原料对强化固相反应合成的LiNi1/3Co1/3Mn1/3O2粉末电化学性能的影响

Impact of Raw Materials on Electrochemical Properties of LiNi1/3Co1/3Mn1/3O2 Powders Prepared by Enhanced Solid State Reaction

分别以碳酸盐和氧化物为原料,利用强化固相反应直接合成LiNi1/3Co1/3Mn1/3O2超微粉末。采用X射线衍射仪和扫描电子显微镜表征了以不同原料合成的产物粉末在结构和形貌上的差异,并分别在常温(25℃)和高温(55℃)下对产物进行了电化学性能测试。结果表明:以碳酸盐为原料的产物LC-BM20相比于以氧化物为原料的产物LO-BM20具有更为完整的晶体结构和更细小的粒径分布;当温度为25℃时,LC-BM20在0.1C(1C=270mA/g)倍率下的首周库伦效率高达91.9%,在6C倍率下的放电比容量仍保持在133.0mAh/g,在1C倍率下循环100次后的容量保持率达到88.2%;当温度为55℃时,LO-BM20的性能更优异,在0.1C倍率下的首次放电比容量达到197.0mAh/g,在1C倍率下循环100次后的容量保持率达到82.9%。

The ultrafine LiNi1/3Co1/3Mn1/3O2 powders were directly synthesized using carbonates or oxides via an enhanced solid state reaction.The microstructures,morphologies and electrochemical properties at 25/55℃ of product powders were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and electrochemical workstation.The results shows that the well-ordered product powders with a finer size distribution are synthesized using carbonates.At 25℃,the initial coulomb efficiency of LC-BM20 reaches 91.9%at 0.1C(1C=270 mA/g)rate,discharge capacity of 133.0 mAh/g is delivered at 6C rate.After cycling 100 times,the capacitance retention still maintains 88.2%at the rate of 1C.At 55℃,LO-BM20 shows better electrochemical properties,the initial discharge capacity of LO-BM20 is 197.0 mAh/g at 0.1C.After cycling 100 times,the capacitance retention still maintains 82.9%at the rate of 1C.