Ying Pingjun, Reith Heiko, Nielsch Kornelius, He Ran
Leibniz Institute for Solid State and Materials Research, 01069, Dresden, Germany.
Institute of Applied Physics, Technical University of Dresden, 01062, Dresden, Germany.
Small. 2022 Jun;18(24):e2201183. doi: 10.1002/smll.202201183. Epub 2022 Apr 28.
Solid-state thermoelectric (TE) technology is a promising approach to harvest low-grade waste heat (<573 K) and converts it to useful electricity in industrial and civilian settings. After decades of efforts in improving the figure-of-merit (zT) of TE materials, the development of advanced modules has started springing up in recent years. Although high-performance modules have been largely reported based on the successful material improvement, it remains less investigated how and whether the module-level designs can further increase the conversion efficiency. Herein, following the recent demonstration of a tellurium (Te)-free TE generator, an increase is demonstrated in the efficiency by reducing both the electrical and thermal energy losses through simply optimizing geometric factors of filling factor and leg-pair numbers. These module-level optimizations enable a record conversion efficiency of 8.2% under a ∆T ≈ 260 K, thus fulfilling 90% of the theoretical efficiency of the materials and solidly exceeding the Bi Te modules. Furthermore, module robustness against > 10 160 thermal cycles while preserving a relative efficiency of 95% is demonstrated. These findings highlight the importance of the optimization strategy at the module level and demonstrate the feasibility of using Te-free thermoelectric compounds to harvest the omnipresent low-grade heat.
固态热电（TE）技术是一种很有前景的方法，可用于收集低品位废热（<573 K）并将其转化为工业和民用环境中的可用电力。在经过数十年努力提高TE材料的品质因数（zT）之后，近年来先进模块的开发开始蓬勃兴起。尽管基于成功的材料改进已大量报道了高性能模块，但模块级设计如何以及是否能进一步提高转换效率仍较少受到研究。在此，继最近展示了一种无碲TE发电机之后，通过简单优化填充因子和腿对数等几何因素来降低电能和热能损失，效率得到了提高。这些模块级优化在ΔT≈260 K的情况下实现了8.2%的创纪录转换效率，从而达到了材料理论效率的90%，并切实超过了Bi Te模块。此外，还展示了模块在超过10160次热循环时的稳健性，同时保持了95%的相对效率。这些发现突出了模块级优化策略的重要性，并证明了使用无碲热电化合物收集无处不在的低品位热量的可行性。
