Suppression of Aluminum Corrosion in Lithium Bis(trifluoromethanesulfonyl)imide-based Electrolytes by the Addition of Fumed Silica

Abstract

The corrosion property of aluminum by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt is investigated in liquid and gel electrolytes consisting of ethylene carbonate/propylene carbonate/ethylmethyl carbonate/diethyl carbonate (20:5:55:20, vol %) with vinylene carbonate (2 wt %) and fluoroethylene carbonate (5 wt %) using conductivity measurement, cyclic voltammetry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. All corrosion behaviors are attenuated remarkably by using three gel electrolytes containing 3 wt % of hydrophilic and hydrophobic fumed silica. The addition of silica particles contributes to the increase in the ionic conductivity of the electrolyte, indicating temporarily formed physical crosslinking among the silica particles to produce a gel state. Cyclic voltammetry also gives lower anodic current responses at higher potentials for repeating cycles, confirming further corrosion attenuation or electrochemical stability. In addition, the degree of corrosion attenuation can be affected mainly by the electrolytic constituents, not by the hydrophilicity or hydrophobicity of silica particles.

An electrochemical approach to measuring oxidative stability of solid polymer electrolytes for lithium batteries

“…No current was observed in our cells without LiTFSI. The shape of the voltammogram is similar to that reported in literature with liquid electrolyte containing LiTFSI (Krause et al, 1997;Louis et al, 2013;Wang et al, 2000). However, there are several distinct differences between our results with PEO-based polymer electrolyte and experiments with liquid electrolyte containing ethylene carbonate.…”

Synthesis of highly electrochemically active Li2S nanoparticles for lithium–sulfur-batteries

“…This is a common problem for high voltage Li-ion batteries, because decomposed LiTFSI is able to corrode aluminum based current collectors. 24 For the cell without polysulde addition this decomposition is visible as a shoulder at 3.25 V for the 1 st cycle (Fig. 9b).…”

Polymerizable Ionic Liquids for Solid-State Polymer Electrolytes

“…In lithium ion batteries the electrolyte can move freely within the cell and thus lead to unwanted side reactions. A common example is the reactions of the aluminum current collector with bis(trifluoromethanesulfonyl)imide (TFSI) containing ionic liquids [9]. This type of degradation mechanism can be avoided if the electrolyte is fixed between the electrodes.…”