间苯二酚–甲醛辅助溶胶–凝胶法制备纳米Li2MnSiO4/C正极材料

采用间苯二酚–甲醛辅助溶胶–凝胶法制备了纳米Li₂MnSiO₄/C正极材料, 采用X射线衍射(XRD)、扫描电镜(SEM)和恒流充放电测试等方法对材料的结构、形貌以及电化学性能进行了分析和表征。结果表明, 所制备的样品属于正交晶系Pmn21空间群, 物相纯度很高, 颗粒尺寸细小(50 nm左右)且分布均匀, 并具有良好的电化学性能, 首次放电比容量为105.7 mAh/g, 50次循环后容量保持率高达90.7%。XRD图谱显示, 经过充放电循环后, Li₂MnSiO₄能始终保持稳定的晶体结构, 表明间苯二酚-甲醛在烧结过程中形成的网络包覆碳层不仅提高了材料的电子电导率, 还维持了材料结构的稳定。

Li2MnSiO4/C Nanocomposite Prepared by Resorcinol-Formaldehyde Assisted Sol-Gel Method

Li₂MnSiO₄/C nanocomposite was prepared by a resorcinol-formaldehyde assisted Sol-Gel method. The crystalline structure, morphology and electrochemical performances of the products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and galvanostatic charge/discharge test. The results demonstrate that the as-prepared nanocomposite has a highly pure Pmn21 orthorhombic structure with uniformly distributed particle size of about 50 nm and exhibits good electrochemical performance. Li₂MnSiO₄/C cathode can deliver an initial discharge capacity of 105.7 mAh/g with 90.7% capacity retention over 50 charge-discharge cycles. It is also found that the crystalline structure of Li₂MnSiO₄ almost remains stable after charge-discharge cycling, indicating that the coated carbon layer formed by pyrolysis of resorcinol-formaldehyde can not only enhance the electronic conductivity, but also maintain the structural stability of the Li₂MnSiO₄/C nanocomposite.