High-performance PANI-coated Ag2Se nanowire and PVDF thermoelectric composite film for flexible energy harvesting

Highlights: • PANI-coated Ag₂Se nanowires/PVDF composite films were fabricated with simple solution mixing and drop casting method. • Synthesized composite shows outstanding thermoelectric performance and durability after 1000 times of bending cycle. • The simple thermoelectric devices consisting of 6 strips of composite film were produced. • Resulting thermoelectric device shown enhanced output voltage, power and power density. -- Abstract: Herein, polyaniline-coated silver selenide nanowire/polyvinylidene fluoride (PANI-Ag₂Se/PVDF) composite are synthesized using simple approach and their application to flexible thermoelectric (TE) film are demonstrated. The TE power factor of PANI-Ag₂Se filler was analyzed with various coating cycle of PANI, which was considered by carrier transport properties. For the composite film with 65 wt% of NWs an optimized power factor of ~ 196.6 μW/m K² is obtained at 300 K. After bending for 1000 cycles, only ~ 8% of the initial power factor is decreased, exhibiting a flexibility. A 6-leg TE device assembled with the synthesized composite film, and this device generated ~ 15.4 mV and a maximum power of ~ 835.8 nW at a temperature difference (∆T) of ~ 30 K. Additionally, this flexible TE device displays a power density of ~ 2.33 W/m² at same ∆T. This study can guide the manufacturing of high-performance flexible TE composite films consisting of inorganic/organic hybrid materials.