Iontronic Regulation of Nanoconfined Electrical Double Layers on Dielectric Solids

The electrical double layer (EDL) at solid‐liquid interfaces has been recognized as a pivotal platform for coupling ionic and electronic processes, through which integrated energy harvesting and intelligent information modulation can be enabled. In this review, the evolution from classical EDL models at conductor‐liquid interfaces to extended frameworks for nonconductor‐liquid systems is revisited, and the structure‐function relationships across diverse interfacial environments are elucidated. Building upon this foundation, the implemented energy and information technologies are systematically classified based on the dynamic regulation strategies of different EDL substructures. For energy harvesting and conversion, solid–liquid triboelectric nanogenerators and charge‐supplementary triboiontronics nanogenerators are developed via the regulation of the diffuse layer, while entire‐EDL modulation gives rise to technologies like hydrovoltaic nanogenerators and triboiontronics nanogenerators based on asymmetric EDLs. Moreover, mechanisms for information scavenging and modulation are examined, where diffuse‐layer dynamics are utilized for interfacial charge probe, entire‐EDL reconfiguration is applied to neuromorphic circuit control, and ionic memory emulation, underwater wireless communication, and neuromimetic logic gates are implemented—largely inspired by biological signal transmission. Finally, future application scenarios are outlined, while key challenges are analyzed. Through this comprehensive overview, guidance is provided for leveraging dynamically regulated EDLs to advance next‐generation multifunctional, energy‐information‐coupled systems.