Hosted by: Gregory Doerk

Center for Functional Nanomaterials Seminar Batteries with high specific energy and energy density higher than that of state-of-the-art Li-ion batteries are considered critical for mass adoption of electric automobiles. Metal-oxygen batteries, Li- and Na-O2 batteries in particular, offer the highest theoretical specific energy among all known battery types. Li2O2 and NaO2, the discharge products in Li- and Na-O2 batteries respectively, are both electronic insulators. Therefore, electrochemical deposition of Li2O2 and NaO2 might lead to battery electrode passivation and to low actual specific energy. I will present experimental results backed by theoretical calculations that suggest the capacity limitations in these batteries can be overcome by enabling solution-mediated electrochemical deposition of Li2O2 and NaO2. This mechanism leads to a higher specific energy than that limited by electrode passivation. We have identified design rules for selecting electrolyte solvents that favor this alternate pathway and enable high specific energy metal-air batteries. I will also discuss our work on dendrite-resistant composite Li-ion conducting membranes which find applications in Li-ion and other lithium battery chemistries that would benefit from using a lithium anode.