Boosting the Output of Liquid-Solid Triboelectric Nanogenerator by an External Charge-Pumping Strategy

In recent years, liquid-solid triboelectric nanogenerator (LSTENG) has attracted great attention. However, its low average power density and long charging time limit the practical application of this technique. Here, for the first time, a liquid-solid triboelectric nanogenerator combined with external charge-pumping method (ECP-LSTENG) is proposed. Compared to traditional LSTENGs, a charge storage capacitor is added in this ECP-LSTENG to store the output charges from the pumping generator. Then, a charge extraction capacitor is formed by the spreading and shrinking processes of falling droplet, while the charging and discharging process between charge storage and extraction capacitors can generate displacement current output for external circuit. Meanwhile, it is found that a special charged droplets adhesion phenomenon happens at the liquid-solid interface, which seriously hinders the continuous output of ECP-LSTENG. To overcome this limitation, a special coaxial deceleration commutation component is designed to ensure continuous output of the ECP-LSTENG. Finally, the peak power density of a droplet (50 mu L) reaches 231.8 W m-2, surpassing the highest research record to date by 1.43 times. This ECP-LSTENG provides a different approach for the future development of large-scale integrated raindrop generators for efficient raindrop energy harvesting. Combining a liquid-solid triboelectric nanogenerator (LSTENG) with external charge-pumping (ECP), an ECP-LSTENG is proposed to harvest water droplet energy efficiently. By using charge storage and extraction capacitors, the output of LSTENG can be enhanced greatly, and a special deceleration commutation component is designed to ensure continuous output. This approach paves new way for effectively harvesting raindrop energy in large scale.image