高容量锂离子电池Li_2MnSiO_4/C正极材料的合成和电化学性能研究（英文）

Synthesis and Electrochemical Performance of Li_2MnSiO_4/C as Cathode Materials with High Capacity for Lithium ion Batteries

在三元液相体系中合成了球形Li2MnSiO4/C复合正极材料,XRD、SEM和电化学性能测试对材料进行了表征。XRD测试表明Li2MnSiO4具有正交结构,对应Pmn21空间群。SEM显示所得样品为小于1μm的球形颗粒。将Li2MnSiO4/C组装成扣式电池进行电化学测试的结果表明,在1.54.6 V,该样品的初始充电容量达310 mAh/g,放电容量高至286 mAh/g,为理论比容量的85.9%;循环30次后放电比容量为142 mAh/g。

Carbon-coated lithium manganese silicate（Li2MnSiO4/C） spherical composite particles were synthesized by solution process in a ternary system.X-ray diffraction（XRD） test of the obtained materials displays that the Li2MnSiO4 is crystallized in an orthorhombic structure with a space group of Pmn21.Scanning electron microscopy（SEM） images of the obtained samples show that the particles are spherical with less than 1 μm sizes.The composite prepared through ternary system shows good performance as cathode materials in lithium cells at room temperature.The charge capacity of the Li2MnSiO4/C samples is 310 mAh/g,and the discharge capacity is 286 mAh/g in the first cycle in the voltage range of 1.54.6 V.A good capacity cycling maintenance of 142mAh/g after 30 cycles is obtained.