, that oxygen/ion interactions are weak. Experi-ments to quantify the novel transport properties are discussed, along with quantitative estimates ofthe cross diffusivity and migration coefficien