TY - JOUR
T1 - Investigating into the intricacies of charge storage kinetics in NbMn-oxide composite electrodes for asymmetric supercapacitor and HER applications
AU - Teli, Aviraj M.
AU - Beknalkar, Sonali A.
AU - Amte, Rutuja U.
AU - Morankar, Pritam J.
AU - Yewale, Manesh A.
AU - Burungale, Vishal V.
AU - Jeon, Chan Wook
AU - Efstathiadis, Harry
AU - Shin, Jae Cheol
N1 - Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/11/25
Y1 - 2023/11/25
N2 - In this paper, we present an effortless hydrothermal method for depositing niobium and manganese composite oxides onto Ni-foam. The formation of the desired NbMn-oxide phase is confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analytical tools. In the study, we systematically investigated the effect of varying Mn concentrations on the physicochemical properties and energy storage performance of the NbMn-oxide composite. The NbMn-oxide exhibited nanoplates assembled from sphere-shaped structures along with irregularly shaped rectangular blocks of nano/micro-structures, forming a porous framework. The electrode with an Mn concentration of 0.02 M displayed an areal capacitance of approximately 5987.8 mF/cm2 and an energy density of 0.13 mWh/cm2, even at a high current density of 10 mA/cm2. Additionally, the hydrogen evolution reaction (HER) performance of the NbMn-oxide composite electrode was evaluated and it exhibited an overpotential of 86 mV to achieve a current density of 10 mA/cm². The electrode also displayed stable performance for approximately 7 h, with only a slight increase in overpotential from − 0.218 to − 0.263 V against the reversible hydrogen electrode (RHE) during the stability test. The investigation of charge storage kinetics revealed the dominance of the diffusion process over the capacitive process, with the quasi-reversible redox reactions in the composite metal-oxides responsible for the high electrochemical performance. The assembled asymmetric supercapacitor device, utilizing NbMn-2 (positive) and activated carbon (negative) electrodes, demonstrated an impressive energy density of 0.20 mWh/cm2 at a power density of 3.75 mW/cm2, coupled with exceptional cyclability (97%). These findings highlight the potential of Nb-based composite electrodes for both supercapacitor and HER water-splitting applications and underscore their significant potential for electrochemical energy conversion and storage.
AB - In this paper, we present an effortless hydrothermal method for depositing niobium and manganese composite oxides onto Ni-foam. The formation of the desired NbMn-oxide phase is confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analytical tools. In the study, we systematically investigated the effect of varying Mn concentrations on the physicochemical properties and energy storage performance of the NbMn-oxide composite. The NbMn-oxide exhibited nanoplates assembled from sphere-shaped structures along with irregularly shaped rectangular blocks of nano/micro-structures, forming a porous framework. The electrode with an Mn concentration of 0.02 M displayed an areal capacitance of approximately 5987.8 mF/cm2 and an energy density of 0.13 mWh/cm2, even at a high current density of 10 mA/cm2. Additionally, the hydrogen evolution reaction (HER) performance of the NbMn-oxide composite electrode was evaluated and it exhibited an overpotential of 86 mV to achieve a current density of 10 mA/cm². The electrode also displayed stable performance for approximately 7 h, with only a slight increase in overpotential from − 0.218 to − 0.263 V against the reversible hydrogen electrode (RHE) during the stability test. The investigation of charge storage kinetics revealed the dominance of the diffusion process over the capacitive process, with the quasi-reversible redox reactions in the composite metal-oxides responsible for the high electrochemical performance. The assembled asymmetric supercapacitor device, utilizing NbMn-2 (positive) and activated carbon (negative) electrodes, demonstrated an impressive energy density of 0.20 mWh/cm2 at a power density of 3.75 mW/cm2, coupled with exceptional cyclability (97%). These findings highlight the potential of Nb-based composite electrodes for both supercapacitor and HER water-splitting applications and underscore their significant potential for electrochemical energy conversion and storage.
KW - Charge storage kinetics
KW - Excellent cyclic stability
KW - Hydrogen evolution reaction catalysis
KW - Hydrothermal
KW - NbMn-oxide
KW - Supercapacitor
KW - Transfer coefficient
UR - http://www.scopus.com/inward/record.url?scp=85165403501&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2023.171305
DO - 10.1016/j.jallcom.2023.171305
M3 - Article
AN - SCOPUS:85165403501
SN - 0925-8388
VL - 965
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
M1 - 171305
ER -
