Enhancing the Seebeck Coefficient and Power Factor of PEDOT:PSS Thermoelectric Films through MXene Incorporation and Post-Treatment

Combining the conductive polymer of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with two-dimensional nanomaterials is an effective approach to develop a thermoelectric composite film and generator. Herein, we exfoliated n-type few-layer MXene nanosheets and explored the effect of the MXene content on the thermoelectric properties of the composite films prepared by vacuum-assisted filtration. When the MXene content reaches 6 wt %, the Seebeck coefficient improves to 28.5 μV/K with an increase ratio of 43.9%. Additionally, a solvent post-treatment method was employed to address the reduced electrical conductivity of the composite film caused by the MXene incorporation. The power factor of the PEDOT:PSS/6 wt % Ti₃C₂T_x composite film could be enhanced from 30.1 to 41.3 μW/m K² after post-treatment with a dimethyl sulfoxide (DMSO) solvent at 333 K. A six-leg generator fabricated from the DMSO-treated composite film achieves an open-circuit voltage of 2.56 mV and a power density of 42.6 μW/cm² under a temperature difference of 30 K. The results reveal the synergy of hybrid and post-treatment and demonstrate that the composite film of PEDOT:PSS/MXene has great potential in wearable thermoelectric fields.