Understanding the structural and dynamic properties of disordered systems at the mesoscale is crucial. This is particularly important in organic mixed ionic–electronic conductors (OMIECs), which undergo significant and complex structural changes when operated in an electrolyte. In this study, we investigate the mesoscale strain, reversibility and dynamics of a model OMIEC material under external electrochemical potential using operando X-ray photon correlation spectroscopy. Our results reveal that strain and structural hysteresis depend on the sample’s cycling history, establishing a comprehensive kinetic sequence bridging the macroscopic and microscopic behaviours of OMIECs. Furthermore, we uncover the equilibrium and non-equilibrium dynamics of charge carriers and material-doping states, highlighting the unexpected coupling between charge carrier dynamics and mesoscale order. These findings advance our understanding of the structure–dynamics–function relationships in OMIECs, opening pathways for designing and engineering materials with improved performance and functionality in non-equilibrium states during device operation.

了解中尺度无序系统的结构和动力学特性至关重要。这对于有机混合离子电子导体（OMIEC）尤其重要，因为当在电解质中工作时，OMIEC 会发生显着且复杂的结构变化。在这项研究中，我们使用原位 X 射线光子相关光谱研究了 OMIEC 模型材料在外部电化学势下的介观应变、可逆性和动力学。我们的结果表明，应变和结构滞后取决于样品的循环历史，建立了连接 OMIEC 宏观和微观行为的综合动力学序列。此外，我们揭示了载流子和材料掺杂态的平衡和非平衡动力学，强调了载流子动力学和介观有序之间的意外耦合。这些发现增进了我们对 OMIEC 中结构-动力学-功能关系的理解，为设计和工程材料开辟了途径，在设备运行期间提高非平衡状态下的性能和功能。