球形MnO/GO复合材料制备及锂离子电池性能研究

Synthesis and lithium ion battery performance of MnO/GO composites

利用简单的溶剂热法,以四水合乙酸锰为锰源、尿素为沉淀剂,在氧化石墨烯(GO)存在条件下,一步制得了球形碳酸锰与GO组成的前驱物。该前驱物在氮气氛围中于500℃煅烧4 h,成功转化为由一氧化锰(Mn O)微球与GO组成的复合材料Mn O/GO。利用X射线衍射仪(XRD)和场发射扫描电镜(FESEM)分别对材料的物相和形貌进行了表征,并对材料的锂电性能进行了研究。结果表明:复合材料首次放电比容量为1 326.8 m A·h/g(0.1 A/g,0.01~3.00 V);在电流密度为0.2 A/g条件下,循环100次后材料的放电比容量仍能保持在626.5 m A·h/g。复合材料的电化学性能较单一Mn O微球有显著提高。

The composite precursors consisting of spherical MnCO3 particles and graphene oxide（GO） were successfully synthesized with Mn Ac2·4 H2O as Mn^（2＋） resource in the presence of urea and graphene oxide（GO） by simple solvothermal method.After calcined at 500 ℃ for 4 h in N2 subsequently,the precursors converted into Mn O/GO composites on a large scale.The composition and morphology of the materials were characterized with XRD and field emission scanning electron microscope（FESEM）.The electrochemical energy storage properties of as-prepared Mn O/GO composites were also investigated.It was found that the specific capacity of Mn O/GO composites reached 1 326.8 m A·h/g at 0.1 A/g（0.01 ~3.00 V）,based on the calculation from the first discharge curve. In addition,the specific capacity of the materials still maintained at 626.5 m A·h/g,after cycling for 100 times at 0.2 A/g.Compared with pristine Mn O microspheres,the electrochemical properties of as-prepared Mn O/GO composites showed enhanced electrochemical performances.