Regenerative Hydrovoltaic Power Generator with Remarkable Duration and Fast Power Generation Achieved by Deep Eutectic Biomass Complex

Abstract Hydrovoltaic power generators (HPGs) are pivotal for addressing the global energy crisis. However, most prevalent HPGs suffer from a conflict: either generating transient electricity or sustaining long‐term output reliant on a continuous water supply, which would rapidly decay without water input, especially under low humidity. This severely restricts their environmental adaptability and durability, while the recyclability of HPGs is also highly concerned for reducing electronic waste. Herein, this work pioneers a biomass‐derived processing strategy that forms a “Deep Eutectic Biomass Complex” (DEBC) via direct combining biomass macromolecules with choline chloride. The strategy constructed a stable yet sensitive hydrogen‐bonded network that endows DEBC simultaneously realizing fast power generation and long‐term duration as HPG. DEBC exhibits ultrahigh sensitivity to external humidity changes (∆R/R₀≈265 000%) and can spontaneously induce Grotthuss proton hopping under moisture flow, leading to rapid voltage generation (113.8 ± 11.5 mV s −1 ). It also demonstrates exceptional durability that maintains an open‐circuit voltage (V oc ≥ 400 mV) at 30%RH for over 10500 s without water input, and sustains V oc in an open environment for 25 days during winter. This work proposes a feasible access for designing renewable HPG with superior durability and environmental adaptability, tackling the operational limitations and sustainability concerns.