High‐Performance Double‐Drive Water Evaporation‐Induced Generator Operating Without Liquid Water Sources

Abstract

Abstract Restricted electrical output and the heavy reliance on liquid water sources severely limit the further development of water evaporation‐induced generators (WEGs) based on the inherently slow phase transition of water molecules. Here, inspired by the rolling logs to transport boulders, a double‐drive WEG (DWEG) is developed, in which double ionic circulations and ion‐electronic friction provide intensive horsepower and grip for energy capture. DWEGs applied in deionized water can continuously generate a high voltage of 1.13 V and a stable current of 10.54 µA (1.76 µA cm −2 ) under ambient conditions (≈20 °C, ≈43% RH). In addition, benefiting from the high osmotic pressure and mechanical strength of ionized composite hydrogels, DWEGs can be directly plugged into soil with minimal water (as little as 12.5 wt.%) to generate electricity, eliminating the reliance on a liquid water source. Interestingly, a high electrical output (0.65 V, 0.89 µA) is sustained (>60 h) at low‐temperature (e.g., −12 °C), overcoming the temporal and geographical restrictions of conventional WEGs in their practical applications.