Harvesting energy from the ambient is a promising approach to fulfil decentralized energy demands and facilitate the transition to low-carbon economy. Moisture-sorption-based energy harvesting (MSEH) is a promising strategy for obtaining heat, cold and electricity from ubiquitous moisture anywhere and anytime. Advances in water-sorption materials have promoted the development of sustainable moisture energy. However, MSEH technology faces the challenges of low-energy productivity and limited recognition of its working mechanisms and thermodynamic analysis. We centre this Perspective article around an in-depth understanding of the underlying mechanisms and thermodynamic limitations of sustainable moisture energy. We first introduce the working principles of MSEH for heat, cold and electricity generation, and summarize recent progress in water sorbents. We then discuss thermodynamic limitations and evaluate global potential for sustainable moisture energy. We outline future challenges of water-sorption kinetics and propose technical directions for accelerating water sorption-desorption with ordered cross-scale energy transfer and mass transport. Finally, we offer an overview of future research areas for water sorbents with higher water uptake, tunable water affinity and faster water sorption for next-generation high-performance MSEH.

从环境中获取能源是满足分散能源需求和促进向低碳经济转型的一种有前途的方法。基于水分吸附的能量收集（MSEH）是一种很有前途的策略，可以随时随地从无处不在的水分中获取热量、冷量和电力。吸水材料的进步促进了可持续湿气能源的发展。然而，MSEH技术面临着能源生产率低、对其工作机制和热力学分析认识有限的挑战。我们这篇观点文章的重点是深入了解可持续湿气能源的基本机制和热力学限制。我们首先介绍了MSEH用于热、冷和发电的工作原理，并总结了吸水剂的最新进展。然后我们讨论热力学限制并评估可持续湿气能源的全球潜力。我们概述了水吸附动力学的未来挑战，并提出了通过有序的跨尺度能量转移和质量传输加速水吸附-解吸的技术方向。最后，我们概述了具有更高吸水率、可调水亲和力和更快吸水速度的吸水剂的未来研究领域，以实现下一代高性能 MSEH。