Construction And Properties Of BaTiO₃ Based Piezoelectric Nanogenerators

With the progress of human civilization and the rapid development of science and technology,more and more portable microelectronic devices have become the mainstream.The energy of these devices has become a popular study.Harvesting energy from the environment and biomechanical motion is an attractive alternative to traditional rechargeable batteries to provide power to low-energy portable devices.Piezoelectric nanogenerators（PENGs）using the piezoelectric effect are important devices for the development of new energy sources and the collection and utilization of mechanical energy.The performance enhancement of PENGs and the development of ultra-tough PENGs are currently the main research hotspots.The specific research content is as follows:Barium titanate（BaTiO₃）nanofiber membranes were prepared based on electrospinning technology and calcination process,and doped with CNTs by a simple physical soaking method.Analyzed the morphology and crystal form of BaTiO₃nanofibers by scanning electron microscopy（FE-SEM）,thermogravimetric test（TG）,Raman spectrometer test（Raman）and X-ray diffraction test（XRD）,and discusses the effect of adding different CNT content on the performance of PENGs.The results showed that the comprehensive performance of BaTiO₃-based PENGs doped with CNT content of 3 wt%is the best.The output voltage and current are as high as 21 V and 2.6μA,which is 4 times better than pure BaTiO₃-based PENGs.Vertically arranged antimony tin oxide-barium titanate composite nanofiber membranes were prepared based on electrospinning technology and calcination process.Antimony tin oxide（ATO）and barium titanate（BaTiO₃）materials have similar spinning and calcination processes.Conductive-piezoelectric composite nanofibers were successfully prepared in one step.Among them,the aligned nanofibers were made by rapid rotation of the collecting roller.Similarly,the morphology,crystal form and uniformity of composite nanofibers were analyzed by the relevant test and characterization methods in the previous chapter,and the properties of PENGs with different ATO contents were discussed.When the ATO content is 12 wt%,the maximum output voltage of PENGs at 0.005 MPa is 16.8 V,the maximum output current is 2.5μA,and the maximum output power is 26.1 m W/m².The prepared PENGs can be directly used as an electromechanical conversion device for human tiny mechanical energy,and can directly light up 9 LED lights without any rectification device.Electric energy can be directly generated by bending the fingers and stepping on the foot.Due to various potential applications ranging from the human Internet to wearable electronic devices and soft robots,stretchable electronic devices have received great attention.Electronic devices that have stretchability in response to high strains are a frequent demand for realizing this technology.Polyethylene glycol（PEG）and polycaprolactone（PCL）molecular chains were prepared as covalent cross-links and 2-amino-4-hydroxy-6-methylpyrimidine（UPy）units as supramolecular bonds composed of tough Polymer supramolecular network.At the optimal UPy loading of 20 wt%,the resulting polymers showed the highest toughness(25.2 MJm^-3).The UPy unit has the ability to effectively absorb ultraviolet rays and convert it into heat energy,which can promote the activation of the hydrogen bond broken by the UPy unit and then reshape the polymer to have photoremediation properties.A layer of graphite is coated with polymer as a carrier to prepare nano generator electrodes.The electrode perfectly inherits the high toughness and self-healing properties of the carrier,the resistance changeΔR/R0 is always less than 1 when the tensile strain is as high as 50%,and it has excellent resistance recovery ability and repeatability.