Application of Alternating Current Scanning Electrochemical Microscopy in Lithium‐Ion Batteries: Local Visualization of the Electrode Surface

Abstract The electrode surface of aqueous lithium‐ion batteries has been studied with alternating‐current scanning electrochemical microscopy (AC‐SECM), which enables the visualization of microscopic domains with different topography. An equivalent circuit was proposed to analyze the appropriate frequency for the interface image. In addition, AC signals (impedance, current, and phase shift) and measurement conditions, including the tip position, step size, and excitation voltage amplitude, were discussed and statistically treated to optimize the interface visualization parameter. This work not only provides some fundamental knowledge for obtaining high‐resolution AC‐SECM images of the electrode surface in lithium‐ion batteries, but also paves way for the solid electrolyte interphase studies in other battery systems.