焙烧温度对锂离子电池正极材料Li2MnSiO4/C 电化学性能的影响

采用液相法合成了Li₂MnSiO₄/C复合正极材料,并研究了不同焙烧温度对材料的结构、形貌和电化学性能的影响.利用热重（TG）分析了材料前驱体的热行为,确定了合成Li₂MnSiO₄/C复合正极材料的焙烧温度范围为600-800℃.X射线衍射（XRD）测试结果表明,不同温度下合成的样品材料均具有正交结构,且空间群为Pmn2₁,同时利用扫描电子显微镜（SEM）对所得样品材料的微观形貌及颗粒大小进行了表征.将所得Li₂MnSiO₄/C复合正极材料组装成扣式电池,并在不同的电流密度下进行充放电测试,结果表明:700℃合成的样品材料电化学性能最佳,具有较高的库仑效率及很好的循环稳定性.

Calcination Temperature Effects on the Electrochemical Performance of Li_2MnSiO_4/C Cathode Material for Lithium Ion Batteries

As a new potential cathode material for lithium ion batteries,Li₂MnSiO₄/C was synthesized by a solution method.The thermal behavior of the precursor for Li₂MnSiO₄/C was measured by thermogravimetric （TG） analysis and the range of calcination temperatures from 600 to 800℃was determined.X-ray powder diffraction（XRD） patterns indicated that all the Li₂MnSiO₄/C samples crystallized in an orthorhombic structure with space group Pmn2₁.The morphology and particle size of the samples were also characterized by scanning electron microscopy（SEM）.The effects of calcination temperature on the electrochemical performance of Li₂MnSiO₄/C were studied using galvanostatic charge-discharge measurements at various current densities.The results showed that the sample prepared at 700℃exhibited a much higher coulombic efficiency and better cyclic performance than the other samples.