Electrospun liquid metal/PVDF-HFP nanofiber membranes with exceptional triboelectric performance

Flexible triboelectric nanogenerators (TENGs) are sustainable energy sources to power a diverse range of intelligent sensing and monitoring devices and poly(vinylidene fluoride) (PVDF) is a common polymer incorporated in TENGs. To further enhance the electrical outputs of PVDF based TENGs, herein we present a technique for introducing liquid metal (LM) Galinstan nanodroplets into electrospun PVDF-co-hexafluoropropylene (PVDF-HFP) nanofibers to enhance their triboelectric performance. Using the PVDF-HFP/2%LM nanofiber membrane as the negative tribo-layer and thermoplastic polyurethane as the positive tribo-layer, the peak open-circuit voltage and power density of the resultant TENG reached 1680 V and 24 W/m2, respectively, which are significantly higher than previous state-of-art values of existing PVDF based TENGs. This outstanding performance is attributed to multiple factors, including the improved surface potential, capacitance, charge trapping capability, and the secondary polarization inside PVDF-HFP nanofiber by the introduced LM nanodroplets. With the mechanical properties of PVDF-HFP nanofiber membranes weakened slightly after the increase of the LM content, the PVDF-HFP incorporating 2% LM showed the highest multifunctionality efficiency of mechanical performance and electrical generation. The LM modified PVDF-HFP nanofiber membranes can be promising materials in high performance TENGs as the negative tribo-layer.