Synthesizing redox-active units containing polymers is a promising route for improving the cycling stability of organic electrode materials. However, constructing uniform electrode architectures with good polymer dispersion is a big challenge in the case of polymer electrode materials. In this work, we design and synthesize two anthraquinone-containing copolymers and compare their electrochemical performance with that of the corresponding homopolymer. It is uncovered that the copolymers with soft units in the main chain display increased chain flexibility, thus leading to a slightly increased solubility. Because of this, the soft copolymers are less likely to precipitate during solvent volatilization of electrode preparation and thus can form more uniform electrode architectures. The cyclic voltammogram and electrochemical impedance spectroscopy measurements indicate that copolymer electrodes display decreased polarization and improved kinetics compared with the homopolymer electrode. The copolymers exhibit significantly enhanced cycling stability and improved rate performance. After 100 cycles, both copolymers reveal very high capacity retention of above 98%, while the homopolymer retains only 71% of its highest capacity. Moreover, the copolymer can discharge/charge at 1C for over 2000 cycles with almost no capacity fading, indicating excellent long-term cycling performance. This work further demonstrates the importance of molecular structure and electrode architecture in determining the electrochemical performance of polymer electrode materials.

中文翻译：

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锂离子电池聚合物电极材料的性能增强：从刚性均聚物到软共聚物。

包含聚合物的氧化还原活性单元的合成是改善有机电极材料循环稳定性的一种有前途的途径。然而，在聚合物电极材料的情况下，构建具有良好聚合物分散性的均匀电极结构是一个巨大的挑战。在这项工作中，我们设计并合成了两种含蒽醌的共聚物，并将它们的电化学性能与相应的均聚物进行了比较。发现在主链中具有软单元的共聚物显示出增加的链柔性，因此导致溶解度稍微增加。因此，软共聚物在电极制备的溶剂挥发期间不太可能沉淀，因此可以形成更均匀的电极结构。循环伏安图和电化学阻抗谱测量表明，与均聚物电极相比，共聚物电极显示出降低的极化和改善的动力学。该共聚物表现出显着增强的循环稳定性和改进的速率性能。在100次循环后，两种共聚物均显示出98％以上的极高容量保留率，而均聚物仅保留其最高容量的71％。此外，该共聚物可在1C下放电/充电超过2000个循环，几乎没有容量衰减，表明优异的长期循环性能。这项工作进一步证明了分子结构和电极结构在确定聚合物电极材料的电化学性能中的重要性。