Switching Reaction Pathway of Medium-Concentration Ether Electrolytes to Achieve 4.5 V Lithium Metal Batteries.

Pursuing high-energy-density lithium metal batteries (LMBs) necessitates the advancement of electrolytes. Despite demonstrating high compatibility with lithium metal anodes (LMAs), ether-based electrolytes face challenges in achieving stable cycling at high voltages. Herein, we propose a strategy to enhance the high-voltage stability of medium-concentration (∼1 M) ether electrolytes by altering the reaction pathway of ether solvents. By employing a 1 M lithium difluoro(oxalato)borate in dimethoxyethane (LiDFOB/DME) electrolyte, we observed that LiDFOB displays a pronounced tendency for decomposition over DME, leading to a modification in the decomposition pathway of DME. This modification facilitates the formation of a stable organic-inorganic hybrid interface. Utilizing such an electrolyte, the Li-LCO cell demonstrates a discharge specific capacity of 146 mAh g-1 (5 C) and maintains retention of 86% over 1000 cycles at 2 C under a 4.5 V cutoff voltage. Additionally, the optimized ether electrolyte demonstrated outstanding cycling performance in Li-LCO full cells under practical conditions.

A low-concentration all-fluorinated electrolyte for stable lithium metal batteries.

A low-concentration (0.5 M) all-fluorinated electrolyte (LCAFE) was designed to stabilize high-energy-density lithium metal batteries. Introducing fluorinated solvents can control the electrolyte's solvation structure, interfacial chemistry, and physicochemical properties. Therefore, this LCAFE has good wettability, nonflammability, and excellent stability for lithium anodes.

A systematic computational investigation of the water splitting and N2 reduction reaction performances of monolayer MBenes.

Recently, transition metal borides (MBenes, analogous to MXenes) have attracted interest due to their potential applications in energy conversion and storage. In this work, we performed density functional theory calculations to systematically explore the exfoliation properties of 14 MAlB phases and their water splitting and N2 reduction reaction (NRR) performances. Results showed a linear relationship between the binding energy and exfoliation energy with the coefficient (R2) of 0.95, indicating that the lower the binding energy of element Al in MAlB (M2AlB2), the higher the exfoliation energy required to synthesize monolayer MB from MAlB (M2AlB2). NiB (B site) was predicted to possess the best electrocatalytic activity for water splitting, hydrogen evolution reaction (HER), and oxygen evolution reaction (OER) among the studied MBenes, and overpotentials on the NiB surface were calculated to be 0.08 V (for HER) and 0.37 V (for OER), respectively. The electronic properties and dynamic simulations indicated that NiB is the best candidate catalyst for water splitting. Conversely, the Fe site on FeB (FeB-Fe) was predicated to have the highest nitrogen reduction reaction (NRR) activity among the studied MBenes, with the overpotential ηNRR of 0.11 V. Furthermore, the B site of TaB (TaB-B) was identified as the best NRR catalyst against HER among the studied MBenes considering the HER side reaction.