• Influence of different dopants and redox forms of PANI in its crystal structure, morphology, electrochemical energy storage to variable extent, unique properties and kinetics

• # Fulltext

https://www.ias.ac.in/article/fulltext/boms/045/0060

• # Keywords

Leucoemaraldine; pernigraniline; cell capacitance; crystal structure; capacitive contribution; diffusional contribution.

• # Abstract

The influences of base and salt forms, dopants used for protonation and different oxidation states of polyaniline (PANI) on its crystal structure, morphology, electrochemical stability, electrical conductivity and different potential-dependent energy storage by electrochemical processes were investigated by synthesizing PANI with two different acid dopants and in two different redox forms. The results reveal that, the methane sulphonic acid (MSA) causes more storage of energy in PANI. The reduced form of PANI furnishes high surface area and stores more energy than the respective oxidized form. The MSA-doped PANI exhibits an inimitable property of increase of specific capacitance ($C_s$) with increase in number of charge/discharge cycles in both oxidized and reduced forms. The structural changes of PANI after 25600 cycles were determined by IR spectroscopy, which confirmed that the irreversible formation of pernigraniline causes property degradation of PANI. The maximum energy storage parameters obtained from oxidized form of PANI doped with MSA (PANIMSA-Ox) are a $C_s$ of 458 F g$^{-1}$, a specific energy ($E_s$) of 91 W h kg$^{-1}$ and a specific power ($P_s$) of 2.0983 kW kg$^{-1}$ at 1 A g$^{-1}$. In addition, the PANIMSA-Ox exhibits an exceptional cyclic stability up to 25600 at 0.4 V s$^{-1}$. The theoretical capacitance of PANI (2000 F g$^{-1}$) is nearly reached with PANIMSA-Ox as it provided the $C_s$ of an electrode of 1834.84 F g$^{-1}$ at 1 A g$^{-1}$. Most significantly, the PANIMSA-Ox presents the maximum of four faradaic couples and exceptional energy storage without using any redox supporting electrolytes.

• # Author Affiliations

1. Department of Chemistry, National Institute of Technology Karnataka, Surathkal 575025, India

• # Bulletin of Materials Science

Volume 46, 2023
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020

Physical Sciences 2020

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Posted on July 25, 2019