Tris(2-carboxyethyl)phosphine hydrochloride (TCEP-HCl) as additive for cathodes in Li-S batteries

MARIA DEL CARMEN ROJAS; MARIA VICTORIA BRACAMONTE; FERNANDO COMETTO; EZEQUIEL LEIVA; DANIEL BARRACO; GUILLERMINA LUQUE

Buenos Aires

Simposio; 8th Symposium on Hydrogen, Fuel Cells and Advanced Batteries; 2022

In recent times great progress has been made in inhibiting the lithium polysulfides (Li PS) transport and its migration ef-fects. However, the nucleation and growth of Li2S2/Li2S spe-cies during the discharge process remains uncontrollable re-sulting in a large accumulation of these insoluble species on the cathode surface [1-3]. A large activation energy is required to transform these insulating Li2S2/Li2S species back to long-chain Li PS, resulting in slow oxidation reaction kinetics and poor performance of the sulfur content of the electrode [4-5]. For this reason, controlling the nucleation and growth of Li2S2/Li2S is the key to improving the electrodeposition kinetics and S utilization [6].It is well known that trialkylphosphines have the property of selectively reducing disulfide bonds, so recent experimental work utilizes the commercially available tris(2-carboxyethyl) phosphine hydrochloride (C9H15O6P∙HCl, TCEP∙HCl), taking ad-vantage of its effect in disrupting disulfide bonds in various proteins to catalyse the cleavage of -S-S- in polysulfides [7-9].In this work, we studied experimentally the effect of using TCEP as an additive in lithium-sulfur batteries.