Flexible Backbone Effects on the Redox Properties of Perylenediimide-Based Polymers.
Flexible Backbone Effects on the Redox Properties of Perylenediimide-Based Polymers.
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DOI：
10.1021/acsami.3c06065
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发表时间：
2023-08
影响因子：
9.5
通讯作者：
Jaehwan Kim;Yogita Shirke;P. Milner
中科院分区：
文献类型：
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作者：
Jaehwan Kim;Yogita Shirke;P. Milner
有机电极材料是广泛应用的有吸引力的候选材料，包括非均相电催化和电化学储能。然而，对这些材料的结构-性能关系的狭隘理解阻碍了它们潜力的充分实现。在此，我们研究了一系列不溶性苝二酰亚胺（PDI）聚合物，以探究主链柔性如何影响其热力学和动力学氧化还原性质。我们证实，由于聚合物的溶剂化壳层/能量较小，并且与减少的 PDI 物质有良好的软-软相互作用，因此聚合物通常会与 K+ 离子（相对于 Na+ 和 Li+）获得最高百分比的氧化还原活性基团。通过循环伏安法，我们表明增加聚合物的柔韧性并不能最大限度地减少离子插入过程的障碍，而是增加了扩散限制过程的水平。此外，我们提出，酰亚胺缩合成亚氨基酰亚胺可以截断某些二胺单体的酰亚胺聚合物链的增长，从而导致更大的聚合物溶解度和降低的循环稳定性。总之，我们的结果提供了对聚合物柔性、离子电极相互作用和聚合副反应如何决定 PDI 聚合物氧化还原性能的深入了解，为下一代有机电极材料的开发铺平了道路。
Organic electrode materials are appealing candidates for a wide range of applications, including heterogeneous electrocatalysis and electrochemical energy storage. However, a narrow understanding of the structure-property relationships in these materials hinders the full realization of their potential. Herein, we investigate a family of insoluble perylenediimide (PDI) polymers to interrogate how backbone flexibility affects their thermodynamic and kinetic redox properties. We verify that the polymers generally access the highest percentage of redox-active groups with K+ ions (vs Na+ and Li+) due to its small solvation shell/energy and favorable soft-soft interactions with reduced PDI species. Through cyclic voltammetry, we show that increasing the polymer flexibility does not minimize barriers to ion-insertion processes but rather increases the level of diffusion-limited processes. Further, we propose that the condensation of imides to iminoimides can truncate the imide polymer chain growth for certain diamine monomers, leading to greater polymer solubilization and reduced cycling stability. Together, our results provide insight into how polymer flexibility, ion-electrode interactions, and polymerization side reactions dictate the redox properties of PDI polymers, paving the way for the development of next-generation organic electrode materials.