Enhanced Supercapacitor Performance of Mn₃O₄ Nanocrystals by Doping Transition-Metal Ions

Abstract

Pristine and transition-metal-doped Mn3O4 nanocrystals shaped in octahedrons have been synthesized by hydrothermal reduction of potassium permanganate and characterized by SEM/TEM, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical experiments. The results reveal that a multistep reduction process is taking place, and the introduction of doping ions causes a direct synthesis of single-phase Mn3O4 nanocrystals. To assess the properties of Mn3O4 nanocrystals for their use in supercapacitors, cyclic voltammetry and galvanostatic charging-discharging measurements are performed. The phase stability during cycling and charge-transfer behavior are greatly improved by doping with transition metal, and Cr-doped Mn3O4 nanocrystals exhibit a maximum specific capacitance of 272 F g(-1) at a current density of 0.5 A g(-1). These doped Mn3O4 nanocrystals could be a promising candidate material for high-capacity, low-cost, and environmentally friendly electrodes for supercapacitors. In addition, these results have verified the ability of doping to improve capacitive performances of spinel-structured transition-metal oxides.

Strongly coupled graphene/Mn 3 O 4 composite with enhanced electrochemical performance for supercapacitor electrode

“…In recent years, SCs have attracted intensive research attention in view of their prominent advantages of fast charging-discharging, long cycling life and convenient operation over a wide temperature range [2,3]. As a consequence, SCs have been widely applied in hybrid electric vehicles (HEVs), backup power and other energy storage devices which require a quick and high power output in a short time [4,5].…”

“…As a consequence, SCs have been widely applied in hybrid electric vehicles (HEVs), backup power and other energy storage devices which require a quick and high power output in a short time [4,5]. Based on the different charge storage mechanisms, SCs can be categorized into two types: (i) electrical double-layer capacitors (EDLCs) and (ii) pseudocapacitors [2,6]. The properties of electrode materials are key factors for the performance of SCs, many intense researches have been focused on various electroactive materials in order to improve the performance of SCs [3].…”

“…Up to now, the carbon-based materials, including graphene, activated carbon (AC) and carbon nanotubes (CNTs), have been intensively studied for EDLCs in light of their readily accessible mesopores, low cost, eco-friendliness, and stability [7,8]. However, EDLCs are plagued by their relatively low energy density, and their capacitance are typically in the range of 75−175 F g −1 due to the restriction of the specific surface area and the pore-size distribution [2]. In contrast, pseudocapacitors can offer far higher specific capacitance and energy density [5].…”

Electric Conduction Mechanisms Study within Zr Doped Mn3O4 Hausmannite Thin Films through an Oxidation Process in Air

“…In addition to its stability, the study of the electrical transport phenomena in Mn 3 O 4 seems so far in demand for various applications such as: lithium-ion batteries (Zhen et al, 2016), supercapacitors (Luo et al, 2016;Xu et al, 2015;Yadav et al, 2016), catalysts and sensors (Saputra et al, 2013;Sharma et al, 2016) because of its low-cost, high natural abundance, great environmental compatibility and good specific capacity. Hausmannite Mn 3 O 4 thin films have been deposited by several techniques such as: the vapor phase growth method (Chang et al, 2005), the pulse laser deposition , the polyol process (Jin et al, 2015), the epitaxy , the hydrothermal method (Dong et al, 2013), the chemical bath deposition (Xu et al, 2006), the chemical successive ionic layer adsorption and reaction (SILAR) process (Gund et al, 2013) and the spray pyrolysis technique (Larbi et al, 2014). Among these deposition methods, the spray pyrolysis with safe, as cost-effective method is widely used to prepare thin film oxides with large surface area for several technological applications.…”

Tailoring the size and electrochemical performance of Mn3O4 nanoparticles by controlling the precipitation process

“…Among Mn-based oxides, Mn 3 O 4 is an interesting electrode material for application in pseudocapacitors, which should be paid much more attention because of its high theoretical capacitance and its EDLC-like behavior [15][16][17][18][19]26]. However, the application of Mn 3 O 4 is greatly limited by its low electrical conductivity, which would result in low performances such as poor chargedischarge rate and frequency response for the high-power applications (especially at a high scan rate).…”