A sequence of N-doped carbon materials has been synthesized using poly(acrylonitrile)-ionic liquid copolymers as carbon precursors. The nitrogen content and configuration in carbon materials has been changed regularly within a certain range by adjusting the proportion of ionic liquids. We found that the capacity and rate performance increased dramatically after the introduction of ionic liquids, which was attributed to incorporation of higher amount pyridinic-N, pyrrolic-N into the carbon materials. Besides, with the increase of the graphitic-N, the initial Coulombic efficiency decreased from 58.5 % to 53.47 % and the R_SEI raised from 66.34 Ω to 140.96 Ω, which was attributed to the higher cohesive energy of Li dimmer than adsorption energy of graphitic-N with Li, since more lithium clusters during the formation of SEI film were formed. The electrochemical tests also revealed the negative role of graphitic-N in the capacity. Therefore, this work provides a feasible method to design the nitrogen content and configuration of the N-doped carbon materials.

中文翻译：

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氮构型对锂离子电池负极材料碳化聚（丙烯腈）离子液体电化学性能的影响

已经使用聚（丙烯腈）-离子液体共聚物作为碳前体合成了一系列的N掺杂碳材料。通过调节离子液体的比例，碳材料中的氮含量和构型在一定范围内有规律地变化。我们发现，引入离子液体后，容量和速率性能显着提高，这归因于碳材料中掺入了更高含量的吡啶-N，吡咯-N。此外，随着石墨氮的增加，初始库仑效率从58.5％降至53.47％，R _SEI从66.34Ω升高到140.96Ω，这归因于Li调光剂的内聚能高于石墨N与Li的吸附能，因为在SEI膜形成过程中形成了更多的锂簇。电化学测试还揭示了石墨N在容量中的负面作用。因此，这项工作为设计氮掺杂碳材料的氮含量和构型提供了一种可行的方法。