In-situ/operando characterization of intricate electrode/electrolyte interfacial processes in secondary battery systems represents a pivotal research direction in the realm of energy electrochemistry. This pursuit holds significant scientific importance in advancing battery technology towards enhanced energy density, extended lifespan, and heightened safety standards. Our group is devoted to pioneering highly time-resolved and sensitive in-situ/operando spectroscopic characterization techniques. These methodologies enable real-time and nondestructive monitoring of the dynamic evolution of complex electrode/electrolyte interfacial phenomena, such as the formation and evolution of the solid-electrolyte interphase (SEI), lithium-ion (de-)solvation, and lithium deposition-dissolution/lithiation-delithiation. Our aim is to uncover the underlying reaction mechanisms, elucidate the associated mechanisms, and identify influencing factors at atomic, molecular, and nanoscale levels. This comprehensive understanding of material transport and transformation laws informs the design and construction of innovative surface/interface systems. Moreover, we are committed to optimizing the design of critical electrode materials for secondary batteries and analyzing their intrinsic relationships within the energy storage process. This dedication aims to foster innovation in electrode materials rooted in fundamental principles. Recently, our research scope has expanded to include the development of solid-state electrolytes and the recycling of spent lithium batteries.