Substituent effect on supercapacitive performances of conducting polymer-based redox electrodes: Poly(3′,4′-bis(alkyloxy) 2,2′:5′,2″-terthiophene) derivatives

Deniz Yiğit, Melis Aykan, Mustafa Güllü

Index: 10.1002/pola.28927

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Abstract

ABSTRACT This work reports the synthesis of novel poly(3′,4′-bis(alkyloxy)terthiophene) derivatives (PTTOBu, PTTOHex, and PTTOOct) and their supercapacitor applications as redox-active electrodes. The terthiophene-based conducting polymers have been derivatized with different alkyl pendant groups (butyl-, hexyl-, and octyl-) to explore the effect of alkyl chain length on the surface morphologies and pseudocapacitive properties. The electrochemical performance tests have revealed that the length of alkyl substituent created a remarkable impact over the surface morphologies and charge storage properties of polymer electrodes. PTTOBu, PTTOHex, and PTTOOct-based electrodes have reached up to specific capacitances of 94.3, 227.3, and 443 F g−1 at 2.5 mA cm−2 constant current density, respectively, in a three-electrode configuration. Besides, these redox-active electrodes have delivered satisfactory energy densities of 13.5, 29.3, and 60.7 W h kg−1 and power densities of 0.98, 1, and 1.1 kW kg−1 with good capacitance retentions after 10,000 charge/discharge cycles in symmetric solid-state micro-supercapacitor devices. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 480–495 The novel poly(terthiophene)-based redox-electrodes were prepared for the first time. Redox electrode materials PTTOBu, PTTOHex, and PTTOOct delivered specific capacitances of 94.3, 227.3, and 443 F g−1, respectively. The micro-supercapacitor devices reached energy densities of 13.5, 29, and 60.7 W h kg−1, respectively. The micro-supercapacitor devices also exhibited good capacitance retentions.