Enhanced thermoelectric performance of W18O49/ZnO composite for waste heat recovery with induced high weighted mobility

• Published in: Journal of alloys and compounds 2024-08, Vol.997, p.174769, Article 174769
• Main Authors: Tran, Nhat Quang Minh, Ngoc Le, Quy Nguyen, Pham, Anh Tuan Thanh, Tran, Vinh Cao, Thi Lai, Hoa, Thi Ta, Hanh Kieu, Seetawan, Tosawat, Vora-ud, Athorn, Pecharapa, Wisanu, Nguyen Le, Thu Bao, Snyder, Gerald Jeffrey, Phan, Thang Bach
• Format: Article
• Language: English
• Subjects: Pisarenko relation; Thermopower factor; Weighted mobility μW; XW18O49/(1-x)ZnO composites; ZnWO4 secondary phase
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.174769

Zinc Oxide (ZnO) exhibits a significant Seebeck coefficient, making it a promising candidate for thermoelectric energy harvesting. This study explores composite materials comprising xW18O49/(1-x)ZnO fabricated through conventional sintering at 1150°C, with x varying from 0 to 0.3. Incorporating a highly conductive secondary phase into the ZnO matrix enhances conductivity by 28 times, reaching 111.4 Scm−1 at 800°C, while maintaining 83 % of the pristine sample's Seebeck coefficient. Notably, the power factor improves to 3.8 mWK−2m−1 for the x = 0.1 sample, representing a 19 times heightening over unmodified ZnO ceramic. Additionally, these composites exhibit high weight mobility, indicating rapid electronic responses. As a result, the ZT value increases by 500 %, reaching 0.15 at 800°C for the x = 1 sample. This study presents a novel approach to fabricating high-power-factor thermoelectric materials by integrating highly conductive oxides into matrices with large Seebeck coefficients. [Display omitted] •A composite xW18O49/(1-x)ZnO materials with variable x being 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3, respectively.•Multi-scale defects are induced in a composite xW18O49/(1-x)ZnO materials.•A conductive W18O49 oxide phase enhanced remarkably thermopower factor of ZnO composites.•Multi-scale defects controlled thermoelectric performances are addressed in terms of weighted mobility μW.