Wang Yixiu, Zhou Heng, Wei Shiqiang, Liu Hengjie, Chen Shuangming, Chen Xin, Zhu Kefu, Zhang Xunshuang, Si Yang, Wu Xiaojun, Long Ran, Li Liangbin, Song Li
National Synchrotron Radiation Laboratory, Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China Hefei 230029 P. R. China
School of National Defence Science & Technology, Southwest University of Science and Technology Mianyang 621010 P. R. China.
Chem Sci. 2025 Mar 3;16(14):6050-6059. doi: 10.1039/d4sc08624d. eCollection 2025 Apr 2.
Separators, regulating the ion transport channels between electrodes, are crucial for maintaining the properties of electrochemical batteries. However, sluggish ion transport and desolvation kinetics in aqueous zinc-ion batteries (AZIBs) cause uneven ion flux at the separator-electrode interface, accelerating Zn dendrite growth. Herein, we systematically dissect ionic favorable hydrogen bond chemistry in a hybrid separator engineered through rational boron nitride (BN) doping into polyacrylonitrile (PAN) separators. Notably, Fourier transform infrared spectroscopy (FTIR) analyses reveal that the hydrogen bond network in a BN-PAN separator improved the desolvation of Zn by immobilizing water molecules through hydrogen bond interactions, thus effectively increasing the transference number of zinc ions. Capitalizing on the ionic favorable properties, uniform electric field distribution and zinc plating/stripping behavior are achieved at the separator-electrode interface, efficiently suppressing the formation of zinc dendrites and by-products. As a result, the BN-PAN separator demonstrates extended cycling stability, exceeding 1100 h at a current density of 1.0 mA cm and 700 h at a current density of 5.0 mA cm, while exhibiting enhanced rate capability and stability in full cells. This work offers valuable insights into leveraging hydrogen bond chemistry for the design of fast ion-transport separators in aqueous batteries.
隔膜调节着电极之间的离子传输通道，对于维持电化学电池的性能至关重要。然而，水系锌离子电池（AZIBs）中缓慢的离子传输和去溶剂化动力学导致隔膜-电极界面处离子通量不均匀，加速了锌枝晶的生长。在此，我们系统地剖析了通过将氮化硼（BN）合理掺杂到聚丙烯腈（PAN）隔膜中设计的混合隔膜中有利于离子的氢键化学。值得注意的是，傅里叶变换红外光谱（FTIR）分析表明，BN-PAN隔膜中的氢键网络通过氢键相互作用固定水分子，改善了锌的去溶剂化，从而有效地增加了锌离子的迁移数。利用有利于离子的特性，在隔膜-电极界面实现了均匀的电场分布和锌的电镀/剥离行为，有效地抑制了锌枝晶和副产物的形成。结果，BN-PAN隔膜表现出延长的循环稳定性，在1.0 mA cm的电流密度下超过1100 h，在5.0 mA cm的电流密度下超过700 h，同时在全电池中表现出增强的倍率性能和稳定性。这项工作为利用氢键化学设计水系电池中快速离子传输隔膜提供了有价值的见解。
