镍铬复合掺杂尖晶石锰酸锂的合成与性能研究

Synthesis and performance of the Ni-Cr multi-doped spinel-lithium manganese oxides

采用高温固相合成法制备了LiMn2O4、Ni和Cr以及Ni-Cr复合掺杂的锂离子电池用锰酸锂正极材料。采用扫描电子显微镜、X射线粉末衍射和充放电性能测试等手段研究了材料的形貌、物相和电化学行为。结果表明:掺杂改善了材料的形貌,稳定了材料的结构。样品LiMn1.85Ni0.075Cr0.075O4的表面光滑,粒度分布范围小,为单一的尖晶石结构的物相。其首次放电容量为81.2mAh/g,300次循环后容量保持率为首次的91%,表现出优异的循环性能。

LiMn2O4 and Ni-Cr co-doped spinel LiMn2-x MxO4 （M= Ni, Cr, x= 0.15） as cathode for lithium-ion batteries were fabricated by high temperature solid--state reaction method. Morphologies, phases and electrochemical properties of the materials were obtained by SEM, XRD and charge-discharge testing, The results showed that morphology and structure of materials were improved due to doping. The sample of LiMn1.85 Ni0.075 Cr0. 075O4 had a smoother surface and a narrow particle size distribution. The XRD spectra showed that the sample had pure spinel structure phase. It dilivers an discharge capacity of 81.2mAh/g for the first cycle and still retained 91% of the initial capacity after 300 cycles. It exhibi- ted an excellent cycling stability.