Tunable polarity reversal phenomenon at the initial working state of triboelectric nanogenerator

Triboelectric nanogenerator (TENG) is a new energy collecting technology based on the basic principles of electrostatic induction and contact electrification (CE). In general, TENGs can be affected by residual surface charges in their initial state during continuous operation and the polarity reversal phenomenon can occur from time to time, which is a negative effect related to the sensory functions of TENG. In this work, by using electrospinning techniques, the PVA and PAN nanofiber films have been attached on different electrification materials and the polarity reversal phenomenon of TENG can be regulated by changing the thickness of the nanofiber layer. Based on Wang transition model, this tunable polarity reversal phenomenon can be explained on the basis of electrification capability and regional mosaic effect of surface functional group. At the same time, a series of additional experiments have been done to isolate the contribution of electron transfer to polarity reversal from other possible influences, such as materials transfer, while specific methods for avoiding this phenomenon are also put forward on the basis of theoretical analysis. Weakening or eliminating the negative effects of TENG during different operating conditions can provide some assurance for device stability under long-term operation.