Abstract The highly efficient n-type Mg3Sb2-xBix thermoelectric materials hold great promise for application in power generation as well as refrigeration. Currently, n-type Mg3Sb2-xBix compounds with high zTs can be easily reproduced on a laboratory scale with ∼10 g per batch. However, scaling up the synthesis of Mg3Sb2-xBix with uniform high thermoelectric performance, which is critical for promoting this compound for practical applications, has yet to be achieved. Here we report a scalable preparation method based on Simoloyer ball-milling, which allows us to obtain over 1 kg Mg3.1Sb1.5Bi0.49Te0.01 powder in a single batch. Subsequently, samples with different diameters (ranging from a half inch to two inches) were successfully prepared and their thermoelectric performance was found to be comparable. In addition, a two-inch sample was sectioned into several parts, and the thermoelectric properties of the separate parts are also similar, indicating the high uniformity of the prepared large-scale sample. Importantly, the single-leg Mg3.1Sb1.5Bi0.49Te0.01 attains a high energy conversion efficiency of ∼12.9% under a temperature difference of ∼480 K at the hot-side temperature of 773 K. This study represents a step toward the practical application of Mg3Sb2-xBix for thermoelectric power generation.

中文翻译：

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用于热电应用的 n 型 Mg3Sb2-xBix 的可扩展合成

摘要 高效的n型Mg3Sb2-xBix热电材料在发电和制冷方面的应用前景广阔。目前，具有高 zT 的 n 型 Mg3Sb2-xBix 化合物可以在实验室规模上轻松复制，每批次约 10 g。然而，扩大具有均匀高热电性能的 Mg3Sb2-xBix 的合成尚未实现，这对于促进该化合物在实际应用中的应用至关重要。在这里，我们报告了一种基于 Simoloyer 球磨的可扩展制备方法，该方法使我们能够在单批中获得超过 1 kg 的 Mg3.1Sb1.5Bi0.49Te0.01 粉末。随后，成功制备了不同直径（范围从半英寸到两英寸）的样品，发现它们的热电性能相当。此外，一个两英寸的样品被分割成几个部分，各个部分的热电特性也相似，表明所制备的大尺寸样品具有较高的均匀性。重要的是，单腿 Mg3.1Sb1.5Bi0.49Te0.01 在 773 K 的热侧温度和约 480 K 的温差下实现了约 12.9% 的高能量转换效率。 Mg3Sb2-xBix 在热电发电中的实际应用。