AgSe Nanowire Fusion-Engineered Nylon Composite films: Boosting the Stability and Thermoelectric Efficiency in Flexible Power Generators.

Near-room-temperature flexible thermoelectric (TE) generators (f-TEGs) can help resolve the energy supply problem of wearable electronic devices during long-term use. Due to their promising TE performance, AgSe nanowires (NWs) are considered as credible candidates to fabricate flexible TE films and devices, but their "liquid-like" properties and loose connection between AgSe NWs leads to instability and low electrical conductivity. Herein, we report an interwoven network structure in a AgSe/nylon composite film via AgSe NWs fusion under hot-pressing to enhance the mechanical flexibility and TE performance stability. The optimal film exhibits an ultrahigh room temperature (RT) power factor (PF) of ∼1864 μWmK (average PF ∼ 2034 μWmK over 300-400 K) and excellent performance stability (a negligible PF difference during 14 repeated tests). After 5000 repeated bending operations, the film shows only a 4% increase in electrical resistance, indicating excellent mechanical flexibility. An assembled 5-leg f-TEG produces an open-circuit voltage () of ∼38 mV and a maximum output power of ∼6.7 μW at a temperature difference (Δ) of 60 K (corresponding power density ∼ 84 Wm). This work demonstrates that AgSe NW fusion is conducive to both TE performance stability and flexibility of AgSeNW-based flexible films and opens an avenue for applications in self-powered wearable electronic devices.