Development of an Amorphous Nickel Boride/Manganese Molybdate Heterostructure as an Efficient Electrode Material for a High-Performance Asymmetric Supercapacitor

Raj Karthik; Ramaraj Sukanya; Shen Ming Chen; Mahmudul Hasan; Ganesh Dhakal; P Muhammed Shafi; Jae-Jin Shim

doi:10.1021/acsami.3c00013

Development of an Amorphous Nickel Boride/Manganese Molybdate Heterostructure as an Efficient Electrode Material for a High-Performance Asymmetric Supercapacitor

ACS Appl Mater Interfaces. 2023 Mar 8;15(9):11927-11939. doi: 10.1021/acsami.3c00013. Epub 2023 Feb 22.

Authors

Raj Karthik¹, Ramaraj Sukanya², Shen Ming Chen², Mahmudul Hasan¹, Ganesh Dhakal¹, P Muhammed Shafi^{1

3}, Jae-Jin Shim¹

Affiliations

¹ School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 38541, The Republic of Korea.
² Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, Republic of China.
³ Department of Physics, National Institute of Technology Calicut, Calicut, Kerala 673601, India.

PMID: 36890694
DOI: 10.1021/acsami.3c00013

Abstract

The exploration of heterostructure materials with unique electronic properties is considered a desirable platform for fabricating electrode/surface interface relationships for constructing asymmetric supercapacitors (ASCs) with high energy density. In this work, a heterostructure based on amorphous nickel boride (Ni_XB) and crystalline square bar-like manganese molybdate (MnMoO₄) was prepared by a simple synthesis strategy. The formation of the Ni_XB/MnMoO₄ hybrid was confirmed by powder X-ray diffraction (p-XRD), field emission scanning electron microscopy (FE-SEM), field-emission transmission electron microscopy (FE-TEM), Brunauer-Emmett-Teller (BET), Raman, and X-ray photoelectron spectroscopy (XPS). In this hybrid system (Ni_XB/MnMoO₄), the intact combination of Ni_XB and MnMoO₄ leads to a large surface area with open porous channels and abundant crystalline/amorphous interfaces with a tunable electronic structure. This Ni_XB/MnMoO₄ hybrid shows high specific capacitance (587.4 F g^-1) at 1 A g^-1, and it even retains a capacitance of 442.2 F g^-1 at 10 A g^-1, indicating superior electrochemical performance. The fabricated Ni_XB/MnMoO₄ hybrid electrode also exhibited an excellent capacity retention of 124.4% (10000 cycles) and a Coulombic efficiency of 99.8% at a current density of 10 A g^-1. In addition, the ASC device (Ni_XB/MnMoO₄//activated carbon) achieved a specific capacitance of 104 F g^-1 at 1 A g^-1 and delivered a high energy density of 32.5 Wh.kg^-1 with a power density of 750 W·kg^-1. This exceptional electrochemical behavior is due to the ordered porous architecture and the strong synergistic effect of Ni_XB and MnMoO₄, which enhances the accessibility and adsorption of OH^- ions that improve electron transport. Moreover, the Ni_XB/MnMoO₄//AC device exhibits excellent cyclic stability with a retention of 83.4% of the original capacitance after 10000 cycles, which is due to the heterojunction layer between Ni_XB and MnMoO₄ that can improve the surface wettability without causing structural changes. Our results show that the metal boride/molybdate-based heterostructure is a new category of high-performance and promising material for the growth of advanced energy storage devices.

Keywords: amorphous nickel boride; asymmetric supercapacitors; heterostructure; high energy density; manganese molybdate.