功能材料纯镍钴酸锂与掺杂后的电化学阻抗谱及红外光谱的探讨  

A Study of Functional Materials about Pure and Doped Lithium Nickel Cobalt Oxides on Their Electrochemical Impedance Spectra and Fourier Transform Infrared Spectra.

作　　者：钟耀东[1] 赵新兵[2] 强颖怀[1] 

机构地区：[1]中国矿业大学材料科学与工程学院,徐州市221116 [2]浙江大学材料系,杭州市310027

出　　处：《金属功能材料》2007年第5期24-27,共4页Metallic Functional Materials

摘　　要：功能材料纯镍钴酸锂与掺杂氟、镁的镍钴酸锂以固相煅烧后,由X衍射分析结果可知,晶形良好,没有不同阳离子互相混杂。再以电化学阻抗谱和红外光谱分析比较,三种试样的红外光谱均显示有碳酸锂的吸收峰,和(Ni,Co)O6吸收峰,经充放电循环后它们的红外光谱在充放电循环时,与电解液反应形成CH2,CH3,C-O,OCO2等官能团。由电化学阻抗分析得知电解液电阻基本不发生变化,但充放电循环可能引起材料内部发生微裂缝而增大电荷传递阻抗,至于固相与电解液界面的电阻任意变动,认为是位于固相与电解液界面的薄膜发生周期性的生长及长大到一定程度后又剥离所致。Pure and doped lithium nickel cobalt oxides were synthesized by solid-state reaction. X-ray diffraction patterns show that the erystallization is very well and there is no mixing between Li ion and （Ni, Co） ions. Their Fourier transform infrared speetra were very similar. The as-ealeined speetra eontained Li2CO3 and （Ni, Co）O6 peaks. However, the peaks of CH2 ,CH3 ,C-O,OCO2 eould be found after eharge/diseharge eyeling. Although the solution resistanee was not ehanged after eharging/diseharging eyeles, their eharge transfer resistanee and solid-eleetrolyte interfaee （SED resistanee were both ehanged through the analysis of eleetroehemieal impedanee speetra. The inereasing eharge transfer resistanee was beeause of the formation of mieroeraeks during the eyeles. The random variation of SEI resistanee was probably due to a periodieally growing and damaged on SEI film.

关 键 词：镍钴酸锂 锂离子电池 电化学阻抗谱 红外光谱 

分 类 号：TB34[一般工业技术—材料科学与工程]