Abstract Our work presents insights from density functional theory calculations on the trapping mechanism of light metal atoms in C2N-h2D. The storage capacity of C2N-h2D for lithium, sodium and calcium ions has been explored for utilisation as a battery anode material. Our calculations show that a significant capacity of over 500 mAh g−1 and excellent mobility of the calcium atoms can be achieved. Overall, we find that all three metals interact strongly with the pyridinic nitrogen in the pores and that the material shows a high initial storage capacity. However, due to the strong binding of the first intercalated metals in the pores, these show poor mobility. Once the pores are loaded with at least one metal atom, the mobility improves significantly. The trapped metal atoms however, affect the capacity of the material, making it much smaller. This limits the suitability of C2N-h2D as an anode material for lithium and sodium ion batteries and explains previous experimental findings on poor performance for lithium. For calcium we find that the trapping of some of the calcium atoms has less of an effect due to the dual valence, leading to the observed higher capacity.

中文翻译：

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深入了解 C2N-h2D 上轻金属的捕获机制：用作金属离子电池的负极材料

摘要 我们的工作提出了密度泛函理论计算对 C2N-h2D 中轻金属原子的俘获机制的见解。C2N-h2D 对锂、钠和钙离子的存储能力已被探索用作电池负极材料。我们的计算表明，可以实现超过 500 mAh g-1 的显着容量和优异的钙原子迁移率。总的来说，我们发现所有三种金属都与孔中的吡啶氮强烈相互作用，并且该材料显示出很高的初始存储容量。然而，由于孔中的第一种嵌入金属的强结合，这些表现出较差的流动性。一旦孔中装载了至少一个金属原子，迁移率就会显着提高。然而，被捕获的金属原子会影响材料的容量，使其更小。这限制了 C2N-h2D 作为锂和钠离子电池负极材料的适用性，并解释了之前关于锂性能不佳的实验结果。对于钙，我们发现由于双价态，捕获一些钙原子的影响较小，从而导致观察到的更高容量。