Investigating ion transport in polymer electrolytes using X-ray photon correlation spectroscopy

Battery electrolytes provide an ideal opportunity to investigate the relationship between polymer dynamics and ion transport, with polymer electrolytes providing a safer alternative to commercially used liquid electrolytes. Here, we propose heterodyne XPCS measurements to directly probe local dynamics and polymer velocities spatially across concentration gradients, considering the nuances of salt concentration on transport and directly determining cation transport. A deeper understanding of ion transport in polymeric materials for energy storage applications will enable the design of new electrolyte and electrode materials, the simulation of device performance and safety and the accurate prediction of electrolyte responses in any electrochemical cell configuration overall operating conditions.

电池电解质为探究聚合物动力学与离子输运之间的关联提供了绝佳的研究契机，而聚合物电解质相较于当前商业化应用的液态电解质，是一种更为安全的替代方案。本研究提出采用外差式X射线光子关联光谱（heterodyne XPCS）测试方法，在考量盐浓度对输运过程的细微影响的基础上，实现对浓度梯度区域内的局域动力学与聚合物速度的空间直接探测，并直接测定阳离子输运行为。针对储能应用场景下聚合物材料中离子输运过程的深入理解，将能够推动新型电解质与电极材料的设计开发、器件性能与安全特性的模拟，以及在全工况运行条件下任意电化学电池构型中电解质响应的精准预测。