xLi2MnO3-（1-x）Li[Ni0.8Co0.15Al0.05]O2（0.5≤x≤0.8）的结构和电化学性能

Structure and Electrochemical Properties of xLi2MnO3-（1-x）Li[Ni0.8Co0.15Al0.05]O2（0.5≤x≤0.8）

采用喷雾干燥法结合后续的热处理,成功地制备了一系列新型的基于富锂层状固溶体Li2MnO3和Li[Ni0.8Co0.15Al0.05]O2结合的xLi2MnO3-(1-x)Li[Ni0.8Co0.15Al0.05]O2(0.5≤x≤0.8)材料,并对其晶体结构、表面形貌、元素价态以及电化学性能进行了一系列的研究。实验结果表明,随着x值的增大,材料的晶体结构逐渐从层状的Li[Ni0.8Co0.15Al0.05]O2过渡到类Li2MnO3结构。对样品进行淬火处理对晶粒的微观晶体结构和元素价态产生复杂影响,这种变化使得淬火的样品表现出较好的电化学性能。其中x=0.6的样品淬火后表现出较好的电化学性能,100次循环后可逆容量可达209mAh·g^-1。

A new type of material based on the rich lithium-layered solid solution material system,xLi2MnO3-(1-x)Li[Ni0.8Co0.15Al0.05]O2 (0.5≤x≤0.8) was obtained by spray dry process with post annealing treatment.The effect of x value on the structural and electrochemical properties of the materials was investigated by XRD,SEM,TEM,XPS,EIS and charge-discharge tested.Our results suggested that the crystal structure of the sample gradually changed from layered Li[Ni0.8Co0.15Al0.05]O2 type to Li2MnO3 type with the increase of x.Moreover,the quenching treatment in liquid nitrogen was helpful to improve the electrochemical properties of xLi2MnO3-(1-x)Li[Ni0.8Co0.15Al0.05]O2 (0.5≤x≤0.8),which was attributed to the change in terms of the micro structure and valence of the transit metals caused by quenching.The sample with x=0.6 after quenching treatment showed good electrochemical properties,with above 209 mAh·g^-1 of reversible capacity after 100 cycles.