High-Performance MnO₂ Nanowire/MoS₂ Nanosheet Composite for a Symmetrical Solid-State Supercapacitor

Abstract

To improve the production rate of MoS 2 nanosheets as an excellent supercapacitor (SC) material and enhance the performance of the MoS 2 -based solid-state SC, a liquid phase exfoliation method is used to prepare MoS 2 nanosheets on a large scale. Then, the MnO 2 nanowire sample is synthesized by a one-step hydrothermal method to make a composite with the as-synthesized MoS 2 nanosheets to achieve a better performance of the solid-state SC. The interaction between the MoS 2 nanosheets and MnO 2 nanowires produces a synergistic effect, resulting in a decent energy storage performance. For practical applications, all-solid-state SC devices are fabricated with different molar ratios of MoS 2 nanosheets and MnO 2 nanowires. From the experimental results, it can be seen that the synthesized nanocomposite with a 1:4 M ratio of MoS 2 nanosheets and MnO 2 nanowires exhibits a high Brunauer–Emmett–Teller surface area (∼118 m 2 /g), optimum pore size distribution, a specific capacitance value of 212 F/g at 0.8 A/g, an energy density of 29.5 W h/kg, and a power density of 1316 W/kg. Besides, cyclic charging–discharging and retention tests manifest significant cycling stability with 84.1% capacitive retention after completing 5000 rapid charge–discharge cycles. It is believed that this unique, symmetric, lightweight, solid-state SC device may help accomplish a scalable approach toward powering forthcoming portable energy storage applications.

Facile Synthesis of Biocarbon-Based MoS2 Composite for High-Performance Supercapacitor Application

“…On the other hand, pseudocapacitor electrodes are made from transition-metal oxides (TMO) and transition-metal sulfides (TMS), which store charges by their rapid and reversible Faradaic behavior aimed at high specific capacitance. , TMO, such as RuO 2 , NiO, MoS 2 , and MnO 2 , have been extensively investigated for their pseudocapacitor output in aqueous Na 2 SO 4 electrolyte . Among these compounds, molybdenum disulfide (MoS 2 ) is a well-known electrode material used for energy conservation. , MoS 2 is not just employed for lithium-ion batteries as a layered assembly, but it also has potential in pseudocapacitors because the oxidation state of Mo can range from +2 to +6. The theoretical capacitance of MoS 2 is 1403 F g –1 .…”

“…10 Among these compounds, molybdenum disulfide (MoS 2 ) is a well-known electrode material used for energy conservation. 11,12 MoS 2 is not just employed for lithium-ion batteries as a layered assembly, but it also has potential in pseudocapacitors because the oxidation state of Mo can range from +2 to +6. The theoretical capacitance of MoS 2 is 1403 F g −1 .…”

Single-Step Synthesis of Ni-Doped MoS2 Nanostructures for Symmetrical Supercapacitor Devices

“…However, despite the increase in electrical conductivity, the doping of nickel does not significantly affect the drift current, and thus, the power density remains the same as that of the undoped sample. In other words, the higher doping concentration of nickel merely increases the rate of energy charge and discharge without significantly affecting its output power E areal = C sp normalΔ V 2 2 × 3600 P areal = 3600 × E areal dt Energy density and power density were derived from expressions 8 and 9, respectively, where C sp is the specific capacitance (F cm –2 ), Δ V is the potential difference (volt), and dt is the discharging time (s).…”

Microwave‐Induced Rapid Synthesis of MoS2@Cellulose Composites as an Efficient Electrode Material for Quasi‐Solid‐State Supercapacitor Application

“…The highest E D , 40.84 Wh kg À1 , and P D , 400 Wk g À1 , were observed for MoS 2 @Cellulose (Figure 8e) and compared with other MoS 2 composites-based electrode materials. [29,32,[38][39][40][41][48][49][50][51] The comparison of specific energy and power density of cellulose, MoS 2 , and MoS 2 @Cellulose is given in (Table S3, Supporting Information). The outstanding interfacial contact between MoS 2 nanosheets and cellulose facilitates the transport of charges through the matrix.…”