Energy storage devices using electrochemical reactions have become an integral part of our daily lives, and further improvement of their performance is highly demanded. An important task for this purpose is to thoroughly understand the electrochemical processes governing their chemistry. Here we develop a method based on Kelvin probe force microscopy that enables dynamic visualization of changes in the internal potential distribution in an operating electrochemical device and use it to characterize an all-solid-state lithium ion battery. Observation of the cathode composite regions during a cyclic voltammetry operation reveals differences between the behavior of local electrochemical reactions in the charge and discharge processes. Based on careful inspection of the results, we show that the difference arises from a change in the state of an electronic conductive path network in the composite electrode. Our method provides new insights into the local electrochemical reactions during electrochemical operation of devices.

使用电化学反应的储能设备已经成为我们日常生活的组成部分，因此人们迫切需要进一步提高其性能。为此，一项重要任务是彻底了解控制其化学性质的电化学过程。在这里，我们开发了一种基于开尔文探针力显微镜的方法，该方法能够动态显示正在运行的电化学装置中内部电势分布的变化，并将其用于表征全固态锂离子电池。在循环伏安法操作期间对阴极复合材料区域的观察揭示了在充电和放电过程中局部电化学反应的行为之间的差异。根据对结果的仔细检查，我们表明，差异是由复合电极中电子导电路径网络状态的变化引起的。我们的方法为器件电化学操作期间的局部电化学反应提供了新的见解。