Jiang Meng, Zhang Qinghua, Zhang Siyuan, Liu Ming, Fu Yuntian, Zhang Zhiyuan, Ai Xin, Mortazavi Bohayra, Wang Lianjun, Zhang Qihao, Makarov Denys, Jiang Wan
State Key Laboratory of Advanced Fiber Materials, Institute of Functional Materials, College of Materials Science and Engineering, Donghua University, Shanghai, China.
Institute of Physics, RWTH Aachen University, Aachen, Germany.
Nat Commun. 2025 Aug 15;16(1):7592. doi: 10.1038/s41467-025-62660-7.
Thermoelectric materials offer an exceptional opportunity to convert waste heat into electricity directly, yet their widespread application remains hindered by intrinsic brittleness and poor processability. Here, we introduce a graded ball milling strategy that fundamentally enhances the mechanical robustness and processability of YbZnSb-based thermoelectrics. By refining grain microstructure, increasing dislocation density, and promoting intermediate-angle grain boundaries, this approach enables the fabrication of crack-free, large-size, disc-shaped, and microscale dices while maintaining excellent thermoelectric performance. Extending this strategy to a broader class of brittle Zintl compounds, including AZnSb, AMgSb, and ACdSb (A = Yb, Mg, Ca, Sr, Ba), we achieve a pre-formation cohesive energy of 9.1 eV atom and relatively low lattice thermal conductivity of 0.5 W m K in YbMgZnSb. Integrated with n-type MgNbSbBiTe, the thermoelectric module achieves a conversion efficiency exceeding 10% under a 458 K temperature gradient, operating for more than 40 hours steadily. This work establishes a scalable and versatile strategy for reconciling mechanical durability with high thermoelectric performance, paving the way for next-generation thermoelectric devices with enhanced reliability and industrial viability.
热电材料为将废热直接转化为电能提供了绝佳机会，但其广泛应用仍受到固有脆性和可加工性差的阻碍。在此，我们引入一种分级球磨策略，从根本上提高了基于YbZnSb的热电材料的机械强度和可加工性。通过细化晶粒微观结构、增加位错密度和促进中角晶界，这种方法能够制造出无裂纹、大尺寸、盘状和微米级切块，同时保持优异的热电性能。将该策略扩展到更广泛的脆性津特耳化合物类别，包括AZnSb、AMgSb和ACdSb（A = Yb、Mg、Ca、Sr、Ba），我们在YbMgZnSb中实现了9.1 eV/原子的预形成结合能和相对较低的0.5 W m⁻¹ K⁻¹的晶格热导率。与n型MgNbSbBiTe集成后，热电模块在458 K的温度梯度下实现了超过10%的转换效率，并稳定运行超过40小时。这项工作建立了一种可扩展且通用的策略，以协调机械耐久性与高热电性能，为具有更高可靠性和工业可行性的下一代热电设备铺平了道路。
