Scalable and environmentally friendly MXene-tetrahedrites for next-generation flexible thermoelectrics

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2025-01, Vol.13 (1), p.654-668
• Main Authors: Banerjee, Priyanshu, Huang, Jiyuan, Lombardo, Jacob, Ambade, Swapnil B, Ambade, Rohan B, Han, Tae Hee, Kulkarni, Srushti, Sengupta, Shreyasi, Rosenzweig, Zeev, Fairbrother, Howard, Li, Sichao, Shin, Sunmi, Madan, Deepa
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Bismuth tellurides; Body temperature; Bulk density; Decoupling; Electrical conductivity; Electrical resistivity; Energy harvesting; Fabrication; High temperature; Manufacturing; MXenes; Nanosheets; Rare earth elements; Room temperature; Seebeck effect; Sustainable materials; Thermal conductivity; Thermoelectric generators; Thermoelectric materials
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta05056h

Traditional thermoelectric generators (TEGs) face scalability challenges due to high-temperature, long-duration curing processes and rare-earth/toxic chalcogenides such as bismuth telluride. Additive manufacturing has been investigated as a more time-, energy- and cost-efficient method that offers greater flexibility than traditional manufacturing techniques. Additionally, tetrahedrites are promising thermoelectric materials in high-temperature applications because they are non-toxic and earth-abundant. Herein, this work demonstrates the fabrication of scalable and sustainable Cu 12 Sb 4 S 13 (CAS) based composite films and flexible TEG devices (f-TEGs) with 2D MXene nanosheets using a low-thermal budget additive manufacturing approach for room temperature applications. 2D MXene nanosheets introduced energy-barrier scattering and nanoscale features to effectively increase the room-temperature ZT to 0.22, 10% higher than bulk CAS, by decoupling electrical conductivity, Seebeck coefficient, and thermal conductivity. CAS and 2D MXenes were found to be environmentally safe through a bacterial viability study. The process is used to create a 5-leg f-TEG device producing a power of 5.3 μW and a power density of 140 μW cm −2 at a Δ T of 25 K. Therefore, this work demonstrates that combining scalable and sustainable materials and methods is an effective strategy for high-performance room-temperature f-TEGs that could potentially harvest the low waste heat energy of the human body. Traditional thermoelectric generators (TEGs) face scalability challenges due to high-temperature, long-duration curing processes and rare-earth/toxic chalcogenides such as bismuth telluride.