Cao Jing, Dong Jinfeng, Wu Jing, Suwardi Ady
Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, 138634 Singapore.
Department of Materials Science and Engineering, National University of Singapore, 117574 Singapore, Singapore.
ACS Nano. 2025 Jul 22;19(28):26249-26258. doi: 10.1021/acsnano.5c10693. Epub 2025 Jul 10.
Evaporation, a ubiquitous process driving Earth's water-energy cycle, has been largely untapped for energy harvesting. Here, we introduce "evapolectrics," a scalable strategy that directly converts evaporation enthalpy into electricity via thermoelectric generators (TEGs). By leveraging porous graphite coatings and optimizing wind speeds (2.8 m/s) and wet-bulb depression, a robust temperature gradient (Δ) over 6 °C can be maintained across TEGs. This translates to a power density of 4.2 W/m, which exceeds other ambient energy harvesting technologies, such as triboelectric and hydrovoltaics. We also demonstrate the evapolectrics' ability to sustain a continuous power output of 2.72 mW over 30 min and scalability via a 7 × 7 device array. Unlike intermittent sources like solar or wind, evaporation's perennial nature offers reliable ambient energy harvesting. With global evaporation rates suggesting harvestable energy of ∼10 TJ/year, evapotetics present a transformative approach to power self-sustaining devices, augmented by advances in thermoelectric materials.
蒸发是驱动地球水 - 能量循环的普遍过程,在能量收集方面很大程度上尚未得到开发。在此,我们引入“蒸发电技术”,这是一种可扩展的策略,通过热电发电机(TEG)将蒸发焓直接转化为电能。通过利用多孔石墨涂层并优化风速(2.8米/秒)和湿球温度差,可在TEG两端维持超过6℃的强大温度梯度(Δ)。这转化为4.2瓦/平方米的功率密度,超过了其他环境能量收集技术,如摩擦电和水力发电技术。我们还展示了蒸发电技术在30分钟内维持2.72毫瓦连续功率输出的能力,以及通过7×7设备阵列实现的可扩展性。与太阳能或风能等间歇性能源不同,蒸发的常年性提供了可靠的环境能量收集。鉴于全球蒸发速率表明每年可收获的能量约为10太焦耳,蒸发电技术借助热电材料的进展,为为自持设备供电提供了一种变革性方法。