近日，清华大学周光敏团队报道了硫电化学中“预介体”分子骨架设计。该研究于2026年5月6日发表在《自然》杂志上。

分子介体已在锂硫电池的电解质化学中展现出广泛的适用性，将传统的多相硫转化反应转变为高活性反应路径。尽管已有大量研究致力于阐明分子介体的机理作用，但分子骨架调控对其介导效应的影响仍鲜为人知。

研究组提出2-氯嘧啶作为一种潜在的“预介体”以及分子骨架设计的模型材料，该分子可在硫反应过程中通过芳香亲核取代原位活化为分子介体，均相地在电极上诱导快速的氧化还原循环。结合量子化学与机器学习，研究组发展了一种分子骨架编程策略，揭示了侧链基团的电子、几何与位点特征与介导性能之间的构效关系，从而能够调控预介体的活化速率与介导活性。

该策略从196个候选分子中识别出2-氯-4-(三氟甲基)嘧啶作为优势预介体，使得锂硫电池在800次循环中实现81.7%的平均容量保持率，并在14.2 Ah级软包电池中达到549 Wh kg^-1的能量密度。研究组预期，该分子骨架编程工作有望在更广泛的有机化学空间中应用于功能分子的设计。

附：英文原文

Title: Molecular skeleton programming of premediators in sulfur electrochemistry

Author: Gao, Runhua, Zhu, Yifei, Tao, Shengyu, Zhang, Mengtian, Lao, Zhoujie, Han, Zhiyuan, Song, Yanze, Li, Hongtai, Song, Linxuan, Zhang, Xuan, Zhu, Yanfei, Zhou, Guangmin

Issue&Volume: 2026-05-06

Abstract: Molecular mediators have demonstrated broad applicability in electrolyte chemistry of lithium–sulfur batteries, transforming sulfur conversion from traditional multiphase reactions to highly reactive pathways1,2,3,4,5,6. Despite tremendous efforts to elucidate the mechanistic roles of molecular mediators7,8,9, the influence of molecular skeleton regulation on their mediating effects remains barely understood. Here we propose 2-chloropyrimidine as a potential ‘premediator’ and a model material for molecular skeleton design, which can be in situ activated into a molecular mediator during sulfur reaction progression by means of aromatic nucleophilic substitution, homogeneously inducing a rapid redox loop over the electrode. Integrating quantum chemistry and machine learning, we develop a molecular skeleton programming strategy that illuminates the structure–property relationship between electronic, geometric and site features of side-chain groups and mediating performance, offering control over the activation rate and mediating activity of premediators. The strategy identifies 2-chloro-4-(trifluoromethyl)pyrimidine as a favourable premediator from 196 candidates, enabling lithium–sulfur batteries to achieve an average capacity retention of 81.7% over 800 cycles together with an energy density of 549Whkg1 in a 14.2-Ah-level pouch cell. We expect that our work on molecular skeleton programming may find application in designing functional molecules in broader organic chemical spaces.

DOI: 10.1038/s41586-026-10505-8

Source: https://www.nature.com/articles/s41586-026-10505-8