3,3′-dithiodipropionic acid as a functional electrolyte additive in lithium-sulfur battery

• Published in: Journal of Central South University Vol. 31; no. 2; pp. 431 - 442
• Main Authors: Shao, Shi-yu, He, Liang, Zhang, Ji-wei, Li, Si-min, Hong, Bo, Zhang, Kai, Li, Jie
• Format: Journal Article
• Language: English
• Published: Changsha Central South University 01.02.2024; Springer Nature B.V
• Subjects: Additives; Electrochemical analysis; Electrolytes; Energy storage; Engineering; Lithium sulfur batteries; Metallic Materials; Polysulfides; shuttle effect; 3, 3′-二硫代二丙酸; 电解质添加剂; 多硫化物转化; 3,3′-dithiodipropionic acid; 锂硫电池; polysulfide conversion; lithium-sulfur battery; electrolyte additive; 穿梭效应
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-024-5562-2

High-energy-density lithium-sulfur (Li-S) batteries are among the most promising energy storage devices, but their potential has been constrained by the shuttle effect and poor active material utilization. Here, 3,3′-dithiodipropionic acid (DTPA), an efficient electrolyte additive, is applied to Li-S batteries while its underlying mechanism on the electrochemical performance is examined. The results show that the DTPA additive can quickly interact with the polysulfides scattered in the electrolyte, facilitating the conversion of long-chain polysulfides to Li 2 S 2 and Li 2 S. In this way, by lessening the shuttle effect of long-chain polysulfides towards the anode, the redox kinetics and the usage of active materials can both be improved. The electrochemical performance of Li-S batteries is thus enhanced by the addition of DTPA, with capacities of 1093.4 mA · h/g for the initial cycle and 714.8 mA · h/g after 250 cycles at 0.5 C (DTPA concentration is 1.5 wt.%). Also, the DTPA-containing batteries have higher electrochemical stability, with a capacity retention rate of 57.5% relative to 0.1 C at 2 C . The improved performance demonstrates the importance of electrolyte additives, and the DTPA introduced in this work offers a potential solution for reducing the shuttle effect of polysulfide to increase the capacity of Li-S batteries.