Diffusion of lithium ions in structural carbon fibre electrodes

Current electric vehicles are hampered by the significant mass required for the battery components, much of which is metallic - current collectors, casing, etc. This can be replaced with structural electrodes, which carry both electrical charge and mechanical load. One promising possibility is to use carbon fibres, which can be tailored to meet a variety of mechanical needs, are reasonably good conductors, and can replace the graphite in a traditional lithium ion battery. However, the diffusive property and location of lithium ions within the fibres are not definitively known. Recent in-house NMR measurements indicate a fast exchange between two ion storage sites. We therefore wish to use µSR as an empirical probe of local ionic behaviour.

当前电动汽车受限于电池组件所需的大量质量，其中大部分为金属部件——如集电器、外壳等。这些部件可由结构电极替代，后者兼具电荷传导和机械承载功能。一种颇具前景的方案是采用碳纤维，其可定制以满足多样化的机械需求，具备良好的导电性，且能替代传统锂离子电池中的石墨。然而，锂离子在碳纤维内的扩散特性及分布位置尚未明确。近期内部核磁共振（NMR）测量显示，两个离子存储位点间存在快速交换现象。因此，我们希望利用μSR作为经验性探针，研究局部离子行为。