Stretchable, Self-Healing, Temperature-Tolerant, Multiple Dynamic Interaction-Enabled Conductive Biomass Eutectogels for Energy Harvesting and Self-Powered Sensing

Abstract

Eutectogels made of deep eutectic solvents (DESs) are promising as key components in flexible triboelectric nanogenerators (TENGs) owing to their ionic conductivity, stretchability and bio-friendliness. However, integrating various advantages into one material remains a major challenge, such as high ionic conductivity, superior mechanical properties, good self-healing capacity, excellent temperature tolerance, and high output power. Here, a multiple dynamic hydrogen bond interaction strategy is proposed to prepare multifunctional biomass eutectogels composed of itaconic acid/ChCl DESs (IA-DESs) and lactic acid/ChCl DESs (LA-DESs). The introduction of LA-DESs can provide multiple hydrogen bond interactions for eutectogels and sufficient mobile charges derived from dissociated cations and anions, thereby improving mechanical property and ionic conductivity of eutectogels. Furthermore, the interactions also endow the biomass eutectogels with good self-healing property, excellent temperature tolerance, and strong interfacial adsorption. By integrating triboelectric materials, a novel biomass eutectogel-based TENG (BE-TENG) is successfully fabricated, which achieved a record-high maximum peak power density of 2.4 W m^-2 in the eutectogel-based TENGs. Moreover, BE-TENG can deliver stable electrical outputs even in a stretching state, under wide temperature environments of −20 and 100 °C, and after self-healing. The BE-TENG also demonstrates efficient powering capability for portable electronics and self-powered sensing for human motions. This work will offer novel strategies to design high-performance eutectogel materials for wearable electronics.