Organic polyimides have received an ever-growing interest in lithium-ion batteries based on the reversible anion stabilization mechanism of redox-active carbonyl groups due to their high theoretical capacities, resource sustainability, and diverse chain structures. Herein, four linear polyimides with different chain structures were synthesized by a facile and green hydrothermal method. The chain structure-electrochemical performance relationship was explored by regulating active anhydride units and diamine linkers. The incorporation of flexible linkers between redox-active anhydrides results in the facile movement of polyimide chains and the formation of porous networks with abundant active sites. In contrast, rigid aromatic linkers with strong π–π conjugation tend to assemble into the orderly-stacked sheets, enabling the efficient electron transfer. When used as the battery cathode, 1,4,5,8-naphthalenetetracarboxylic dianhydride-based polyimide with a relatively flexible linker delivers the largest specific capacity. Such a polyimide also demonstrates the high cycling stability with a capacity retention up to 52% over 10000 cycles. In contrast, pyromellitic dianhydride-based polyimide with a benzene-enriched linker exhibits the lowest capacity and poor rate capability due to its densely-stacked sheets and limited exposure of active groups. The chain structure-dependent performance relationship of polyimides would offer new insights into the rational design of high-performance organic electrodes for the next-generation batteries.

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锂离子电池用聚酰亚胺正极材料的链结构依赖性电化学性能

有机聚酰亚胺由于其高理论容量、资源可持续性和多样化的链结构，基于氧化还原活性羰基的可逆阴离子稳定机制，在锂离子电池中越来越受到关注。在此，通过简便、绿色的水热法合成了四种具有不同链结构的线性聚酰亚胺。通过调节活性酸酐单元和二胺接头来探索链结构-电化学性能关系。在氧化还原活性酸酐之间掺入柔性接头导致聚酰亚胺链的轻松移动和具有丰富活性位点的多孔网络的形成。相比之下，具有强 π-π 共轭的刚性芳族接头倾向于组装成有序堆叠的薄片，实现有效的电子转移。当用作电池正极时，基于 1,4,5,8-萘四甲酸二酐的聚酰亚胺具有相对灵活的接头，可提供最大的比容量。这种聚酰亚胺还表现出高循环稳定性，在 10000 次循环中容量保持率高达 52%。相比之下，具有富苯连接体的均苯四酸二酐基聚酰亚胺由于其密集堆叠的片层和有限的活性基团暴露而表现出最低的容量和较差的倍率性能。聚酰亚胺的链结构依赖性性能关系将为下一代电池的高性能有机电极的合理设计提供新的见解。基于 8-萘四甲酸二酐的聚酰亚胺具有相对灵活的接头，可提供最大的比容量。这种聚酰亚胺还表现出高循环稳定性，在 10000 次循环中容量保持率高达 52%。相比之下，具有富苯连接体的均苯四酸二酐基聚酰亚胺由于其密集堆叠的片层和有限的活性基团暴露而表现出最低的容量和较差的倍率性能。聚酰亚胺的链结构依赖性性能关系将为下一代电池的高性能有机电极的合理设计提供新的见解。基于 8-萘四甲酸二酐的聚酰亚胺具有相对灵活的接头，可提供最大的比容量。这种聚酰亚胺还表现出高循环稳定性，在 10000 次循环中容量保持率高达 52%。相比之下，具有富含苯的连接基的均苯四酸二酐基聚酰亚胺由于其密集堆叠的片层和有限的活性基团暴露而表现出最低的容量和较差的倍率性能。聚酰亚胺的链结构依赖性性能关系将为下一代电池的高性能有机电极的合理设计提供新的见解。具有富苯连接体的均苯四酸二酐基聚酰亚胺由于其密集堆叠的片层和有限的活性基团暴露而具有最低的容量和较差的倍率性能。聚酰亚胺的链结构依赖性性能关系将为下一代电池的高性能有机电极的合理设计提供新的见解。具有富苯连接体的均苯四酸二酐基聚酰亚胺由于其密集堆叠的片层和有限的活性基团暴露而具有最低的容量和较差的倍率性能。聚酰亚胺的链结构依赖性性能关系将为下一代电池的高性能有机电极的合理设计提供新的见解。