The rapid expansion of self-powered wearable electronics has intensified the demand for thermoelectric materials that integrate mechanical flexibility, scalable solution processability, and high thermoelectric performance. Herein, we report ionic additive engineering as an effective strategy to enhance the thermoelectric performance of a water-processable single-walled carbon nanotube and carboxymethyl cellulose (SWCNT/CMC) composite. The introduction of either ionic additive, 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA) or sodium dicyanamide (Na DCA), improves network connectivity and structural ordering of SWCNTs, thereby increasing electrical conductivity. Notably, unlike Na DCA, EMIM DCA modulates the electronic structure of SWCNTs and induces pronounced counter-ion exchange through ionic interactions with CMC, resulting in a substantial increase in the Seebeck coefficient and an over eightfold improvement in the power factor compared to pristine films. Finally, water-processed thermoelectric generators fabricated using EMIM DCA-added films exhibit reliable output characteristics with excellent air stability, demonstrating the practical viability of our thermoelectric composite system.
Yeom et al. (Wed,) studied this question.