Technological development requires reliable power sources where energy storage devices are emerging as critical components.  Wide range of energy storage devices, Redox-flow batteries (RFB), Lithium ion-based batteries (LIB), and Lithium-sulfur (LSB) batteries are being developed in recent years for various applications ranging from grid-scale level storage to mobile electronics. Material complexities associated with these energy storage devices with unique electrochemistry are formidable challenge which needs to be addressed for transformative progress in this field.  X-ray photoelectron spectroscopy (XPS) - a powerful surface analysis tool - has been widely used to study these energy storage materials because of its ability to identify, quantify and image the chemical distribution of redox active species.  However, accessing the deeply buried solid-electrolyte interfaces (which dictate the performance of energy storage devices) has been challenging in XPS usage. Herein we report our recent efforts to utilize the XPS to gain deep insight into these interfaces under realistic conditions with varying electrochemistry involving RFB, LIB and LSB.