(Battery Division Research Award) Advanced Characterization of Electrochemical Interfaces and Systems for Next-Generation Batteries

Abstract

Lithium (Li) metal has been considered as an ideal anode for high-energy rechargeable Li batteries while Li nucleation and growth at the nano scale remains mysterious as to achieving reversible stripping and deposition. A few decades of research have been dedicated to this topic and we have seen breakthroughs in novel electrolytes in the last few years, where the efficiency of lithium deposition is exceeding 99.6%. Here, cryogenic-transmission electron microscopy (Cryo-TEM/Cryo-FIB) was used to reveal the evolving nanostructure of Li deposits at various transient states in the nucleation and growth process, in which a disorder-order phase transition was observed as a function of current density and deposition time. More importantly, the complementary techniques such as titration gas chromatography (TGC) reveals the important insights about the phase fraction of solid electrolyte interphases (SEI) and electrochemical deposited Li (EDLi). While cryo-EM has made significant contributions to enabling lithium metal anodes for batteries, its applications in the area of electrochemical interphases such as those in all solid state batteries, beyond lithium batteries are still in the infancy, therefore, I will discuss a few new perspectives about how future advanced imaging and spectroscopic techniques can help to accelerate the innovation of novel energy storage materials and architectures.