Design And Research Of Flexible Moisture Power Generation And Integrated Energy Storage Devices

Clean and sustainable energy harvest and conversion technologies will be the future development direction of the energy field and are of great significance to the sustainable development of human society.Moisture-enabled electricity generation（MEG）technology,that is,the direct generation of electrical energy by using the interaction between ambient moisture and functional materials,holds the promising potential to develop a huge amount of water vapor resources in the air to provide electricity for human society.Although the researchers are making progress in developing advanced materials and devices for MEG,however,the power generation mechanism is still unclear.Furthermore,designs for specific applications such as flexibility are still lacking,and energy storage and utilization will be the key point to the research and development of-MEG technology.Based on this,the thesis helps to advance the understanding of the MEG mechanism by studying the moisture absorption and ion migration behavior of polystyrene sulfonic acid and developing high-performance fiber-shaped MEG devices.Design and fabricating spatial-interleaving supercapacitor（SI-SC）,which realizes the combination of high capacity performance and mechanical flexibility.Moreover,developed an all-in-one flexible device that integrates MEG and an electrochemical capacitor,which can generate electricity from moisture in the ambient environment and store energy synchronously.It realizes 120 hours of ultralong moisture-induced energy storage in the atmospheric environment and provides electrical energy for a variety of electronic components.The main contents are summarized as follows:（1）By controlling the water diffusion direction inside polystyrene sulfonate acid fiber,we deeply promoted the understanding of water diffusion-ion migration behavior on moisture power generation and developed a high-performance fibershaped MEG device.In addition,a hydrogen ion fluorescent probe was introduced to the fiber.In the process of moisture-induced power generation,in-situ tracking of the hydrogen ions shows that the distribution and diffusion of hydrogen ions determine the output performance of the moisture power generator.With a 60%relative humidity difference,the device produced a stable voltage output of 1.25 V due to the maximized ion concentration gradient value.Afterward,large-scale integration of fiber-shaped moisture-induced electricity generators was achieved by laser processing and 3D printing technologies.（2）To improve the capacitance of the energy storage device,a spatialinterleaving configuration supercapacitor was fabricated.The internal graphene microelectrodes are stacked reversed layer by layer in three-dimensional space,realizing the combination of high energy density per unit area and mechanical flexibility.Because each microelectrode matches well with four counter microelectrodes and all 3D spatial-interleaving microelectrodes have narrow interspaces that maintain the efficient ions transport in the whole device,this SI-SC has a prominent liner capacitance increase along with the device thickness.Especially,the microelectrodes in each layer are interdigitated,ensuring the outstanding mechanical flexibility of SI-SC,with～98.7%performance retention after 104 cycles of bending tests.（3）An integrated device with a combination of MEG and energy storage devices using laser processing and screen printing techniques,which can absorb moisture to generate electrical energy and store it in the device,realizing the functions of spontaneous energy generation and ultra-long-term electrochemical energy storage.The all-in-one device can deliver a voltage duration of more than 120 h and an areal capacity of 138.27 mF cm^-2 as well as a power density of 49.38μW cm^-2.Meanwhile,the device shows excellent mechanical flexibility and can drive electronic devices such as electronic watches,temperature and humidity meters,and calculators in the bending/tiling state.