广东工业大学李成超小组通过分子桥接诱导的抗盐析效应，制备了准固态锌离子电池的高离子导电性ZnSO₄基水凝胶。这一研究成果于2024年7月30日发表在国际顶尖学术期刊《德国应用化学》上。

水凝胶电解质(HEs)在解决水基锌离子电池中出现的严重问题方面具有很大的前景，但普遍存在的全向盐盐析效应会导致低离子电导率和电化学不稳定性。

这项研究从氢键微环境重建的角度出发，提出了一种微妙的分子桥接策略来增强PVA与ZnSO₄之间的相容性。通过引入同时含有氢键受体和供体的尿素，由SO₄^2-驱动的H₂O极化引发的PVA和H₂O之间断裂的氢键，可以通过强烈的分子间氢键重新结合，从而大大提高ZnSO₄的携带能力。尿素修饰的PVA-ZnSO₄ HEs具有高达31.2 mS cm^-1的高离子电导率，成功解决了固-固界面离子传输缓慢的难题。

此外，尿素的原位电聚合可以得到有机固体-电解质界面，以防止H₂O参与的副反应，从而显著提高Zn化学的可逆性。因此，在0.1 mA cm^-2下，锌阳极的寿命从50小时延长到2200小时，而锌-碘全电池即使在8000次循环后仍保持显着的库仑效率(>99.7%)。本文提出的抗盐析策略为解决功能性水凝胶电解质的相分离问题，提供了一个有见解的概念。

附：英文原文

Title: Molecular Bridging Induced Anti-salting-out Effect Enabling High Ionic Conductive ZnSO4-based Hydrogel for Quasi-solid-state Zinc Ion Batteries

Author: Xuan Zhou, Song Huang, Liang Gao, Zicheng Zhang, Qinyang Wang, Zuyang Hu, Xiaoting Lin, Yulong Li, Zequn Lin, Yufei Zhang, Yongchao Tang, Zhipeng Wen, Minghui Ye, Xiaoqing Liu, Cheng Chao Li

Issue&Volume: 2024-07-30

Abstract: Hydrogel electrolytes (HEs) hold great promise in tackling severe issues emerging in aqueous zinc-ion batteries, but the prevalent salting-out effect of kosmotropic salt causes low ionic conductivity and electrochemical instability. Herein, a subtle molecular bridging strategy is proposed to enhance the compatibility between PVA and ZnSO4 from the perspective of hydrogen-bonding microenvironment re-construction. By introducing urea containing both an H-bond acceptor and donor, the broken H-bonds between PVA and H2O, initiated by the SO42--driven H2O polarization, could be re-united via intense intermolecular hydrogen bonds, thus leading to greatly increased carrying capacity of ZnSO4. The urea-modified PVA-ZnSO4 HEs featuring a high ionic conductivity up to 31.2 mS cm–1 successfully solves the sluggish ionic transport dilemma at the solid-solid interface. Moreover, an organic solid-electrolyte-interphase can be derived from the in-situ electro-polymerization of urea to prohibit H2O-involved side reactions, thereby prominently improving the reversibility of Zn chemistry. Consequently, Zn anodes witness an impressive lifespan extension from 50 h to 2200 h at 0.1 mA cm-2 while the Zn-I2 full battery maintains a remarkable Coulombic efficiency (>99.7%) even after 8000 cycles. The anti-salting-out strategy proposed in this work provides an insightful concept for addressing the phase separation issue of functional HEs.

DOI: 10.1002/anie.202410434

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202410434