新型的能量转化技术在人类生产生活中起着至关重要的作用，将自然环境中的能量收集起来转化为可以直接利用的电能，作为解决人类能源短缺和环境污染问题的一种有效手段，这一研究领域受到研究人员的广泛关注。地球上水动态循环过程中吸纳/释放的能量巨大，却很少被有效开发利用。湿气发电技术能够将周围环境中广泛存在的湿气收集起来，直接产生电能，这一全新的绿色能源收集技术，对于缓解全球日益严峻的能源短缺和环境污染具有重要的意义，有望在能源供给、物联网、柔性电子器件等领域展现出巨大的应用前景。然而，由于对湿气发电过程中的基本原理缺乏深入理解，在新型湿气发电材料的开发过程中缺乏理论指导与针对性设计，导致器件的输出性能普遍不高，无法满足电子设备的需求，且规模化制备与集成受到材料稳定性和加工方法的限制，实际应用场景非常受限。本论文基于界面调控的策略，对湿气发电技术中湿气-材料，材料-电极，器件-器件的多级界面进行优化与设计。通过实验、理论和模拟相结合的方式系统研究了湿气与材料相互作用过程中水分子吸附、官能团解离和离子传输等关键问题，提出了多梯度协同作用的湿气发电工作原理。通过构筑单元纳米化、材料复合、离子掺杂等形式开发了一系列具有高吸湿性、高离子电导率的湿气发电材料。提出了定向激光加工技术构建异质梯度材料的新方法，可以快速、高效地制备具有亲水性网络和内部含氧官能团异质分布的石墨烯基材料。首次引入界面调控的策略，在材料与电极界面上构建了肖特基势垒，有效实现了对带电离子迁移行为的调控，提升了内部异种电荷的分离效率。通过化学结构梯度和水含量梯度结合的方式，开发了非对称型湿气发电器件，实现了输出性能从交流到直流的转变，有效拓展了湿气发电的适用条件和应用场景。开发了可靠的大规模加工与集成技术，利用3D打印实现了湿气发电器件的批量化制备与集成，并系统研究了集成器件的输出性能，构建了一系列小型应用原型装置，初步实现了湿气发电技术在能源供给、柔性电子等领域的应用。本论文从湿气发电技术的基本原理、材料开发、器件设计和集成应用等四个层面进行了系统研究，加深了湿气产电工作原理的理解，为新型湿气发电材料的开发以及湿气发电技术从实验室走向工业应用奠定了坚实的基础，也为开发高效的新型能量转化技术开拓了新的思路。
Energy conversion technologies are vital to the development of modern society. Faced with the pressing energy shortages and environmental pollution, harvesting energy from the natural environment and converting it into electric energy has proven to be an effective strategy, sparking enormous research interest. Despite the fact that the amount of energy consumed and released during the hydrologic water cycle on Earth is extremely huge, but it is rarely exploited. Moisture-enabled electricity generation (MEG) is a novel and highly efficient green energy harvesting technology capable of extracting moisture from the ambient environment to directly generate electric energy, which is of great significance in alleviating serieously increasing energy shortages and environmental pollution, and promising in the fields of Internet of things, flexible electronic devices and a number of other fields. However, the poor understanding of the working principle, the low output performance and the lack of massive production of materials and devices severely restrict its practical applications.To improve the output performance of MEG devices, the moisture-material interfaces, material-electrode interfaces and device-device interfaces are routinely optimized based on interface-mediation strategies. The key questions during MEG process, including the moisture adsorption, dissociation of chemical groups and ions transport, have been systematically investigated by combining advanced characterizations, theory analysis and modeling simulations, and a new synergistic working mechanism for MEG has been proposed. By reducing building blocks, material composites and ionic doping, a series of functional materials with super moisture absorption and excellent ionic conductivity have been developed. The directional laser processing technology has been proposed a new method of constructing heterogeneous gradient materials, which can fabricate gradient graphene-related materials with excellent hydrophilicity in a highly efficient way. The interface-mediation strategy has been proposed in the MEG for the first time, and a Schottky barrier is built at the material/electrode interface, which can effectively regulate the migration of charged ions and enhance the efficiency of charge separation. Throught the combination of both chemical gradient and water gradient, a novel asymmetric MEG device is developed to realize the conversion of output electricity from AC to DC, significatly expanding the condtions and scenarios in which MEG technology can be employed. Furthermore, a reliable processing and integration method is developed to achieve a large-scale integration of MEG devices by 3D printing, and the output performance of integrated devices is systematically studied. Finally, a series of prototype devices are designed to demonstrate applications of MEG technologies in the areas of energy, flexible electronics and others.To summarize, the basic working principle, material development, device design, integration and application of MEG technology are systematically studied to in depth to gain a better understanding of the power generation process, which not only lays a solid foundation for MEG technology from the lab to real-world applications, but also opens up new ideas for the development of efficient energy conversion technologies.
