PNNL

Abstract

The electrochemical interface between the solid electrode and liquid electrolyte has long been studied because of its importance in electrical energy storage, material synthesis, catalysis, and energy conversions.1 However, such interfaces are complex and extremely di?cult to observe directly and are poorly under-stood due to lack of true in situ tools.2 Although electrochemical techniques have been widely used to investigate such interfaces, they are based on macroscopic models or current changes that could not provide direct ionic and molecular information of the interfacial structure. Many in situ and ex situ spectroscopy and microscopy techniques have been used to study the solid–liquid (s–l) interface.3,4 In situ TEM in sealed liquid cells has notably become a popular choice to provide structural information of s–l at the atomic level.5,6 However, real-time spatial mapping of the ionic and molecular intermediate species at the dynamic inter-face still remains a key challenge.