Elucidating the Origins of Rechargeability Limitations in Li-O2 Batteries

Li-air batteries have received significant attention as a potential high specific energy alternative to current state-of-the-art rechargeable Li-ion batteries.  However, numerous scientific challenges remain unsolved in the pursuit of attaining a coulombically efficient Li-air battery with high capacity.  This presentation will highlight current efforts to understand the nature of Li-O₂ electrochemistry occurring at the cathode.  A quantitative ex-situ peroxide analysis is coupled with quantitative Differential Electrochemical Mass Spectrometry (DEMS) to better understand factors that control, and hinder, the desired rechargeable cathodic reaction (i.e., 2Li⁺ + O₂ + 2e^- ↔ Li₂O₂).  These measurements allow a comparison of Li₂O₂ formation/oxidation to O₂ consumption/evolution, giving us the ability to decouple parasitic processes occurring during discharge and charge in Li-O₂ cells.  These measurements are employed to more completely understand factors that influence both electrolyte and cathode stability.