Thermally Self-Healing Silver Nanowires–Diels–Alder Polyurethane Composite Films for Flexible Transparent Conductive Electrodes

Flexible transparent conductive electrodes (FTCEs) with thermal self-healing capabilities are essential for developing durable and sustainable electronic devices. However, simultaneously optimizing optical transparency, electrical conductivity, mechanical flexibility, and efficient self-healing performance remains a significant challenge. Herein, we report a thermally self-healing silver nanowire (AgNWs)-Diels–Alder polyurethane (DAPU) composite film fabricated via a tailored transfer method, which preserves the integrity of preformed AgNWs networks. The composite film integrates high optical transparency (>80% at 550 nm for 4-layer AgNWs), low sheet resistance (∼2.6 Ω·sq –1 ), and efficient self-healing capability under mild thermal treatment (130 °C for 15 min followed by 60 °C for 12 h). The multicycle thermal self-healing efficiency exhibits a strong dependence on the initial AgNWs layer number, with an increased number of layers leading to a denser network. Such a dense network can continuously maintain the reconstruction of conductive pathways during repeated cycles of damage and healing. The thermal self-healing mechanism relies on the synergy between Diels–Alder (DA) bond cleavage/reformation and AgNWs repositioning, enabling the simultaneous restoration of mechanical integrity and electrical conductivity. Practical feasibility is demonstrated through a self-healing LED circuit and a flexible heater. This work provides reference for durable, sustainable FTCEs, providing a feasible solution for flexible optoelectronic devices requiring multiple short-term self-healing cycles (≤3 cycles).