(湖南大學(xué) 新型炭材料研究所, 長(zhǎng)沙 410082)
摘 要: 研究鋰離子電池正極活性材料尖晶石LiMn2O4和LiCoO2與6種電解液充、 放電時(shí)的相容性。 用X射線衍射檢測(cè)自制的LiCoO2試樣和尖晶石LiMn2O4試樣的結(jié)構(gòu)； 用粉末微電極循環(huán)伏安法測(cè)定6種電解液在導(dǎo)電劑乙炔黑表面的氧化電位； 將制得的尖晶石LiMn2O4試樣和LiCoO2試樣在上述電解液中進(jìn)行恒電流充放電實(shí)驗(yàn)。 結(jié)果表明： 充電至高電位3.3~4.3 V（vs Li/Li+）時(shí), 如果正極活性材料表面與電解液發(fā)生不可逆反應(yīng)并在其上覆蓋一薄層電子不可導(dǎo)的鈍化膜, 則將導(dǎo)致活性材料的充、放電效率降低， 放電容量減少, 即正極活性材料與電解液的相容性差； 反之, 則相容性好；尖晶石LiMn2O4與上述6種電解液的相容性都很好，普適性強(qiáng)； LiCoO2與上述6種電解液的相容性差別較大，呈選擇性。
關(guān)鍵字: 尖晶石LiMn2O4； LiCoO2； 鋰離子電池； 相容性
（Institute of New Carbon Materials, Hunan University,
Changsha 410082, China）
Abstract: The compatibilities of six kinds of electrolytes with positive electrode active materials spinel LiMn2O4 and LiCoO2 were studied. The structures and properties of the spinel LiMn2O4 and LiCoO2 prepared were detected by XRD. The oxidation potentials of the above electrolytes on the surface of the conductive reagent, acetylene black were determined by microelectrode cyclic voltammetry experiments. The galvanostatic charge-discharge experiments of the spinel LiMn2O4 and LiCoO2 were carried out in the electrolytes. The results show that if the irreversible oxidation occurs on the interface between the positive electrode active material and the electrolyte, and a thin electron-nonconductive passivated film covers on it, both the charge-discharge efficiency and the discharge capacity of the positive electrode active material will decrease. This means that the compatibility of the electrolyte with the positive electrode active material is bad, conversely the compatibility is good. The compatibilities of the above electrolytes with the spinel LiMn2O4 are all very good. The adaptability of spinel LiMn2O4 to electrolytes is excellent, while the compatibilities of the above electrolytes with LiCoO2 are quite different. The adaptability of sample LiCoO2 to electrolytes is selective.
Key words: spinel LiMn2O4; LiCoO2; lithium ion batteries; compatibilities
