Combinatorial synthesis of Li-ion batteries has proven extremely powerful in screening complex compositional spaces for next-generation materials. To date, no Na-ion counterpart exists wherein Na-ion cathodes can be synthesized in such a way to be comparable to that obtained in bulk synthesis. Herein, we develop a synthesis route wherein hundreds of milligram-scale powder samples can be made in a total time of 3 days. We focus on materials in the Na–Fe–Mn–O pseudoternary system of high immediate interest. Using a sol–gel method, developed herein, yields both phase-pure combinatorial samples of Na_2/3Fe_1/2Mn_1/2O₂ and NaFe_1/2Mn_1/2O₂, consistent with previous reports on bulk samples of interest commercially. By contrast, the synthesis route used for Li-ion cathodes (namely coprecipitations) does not yield phase pure materials, suggesting that the sol–gel method is more effective in mixing the Na, Fe, and Mn than coprecipitation. This has important consequences for all attempts to make these materials, even in bulk. Finally, we demonstrate that these milligram-scale powder samples can be tested electrochemically in a combinatorial cell. The resulting cyclic voltammograms are in excellent agreement with those found on bulk samples in the literature. This demonstrates that the methodology developed here will be effective in characterizing the hundreds of samples needed to understand the complex ternary systems of interest and that such results will scale-up well to the gram and kilogram scale.

中文翻译：

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钠离子电池阴极高通量方法的开发。

事实证明，锂离子电池的组合合成在筛选下一代材料的复杂成分空间方面极为有效。迄今为止，不存在可以以与本体合成中获得的方式相当的方式合成Na-离子阴极的Na-离子对应物。在本文中，我们开发了一种合成路线，其中可以在3天的总时间内制作数百毫克级的粉末样品。我们专注于高度关注的Na–Fe–Mn–O伪三元体系中的材料。使用本文开发的溶胶-凝胶法，可得到Na _2/3 Fe _1/2 Mn _1/2 O ₂和NaFe _1/2 Mn _1/2 O ₂的纯相组合样品，与先前关于商业性批量样品的报告一致。相比之下，用于锂离子阴极的合成路线（即共沉淀）不能产生相纯的材料，这表明溶胶-凝胶法比共沉淀法更能有效地混合Na，Fe和Mn。这对所有尝试制造这些材料（甚至是批量生产）都具有重要的影响。最后，我们证明了这些毫克级粉末样品可以在组合电池中进行电化学测试。所得的循环伏安图与文献中大量样品上的循环伏安图非常一致。