Robustly Enhanced Seebeck Coefficient in the MXene/Organics/TiS₂ Misfit Structure for Flexible Thermoelectrics

Theflexible thermoelectric (TE) generator has emerged as a superioralternative to traditional batteries for powering wearable electronicdevices, as it can efficiently convert skin heat into electricitywithout any safety concerns. MXene, a highly researched two-dimensionalmaterial, is known for its exceptional flexibility, hydrophilicity,metallic conductivity, and processability, among other properties,making it a versatile material for a wide range of applications, includingsupercapacitors, electromagnetic shielding, and sensors. However,the low intrinsic Seebeck coefficient of MXene due to its metallicconducting nature poses a significant challenge to its TE application.Therefore, improving the Seebeck coefficient remains a primary concern.In this regard, a flexible MXene/organics/TiS2 misfit filmwas synthesized in this work through organic intercalation, exfoliation,and re-assembly techniques. The absolute value of Seebeck coefficientof the misfit film was significantly enhanced to 44.8 & mu;V K-1, which is five times higher than that of the originalMXene film. This enhancement is attributed primarily to the weightedeffect of the Seebeck coefficient and possibly to energy-filteringeffects at the heterogeneous interfaces. Additionally, the power factorof the misfit film was considerably improved to 77.2 & mu;W m(-1) K-2, which is 18 times higher thanthat of the original MXene film. The maximum output power of the TEdevice constructed of the misfit film was 95 nW at a temperature differenceof 40 K, resulting in a power density of 1.18 W m(-2), demonstrating the significant potential of this technology fordriving low-energy consumption wearable electronics.