The reaction mechanism of a spinel-type sodium titanium oxide (Na₃LiTi₅O₁₂) was investigated using in situ XRD during the Na insertion/extraction process. The XRD profiles gradually shifted to lower and higher angles during the sodiation and de-sodiation processes, respectively, while maintaining a spinel-type structure and no new peaks were observed, indicating a solid-solution reaction according to the following reaction; (Na)${}_3^{8a}$(Li₁Ti₅)^16dO${}_{12}^{192i}$ + 3Na⁺ + 3e⁻ ↔ (Na)${}_6^{16c}$(Li₁Ti₅)^16dO${}_{12}^{192i}$. The evolution of the XRD profile was confirmed to be highly reversible, which explains the high cycling stability of the NTO electrode. There are two possible sites for Na to occupy: 8a and 16c. The Na ion initially occupies only the 8a site, as confirmed by the 220 peak. The intensity of the 220 peak gradually decreased with increasing SOC and was hardly detected at an SOC of 50%, indicating that all the Na ions at the 8a sites moved to the 16c sites. Topological analysis combined with XRD revealed that the Na ion at the 8a site is stable with one other Na ion at an adjacent 16c site despite the interatomic distance being too short.

使用原位XRD研究了尖晶石型钠钛氧化物（Na ₃ LiTi ₅ O ₁₂）在Na插入/提取过程中的反应机理。在钠化和去钠化过程中，XRD 谱图分别逐渐向低角度和高角度移动，同时保持尖晶石型结构且未观察到新峰，表明根据以下反应进行固溶反应；(Na)${}_3^{8\mathrm{一种}}$(Li ₁ Ti ₅ ) ^{16 d} O${}_{12}^{192\mathrm{一世}}$ + 3Na ⁺ + 3e ⁻ ↔ (Na)${}_6^{16C}$(Li ₁ Ti ₅ ) ^{16 d} O${}_{12}^{192\mathrm{一世}}$. XRD 谱的演变被证实是高度可逆的，这解释了 NTO 电极的高循环稳定性。Na 可能占据两个位置：8 a和 16 c。正如 220 峰所证实的那样，Na 离子最初仅占据 8 a位点。220峰的强度随SOC逐渐降低，并在50％的SOC被几乎检测不到，这表明所有的Na离子在8个一个站点移动到16个Ç位点。结合 XRD 的拓扑分析表明，尽管原子间距离太短，但 8 a位点的 Na 离子与相邻 16 c位点的另一个 Na 离子是稳定的。