Influence of Electrolyte Composition on Electrochemical Performance of Li-S Cells

Abstract

The electrochemical performance of Li-S cells was investigated in various ternary electrolyte solutions composed of 1,2-dimethoxyethane (DME), tetra(ethylene glycol) dimethyl ether (TGM), and 1,3-dioxolane (DOX). The discharge capacity values and cycle data obtained at each composition were statistically treated with the Minitab program to obtain mixture contour plots, from which the optimal composition of the ternary solvent systems was predicted. The discharge capacities and capacity retention were quite dependent on the electrolyte composition. It was estimated from the contour plots of the capacity at 1.0 C that the discharge capacity sharply increased with a decrease in the TGM content. High capacities greater than 900 mAh/g at 1.0 C were expected for the electrolyte composition with a volume ratio of DME/TGM/DOX = 1/0/1. In contrast, it was predicted from the mixture contour plot of the capacity retention that the cycle performance would significantly increase with an increase in the DME content.

Recent Advances in Electrolytes for Lithium–Sulfur Batteries

“…[ 25,79 ] Both linear and cyclic, short-chain and polymeric ethers such as DME (or G1), [ 80 ] tetrahydrofuran, [ 23,24 ] DOL REVIEW wileyonlinelibrary.com (DOX, DOXL, or DIOX), [ 80,81 ] TEGDME (G4), [82][83][84][85] tri(ethylene glycol)dimethyl ether, diglyme (DGM or G3), [ 80 ] partly silanized ether, [ 86 ] and poly(ethylene glycol) dimethyl ether (PEGDME) [ 79,87 ] have been explored as electrolyte solvents for Li-S batteries. Electrolytes consisting of mixtures (either binary or ternary) such as DOL/DME, [ 51 ] DOL/TEGDME, [ 52,53,88,89 ] tetrahydrofuran (THF)/DOL/toluene, [ 81 ] DME/DOL/DGM, [ 80 ] and DME/DOL/ TEGDME, [ 90 ] have also been considered as potential candidates for use in Li-S batteries. [ 18 ] Compared with small-molecule ethers, the long-chain analogs, which have high boiling and fl ash points, non-fl ammability, and strong resistivity to high oxidative potentials, are more suitable electrolytes for Li-S batteries.…”

Geometric origin of pair production by electric field in de sitter space

“…The above conditions can be satisfied for the Hamiltonian (7) in the de Sitter space since a(t) = e Ht has an analytical continuation in the complex plane of time. Furthermore, the othornormal basis can be constructed in the complex plane from those operators (12) with ϕ k (t) for ϕ * k (t) since the positive and negative frequency solutions satisfy the Wronskian condition in the complex plane [24].…”

“…Recently the author has introduced a complex analysis method for particle production in an electric field or a de Sitter space by expressing the production rate as the contour integral of the frequency in the complex plane of time [4][5][6]. The particleproduction rate is given by [7]…”

“…The Hamiltonian (7) and the frequency (8) in the de Sitter space have an analytical continuation by introducing the conformal mapping…”

Developments of Electrolyte Systems for Lithium–Sulfur Batteries: A Review

“…A followed EIS analysis indicated that high content of DME in electrolyte raised the interfacial resistance due to the formation of an impermeable layer on the surface of the sulfur cathode, while the increase of DOL could ameliorate this phenomenon. Parallel works were also conducted by Jung's group (Kim et al, 2014) and Lim's group (Kim et al, 2004).…”