Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries(LMBs).However,the implementation of traditional carbonate electrolyte is greatly hindered by the generat...Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries(LMBs).However,the implementation of traditional carbonate electrolyte is greatly hindered by the generation of an unstable electrode interphase and corrosive by-product(HF).Herein,we propose a triple-function eutectic solvent additive of N-methylacetamide(NmAc)with LiNO_(3) to enhance the stability and compatibility of carbonate electrolyte.Firstly,the addition of NmAc significantly improves the solubility of LiNO_(3) in carbonate electrolyte by forming an eutectic pair,which regulates the Li~+solvation structure and leads to dense and homogenous Li plating.Secondly,the hydrolysis of acidic PF_5 is effectively alleviated due to the strong complexation of NmAc with PF_5,thus reducing the generation of corrosive HF.In addition,the optimized cathode electrolyte interphase layer decreases the structural degradation and transition metal dissolution.Consequently,Li||LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cells with the designed electrolyte deliver superior long-term cycle reversibility and excellent rate capability.This study unveils the rationale for incorporating eutectic solvent additives within carbonate electrolytes,which significantly contribute to the advancement of their practical application for high-voltage LMBs.展开更多
基金supported by the National Natural Science Foundation of China(22379166)Natural Science Foundation for Distinguished Young Scholars of Hunan Province(2022JJ10089)+1 种基金Central South University Innovation-Driven Research Program(2023CXQD034)supported in part by the High-Performance Computing Center of Central South University。
文摘Rational carbonate electrolyte chemistry is critical for the development of high-voltage lithium metal batteries(LMBs).However,the implementation of traditional carbonate electrolyte is greatly hindered by the generation of an unstable electrode interphase and corrosive by-product(HF).Herein,we propose a triple-function eutectic solvent additive of N-methylacetamide(NmAc)with LiNO_(3) to enhance the stability and compatibility of carbonate electrolyte.Firstly,the addition of NmAc significantly improves the solubility of LiNO_(3) in carbonate electrolyte by forming an eutectic pair,which regulates the Li~+solvation structure and leads to dense and homogenous Li plating.Secondly,the hydrolysis of acidic PF_5 is effectively alleviated due to the strong complexation of NmAc with PF_5,thus reducing the generation of corrosive HF.In addition,the optimized cathode electrolyte interphase layer decreases the structural degradation and transition metal dissolution.Consequently,Li||LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)cells with the designed electrolyte deliver superior long-term cycle reversibility and excellent rate capability.This study unveils the rationale for incorporating eutectic solvent additives within carbonate electrolytes,which significantly contribute to the advancement of their practical application for high-voltage LMBs.
