Abstract Scope |
Achieving a stable and reversible Li metal anode would enable a step-change in Li-ion battery energy densities if critical issues of reactivity, insufficient Coulombic Efficiency, electrolyte consumption and loss of active Li can be addressed. The chemistry and physics governing the solid electrolyte interphase (SEI), which underlies these issues, require further illumination so that better interfaces can be designed. I will describe our studies on individual ionic SEI phases as model interfaces, which have revealed new quantitative insights into transport properties at the chemical potential of Li. Next, I describe X-ray absorption spectroscopy measurements used to probe the chemical stability of these phases in common electrolytes, revealing chemical insights into SEI evolution. Finally, I present emerging understanding of dynamic processes at the Li interface during cycling, and new chemical insights correlating with increasing Coulombic Efficiency. Integration of this knowledge to guide design of improved SEI chemistries will be discussed. |