Organic electrode materials (OEMs), particularly small molecules, are promising for the next-generation batteries due to their advantages of mass production with potentially low cost, flexibility, high capacity, and facile molecular design. However, small molecules usually have high solubility in organic electrolytes, resulting in low actual capacity and poor cyclability. Herein, we demonstrated a strategy that abutting functional groups could boost the performance via several aspects by utilizing a small molecule (QAPs) as a proof-of-concept. The QAPs contains plentiful abutting functional groups. We found that the abundant abutting functional groups could on one hand guarantee the high specific capacity, and on the other hand effectively boost the sodium storage by forming chelation with sodium ions. Moreover, due to the strong chelation effect, the complete extraction of Na ions required high potential, which led to the always existence of ionic intermolecular interactions and hence insolubility and high cyclability. As a result, the QAPs electrodes involved a reversible five-electrons redox process, delivering a high capacity of 562 mAh g-1 at 100 mA g-1, rate capability and long-term cyclability. The presence of chelation effect was substantially verified by high resolution mass spectrometry, control experiments and theoretical calculations.

中文翻译：

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丰富的邻接官能团可促进小分子中的钠储存


有机电极材料（OEM），特别是小分子材料，由于其具有大规模生产的优势，具有潜在的低成本、灵活性、高容量和易于分子设计的优势，因此有望用于下一代电池。然而，小分子通常在有机电解质中具有较高的溶解度，导致实际容量较低且循环性能较差。在此，我们展示了一种策略，即通过利用小分子（QAP）作为概念验证，邻接官能团可以通过多个方面提高性能。 QAP 包含大量相邻的功能组。我们发现丰富的邻接官能团一方面可以保证高比容量，另一方面通过与钠离子形成螯合有效地促进钠储存。此外，由于强螯合效应，钠离子的完全萃取需要高电势，这导致离子分子间相互作用始终存在，因此具有不溶性和高循环性。因此，QAP 电极涉及可逆五电子氧化还原过程，在 100 mA g-1 电流下提供 562 mAh g-1 的高容量、倍率性能和长期循环性能。通过高分辨率质谱、对照实验和理论计算充分验证了螯合效应的存在。