Stabilizing a lithium metal anode through the sustainable release of a multi-functional AgNO3 additive

Abstract

Despite their low redox potential and high specific capacity, lithium (Li) metal anodes pose stability and safety issues, especially in commercial carbonate-based electrolytes, due to dendritic growth of Li and formation of unstable solid-electrolyte interphase (SEI). To address these, we adopted AgNO3 as an electrolyte additive in carbonate-based electrolyte. Given that AgNO3 has low solubility in carbonate electrolytes, we developed a porous film made of silver nitrate (AgNO3)-containing polyacrylonitrile (PAN) nanofibers (AgNO3/PAN) enabling the sustainable release of Ag+ and NO3 into the electrolyte. AgNO3 acts as a multifunctional electrolyte additive, Ag+ serving as a nucleation seed for uniform and dendrite free Li plating, and NO3- forming a highly Li+-ion-conductive Li3N-rich SEI. As a verification of these effects, the cycle life of a Li parallel to Li symmetric cell increased and a full cell (Li parallel to LCO) shows an excellent capacity retention of 85.8 % after 100 charge-discharge cycles (@0.54C). Our findings suggest that AgNO3 can be a promising electrolyte additive in high-voltage lithium metal batteries.