Electrochemical Metallization Memristors: From Bulk to 2D Materials

Electrochemical metallization (ECM) memristors represent a key class of resistive switching devices, where metal ion migration and redox reactions govern the formation and rupture of conductive filaments. These systems have evolved from conventional bulk oxides to architectures employing atomically thin two‐dimensional (2D) materials as switching layers, enabling new opportunities for voltage scaling, interface control, and multifunctional behavior. This review presents a comprehensive overview of ECM‐based devices across this dimensional transition, emphasizing how material composition, structural confinement, and interface chemistry determine switching mechanisms, variability, and endurance. Particular attention is given to the interplay between electrochemical kinetics, filament geometry, and the switching layer thickness, which together define the trade‐offs between non‐volatile, volatile, and neuromorphic operation. The discussion integrates experimental insights, mechanistic models, and quantitative performance trends to clarify the distinct characteristics of 2D‐material‐based ECM systems. Finally, emerging challenges related to reliability, large‐area integration, and cross‐platform benchmarking are outlined, highlighting future directions toward scalable and deterministic memristive technologies.