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.