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ORIGINAL PAPER

Nanostructured MnCo2O4 as a high-performance electrode for supercapacitor application M. Haripriya 1 & Anuradha M. Ashok 2 & Shamima Hussain 3 & R. Sivasubramanian 1 Received: 29 January 2020 / Accepted: 18 September 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract In this work, the MnCo2O4 nanorods are prepared by a simple hydrothermal route using urea as both a stabilizing and structuredirecting agent for supercapacitor application. The morphological features of the prepared materials were characterized by a scanning electron microscope (SEM) and transmission electron microscope (TEM). The chemical and the crystal structure were studied using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis. The morphological analysis showed rod-like structures with a diameter of 50–60 nm and length of 1–2 μm respectively. The XRD pattern showed that the particles are crystalline and belong to the cubic spinel structure. The chemical composition was inferred from the XPS analysis. The formation of metal-oxygen bond is inferred using FTIR, and BET showed a high surface area of 41.80 m2g−1. The electrochemical characterization of MnCo2O4 nanorods was performed in 2 M KOH solution using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and impedance analysis. The CV studies showed a pseudocapacitance behaviour of the electrode, and the GCD studies revealed a specific capacitance of 187.5 Fg−1 at a current density of 0.25 Ag−1. The electrode exhibited good cyclic stability by retaining 90% of the initial value after 5000 cycles. The specific capacitance was also estimated from the impedance analysis and the pseudocapacitive nature of the MnCo2O4 electrode was analysed. Further, the fabricated asymmetric supercapacitor (AC MnCo2O4 nanorods) provides the specific capacitance of 76 Fg−1 at a current density of 0.25 Ag−1. The results indicate that the MnCo2O4 can be a promising candidate for supercapacitor application. Keywords MnCo2O4 . Nanorods . Hydrothermal . Supercapacitors . Energy storage

Introduction The electrochemical energy storage technologies like batteries and supercapacitors have a huge demand in the market owing to their capability to serve as an alternative to fossil fuels [1]. They are clean energy technologies complementary to renewable energy systems. According Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11581-020-03788-y) contains supplementary material, which is available to authorized users. * R. Sivasubramanian [email protected] 1

Electrochemical Sensors & Energy Materials Laboratory, PSG Institute of Advanced Studies, Coimbatore, Tamilnadu 641004, India

2

Functional Materials Laboratory, PSG Institute of Advanced Studies, Coimbatore, Tamilnadu 641004, India

3

UGC DAE CSR, Center, Kokilamedu, Kalpakkam, Tamilnadu 603104, India

to the Ragone plot, batteries have high energy density and low power density. On the other hand, supercapacitors have high power density, long cy