Performance of all-solution-processed, durable 2D MoS2 flakes−BaTiO3 nanoparticles in polyvinylidene fluoride matrix nanogenerator devices using N-methyl-2-pyrrolidone polar solvent

Abstract

Piezoelectric nanogenerator (PENG) is an alternative sustainable solution by transforming surrounding mechanical energy into electrical power. In this work, the optically transparent and mechanically flexible PENG devices were fabricated using simple all-solution-processed techniques. The device was constructed using spin- and spray coating methods to form the structure of silver nanowires/nanocomposite/poly (3,4-ethylenedioxythiophene) polystyrene sulfonate. The nanocomposite is a blending of barium titanite nanoparticles and molybdenum disulfide flakes in the polyvinylidene fluoride matrix. PENG devices were prepared with dimethylformamide (DMF) and N-Methyl-2-pyrrolidone (NMP) solvents, respectively to examine the influence of the solvents towards the output voltage. It is found that the PENG device prepared with the NMP solvent generated a voltage of 750 mV, significantly higher output voltage than the PENG device prepared by DMF, which is about 100 mV. The probable reasons could be the higher dipole moment of NMP solvent, interaction, and intercalation of MoS2 flakes in the PVDF polymer chain matrix. An automated self-tapping machine was designed to perform the endurance study. The device was able to generate stable 1.5 V of peak-to-peak voltage up to 5000 cycles in a total 5-day intermittent test without significant degradation. The PENG device prepared in the NMP solvent maintained at least 95% of its 1.5 V throughout the whole testing cycle.