Enhanced lithium storage performance of graphene nanoribbons doped with high content of nitrogen atoms.
Enhanced lithium storage performance of graphene nanoribbons doped with high content of nitrogen atoms.
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高含量氮原子掺杂的石墨烯纳米带增强储锂性能。
DOI：
10.1088/1361-6528/ab0434
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发表时间：
2019
期刊：
影响因子：
3.5
通讯作者：
Liu L W
中科院分区：
文献类型：
--
作者：
Qian Yuting;Jiang Lai;Ullah Zaka;Guan Zhixing;Yu Congcong;Zhu Shoupu;Chen Mingliang;Li Weiwei;Li Qi;Liu L W
氮掺杂可以为锂离子存储提供大量的活性位点，从而可以产生更高的锂离子电池容量。然而，大多数报道的N掺杂的石墨烯基材料具有低氮含量（<10重量%），因为氮原子的引入优选在石墨烯晶格中的边缘和缺陷处产生。由于边缘和缺陷的形成，可以容易地定位掺杂态或活性位点，并且可以精确地确定氮含量。在这里，我们提出了制备的N-掺杂的石墨烯纳米带具有高的氮含量（11.8重量%）和一个简单的可调配置的掺杂状态。该材料可用作锂离子电池的阳极，并显示出更高的容量（该电极在100 mA g-1的充电/放电速率下具有1100.34 mA h g-1的可逆容量，对应于约9 h的放电时间），更好的速率性能（该电极在2 A g-1的电流密度下具有471 mA h g-1的可逆容量，对应于约11.6分钟的放电时间）和改善的循环稳定性（200次循环后初始容量的87.37%）。实验结果和第一性原理计算表明，氮掺杂石墨烯纳米带中残留的含氧官能团促进了边缘吡咯氮的形成，并大大增加了氮掺杂的空间。这项工作为设计和开发用于高性能锂离子电池的N掺杂石墨烯阳极开辟了新的策略。
Nitrogen doping can provide a large number of active sites for lithium-ion storage, thus can yield a higher capacity for lithium-ion batteries. However, most of the reported N-doped graphene-based materials have low nitrogen content (<10 wt%) as the introduction of nitrogen atoms prefer to be produced at edges and defects in the graphene lattices. Owing to the formation of edges and defects, the doped states or active sites can easily be located and nitrogen contents can be determined precisely. Here we present the preparation of N-doped graphene nanoribbons with high nitrogen contents (11.8 wt%) and a facile tunable configuration of doped states. The material can be used as an anode for lithium-ion batteries and shows a higher capacity (the electrode has a reversible capacity of 1100.34 mA h g−1 at a charge/discharge rate of 100 mA g−1, corresponds to a discharge time of about 9 h), better rate performance (the electrode has a reversible capacity of 471 mA h g−1 at the current density of 2 A g−1, corresponds to a discharge time of about 11.6 min) and improved cycling stability (87.37% of the initial capacity after 200 cycles). The experimental results and first-principle calculations suggest that the residual oxygen-containing functional groups of N-doped graphene nanoribbons promote the formation of pyrrolic nitrogen at edges and substantially increase the room for nitrogen doping. This work opens new strategies for designing and developing N-doped graphene anodes for high performance lithium-ion batteries.