A Trilayer Nanofluidic Ionic Diode for High‐Performance Moisture‐Enabled Energy Harvesting and Ionic Logic Operations

Abstract Nanofluidic ionic diodes enable directional ion transport through confined nanochannels, holding great promise for energy harvesting and iontronic applications. However, their development in moisture‐enabled power generation remains limited by insufficient carrier generation and unstable device performance. Here, a trilayer nanofluidic ionic diode‐based moist‐electric generator is reported, integrating positively charged fabrics, lithium chloride‐doped neutral fabrics, and negatively charged fabrics into a p‐i‐n configuration. The hygroscopic neutral layer promotes efficient moisture absorption and ion dissociation, while the adjacent charged layers, featuring nanochannels formed by graphene oxides, establish a built‐in electric field to rectify cation and anion fluxes. This unique structural and functional synergy enables continuous carrier generation and directional transport, achieving both a remarkable voltage of ≈1.38 V and a current of ≈35 µA cm −2 and further exhibiting a peak voltage of ≈1.6 V with stable operation for over 600 h by employing active metal electrodes. Beyond energy harvesting, the diode‐like rectification allows implementation of ionic logic gates and foldable configurations for powering portable electronics. This work establishes a versatile platform for high‐performance nanofluidic diode‐based devices, bridging sustainable power generation with emerging iontronic systems.