Understanding the mechanical response of an electrode during electrochemical cycling and its correlation to the device electrochemical performance is crucial to improving the performance of insertion-type energy storage devices, electrochemical actuators, water purification, ion separation and neuromorphic computing applications. In this work, we visualized the electro-chemo-mechanical coupling behaviors during charge storage of anhydrous and hydrated WO₃ electrodes via in situ atomic force microscopy (AFM) and developed the concept of mechanical cyclic voltammetry (mCV) curves. The relationship between electrochemical current and strain was investigated with simplified models and the results revealed that the proton insertion/deinsertion process could be described through potential-dependent electro-chemo-mechanical coupling coefficients which might indicate changes in insertion processes during electrode cycling. The mCV mapping results highlight the local heterogeneity and show that the charging processes varied across the electrode. These local variations could be further correlated to local morphology, crystal orientations or chemical compositions with proper electrode designs.

了解电极在电化学循环过程中的机械响应及其与设备电化学性能的相关性对于提高插入式储能设备，电化学致动器，水净化，离子分离和神经形态计算应用的性能至关重要。在这项工作中，我们通过原位观察了无水和水合WO ₃电极电荷存储过程中的电化学-机械耦合行为原子力显微镜（AFM）并开发了机械循环伏安法（mCV）曲线的概念。电化学电流和应变之间的关系进行了简化的模型研究，结果表明，质子插入/插入过程可以通过电势相关的电化学-机械耦合系数来描述，这可能表明电极循环过程中插入过程的变化。mCV映射结果突出显示了局部异质性，并表明整个电极的充电过程均发生了变化。这些局部变化可以与具有适当电极设计的局部形态，晶体取向或化学组成进一步相关。