Organic electrodes have aroused growing interest by virtue of their molecular diversity, environmental friendliness, and operation safety. However, sluggish lithium diffusion kinetics, dissolution in the organic electrolyte, poor electrical conductivity and low reversible capacities are the bottlenecks compared to their inorganic counterparts. Herein, we report a new type of exfoliated covalent organic nanosheet (E-CON) based composite electrode with large reversible capacities for lithium organic batteries based on intriguing new lithium storage sites of CC and higher utilization efficiency of CN redox sites compared to its bulk counterpart. The surface modification of the E-CONs by carboxyl-functionalized graphene quantum dots (GQDs) and carbon nanotubes can ensure long cycle life of the electrode due to the facilitated transfer of charge or lithium and prevent restacking of E-CONs. The E-CON based composite electrode exhibits an extremely large reversible capacity of 1386 mA h g⁻¹ (1687 mA h g⁻¹ based on E-CON contribution in the composite) after 300 cycles at 100 mA g⁻¹ with good high-rate capability. The lithium storage mechanism is determined to be one lithium ion per CN and two lithium ions per CC group from five hyper-conjugated benzene rings.

中文翻译：

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通过石墨烯量子点/碳纳米管稳定的三维结构实现少层共价有机纳米片的长寿命超锂化

有机电极因其分子多样性、环境友好性和操作安全性而引起了越来越多的关注。然而，与无机对应物相比，锂扩散动力学缓慢、在有机电解质中溶解、导电性差和可逆容量低是瓶颈。在此，我们报告了一种新型的剥离共价有机纳米片（E-CON）基复合电极，具有大可逆容量的锂有机电池，其基于有趣的新锂存储位点C 和更高的 C 利用率。与其大容量对应物相比，N 个氧化还原位点。通过羧基功能化石墨烯量子点（GQDs）和碳纳米管对 E-CONs 进行表面改性，由于促进了电荷或锂的转移，可以确保电极的长循环寿命，并防止 E-CONs 重新堆叠。^{基于 E-CON 的复合电极在 100 mA g -1下循环 300 次后表现出 1386 mA hg -1}的极大可逆容量（1687 mA hg ^-1基于复合材料中的 E-CON 贡献），具有良好的高倍率性能. 锂存储机制被确定为每个 C N 一个锂离子和来自五个超共轭苯环的每个 C C 基团两个锂离子。