Enhanced Performance of All‐Solid‐State Li Metal Battery Based on Polyether Electrolytes with LiNO3 Additive

Abstract Lithium metal is one of the most promising anode candidates for high‐energy‐density rechargeable batteries. However, uncontrolled lithium dendrites and other safety issues limit their practical applications. In this work, solid polymer electrolytes based on ethylene oxide and propylene oxide random copolymer (P(EO/PO)) and lithium bis(fluorosulfonyl)imide (LiFSI) with lithium nitrate (LiNO 3 ) electrolyte additive are prepared. The LiNO 3 is expected to form stable and adequate solid electrolyte interphase (SEI) layer to regulate the lithium deposition and limit lithium dendrites during cycles. As the results, it is cleared that the addition of LiNO 3 to P(EO/PO)‐LiFSI‐based electrolyte effectively reduces the lithium/electrolyte interface resistance, decreases the polarization voltage during charging and discharging, and improves the cycle stability.