为了研究酸化条件对V2O5粉末结构和电化学性能的影响,利用HNO3和H2C2O4酸化NH4VO3溶液,经水热和后续热处理制备了V2O5粉体。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和电化学工作站等对V2O5粉体的微观结构与电化学性能进行了测试。结果表明,所得粉体为纯V2O5相,前驱体溶液的pH值和酸化所用酸的酸根阴离子影响了最终粉体的晶体发育和微观结构。其中,利用HNO3酸化NH4VO3溶液至pH值=3制得的粉体为直径约100nm的纳米棒,在0.5和1C的放电速率下循环30次后,放电比容量仍有150mAh/g左右,且大电流放电性能更好。
In order to investigate the effects of acidification conditions on its microstructure and electrochemical performance,vanadium pentoxide powder was prepared by hydrothermal synthesis and post heat treatment of ammonium metavanadate solution which was acidized by nitric acid or oxalic acid.The microstructure and electrochemical performance of the powder were investigated by X-ray diffraction(XRD),field emission scanning electron microscope(SEM),transmission electron microscope(TEM) and electrochemical workstation,respectively.The results showed that the powder was pure vanadium pentoxide.Both the pH value of the precursor solution and the radical anion of the used acid had influence on the crystal growth and microstructure of the final powder.Among all,the powder obtained by nitric acid acidizing ammonium metavanadate solution to pH=3 was nanorods about 100nm in diameter.Its 30th discharge specific capacities were both about 150mAh/g at 0.5 and 1C discharge rate,and behaved better at rate capability.