Rechargeable batteries (Li-ion batteries and beyond) have received extensive attention as powerful boosters for the development of human society. The rapid progress achieved in this research area largely relies on the in-depth efforts on the improvement of battery electrode materials and decrease of the cost. However, the application of rechargeable batteries is still hindered by low energy density, serious voltage hysteresis, and long-term degradation. Therefore, it is of great importance for understanding the underlying redox reaction and capacity fading mechanisms to circumvent these problems and improve the overall battery performance. Advanced characterization techniques, especially synchrotron-based x-ray absorption spectroscopy (XAS), have been widely applied to the mechanistic understanding of rechargeable batteries. Particularly, in situ/operando XAS allows the characterization of practical working mechanisms by measuring the electronic structure evolution of the electrode materials under real operation conditions, which is an imperative prerequisite for the further optimization of the battery performance. Herein, the recent progress in the understanding of the operating principles of several common rechargeable batteries (including lithium-ion batteries, sodium-ion batteries, and lithium–sulfur batteries) based on in situ/operando XAS technique is reviewed and summarized. We aim to provide a comprehensive treatise on in situ/operando characterization of rechargeable batteries using XAS, which could provide guidance for further improvement of battery performance.

可充电电池（锂离子电池及其他电池）作为人类社会发展的强大助推器而受到广泛关注。该研究领域取得的快速进展很大程度上依赖于对电池电极材料改进和成本降低的深入努力。然而，充电电池的应用仍然受到能量密度低、电压滞后严重、长期退化等问题的阻碍。因此，了解潜在的氧化还原反应和容量衰减机制对于规避这些问题并提高整体电池性能具有重要意义。先进的表征技术，尤其是基于同步加速器的 X 射线吸收光谱 (XAS)，已广泛应用于可充电电池的机械理解。特别，原位/操作XAS 允许通过测量实际操作条件下电极材料的电子结构演变来表征实际工作机制，这是进一步优化电池性能的必要先决条件。在此，对基于原位/操作XAS技术的几种常见可充电电池（包括锂离子电池、钠离子电池和锂硫电池）工作原理的理解的最新进展进行了综述和总结。我们的目标是提供关于原位/操作的综合论文 使用 XAS 表征可充电电池，这可以为进一步提高电池性能提供指导。