Two-Dimensional β-MnO2 Nanowire Network with Enhanced Electrochemical Capacitance

Abstract

Conventional crystalline β-MnO2 usually exhibits poor electrochemical activities due to the narrow tunnels in its rutile-type structure. In this study, we synthesized a novel 2D β-MnO2 network with long-range order assembled by β-MnO2 nanowires and demonstrated that the novel 2D β-MnO2 network exhibits enhanced electrochemical performances. The 2D network is interwoven by crossed uniform β-MnO2 nanowires and the angle between the adjacent nanowires is about 60°. Such a novel structure makes efficient contact of β-MnO2 with electrolyte during the electrochemical process, decreases the polarization of the electrode and thus increases the discharge capacity and high-rate capability. The specific capacitance of the obtained 2D β-MnO2 network is 453.0 F/g at a current density of 0.5 A/g.

Two‐Dimensional Metal Oxide Nanomaterials for Next‐Generation Rechargeable Batteries

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Sodium‐Doped Mesoporous Ni2P2O7 Hexagonal Tablets for High‐Performance Flexible All‐Solid‐State Hybrid Supercapacitors

“…Over the past few years, considerable progress has been made in the synthesis of inorganic materials with various morphologies for exploring their potential applications in various fields. [12][13][14][15][16] In particular, inorganic materials with ap orous structure can provide ah igh surface area, large surface-tovolumer atio, and favorable structural stabilitya gainst volume expansion/contraction.T hese characteristics improve the electrochemical performance because they can lead to fast ion/ electron transfer and as ufficientc ontact interface between the active materials and electrolyte. [17][18][19] Inorganic materials doped with metal ions (such as Ni 2 + , Cu 2 + ,Z n 2 + ,M n 4 + )h ave gainedm uch interest in recent years, which can favorably alter the properties of the materials by increasingt he overall electron density as wella sc hangingt he electricalc onductivities.…”

Pine needle β-Co(OH)2 grown on Ni foam substrate for high specific capacitance and good cycling stability as advanced electrochemical pseudocapacitor materials

“…3(c)). The 3D network of b-Co(OH) 2 /NF possesses more channels and higher surface area, which enable effective electrolyte transport and more active sites accessibility, leading to the enhanced specific capacitance [20] (as confirmed by SEM). The specific capacitance of pine needle b-Co(OH) 2 /NF was calculated to be 1243 F/g, 1095 F/g, 958.5 F/g, 813.5 F/g, 761.3 F/g, 606.8 F/g at scan rates of 5, 10, 20, 40, 50 and 100 mV/s, respectively.…”