北京大学庞全全团队在研究中取得进展。他们发现了表面定域相介质加速硫电池准固态反应动力学。相关论文于2025年2月13日发表在《自然-化学》杂志上。

在这里，研究组提出了一种表面局部化的多硫化物溶剂化策略，通过利用有机相介质和弱溶剂化电解质来介导“准固体”多硫化物的反应。这种电解质限制了多硫化物的整体溶解，而相介质与表面多硫化物配合，促进了多硫化物在表面的溶剂化，促进了快速的表面局部化溶液相硫反应。采用表面局部化相介质的锂硫电池在494mA h g时表现出优异的速率性能。1-硫在16稳定循环300次，容量保留率为90.2%。该策略可实现2.4 Ah 331 Wh kg⁻¹聚合物电池。他们的工作突出了表面相介质在通过合理设计电解质控制电极反应途径和动力学方面的优势。

据了解，锂硫电池有望实现高能量密度存储，但由于不受控制的多硫化物溶解，其稳定性较差。虽然限制多硫溶剂化以建立准固态硫反应可以将电极反应与电解质体积解耦，但这种方法的反应动力学缓慢。

附：英文原文

Title: Surface-localized phase mediation accelerates quasi-solid-state reaction kinetics in sulfur batteries

Author: Liu, Yatao, An, Yun, Fang, Chi, Ye, Yaokun, An, Yifeng, He, Mengxue, Jia, Yongfeng, Hong, Xufeng, Liu, Yumei, Gao, Song, Hao, Yizhou, Chen, Jianhao, Zheng, Jiaxin, Lu, Yunfeng, Zou, Ruqiang, Pang, Quanquan

Issue&Volume: 2025-02-13

Abstract: Lithium–sulfur batteries promise high energy density storage but show poor stabilities owing to uncontrolled polysulfide dissolution. Although limiting polysulfide solvation to establish quasi-solid-state sulfur reaction can decouple electrode reactions from the electrolyte volume, this approach suffers from slow reaction kinetics. Here we propose a surface-localized polysulfide-solvation strategy to mediate the reaction of ‘quasi-solid’ polysulfide by leveraging an organic phase mediator with a weakly solvating electrolyte. This electrolyte restricts polysulfide dissolution globally while the phase mediator complexes with the surface polysulfide, promoting polysulfide solvation at the surface and facilitating fast surface-localized solution-phase sulfur reactions. Lithium–sulfur batteries using surface-localized phase mediation show excellent rate performance with 494mAhg^-1-sulfur at 16C and stabilized cycling for 300 cycles with 90.2% capacity retention. The strategy enables steady operation of a 2.4Ah 331Whkg^-1 pouch cell. Our work highlights the advantages of surface phase mediation in controlling electrode reaction pathways and kinetics via electrolyte rational design.

DOI: 10.1038/s41557-025-01735-w

Source: https://www.nature.com/articles/s41557-025-01735-w