锂离子电池正极材料V_2O_5多孔微球的合成及电化学性能研究

Synthesis and Improved Electrochemical Property of V_2O_5 Porous Microspheres for Cathode of Lithium Ion Battery

多孔结构V_2O_5材料在锂离子嵌入和循环稳定性方面有明显优势而引起广泛关注,然而通过简易方法来制备均匀且具有多孔结构的V_2O_5微球仍面临挑战。本文以偏钒酸铵作为钒源,通过简单的一步溶剂热反应后置于大气中进行烧结,最后制备了V_2O_5多孔微球。采用X射线衍射(XRD)、扫描电镜(SEM)以及电化学测试等手段对其进行表征和测试。结果表明,V_2O_5多孔微球作为锂离子电池正极材料具有良好的电化学性能,其首次放电比容量在0.2 C、1 C和4 C倍率时分别为249.7 m Ah·g-1、212 m Ah·g-1和160.1 m Ah·g-1,同时也表现出了良好的循环性能,其在1 C条件下循环50圈后的比容量为172.8 m Ah g-1,其保持率约为81%。

Porous-structured V2O5 materials have drawn extensive interests because of their advantageous for facile Li＋ion insertion and good cycling stability. However,the controllable fabrication of V2O5 materials with high uniformity and porous structure through simple synthesis procedures still remains challenging. The porous structure V2O5 microsphere was successfully fabricated via one-step solvothermal treatment using NH4VO3 as the source of vanadium followed by subsequent air annealing. The samples were characterized by XRD,SEM and electrochemical measurements. The results indicated the synthesized V2O5 porous microspheres exhibited well improved electrochemical performance. It delivered a high initial reversible capacity of 249. 7 m A h·g-1 at 0. 2 C,212 m Ah·g-1 at 1 C and 160. 1 m Ah·g-1 at 4 C,and it also exhibited good cycling stabilities,a capacity of 172. 8 m Ah·g-1 was obtained after 50 cycles at 1 C with a capacity retention about 81%.