Liquid-free ionic conductive elastomers with high mechanical properties and ionic conductivity for multifunctional sensors and triboelectric nanogenerators

Liquid-free ionic conductive elastomers (ICEs) are ideal materials for constructing flexible electronic devices by avoiding the limitations of liquid components. However, developing all-solid-state ionic conductors with high mechanical strength, high ionic conductivity, excellent healing, and recyclability remains a great challenge. Herein, a series of liquid-free polyurethane-based ICEs with a double dynamic crosslinked structure are reported. As a result of interactions between multiple dynamic bonds (multi-level hydrogen bonds, disulfide bonds, and dynamic D-A bonds) and lithium-oxygen bonds, the optimal ICE exhibited a high mechanical strength (1.18 MPa), excellent ionic conductivity (0.14 mS cm^-1), desirable healing capacity (healing efficiency >95%), and recyclability. A multi-functional wearable sensor based on the novel ICE enabled real-time and rapid detection of various human activities and enabled recognizing writing signals and encrypted information transmission. A triboelectric nanogenerator based on the novel ICE exhibited an excellent open-circuit voltage of 464 V, a short-circuit current of 16 μA, a transferred charge of 50 nC, and a power density of 720 mW m^-2, enabling powering of small-scale electronic products. This study provides a feasible strategy for designing flexible sensor products and healing, self-powered devices, with promising prospects for application in soft ionic electronics.