Enabling High-Energy Lithium Metal Batteries through Electrolyte Strategy

Abstract

Lithium (Li) metal has been regarded as an ideal anode material for high-energy rechargeable batteries because metallic Li has an ultrahigh theoretical specific capacity (3860 mAh g-1) and a very low standard electrochemical redox potential (-3.040 V), thus the potential to double the specific energy density of the state-of-the-art Li ion batteries. However, the safety concern from Li dendrite growth and the short cycle life due to low Li Coulombic efficiency still hinder the application of rechargeable Li metal batteries. In the past six years, lots of great progresses have been made in stabilizing Li metal anode including smoothening Li deposition morphology and increasing Li Coulombic efficiency during repeated deposition/stripping processes, which have made the application of rechargeable Li metal batteries very promising although there are still many challenges to overcome. Among these progresses, one of the most important things is the development of electrolytes which can not only protect Li metal anode with high safety and good stability, but also to stabilize high voltage cathodes. The mechanisms for these advancements by the new electrolytes are the formation of high quality Li/electrolyte and cathode/electrolyte interface layers. More details of the electrolytes on advancing Li metal anodes and Li metal batteries will be discussed during the presentation.