近日，东北大学宋禹团队研究了高压锌硫水电池的共溶剂电解液设计。2025年7月22日出版的《美国化学会志》发表了这项成果。

水中锌硫电池（AZSBs）具有成本和安全性方面的优势，但也面临着严重的电池极化问题。

研究组在ZnSO₄电解质中引入助溶剂N，N-二乙基甲酰胺（DEF）来促进硫阴极转化反应。与Zn(H₂O)₆²⁺相比，共溶剂电解质中的重构溶剂化[Zn(H₂O)₅DEF]²⁺具有更窄的HOMO-LUMO间隙（0.74 eV vs 1.31 eV），导致电解质-电极界面的电荷转移动力学更快。由于DEF与硫电极之间的强相互作用，DEF提供的电子占据了硫的反键轨道，增加了硫原子之间的电子密度和静电斥力，从而减弱了S-S键的相互作用。

这种电子注入效应也减小了带隙，提高了硫的本征电导率。结果表明，AZSBs的共溶剂电解质设计实现了0.8 V vs Zn²⁺/Zn的高放电平台，并降低了0.32 V的电池极化，优于大多数报道的AZSBs。此外，研究组提出了AZSBs中共溶剂电解质的设计原则，机器学习结果表明，共溶剂的供体数和HOMO能量是预测AZSBs放电电压的关键描述符。这项工作为高性能AZSBs的开发提供了新的见解。

附：英文原文

Title: Cosolvent Electrolyte Design for High-Voltage Aqueous Zinc–Sulfur Batteries

Author: Peng Hei, Ya Sai, Lin Yu, Yulai Lin, Bo Li, Guangxu Hu, Wanlong Wu, Jing Wang, Xiaoqi Sun, Xiao-Xia Liu, Yu Song

Issue&Volume: July 22, 2025

Abstract: Aqueous zinc–sulfur batteries (AZSBs) offer cost and safety advantages but face challenges related to severe cell polarization. Herein, we introduce a cosolvent, N,N-diethylformamide (DEF), in the ZnSO4 electrolyte to facilitate the sulfur cathode conversion reaction. Compared to Zn(H2O)62+, the reconstructed solvated [Zn(H2O)5DEF]2+ in the cosolvent electrolyte exhibits a narrower HOMO–LUMO gap (0.74 eV vs 1.31 eV), leading to faster charge transfer kinetics at the electrolyte–electrode interface. Due to the strong interaction between DEF and sulfur electrode, the electrons donated by DEF occupy the antibonding orbitals of sulfur, increasing the electron density and electrostatic repulsion between sulfur atoms, thereby weakening the S–S bond interaction. This electron injection effect also reduces the band gap and enhances the intrinsic electrical conductivity of sulfur. As a result, this cosolvent electrolyte design for AZSBs achieves an elevated discharge plateau of 0.8 V vs Zn2+/Zn and reduced cell polarization of 0.32 V, outperforming most reported AZSBs. Additionally, we present design principles for cosolvent electrolytes in AZSBs, with machine learning results suggesting that the donor number and HOMO energy of the cosolvents are critical descriptors for predicting the discharge voltage of AZSBs. This work offers new insights into the development of high-performance AZSBs.

DOI: 10.1021/jacs.5c06710

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c06710