Facile Synthesis of Sea-Urchin-like VN as High-Performance Anode for Lithium-Ion Batteries

Abstract

Lithium-ion batteries are still the main theme of the contemporary market. Commercial graphite has struggled to meet the demand of high energy density for various electronic products due to its low theoretical capacity. Therefore, exploring for a new anode with high capacity is important. Vanadium nitride has attracted widespread attention due to its high theoretical specific capacity and good chemical/thermal stability. However, vanadium nitride is accompanied by huge volume expansion and nanoparticle agglomeration during the electrochemical reaction, which limits its application. Herein, sea-urchin-like vanadium nitride (SUK-VN) was successfully prepared with a simple hydrothermal method combined with an annealing strategy to boost the actual capacity of the vanadium nitride. The special sea-urchin-like morphology effectively suppresses the agglomeration of vanadium nitride nanoparticles and exposes more reactive sites, which facilitates the electrochemical performance of electrode materials. In the half-cells, sea-urchin-like vanadium nitride exhibits a specific capacity of 361.5 mAh g−1 at 0.1 A g−1 after 60 cycles, and even still achieves a specific capacity of 164.5 with a Coulomb efficiency of approximately 99.9% at 1 A g−1 after 500 cycles. Such a strategy provides the potential to enhance the electrochemical properties of vanadium nitride anodes in terms of solving the nanoparticle agglomeration.

Ultrafine VN quantum dots modified with a nitrogen-doped reduced graphene oxide anode material for enhanced rate capability and lifespan of lithium-ion batteries

“…Yet, the weak interconnection between VN nanoparticles, coupled with the considerable volumetric change during cycling, results in severe particle comminution and loss of particle-particle contact. 27,28 Moreover, the nanomaterials tend to agglomerate during the charge and discharge processes, adversely impacting the electrochemical performance. The greatest weakness of VN is its poor cycling retention and rate capability, which result from a partially nonreversible redox reaction and damage to the structure.…”