Composite Based Piezoelectric Nanogenerator And Triboelectric Nanogenerator

With the rapid development of digital information technology and network technology,various types of mobile and portable electronics has been widely used in people's daily life and plays a more and more important role,in order to work for a longer time,demand of portable power supply is becoming more and more urgent.Furthermore,the miniaturization of devices is a trend,micro-nano devices have been used in many fields,playing an increasingly important role.The traditional chemical battery energy,there is a large volume,heavy weight,often recharge,heavy metal will cause serious environmental pollution and other issues,it is hard to match size of micro-nano devices.Looking for the environmentally friendly power supply and the miniaturization of portable power supply are more and more important,the piezoelectric nanogenerators and triboelectric nanogenerators can capture various forms of mechanical energy in the work environment and transform into electrical energy,this is a practical and effective solution.This thesis mainly consists of the following three parts of work:As a traditional piezoelectric material,BaTiO₃ has drawn significant attentions due to its strong piezoelectric and environmentally friendly properties.We prepare polycrystalline tetragonal perovskite structure BaTiO₃ nanofibers by sol-gel method and electrostatic spinning method,studied the effects of the sintering temperature and PVP content in the precursors on BaTi O3 nanofibers structure and morphology.We fabricate a type of flexible piezoelectric nanogenerator based on single BaTiO₃ nanofiber,and test the output performance of the nanogenertor drived by a linear motor,its short circuit current and open circuit voltage up to 1.33 nA and 0.214 V respectively.it showed that as-prepared BaTi O3 nanofibers by sol-gel method and electrostatic spinning method has excellent piezoelectric properties,and with the increase of strain and strain rate,the output performance of devices has significantly enhancement.We synthesize ultra-long BaTiO₃ nanowires via a simple hydrothermal method.The as-prepared BaTiO₃ nanowires show good crystallinity with tetragonal phase.Utilizing BaTiO₃ nanowires and PDMS,we fabricate a type of high performance flexible piezoelectric nanogenerator to effectively harvest mechanical energy.This flexible naogenerator could generate a maximum current up to 50 ?A,which is larger than that of the previous reported lead free flexible nanogenerators.The output electricity can be directly used to instantaneously lighten a commercial light-emitting diode?LED?without the energy storage process.We designed a multi-layer composite structure as the positive friction layer,it is composed of charge collection sublayer?CCL?,charge transport sublayer?CTL?,charge storage and barrier sublayer?CSBL?in turn from surface to the electrode.This composite structure design increases the charge density by a factor of 3.7 for the triboelectric nanogenerator's positive friction layer.When this multi-layer composite structure is applied in both the negative and the positive friction layer of triboelectric nanogenerator,the charge density can be raised by a factor of 16.5.