Jeddi Javad, Niskanen Jukka, Lessard Benoît H, Sangoro Joshua
Department of Chemical and Biomolecular Engineering Ohio State University, Columbus, Ohio 43210, USA.
Department of Chemical and Metallurgical Engineering, Aalto University, Kemistintie 1, 02150 Espoo, Finland.
Faraday Discuss. 2024 Oct 25;253(0):426-440. doi: 10.1039/d4fd00070f.
The correlation among chemical structure, mesoscale structure, and ion transport in 1,2,3-triazole-based polymerized ionic liquids (polyILs) featuring comparable polycation and polyanion backbones is investigated by wide-angle X-ray scattering (WAXS), differential scanning calorimetry, and broadband dielectric spectroscopy (BDS). Above the glass transition temperature, , higher ionic conductivity is observed in polycation polyILs compared to their polyanion counterparts, and ion conduction is enhanced by increasing the counterion volume in both polycation or polyanion polyILs. Below , polyanions show lower activation energy associated with ion conduction. However, the validity of the Barton-Nakajima-Namikawa relation indicates that hopping conduction is the dominant charge transport mechanism in all the polyILs studied. While a significant transition from a Vogel-Fulcher-Tammann to Arrhenius type of thermal activation is observed below , the decoupling index, often used to quantify the extent to which segmental dynamics and ion conduction are correlated, remains unaltered for the polyILs studied, suggesting that this index may not be a general parameter to characterize charge transport in polymerized ionic liquids. Furthermore, detailed analyses of the WAXS results indicate that both the mobile ion type and the structure of the pendant groups control mesoscale organization. These findings are discussed within the framework of recent models, which account for the subtle interplay between electrostatic and elastic forces in determining ion transport in polyILs. The findings demonstrate the intricate balance between the chemical structure and interactions in polyILs that determine ion conduction in this class of polymer electrolytes.
通过广角X射线散射（WAXS）、差示扫描量热法和宽带介电谱（BDS），研究了具有可比聚阳离子和聚阴离子主链的1,2,3-三唑基聚合离子液体（聚离子液体，polyILs）的化学结构、介观结构和离子传输之间的相关性。在玻璃化转变温度以上，与聚阴离子型聚离子液体相比，聚阳离子型聚离子液体具有更高的离子电导率，并且在聚阳离子或聚阴离子型聚离子液体中，通过增加抗衡离子体积可增强离子传导。在玻璃化转变温度以下，聚阴离子显示出与离子传导相关的较低活化能。然而，Barton-Nakajima-Namikawa关系的有效性表明，跳跃传导是所有研究的聚离子液体中的主要电荷传输机制。虽然在玻璃化转变温度以下观察到从Vogel-Fulcher-Tammann型到Arrhenius型热活化的显著转变，但常用于量化链段动力学和离子传导相关程度的解耦指数，对于所研究的聚离子液体保持不变，这表明该指数可能不是表征聚合离子液体中电荷传输的通用参数。此外，对WAXS结果的详细分析表明，移动离子类型和侧基结构都控制着介观组织。在最近的模型框架内讨论了这些发现，这些模型解释了在确定聚离子液体中的离子传输时，静电力和弹力之间的微妙相互作用。这些发现证明了聚离子液体中化学结构和相互作用之间的复杂平衡，这种平衡决定了这类聚合物电解质中的离子传导。
