Revitalization of Diluent Amide-Based Electrolyte for Building High-Voltage Lithium-Metal Batteries.

Hitherto, highly concentrated electrolyte is the overarching strategy for revitalizing the usage of amide - in lithium-metal batteries (LMBs), which simultaneously mitigates the reactivity of amide toward Li and regulates uniform Li deposition via forming anion-solvated coordinate structure. However, it is undeniable that this would bring the cost burden for practical electrolyte preparation, which stimulates further electrolyte design toward tailoring anion-abundant Li+ solvation structure in stable amide electrolytes under a low salt content. Herein, a distinct method is conceived to design anions-enriched Li+ solvation structure in dilute amide-electrolyte (1 m Li-salt concentration) with the aid of integrating perfluoropolyethers (PFPE-MC) with anion-solvating ability and B/F-involved additives. The optimized electrolyte based on N,N-Dimethyltrifluoroacetamide (FDMAC) exhibits outstanding compatibility with Li and NCM622 cathode, facilitates uniform Li deposition along with robust solid electrolyte interphase (SEI) formation. Accordingly, both the lab-level LMB coin cell and practical pouch cell based on this dilute FDMAC electrolyte deliver remarkable performances with improved capacity and cyclability. This work pioneers the feasibility of diluted amide as electrolyte in LMB, and provides an innovative strategy for highly stable Li deposition via manipulating solvation structure within diluent electrolyte, impelling the electrolyte engineering development for practical high-energy LMBs.

LiNi0.5Mn1.5O4 Joins to Alleviate Self-Discharge of Anion-Graphite Intercalation Compounds.

A straightforward hybrid approach of a blend cathode is put forward to alleviate self-discharged anion-graphite intercalation compounds in dual-ion batteries. The self-discharge mechanism of the LiNi0.5Mn1.5O4/graphite blend cathode is investigated by conventional electrochemical tests and in situ X-ray diffraction measurements. A charging behavior between electrode materials during self-discharge has been discovered. This work will contribute to advancing the practical implementation of dual-ion batteries and provide valuable theoretical support for the research of blend electrodes.