Strong Dipole Moments and Increased Charge Transfer in Polymer-Based Solid Electrolyte Enable Wide-Temperature Solid-State Lithium Metal Batteries.

Abstract

The development of solid electrolyte interfaces (SEI) using lithium and nitrate salts represents a promising approach to enhancing the performance of lithium metal batteries (LMBs). However, the inherent stability of lithium and nitrate salts often results in incomplete decomposition, leading to the formation of inhomogeneous SEI that degrade battery performance. In this study, a strong dipole moment and increased charge transfer strategy are used, which can effectively catalyze the decomposition of NO₃ ^- and TFSI^- and accelerate the migration of Li⁺, as well as the formation of Li₃N-LiF-rich SEI. Li/CSEs/LFP batteries demonstrated excellent cycling stability over a wide temperature range (30-100 °C) and across various charge/discharge rates (1C-5C). Notably, pouch cells with high loading of Ni₉₀Co₅Mn₅ and LFP exhibited remarkable electrochemical performance and safety. This work presents a strong dipole moment and increased charge transfer strategy for optimizing polymer electrolytes, providing new insights into optimizing the performance of LMBs.