Bioinspired dual-ion-transport synergy in hydrogel enables high-performance moisture-electric generation over a wide humidity range

Triple-layer hydrogel MEG builds sustained ionic gradient via dual ion-transport synergy. • Device outputs 0.47 V at 10% RH and 0.72 V at 100% RH, showing excellent adaptability. • At 80% RH, the device outputs 0.895 V and 201.8 µA cm ⁻2 for over 200 h. • This device enables self-powered hydrogen production. Moisture-enabled generators (MEGs) harvest electricity from atmospheric humidity, yet their performance declines under extremely low or high humidity owing to inadequate or excessive moisture uptake. Inspired by ion-selective migration in electric eels, an integrated triple-layer hydrogel-based MEG (QLT-MEG) is developed. It features a central hygroscopic layer (LGP) sandwiched between anion- (QP) and cation-selective (TPP) layers. A water gradient from the LGP drives intrinsic ion (Cl − /H + ) diffusion in the side layers, while the side layers selectively and directionally guide reservoir ions (Cl − /Li + ) from the LGP. This dual-ion-transport synergy builds a sustained concentration gradient for efficient power generation. A single QLT-MEG delivers a high output of 0.895 V and 201.87 µA cm −2 at 80% relative humidity (RH). Using an Al electrode boosts the performance to 1.38 V and 1.41 mA, respectively. Remarkably, it retains substantial outputs of 0.47 V and 29.22 µA cm −2 at 10% RH, and 0.72 V with 154.31 µA cm −2 at 100% RH, demonstrating exceptional humidity adaptability. Experimental and DFT/MD analyses confirm sustained water gradient and ion-selective migration as the underlying mechanisms for its high performance. Furthermore, integrated QLT-MEG arrays reliably power small electronics and drive water electrolysis, showcasing their potential for flexible, scalable off-grid power solutions. Download: Download high-res image (225KB) Download: Download full-size image