Performance Research Of Vibration Energy Harvester Based On Graphene Aerogel And Its Composite Materials

Vibration energy harvester is a self-powered device,which has attracted more attention because of its ability to directly convert vibrational mechanical energy into electrical energy from the environment.However,most of the vibration energy collectors have poor output performance in low frequency environment,which hinders the application and development of vibration energy collectors.In this paper,as for the low-frequency vibration environment,a lowfrequency vibration energy harvester based on graphene aerogel was designed after analyzing the mechanism of graphene power generation,and its electrical properties and influencing factors were analyzed.Then,the graphene composite aerogel was synthesized through intercalation of MXene and CNT materials,which improved the output performance and cycle performance of the vibration energy harvester.After that,the applications of this device in the fields of seawater energy harvesting and human motion energy harvesting were discussed.The main research contents of the thesis are listed as follows:(1)A graphene aerogel was prepared by hydrothermal reduction method and freeze-drying method,and a low-frequency vibration energy harvester based on graphene aerogel was designed.When the vibration frequency is 0.2Hz and the amplitude is 3 mm,the output voltage is 165.7 m V in the 0.5 M sodium chloride electrolyte;at this point,when the load resistance is 200 ?,the output power density is 1.56 m W/g.In addition,the frequency,amplitude,electrolyte and other performance influencing factors of the vibration energy harvester were also analyzed in detail.(2)In order to improve the output performance of the vibration energy harvester,a MXene/graphene composite aerogel was synthesized,and a lowfrequency vibration energy harvester based on MXene/graphene composite aerogel was prepared.When the vibration frequency is 0.2 Hz and the amplitude is 3 mm,a output voltage of 227.5 m V was obtained using the 0.5 M sodium chloride electrolyte.Also,the output power density is 2.23 m W/g when the load resistance is 100 ? at this time.After analyzing the effect of MXene on the performance of graphene aerogel and its vibration energy harvester,the practical application of MXene in seawater energy harvesting was tested,and its application value in seawater energy harvesting was proved.(3)In order to improve the output performance and cycle performance of the vibration energy harvester at the same time,a CNT/graphene composite aerogel was synthesized and a low-frequency vibration energy harvester based on the CNT/graphene composite aerogel was prepared.When the vibration frequency is 0.2 Hz and the amplitude is 3 mm,a output voltage of 215.6 m V was obtained using the 0.5 M sodium chloride electrolyte.Also,the output power density is 2.12 m W/g when the load resistance is 150 ? at this time.In addition,after 10,000 cycles,the output voltage of 150 m V is still maintained.After analyzing the effect of CNT on the performance of graphene aerogel and its vibration energy harvester,the practical application of harvesting human movement energy was tested,which proved its potential value in human movement energy harvesting.