Acacia Senegal–Inspired Bifunctional Binder for Longevity of Lithium–Sulfur Batteries

Abstract

needs while signifi cantly reducing battery cost. For this reason, the combination of lithium and sulfur has been considered as one of the most promising battery chemistries for full electrifi cation of vehicles. [ 3 ] Despite these advantages, Li S batteries have a few critical barriers to be overcome. Besides the insulating properties of sulfur and polysulfi des, Li S batteries also suffer from dramatic (i.e., ≈76%) volume change of sulfur during cycling and shuttling effect of polysulfi des that sulfur species transport back and forth between electrodes. These lead to the destruction of sulfur cathodes and the corrosion of lithium anode resulting in short battery life.In a traditional Li S cell, a typical sulfur electrode consists of three components, i.e., the electrochemically active sulfur material, the conductive carbon additive, and the polymeric binder. [ 4 ] Through the syntheses of nanoarchitectured carbon additives, the electrochemical performance and cycle life of Li S batteries have been successfully improved. [ 5 ] Although signifi cant achievements have been made in designing nanostructured carbon/sulfur composites for cycle life improvement of Li S batteries, these processes are commonly sophisticated, high cost, and not suitable for large-scale manufacturing.The sulfur cathode in traditional lithium-sulfur batteries suffers from poor cyclability due to polysulfi de shuttling effect as well as large volume change during charge/discharge processes. Gum arabic (GA), a low cost, nontoxic, and sustainable natural polymer from Acacia senegal , is adopted as a binder for the sulfur cathode to address these issues. The excellent mechanical properties of GA endow the cathode with high binding strength and suitable ductility to buffer volume change, while the functional groups chemically and physically confi ne sulfur species within the cathode to inhibit the shuttling effect of polysulfi des. Additionally, GA shifts the electrode fabrication process from the organic solvent process to an aqueous process, eliminates the use of toxic organic solvents, and achieves uniformly distributed electrode with lower impedance. A remarkable cycling performance, i.e., 841 mAh g −1 at low current rate of C /5, is achieved throughout 500 cycles due to the bifunctions of the GA binder.

The dual actions of modified polybenzimidazole in taming the polysulfide shuttle for long-life lithium–sulfur batteries

“…30,31 It should be noted that several new peaks at 1304, 667 and 500 cm − 1 are ascribed to the S = O, C-S and S-S stretching vibrations, respectively. 10,32 This finding clearly suggests that mPBI is able to chemically adsorb PS via these chemical bonds. The chemical bonds between PS and mPBI can also be verified in the ultraviolet-vis spectroscopic investigation.…”

“…To tackle these problems, polymer-based strategies have recently demonstrated encouraging potential with the success of a polymer binder and separators in Li-S batteries. Multifunctional polymer binders such as gum arabic, 10 gelatin 11 and PEO, 12 among others, have demonstrated great effectiveness in maintaining electrode integrity and in confining PSs within the cathodic chamber, whereas the use of a functionalized polymer separator also revealed significant PS shuttle suppression by blocking the penetration of the PS to the anode. 13,14 Polybenzimidazole (PBI) (Scheme 1), which has a high melting point, has been extensively used in high-performance protective applications such as firefighter implements, astronaut space suits and aircraft wall fabrics, among others, owing to its superior stability and retention of mechanical strength at elevated temperatures.…”

Nucleophilic substitution between polysulfides and binders unexpectedly stabilizing lithium sulfur battery

“…2C, D). The total fluorescence yield (TFY) spectra of PVS and carrageenan all have a prominent peak at 2482.5 eV, which is attributed to the R-OSO3 -Sσ* [33] .…”

“…[6][7] Efforts to trap the shuttling polysulfides have mainly focused on meso/nano-carbon matrix as summarized by Liu et al, [8][9][10][11][12][13][14][15][16][17][18][19][20] formation of sulfur composites initiated by Wang et al [21][22][23] and metal oxide/sulfide hosts reviewed by Mai et al [24] Since divinyloxyhydroxyolysulphides was first developed by T.A. Skotheim et al as an alternative binder solution for Li-S batteries, [25] polymers including gelatin, [26][27][28] polyethylene oxide, [29] polyacrylic acid, [30] carboxyl methyl cellulose, [31] polyvinylpyrrolidone [32] , gum arabic binder, [33] carbonyl-β-cyclodextrin [23] and polyamidoamine dendrimer [34] were identified as promising binders to address the issue.…”

Nature‐Inspired Electrochemical Energy‐Storage Materials and Devices

“…[152] Compared with the abundant progress achieved in developing active materials, binders has not attracted extensive interests due to its intrinsic inactivity. [153] However, it has a significant influence on the electrochemical performance of the energystorage devices, especially for the alloy-type anode materials with high capacitance but large volume change during charge/discharge. [76,154,155] An ideal binder should usually meet the following prerequisites: (i) containing polar groups to provide strong adhesion and high tensile strength at the interfaces between the active materials, conducive additive and the current collector; (ii) acting as dispersant to uniformly distribute the active materials and conductive additive; (iii) don't deteriorate the electrons transfer and ions diffusion; (iv) physically and chemically stable in the electrolyte, as well as electrochemically stable under charge/discharge cycles; (v) low-cost, safe and environmental-friendly.…”