LiNO3‐Based Electrolytes via Electron‐Donation Modulation for Sustainable Nonaqueous Lithium Rechargeable Batteries

Abstract

AbstractLiPF6 as a dominant lithium salt of electrolyte is widely used in commercial rechargeable lithium‐ion batteries due to its well‐balanced properties, including high solubility in organic solvents, good electrochemical stability, and high ionic conductivity. However, it suffers from several undesirable properties, such as high moisture sensitivity, thermal instability, and high cost. To address these issues, herein, we propose an electron‐donation modulation (EDM) rule for the development of low‐cost, sustainable, and electrochemically compatible LiNO3‐based electrolytes. We employ high donor‐number solvents (HDNSs) with strong electron‐donation ability to dissolve LiNO3, while low donor‐number solvents (LDNSs) with weak electron‐donation ability are used to regulate the solvation structure to stabilize the electrolytes. As an example, we design the LiNO3‐DMSO@PC electrolyte, where DMSO acts as an HDNS and PC serves as an LDNS. This electrolyte exhibits excellent electrochemical compatibility with graphite anodes, as well as the LiFePO4 and LiCoO2 cathodes, leading to stable cycling over 200 cycles. Through spectroscopy analyses and theoretical calculation, we uncover the underlying mechanism responsible for the stabilization of these electrolytes. Our findings provide valuable insights into the preparation of LiNO3‐based electrolytes using the EDM rule, opening new avenues for the development of advanced electrolytes with versatile functions for sustainable rechargeable batteries.