Affiliation:
1. School of Materials Science and Engineering Key Laboratory of Electronic Packaging and Advanced Functional Materials of Hunan Province Central South University Changsha 410083 P. R. China
2. School of Materials Science & Engineering and BIC-ESAT College of Engineering Peking University Beijing 100871 P. R. China
Abstract
AbstractThe carbonate electrolyte chemistry is a primary determinant for the development of high‐voltage lithium metal batteries (LMBs). Unfortunately, their implementation is greatly plagued by sluggish electrode interfacial dynamics and insufficient electrolyte thermodynamic stability. Herein, lithium trifluoroacetate‐lithium nitrate (LiTFA−LiNO3) dual‐salt additive‐reinforced carbonate electrolyte (LTFAN) is proposed for stabilizing high‐voltage LMBs. We reveal that 1) the in situ generated inorganic‐rich electrode‐electrolyte interphase (EEI) enables rapid interfacial dynamics, 2) TFA− preferentially interacts with moisture over PF6− to strengthen the moisture tolerance of designed electrolyte, and 3) NO3− is found to be noticeably enriched at the cathode interface on charging, thus constructing Li+‐enriched, solvent‐coordinated, thermodynamically favorable electric double layer (EDL). The superior moisture tolerance of LTFAN and the thermodynamically stable EDL constructed at cathode interface play a decisive role in upgrading the compatibility of carbonate electrolyte with high‐voltage cathode. The LMBs with LTFAN realize 4.3 V‐NCM523/4.4 V‐NCM622 superior cycling reversibility and excellent rate capability, which is the leading level of documented records for carbonate electrode.
Funder
National Natural Science Foundation of China
Science Fund for Distinguished Young Scholars of Hunan Province