The Nanogenerator Based On Electric Double Layer In Liquid

At present,China’s fossil energy-based energy consumption structure has not changed,and the proportion of renewable energy is still very low.The resulting energy shortage and environmental pollution are becoming more and more serious.We urgently need to accelerate the development of clean renewable energy.Wave energy is a renewable energy in the ocean and considered to be a highly competitive but largely underutilized,green and non-polluting source of energy.Triboelectric Nanogenerators is an emerging way of using wave energy,which can convert mechanical energy in the environment into electrical energy by using the triboelectric effect.However,current marine energy conversion equipment based on Triboelectric Nanogenerators needs to adopt a full package structure to avoid the influence of humidity on its output,which limits the application of Triboelectric Nanogenerators in the development of ocean energy to some extent.In this thesis,a new Nanogenerator based on liquid electric double layer was prepared,which is not affected by the environmental humidity and can realize the open underwater work.The Nanogenerator based on liquid electric double layer structure includes upper and lower parts.The upper part is a PDMS dielectric layer with a micro-nano structure on the surface,prepared by plasma etching and template transfer method.The lower part is the PET dielectric layer,which is chemically modified to carry carboxyl functional groups on the surface.Magnetron sputtering is used to deposit uniform Ag on the upper and lower materials as electrodes.The prepared electrode layer and dielectric layer are fixedly packaged on the acrylic plate substrate,and the electrode layer is led out through the enameled copper wire to obtain a Nanogenerator based on liquid electric double layer.Here,the periodic contact of the Nanogenerator is drived by the exciter to simulate the driving effect of the sea wave in reality,and explore the working principle and output characteristics of the generator.The experimental results show that the generator can achieve an open circuit voltage of 10 V and short circuit current of 1.9 μA.In addition,we also studied the effect of surface charge and ion concentration on the electrical output of the generator.By changing the functional group density on the surface of the dielectric layer and selecting different concentrations of solution,the energy output of the generator can be effectively improved.Through the method of numerical simulation,the working mechanism of the Nanogenerator is studied.By establishing a two-dimensional model based on the Nanogenerator based on electric double layer in liquid and using the finite element method to solve the simultaneous Poisson and Nernst-Planck equations,the space potential change and charge distribution of the generator during a working cycle are obtained.The simulation results show that the asymmetric charged system will produce asymmetric potential distribution.The reason for the potential difference is that the surface electric double layer is destroyed and reformed during the approach-separation of the upper and lower parts,thereby inducing a net surface charge in the dielectric.The efect of generating a net charge is related to external forces,material properties,working liquid ion concentration,and pH.This emerging Nanogenerator is different from the existing triboelectric power generation principle,which can convert the kinetic energy of the liquid double charge layer driven by the external driving force into electrical energy and output it to the external circuit.The design provides new inspiration for the application of ocean wave energy.