Commercial lithium-ion batteries with carbon-based anodes exhibit low specific capacities and pose potential safety risks of lithium plating. As possible alternatives, conjugated carboxylic acid-based electrode materials have attracted extensive attention owing to their suitable discharge potential, low solubility in electrolytes, and low-cost reproducibility. However, their theoretical capacities are limited by the number of active sites. In this paper, we introduce 2,2′-bipyridine-5,5′-dicarboxylic acid (H₂bpy) as a new anode material demonstrating high specific capacity, good cycle stability, and remarkable rate performance in both lithium- and sodium-ion batteries. In particular, H₂bpy possesses an ultrahigh initial capacity of lithium-ion battery of 1200 mAh g⁻¹ at a current density of 200 mA•g⁻¹, and the specific capacity can maintain 550 mAh•g⁻¹ after 100 cycles. Whereas the sodium-ion battery retains a specific capacity of 258 mAh•g⁻¹ under the same conditions. We find, through density functional theory analysis, that the superior performance is due to the molecular structure and stacking form of H₂bpy. Furthermore, we perform an ex situ spectroscopic analysis and find that the H₂bpy electrode has good electrochemical stability. These findings suggest that bipyridine carboxylic acids can effectively broaden the application of heterocyclic carboxylic acids as anode materials.

具有碳基负极的商用锂离子电池比容量低，存在镀锂的潜在安全风险。作为可能的替代品，共轭羧酸基电极材料因其合适的放电电位、在电解质中的低溶解度和低成本的再现性而受到广泛关注。然而，它们的理论容量受到活性位点数量的限制。在本文中，我们介绍了 2,2'-联吡啶-5,5'-二羧酸 (H ₂ bpy) 作为一种新型负极材料，在锂和钠-离子电池。特别是H ₂ bpy 具有1200 mAh g ^-1的超高锂离子电池初始容量在200 mA•g ^-1的电流密度下，100次循环后比容量可保持550 mAh•g ^-1。而钠离子电池在相同条件下保持258 mAh•g ^-1的比容量。我们通过密度泛函理论分析发现，优异的性能是由于H ₂ bpy的分子结构和堆积形式。此外，我们进行了非原位光谱分析，发现 H ₂ bpy 电极具有良好的电化学稳定性。这些发现表明联吡啶羧酸可以有效拓宽杂环羧酸作为负极材料的应用。