Na-ion batteries are nowadays receiving renewed attention because of its propitiousness for large-scale stationary applications. Although the Na storage mechanism is still not completely understood, TiO₂ nanoparticles are very promising active anode materials in Na-ion batteries provided that a correct dispersion is achieved within the battery electrode. Whilst the structural changes, either in crystallinity or crystalline phase, that occur during operation are receiving much recent attention, the nanometric morphological evolution of the TiO₂ nanoparticles within the electrode is yet to be thoroughly addressed, despite its implication in battery efficiency. In the present work, operando small-angle x-ray scattering studies on TiO₂/Na-ion batteries show that whereas the nanoparticle size is preserved during the discharge-charge cycles, the mean distance between nanoparticles increases. The observed morphological changes are consistent with electrode swelling and nanoparticle aggregation during operation, being one phenomenon dominant over the other depending on the applied density current; thus, depending on the differences in ion diffusion within the electrode.

钠离子电池由于其适合大规模固定应用而如今重新受到关注。尽管Na存储机制尚未完全了解，但只要在电池电极内实现正确的分散，TiO ₂纳米粒子是钠离子电池中非常有前途的活性阳极材料。虽然操作过程中发生的结晶度或晶相的结构变化最近受到广泛关注，但电极内 TiO ₂纳米颗粒的纳米形态演变尚未得到彻底解决，尽管它对电池效率有影响。在目前的工作中，对 TiO _{2 /Na 离子电池}进行的原位小角度 X 射线散射研究表明，虽然纳米颗粒尺寸在放电-充电循环期间保持不变，但纳米颗粒之间的平均距离增加。观察到的形态变化与操作过程中的电极膨胀和纳米颗粒聚集一致，这是一种占主导地位的现象，具体取决于所施加的密度电流；因此，取决于电极内离子扩散的差异。