形貌对LiNi0.5Mn1.5O4正极材料性能影响研究

Effect of morphology on the Properties of Cathode Material LiNi0.5Mn1.5O4

采用高温固相法通过不同混料介质与相应的干燥方法合成了形貌为球状和分散状的LiNi0.5Mn1.5O4。利用FE-SEM、XRD及充放电性能测试等手段对比了材料的形貌、物相和电化学行为。结果表明:分散状的材料由于一次粒子更小具有优良的电化学性能,0.2 C倍率下材料的首次放电比容量为135 mAh/g,12 C倍率下放电比容量为115 mAh/g。1C倍率充放电循环50次容量保持率为99.5%。

LiNi0.5Mn1.5O4 with spherical and dispersive morphology was synthesized by high temperature solid-state reaction method through different mixing medium and corresponding drying method.The as-prepared samples were characterized by X-ray Diffraction and Field Emission Scanning Electronic Microscope for identifying their phase and morphology.For estimating their electrochemical performance,the samples were measured by charge-discharge test.The results showed that the dispersive morphology materials had excellent electrochemical properties due to the smaller primary particles.The specific discharge capacity is about 135 mAh/g at 0.2 C.When the discharge rate increases to 12 C,the specific discharge capacity can reach 115 mAh/g.Meanwhile,this sample also shows good cycling stability,the specific discharge capacity can retain 99.5%compared to the initial discharge capacity.