In this study, four thiophene-diketopyrrolopyrrole-based (TDPP-based) polymer derivatives modified by different groups and alkyl chains were synthesized. The effects of various functional groups on the electrochemical properties of the polymers for application in lithium-ion batteries were compared, where the carbazole (C) and tert-butyl acetate (TA) groups improved the capacity performance of the polymer electrodes, while hexane (H) and fluorene (F) groups enhanced the cycle stability of the polymer electrodes. The P(C-TDPP-TA) polymer electrode, i.e., the TDPP-based polymer composed of carbazole and tert-butyl acetate groups, exhibited the best capacity performance among the four polymer electrodes, where its discharge specific capacity and capacity retention were up to 357 mA h g⁻¹ and 82% and its energy density and power density were 213 W h kg⁻¹ and 149 W kg⁻¹ at 100 mA g⁻¹ after 500 cycles, respectively. The P(F-TDPP-H) polymer electrode, i.e., the TDPP-based polymer composed of fluorene and hexane groups, possessed the best cycle stability and conductivity, where its capacity retention was up to 92% at 100 mA g⁻¹ for 500 cycles and its electronic conductivity and ionic conductivity were 4.80 × 10⁻³ and 6.68 × 10⁻³ S m⁻¹, respectively. For application in lithium-ion batteries, the P(C-TDPP-TA) electrode exhibited the best comprehensive performance. When the current density reached up to 1000 mA g⁻¹, after 1000 cycles, the P(C-TDPP-TA) electrode still exhibited a high discharge specific capacity (203.6 mA h g⁻¹) and excellent capacity retention (88.8%), and its energy density and power density were 116 W h kg⁻¹ and 376 W kg⁻¹ (1000 mA g⁻¹, after 1000 cycles), respectively. Therefore, the P(C-TDPP-TA) electrode has potential as a promising anode material for lithium-ion batteries.

中文翻译：

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功能性噻吩-二酮基吡咯并吡咯基聚合物衍生物作为锂离子电池的有机阳极材料

在这项研究中，合成了四种由不同基团和烷基链修饰的噻吩-二酮基吡咯并吡咯基（TDPP基）聚合物衍生物。比较了各种官能团对用于锂离子电池的聚合物电化学性能的影响，其中咔唑（C）和乙酸叔丁酯（TA）基团改善了聚合物电极的容量性能，而己烷（ H）和芴（F）基团增强了聚合物电极的循环稳定性。在P（C-TDPP-TA）聚合物电极，即，所述基于TDPP类聚合物组成的咔唑和的叔乙酸丁酯基团在四个聚合物电极中表现出最佳的容量性能，其放电比容量和容量保持率分别高达357 mA hg ^-1和82％，能量密度和功率密度为213 W h kg ^-1和500个循环后，在100 mA g ^-1下分别为149 W kg ^-1。P（F-TDPP-H）聚合物电极，即由芴基和己烷基组成的TDPP基聚合物，具有最佳的循环稳定性和导电性，在100 mA g ^-1下其容量保持率高达92％。 500次循环，其电导率和离子电导率分别为4.80×10 ^-3和6.68×10 ^-3 S m^-1。对于锂离子电池，P（C-TDPP-TA）电极表现出最佳的综合性能。当电流密度达到1000 mA g ^-1时，经过1000次循环后，P（C-TDPP-TA）电极仍显示出高放电比容量（203.6 mA hg ^-1）和出色的容量保持率（88.8％），其能量密度和功率密度分别为116 W h kg ^-1和376 W kg ^-1（1000 mA g ^-1，经过1000次循环）。因此，P（C-TDPP-TA）电极具有作为锂离子电池有希望的负极材料的潜力。