Surface Modification of Materials for Electrochemical Energy Storage Devices: A Review

The development of sustainable energy systems imposes increasingly stringent requirements on the energy density, cycle life, and safety of electrochemical energy storage devices. However, during prolonged charge–discharge cycling, the electrode–electrolyte interface continuously undergoes reactions and evolution, which can readily induce interphase instability, intensified side reactions, increased transport resistance, and structural degradation, thereby limiting further performance improvement. Surface modification of materials provides an effective strategy for enhancing interfacial stability by regulating the surface chemical environment and interfacial reaction processes while largely preserving the bulk structure of active materials. Focusing on typical interfacial failure issues in liquid‐electrolyte lithium batteries, solid‐state batteries, and supercapacitors, this review systematically summarizes major surface modification strategies, including surface coating and artificial interface construction, doping and defect engineering, surface functionalization, and pore structure reconstruction. The underlying mechanisms are analyzed from the perspectives of suppressing side reactions, stabilizing interfacial films, and improving transport kinetics. On this basis, the roles of in situ/operando characterization, theoretical calculations, multiscale simulations, and AI‐assisted methods in identifying interfacial evolution, elucidating mechanisms, and optimizing modification schemes are further discussed, with the aim of providing a reference for interface engineering and materials design in high‐performance electrochemical energy storage devices.