Sulfidation‐Carbonization Enabled Smart Thermal Management for Moisture‐Driven Energy Generators

Moisture‐driven energy generators (MEGs) offer a sustainable route for low‐grade energy harvesting, yet their integration into high‐power electronics is limited by internal Joule heating and external thermal loads. Conventional MEGs also lack integrated thermal management and waste heat recovery. Guided by Density Functional Theory and Molecular Dynamics simulations of selective sulfidation, Grotthuss proton hopping, and thermal transport, we develop a sulfidation‐carbonization strategy for a multifunctional hydrogel MEG. Gradient organosulfate groups provide proton‐transport pathways, while highly dispersed in situ carbon dots enhance heat dissipation, structural robustness, and waste heat capture. Theoretical predictions agree with experimental observations. The optimized Al‐based MEG delivers 89 µW cm −2 (0.8 V, 0.35 mA cm −2 ) and operates from −24.9°C to 90.4°C. Importantly, an inert Pt/carbon‐cloth device also retains favorable electrical performance, reaching 29.2 µW cm −2 (0.56 V, 133 µA cm −2 ) at 70% RH. The system achieves a thermal dissipation efficiency of 38.9%, reduces LED temperature by 40.3°C, and enables closed‐loop energy utilization. This work establishes a coupled energy‐harvesting and thermal‐management platform for high‐temperature electronics.