Metal-free And Non-fluorine Paper-based Generator

With the rapid growth of flexible electronics, flexible power generally is achieving the concern of the industry. However, most of the power sources on the market are block button batteries or lithium batteries, which are not suitable to bridge full flexible electronic systems. In addition, the existence of potential hazards such as explosion restrains broader applications for batteries that are often restricted in the air shipment. Therefore, researchers is expecting to seek a fully flexible power source or generator, which can directly drive flexible electronic products such as miniature portable/wearable electronics or smart packaging, and simultaneously remain green and safe. The paper as a traditional carrier of message transmission has many advantages including cheap, lightweight, biodegradable and recyclable features, by virtue of which, the paper has aroused widespread concern in some areas, like flexible electronic paper, transistors, touchpad and smart packaging display. Thus, the paper-based generators is desirable to develop as an alternative or supplement of the external power and expand the use of paper-based electronics. Herein, we introduce a metalfree, non-fluorine and environmentally friendly paper-based generator, which can collect energy from the surrounding environment and convert it into electrical energy. The main research contents and results are as follows:1. By the virtue of carbon nanotubes with corrosion resistance, impact resistance and good electric/ thermal conductivity, we chose carbon nanotubes as conductive material, and fabricated a carbon nanotube conductive layer through scraping coating method, then tested its tensile properties and stability. Experimental results clearly revealed that the sheet resistance of the carbon nanotube layer could remain around 154.9 ?/? under different bending conditions, showing good tensile properties. In addition, the carbon nanotube layer conductivity in the original state coinciding with that after 1000 cycles indicates the carbon nanotubes conductive layer has good stability. On the other hand, the use of carbon nanotubes to replace metal as the conductive layer can avoid the effect of metal recycling.2. Based on the consideration of fluorine-contained influence to environment, we choose polypropylene electret as the functional material which can retain residual charge for a long time. Through the experimental contrast, we found that the generator performance using cellular polypropylene has more than doubled output that using ordinary polypropylene. Thus, in this paper we select cellular polypropylene. The study clearly shows the surface potential of the cellular polypropylene can be maintained around-620 V over a longer period of natural attenuation after polarization by negative corona polarization.3. Based on the principle of electrostatic induction, we have designed a novel V-shape metal-free and non-fluorine paper-based generator. The paper-based generator is composed of commercial photopaper substrate, carbon nanotube electrodes and cellular polypropylene electret. For further studying the mechanism of the V-shape generator, we build a model similar to the real V-shape structure, and then a basic equation for the V-shape generator could be derived. The solution could be given via a numerical calculation method. Then the relationships between the output load peak current versus frequencies, as well as the optimum load resistance versus frequencies for the generator were derived. All the above studies propose a way to quantifiably analyze the output performance of the V-shape metalfree non-fluorine paper-based generator.4. In the practical test, we find that the experimental results clearly verify the reliability of the assumption model. That is, under external force, the distance between two layers of a V-shape generator changes, forming a charge separation and the potential difference, and driving electronics flowing in the external circuit. For a V-shape metal-free and non-fluorine paper-based generator, a maximum load peak power was up to 646.4 ?W at 25 Hz in the experiment. In addition, after 72,000 cycles continuous working, the generator remains the integrated morphology and output performances, which indicates the generator has excellent stability and durability. At the same time, it's demonstrated that the V-shaped metal-free non-fluorine paper-based generator stimulated by human motion could drive a commercial liquid crystal display, showing its potential application in smart package.5. To further enhance the area output, a multiple-fold metal-free and non-fluorine paper-based generator was also fabricated. The load peak current with ~3.85 ?A of the threefold generator has 2.2 times of the single-fold generator output current with ~1.75 ?A. On the other hand, the transferred charges of the three-fold generator(28.71 n C) is 2.75 times of the single-fold generator transferred charges. The solid results reveal that multi-foldable structure could enhance the output energy, and simultaneously, save space and materials for generators.