Abstract In this work, we demonstrate the advantage of introducing extrinsic pseudocapacitance behavior in the active material for designing low-cost, high energy, and power density sodium-ion full cells. Here, tin and antimony based alloy nanopowder is synthesized via microwave assisted hydrothermal process (MAHP) for use as a negative electrode. Ex-situ x-ray diffraction studies reveal that the alloy nanopowder stores Na+ via a diffusion-controlled alloying mechanism. Extrinsic pseudocapacitance behavior is subsequently introduced by sandwiching the alloy nanopowder between nitrogen doped reduced graphene oxide nanosheets via MAHP. When coupled with a diffusion-controlled positive electrode comprising of an iron-based prussian blue analog, the resulting full cell demonstrates a high energy density of 262.5 Wh kg−1 at 1C rate with 85.7% capacity retention at the end of 100 cycles. Detailed cyclic voltammetry and electrochemical impedance studies provide insight into the effect of extrinsic pseudocapacitance in improving the electrochemical performance of the full cell.

中文翻译：

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设计低成本、环保、高能量和功率密度钠离子全电池的策略：外在赝电容的影响

摘要 在这项工作中，我们展示了在活性材料中引入外在赝电容行为以设计低成本、高能量和功率密度的钠离子全电池的优势。在这里，锡和锑基合金纳米粉末是通过微波辅助水热法 (MAHP) 合成的，用作负极。异位 X 射线衍射研究表明，合金纳米粉末通过扩散控制的合金化机制存储 Na+。随后通过 MAHP 将合金纳米粉末夹在氮掺杂的还原氧化石墨烯纳米片之间来引入外在赝电容行为。当与由铁基普鲁士蓝类似物组成的扩散控制正极结合时，所得全电池在 1C 倍率下表现出 262.5 Wh kg-1 的高能量密度，85。100 次循环结束时容量保持率为 7%。详细的循环伏安法和电化学阻抗研究有助于深入了解外在赝电容在改善全电池电化学性能方面的作用。