Intrinsically Self-Healable and Wearable All-Organic Thermoelectric Composite with High Electrical Conductivity for Heat Harvesting.

ABSTRACT

The development of wearable electronics has led to the growing demand for the self-powered and maintenance-free power sources. Under these circumstances, thermoelectric generators are considered promising candidates, which can directly convert body heat into electricity to power wearable electronics. However, most of the thermoelectric materials are either brittle or unrecoverable under external physical damage. It is urgent to develop thermoelectric materials that possess both stretchability and intrinsic self-healing property, and the remaining challenge is to combine the high mechanical robustness and excellent electrical conductivity. Herein, a self-healing and wearable all-organic thermoelectric composite is reported. The composite film exhibits high electrical conductivity of 238 S cm-1, high flexibility of up to 119% strain, and a maximum tensile strength of 23 MPa. When the composite film is subjected to external physical damage, most functionalities can be maintained after self-healing, 78% recovery in electrical conductivity, and 80% recovery in tensile strength. Using the self-healing composite, we fabricated a thermoelectric generator with a power output of 85.5 nW at a temperature difference of 48 K, which is a significant advance over the recently reported thermoelectric generators based on intrinsic self-healing thermoelectric materials. This work represents a crucial step toward achieving intrinsic self-healing all-organic thermoelectric materials with high electrical conductivity.