Effect of topological structure on the supercapacitive performance of redox-active triblock copolymers electrode-based asymmetric supercapacitors

In order to study the effect of topological structure of electrodes material on their supercapacitive per-formance, the different ratio of hydrophilic and hydrophobic moieties were designed in the redox-active triblock copolymers PFcn -b-PEG-b-PFcn ( n = 10, 17, 28). And then, PFcn -b-PEG-b-PFcn coated on Ni foam (PFcn -b-PEG-b-PFcn/Ni, n = 10, 17, 28) was applied as electrode materials for supercapacitors. Result dis-playing that with the value n increased from 10 to 28, the specific capacitances of PFcn -b-PEG-b-PFcn in-creased. That is to say, the capacitive behaviors of PFcn -b-PEG-b-PFcn could be greatly regulated by topo-logical structure. Among the three copolymers, the as-prepared PFc28-b-PEG-b-PFc28 possessed a specific capacitance up to 358 F g -1 calculated from discharge curve with current density 1 A g -1. Further, the cy-cle stability test for PFc28-b-PEG-b-PFc28 was performed and the results show that the capacitance decay is only 5% over 20 0 0 cycles, indicating its long cycle life. The reasons for the high capacitance perfor-mance of PFc28-b-PEG-b-PFc28 are due to the ferrocenyl groups with a favorable redox environment and faster electron transport and better ion diffusion, which make the material fully utilized. Furthermore, PFc28-b-PEG-b-PFc28 was successfully used to assemble a simple asymmetric solid-state supercapacitor. In summary, the topological structure of the PFcn -b-PEG-b-PFcn effect on their supercapacitive performance, that is, with the value n increasing, their specific capacitances increase. Can be looked forward to, the PFcn -b-PEG-b-PFcn could be as promising candidates towards high performance electrodes for pseudoca-pacitive supercapacitors. (c) 2023 Published by Elsevier B.V.

Automated summary

To investigate the impact of topological structure on the performance of electrodes in supercapacitors, redox-active triblock copolymers PFcn-b-PEG-b-PFcn (n = 10, 17, 28) with different ratios of hydrophilic and hydrophobic moieties were synthesized and applied as electrode materials. It was found that increasing the value of n from 10 to 28 led to an increase in the specific capacitances of PFcn-b-PEG-b-PFcn. The PFc28-b-PEG-b-PFc28 copolymer demonstrated a specific capacitance of 358 F g-1 and a 5% capacitance decay after 2000 cycles, indicating its high capacitance performance and long cycle life. The favorable redox environment, faster electron transport, and better ion diffusion of the ferrocenyl groups in PFc28-b-PEG-b-PFc28 contributed to its superior performance. Furthermore, PFc28-b-PEG-b-PFc28 was successfully used to assemble a simple asymmetric solid-state supercapacitor.