Real-time XRD studies of Li-O 2 electrochemical reaction in nonaqueous lithium-oxygen battery

Abstract

Understanding of electrochemical process in rechargeable Li-O 2 battery has suffered from lack of proper analytical tool, especially related to the identification of chemical species and number of electrons involved in the discharge/recharge process. Here we present a simple and straightforward analytical method for simultaneously attaining chemical and quantified information of Li 2O 2 (discharge product) and byproducts using in situ XRD measurement. By real-time monitoring of solid-state Li 2O 2 peak area, the accurate efficiency of Li 2O 2 formation and the number of electrons can be evaluated during full discharge. Furthermore, by observation of sequential area change of Li 2O 2 peak during recharge, we found nonlinearity of Li 2O 2 decomposition rate for the first time in ether-based electrolyte. © 2012 American Chemical Society.