Morphology formation mechanism and electrochemical performance of poly(o-phenylenediamine) based electrode materials

Abstract

Polystyrene-b-poly(acrylic acid) (PS57-b-PAA54) is prepared by the Atom Transfer Radical Polymerization (ATRP), and poly(o-phenylenediamine) (PoPD) and its carbon dots composites (CDs/PoPD) are synthesized by using the self-assembled micelles of PS57-b-PAA54 as template. Rod-shaped PoPD and CDs/PoPD particles are formed with the average diameters of 263 nm and 322 nm, respectively. The PoPD exhibit a wide size distribution and diverse morphologies, while the CDs/PoPD is mostly composed of olive-shaped particles with a narrow size distribution. The PS57-b-PAA54 induced morphological formation mechanism of PoPD and CDs/PoPD is then proposed. The electrochemical performances test characterized by cyclic voltammetry, chronopotential, AC impedance and constant current charge-discharge tests in a three-electrode system reveals that the initial specific discharge capacitances of CDs/PoPD and PoPD can reach up to 1316 F·g−1 and 216 F·g−1, respectively, at the current density of 1 A·g−1. CDs/PoPD shows better cycle stability with the specific discharge capacitance of 830 F·g−1 for the first cycle, and the decline to 357 F·g−1 in 2000 cycles at the current density of 1 A·g−1 within the potential window of −0.2–1.4 V.