Influence of Temperature and Electrolyte Composition on the Performance of Lithium Metal Anodes

Abstract

Lithium metal anodes have again attracted widespread attention due to the continuously growing demand of cells with higher energy density. However, the lithium deposition mechanism and the affecting process of influencing factors, such as temperature, cycling current density, and electrolyte composition are not fully understood and require further investigation. In this article, the behavior of lithium metal anode at different temperatures (25, 40, and 60 ∘C), lithium salts, electrolyte concentrations (1 and 2 M), and the applied cell current (equivalent to 0.5 C, 1 C, and 2 C). is investigated. Two different salts were evaluated: lithium bis(fluorosulfonyl)imide (LiFSI) and lithium bis(trifluoromethanesul-fonyl)imide (LiTFSI). The cells at a medium temperature (40 ∘C) show the highest Coulombic efficiency (CE). However, shorter cycle life is observed compared to the experiments at room temperature (25 ∘C). Regardless of electrolyte type and C-rate, the higher temperature of 60 ∘C provides the worst Coulombic efficiency and cycle life among those at the examined temperatures. A higher C-rate has a positive effect on the stability over the cycle life of the lithium cells. The best performance in terms of long cycle life and relatively good Coulombic efficiency is achieved by fast charging the cell with high concentration LiFSI in 1,2-dimethoxyethane (DME) electrolyte at a temperature of 25 ∘C. The cell has an average Coulombic efficiency of 0.987 over 223 cycles. In addition to galvanostatic experiments, Electrochemical Impedance Spectroscopy (EIS) measurements were performed to study the evolution of the interface under different conditions during cycling.

Fast‐Charging Strategies for Lithium‐Ion Batteries: Advances and Perspectives

“…Besides, due to the reaction between the Li plating and the electrolyte, the gas is generated earlier and the internal pressure is too high. Boroujeni's team [94] investigated the battery behavior of anodes with different Li salts (LiFSI and LiTFSI), electrolyte concentrations (1 and 2 M), and rates (equivalent to 0.5 C, 1 C, and 2 C) at different temperatures (25, 40 and 60 °C). Through the analysis, it is found that the long cycle life and relatively good CE are obtained by 2 C fast‐charging of batteries with high concentration of LiFSI in 1,2‐DME electrolyte at 25 °C.…”

Ameliorating Phosphonic-Based Nonflammable Electrolytes Towards Safe and Stable Lithium Metal Batteries

“…Under this background, the development of renewable clean energy, including wind, solar and electrochemical storage technology, is of great significance to the sustainable application of energy. Among them are rechargeable lithium metal batteries (LMBs); their high-energy-density has drawn much attention around the world [ 1 , 2 , 3 , 4 , 5 ]. In recent years, LMBs have been regarded as the ideal choice to replace traditional lithium-ion batteries in the stationary energy storage field and electric vehicles [ 6 , 7 , 8 , 9 , 10 ]; however, accompanied by the application of highly active metallic Li anodes, safety concerns for LMBs also increased.…”