Methods for correctly characterizing the output performance of nanogenerators

Nanogenerators (NGs) based on triboelectric effect, piezoelectric effect, and pyroelectric effect have rapidly developed in applications of energy harvesting and self-powered sensing. However, a standard output performance characterization system for NG devices is still lacking, which greatly reduces the reference and inheritance of scientific research results, and hinders the development of NG technology. Owing to the mismatch of impedance between the instrument and NG devices, commercial instruments have serious measurement error of up to 77.3%, which causes some experimental phenomena violating the theories. In this work, the influencing factors of measurement error from traditional measurement methods are systematically analyzed through Multiphysics simulations and comparison experiments. Some methods to improve the accuracy are proposed, and a multi-functional and high-precision instrument is designed to improve the measurement accuracy from 22.7% to 64.7%. This discovery points out the shortcomings of the current characterization methods of NG performance, which has important guiding meaning for the development of measurement technology and theoretical research of NGs.