Synthesis of Flower-Like Nb₂Se₉ as High-Performance Anode Materials for Lithium-Ion and Sodium-Ion Batteries

Abstract

In this work, a flower-like Nb2Se9 material was obtained by a simple oil-phase-assisted synthesis route and used as an anode in lithium-ion and sodium-ion batteries first. It exhibited a high charge capacity (672.35 mAh g–1 at 100 mA g–1), good cycling stability (596.63 mAh g–1 after 250 cycles at 100 mA g–1), and outstanding rate performance (285 mAh g–1 at 5 A g–1) in lithium-ion batteries. Meanwhile, the ex situ X-ray diffraction result reveals that the lithium storage mechanism of Nb2Se9 is the conversion reaction. As an anode for sodium-ion batteries, Nb2Se9 delivered an initial reversible capacity of 342.60 mAh g–1 at the current density of 100 mA g–1 and was stabilized at 230.36 mAh g–1 over 500 cycles after the initial 50 cycles. Excellent electrochemical performance may be attributed to the special micro–nano hierarchical structure of the flower-like Nb2Se9 material, which greatly promotes ion diffusion and provides abundant active sites. These results indicate that flower-like Nb2Se9 is a promising anode material for both lithium-ion and sodium-ion batteries.

Dual Regulation of Metal Doping and Adjusting Cut‐Off Voltage for MoSe2 to Achieve Reversible Sodium Storage

“…[23,24] Up to now, several kinds of 2D transition metal selenides have been successfully prepared and employed in storing Na-ions, such as MoSe 2 , WSe 2 , VSe 2 , and Nb 2 Se 9 . [25][26][27][28][29] Despite the above benefits, the nanosheets of 2D transition metal selenides bonded with van der Waals interaction are vulnerable to aggregation, decreasing the exposed active sites and destroying the unique energy storage performance of 2D structure in SIBs. [30] Moreover, the poor intrinsic electronic conductivity, the significant volume expansion, and irreversible conversion reaction in storing Na-ions limit the advantage of 2D transition metal selenides as well.…”

Colloidal synthesis of 1-D van der Waals material Nb2Se9: study of synergism of coordinating agent in a co-solvent system

“…5,6 Furthermore, various synthesis methods, including solid-state reaction, chemical vapour transport, and flux method, resulted in numerous applications in solar cells, electrocatalysts, Li-ion batteries, gas sensors, and bio-application. 7,8 Only recently has niobium selenide been synthesised using solution-based colloidal synthesis, which addresses the issue of high reaction temperature and high vacuum processing, additional post-synthetic treatments, scalability, and expensive apparatus. 7,9 The colloidal synthesis enables access to thermodynamic and kinetic growth control of nanoparticles by the greatest variety of reaction conditions, such as concentration of reactants, growth time and temperature, heating rate, material sources, stabilisers, and medium identity.…”

“…7,8 Only recently has niobium selenide been synthesised using solution-based colloidal synthesis, which addresses the issue of high reaction temperature and high vacuum processing, additional post-synthetic treatments, scalability, and expensive apparatus. 7,9 The colloidal synthesis enables access to thermodynamic and kinetic growth control of nanoparticles by the greatest variety of reaction conditions, such as concentration of reactants, growth time and temperature, heating rate, material sources, stabilisers, and medium identity. While these systematic variations of tuneable parameters increase the overall complexity of the procedure, they allow for exquisite governance over nucleation and growth mechanism, mediating regulated size and morphological control.…”

“…5,6 Furthermore, various synthesis methods, including solid-state reaction, chemical vapour transport, and flux method, resulted in numerous applications in solar cells, electrocatalysts, Li-ion batteries, gas sensors, and bio-application. 7,8 Only recently has niobium selenide been synthesised using solution-based colloidal synthesis, which addresses the issue of high reaction temperature and high vacuum processing, additional post-synthetic treatments, scalability, and expensive apparatus. 7,9…”

Liquid Precursor-Assisted Chemical Vapor Deposition of One-Dimensional van der Waals Material Nb2Se9: Tunable Growth for Room-Temperature Gas Sensors

“…It has been reported that theoretically, an indirect-to-direct band transition occurs when Nb 2 Se 9 is exfoliated into an ideal unit chain, and density functional theory calculations have indicated that the mobility of the (010) plane can reach up to 2400 cm 2 /V s . In addition, this 1D material has a high specific surface area and many active sites, meaning it is receiving abundant attention as a catalyst and sensor device. − So far, fabrication methods for Nb 2 Se 9 as a nanoscale device have involved a single crystal being synthesized by a solid-state reaction, after which mechanical or chemical exfoliation has been applied. − , However, in the case of mechanical exfoliation, it is difficult to obtain regular and uniform peeling of the material. In addition, chemical exfoliation can reduce the sensitivity of sensors or catalysts based on surface reactions (adsorption and desorption) caused by surface residues left by the dispersant …”