掺杂对混合锰源合成锰酸锂正极材料的影响

Effect of doping on synthesis of lithium manganate cathode material from mixed manganese source

以电解二氧化锰及自带掺杂元素的四氧化三锰为混合锰源,采用高温固相法合成锰酸锂材料,通过XRD、SEM和扣电测试等方法表征材料的结构、形貌和电化学性能。研究发现,此方法合成的单晶锰酸锂材料,形貌呈类球型,(111)面面积较小,能有效抑制锰溶解的发生。通过掺杂改性,更好地稳定了材料晶体结构,有效抑制了Jahn-Teller畸变,从而得到电化学性能优异的单晶锰酸锂材料。当掺杂质量分数为0.5%LiF、0.1%Al_(2)O_(3)时,0.1 C首次放电比容量为106.11 mAh/g,首次效率可达98.07%,常温1 C循环200次容量保持率为95.94%。

In this study,electrolytic manganese dioxide and manganese tetroxide with their own doped elements were used as mixed manganese sources,and lithium manganese oxide was synthesized by high-temperature solid-state method.The structure,morphology and electrochemical properties of the materials were characterized by XRD,SEM and button-battery-test.It is found that the morphology of single crystal lithium manganate synthesized by this method is quasi-spherical and has smaller(111)surface area,which can effectively inhibit the dissolution of manganese.Through doping modification,the crystal structure of the material is better stabilized,and Jahn-Teller distortion is effectively inhibited,so the single crystal lithium manganate material obtains excellent electrochemical performance.When doped with 0.5%LiF and 0.1%Al_(2)O_(3),the initial discharge specific capacity of 0.1 C is 106.11 mAh/g,the coulombic efficiency is 98.07%,and the capacity retention rate of 200 cycles at room temperature is 95.94%.