In situ Raman spectroscopy is a powerful tool to elucidate the lithium-ion dynamics in solid-state batteries. Thus, in this work, in situ Raman spectroscopy of thin-film batteries is used to study the structural changes of Li_xMn₂O₄ during battery operation. Thin-film batteries with Li/Li₃PO₄/LiMn₂O₄ structures are fabricated, and in situ Raman measurements are performed from both the front and back sides of the thin-film battery. The Li_xMn₂O₄ in the thin-film batteries present characteristic Raman spectra originating from the α, β, and λ phases. Notably, the Raman intensity of Li_xMn₂O₄ shows hysteresis during charging and discharging when observed from the front-surface configuration, whereas only small hysteresis is observed when measured from the back surface. This behavior is explained by the lithium diffusion and phase transition behavior in Li_xMn₂O₄. The value of diffusion coefficients estimated from the simulations are in good agreement with those previously obtained using thin-film batteries.

原位拉曼光谱是阐明固态电池中锂离子动力学的有力工具。因此，在这项工作中，薄膜电池的原位拉曼光谱用于研究电池运行过程中 Li _x Mn ₂ O _{4的结构变化。}制作了具有Li/Li ₃ PO ₄ /LiMn ₂ O ₄结构的薄膜电池，并从薄膜电池的正面和背面进行了原位拉曼测量。薄膜电池中的 Li _x Mn ₂ O _{4呈现出源自 α、β 和 λ 相的特征拉曼光谱。}值得注意的是，Li 的拉曼强度_× Mn ₂ O ₄从正面观察时显示出充电和放电期间的滞后，而从背面测量时仅观察到小的滞后。_{这种行为可以通过Li x} Mn ₂ O ₄中的锂扩散和相变行为来解释。从模拟中估计的扩散系数值与之前使用薄膜电池获得的值非常一致。