Despite the challenges in achieving its full theoretical capacity of reversible extraction of two Li ions, the Li₂FeSiO₄ (LFS) cathode shows a remarkable cycling stability once its low electronic conductivity is addressed. By studying the local structure around the iron during electrochemical cycling using in situ x-ray absorption spectroscopy (XAS), it is possible to gain insight into the factors which determine the electrochemical properties of this material. In order to practically perform in situ XAS studies, the charge/discharge of LFS was maximized using two approaches: (a) reducing the particle size of LFS samples from micro-scale to nano-scale in order to reduce the diffusion path for intercalating ions; and (b) applying a conductive coating to each nanoparticle to facilitate electron transfer. A family of LFS materials was synthesized and characterized using x-ray diffraction, and scanning electron microscopy with energy dispersive analysis for structural and morphological analysis, as well as cyclic voltammetry and cycling tests for electrochemical performance diagnosis. This material was then characterized by in situ XAS. The results provide insight into the stable electrochemical performance of LFS and suggest new synthetic routes to reaching the theoretical capacity.

尽管在实现其可逆提取两个锂离子的全部理论能力方面存在挑战，但 Li ₂ FeSiO ₄ (LFS) 阴极在解决其低电子电导率问题后表现出显着的循环稳定性。通过使用原位X 射线吸收光谱 (XAS) 研究电化学循环过程中铁周围的局部结构，可以深入了解决定该材料电化学性能的因素。为了在现场实际执行XAS 研究中，LFS 的充电/放电使用两种方法最大化：(a) 将 LFS 样品的粒径从微米级减小到纳米级，以减少嵌入离子的扩散路径；(b) 对每个纳米颗粒施加导电涂层以促进电子转移。合成了一系列 LFS 材料，并使用 X 射线衍射和具有能量色散分析的扫描电子显微镜进行结构和形态分析，以及用于电化学性能诊断的循环伏安法和循环测试进行表征。然后通过原位XAS表征该材料。结果提供了对 LFS 稳定电化学性能的深入了解，并提出了达到理论容量的新合成路线。