Azo-linked covalent triazine-based framework as organic cathodes for ultrastable capacitor-type lithium-ion batteries
Azo-linked covalent triazine-based framework as organic cathodes for ultrastable capacitor-type lithium-ion batteries
复制标题
偶氮连接共价三嗪骨架作为超稳定电容器型锂离子电池的有机阴极
DOI：
10.1016/j.ensm.2021.01.016
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发表时间：
2021
影响因子：
20.4
通讯作者：
Yang Jun
中科院分区：
文献类型：
--
作者：
Wu Chuanguang;Hu Mingjun;Yan Xiaorong;Shan Guangcun;Liu Jinzhang;Yang Jun
提出了一个高度稳定的3Dπ-偶联三嗪芯框架（Azo-CTF），其作为由Azo氧化还原活性接头桥接的电子富含电子中心，并作为阴极材料制备，以改善LIBS的速率性能和周期稳定性，这两个关键问题在有机电极中解决了两个关键问题。在共轭聚合物框架中的同步和有序引入抽奖单元和氧化还原活性单元可以有效地调整电子结构和材料的氧化还原电位，从而有助于改善电气和电化学行为。归因于丰富的氧化还原偶氮网站，弹性且可访问的毛孔网络以及良好的分子内和界面电子转移能力，Azo-CTF阴极显示了205.6 mAh G-1的大型且可逆的容量输出，超级循环寿命（89.1％）在5000个周期和4253的能源持续时间（89.1％的能力），4253 kg k k k k k k k k k k k k k k k k k k k k k k k k k k k k k k k。 KG -1，比许多报道的有机阴极要好得多，甚至比某些商业无机阴极更好。此外，进行了原位拉曼光谱和理论计算，并进一步验证了偶氮活性位点的氧化还原过程，并在共价框架中优化了分子轨道的更好的电池阴极，表明分子级电子结构的可用性。
A highly stable 3D π-conjugation covalent triazine-cored framework (Azo-CTF) with triazine as the electron-rich center bridged by azo redox-active linkers is proposed and prepared as cathode materials for improving both rate performance and cycle stability of LIBs, two critical issues addressed in organic electrodes. The synchronous and orderly introduction of electron-withdrawing units and redox active units in conjugated polymer framework can effectively tune electronic structure and redox potential of materials, contributing to the improvement of electrical and electrochemical behavior. Attributed to abundant redox azo sites, resilient and accessible pores network, and good intramolecular and interfacial electron transfer ability, Azo-CTF cathode shows a large and reversible capacity output of 205.6 mAh g−1, a ultralong cycle life (89.1% capacity retention after 5000 cycles), and a high power density of 4253 W kg−1even at an energy density of 258 Wh kg−1, much better than many reported organic cathodes and even better than some commercial inorganic cathodes. In addition, in-situ Raman spectroscopy and theoretical calculations were done and further verified the redox process of azo active sites and the optimization of molecular orbital in covalent framework for better battery cathode, indicating the availability of molecular-level electronic structure tuning.