High Concentrated Electrolytes for Li Metal Anodes

Thursday, 5 October 2017: 08:00
Maryland A (Gaylord National Resort and Convention Center)
J. Alvarado (Department of NanoEngineering UC San Diego), M. A. Schroeder (U.S. Army Research Laboratory), X. Wang (UC San Diego), K. C. Xu (Center for Research on Extreme Batteries), and Y. S. Meng (University of California at San Diego)
Li metal is seen as the ultimate anode for LIBs due to its extremely high theoretical energy density (3860 mAh g-1) and low negative redox potential (-3.04 V vs. standard hydrogen electrode). Making Li metal a ubiquitous anode is the key in propelling energy storage and conversion systems. It is one of the key components that will further the development of next-generation batteries, such as Li-S, Li-O2, and high energy density batteries (500Wh/kg) for the automotive industry. One way to address the dendritic growth and low coloumbic efficiency of the Li metal, is to focus on the electrolyte to form a robust and stable solid electrolyte interphase (SEI). There are several types of electrolytes that one can use for Li metal, each serving its purpose to fulfill a need in high voltage and low voltage applications.

Herein, the focus on electrolytes for both high and low voltage applications. Simple electrolyte formulations containing LiFSI, yield a robust and stable SEI that is primarily composed of inorganic functionalities due to salt reduction. A bisalt formulations yield high plating and stripping efficiencies (98.5 at 0.5mA/cm2), even higher efficiencies at elevated temperatures. We further demonstrate the use of a high concentrated carbonate based electrolyte in a high voltage anode free and half cell that out performs the conventional carbonate electrolyte.