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⁻¹ even 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.

提出了一种高度稳定的3Dπ共轭共价三嗪核骨架（Azo-CTF），以三嗪为偶氮氧化还原活性连接基桥接的富电子中心，并被用作阴极材料，以提高LIB的速率性能和循环稳定性。有机电极解决了两个关键问题。在共轭聚合物骨架中同步有序地引入吸电子单元和氧化还原活性单元可以有效地调节材料的电子结构和氧化还原电位，有助于改善电学和电化学性能。归因于丰富的氧化还原偶氮位点，有弹性且易于接近的孔网络以及良好的分子内和界面电子转移能力，Azo-CTF阴极显示出205.6 mAh g ^-1的大且可逆的容量输出，超长的循环寿命（5000次循环后的容量保持率为89.1％）以及即使在258 Wh kg ^-1的能量密度下仍具有4253 W kg ^-1的高功率密度，远优于许多报道的有机阴极，甚至优于某些有机阴极商业无机阴极。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和共价框架中分子轨道的优化，以获得更好的电池阴极，表明了分子级电子结构调节的可用性。