Organic battery materials are receiving increasing attention owing to their elemental abundance, environmental sustainability, and structural diversity. Challenges including the solubility in electrolytes, moderate redox potentials, and inactive molecular fragments prevent organic materials from being ideal cathodes for practical implementation. Although polymerization, salification and alike solutions are effective in lowering the solubility in electrolytes, they unavoidably bring additional inactive fragments into the molecular structures, resulting in the sacrifice of theoretical galvanometric capacity compared with the pristine molecule. In this study, we use two redox-active fragments to construct an insoluble copolymer as a cathode material for organic batteries. The copolymer avoids the use of unnecessary molecular weight while maintaining high specific capacity and cycling stability. We find that a twisted geometry between the two redox-active fragments leads to a cross-conjugation effect that further consolidates the low stability of the individual fragment and enhances the flexibility of copolymer chains by forming mesopores that accelerate ion diffusion. The copolymer shows a high capacity of 142.5 mAh/g with energy / power density of 577 Wh/kg / 1,685 W/kg and a decent capacity retention of 87% after 500 cycles. Our strategy demonstrates the feasibility of designing organic battery materials that are qualified for taking solubility, capacity, and stability into consideration.

有机电池材料因其元素丰富、环境可持续性和结构多样性而受到越来越多的关注。包括在电解质中的溶解度、中等氧化还原电位和非活性分子碎片在内的挑战阻碍了有机材料成为实际应用的理想阴极。尽管聚合、成盐等溶液可有效降低在电解质中的溶解度，但它们不可避免地将额外的非活性碎片带入分子结构中，导致与原始分子相比，牺牲了理论电流容量。在这项研究中，我们使用两个氧化还原活性片段来构建不溶性共聚物作为有机电池的正极材料。该共聚物避免使用不必要的分子量，同时保持高比容量和循环稳定性。我们发现两个氧化还原活性片段之间的扭曲几何形状导致交叉共轭效应，进一步巩固了单个片段的低稳定性，并通过形成加速离子扩散的中孔来增强共聚物链的柔韧性。该共聚物显示出 142.5 mAh/g 的高容量，能量/功率密度为 577 Wh/kg / 1,685 W/kg，并且在 500 次循环后容量保持率为 87%。我们的策略证明了设计符合溶解性、容量和稳定性的有机电池材料的可行性。