(1. 華南農(nóng)業(yè)大學(xué) 理學(xué)院 生物材料研究所，廣州 510642；
2. 中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用共沉淀法制備鋰離子電池?fù)诫s型層狀LiNi1/3Co1/3Mn1/3−xMxO2(M=Mg、Al、Cr)正極材料。采用X射線(xiàn)衍射、掃描電鏡、充放電實(shí)驗(yàn)和交流阻抗實(shí)驗(yàn)對(duì)LiNi1/3Co1/3Mn1/3−xMxO2正極材料的結(jié)構(gòu)、形貌、電化學(xué)性能以及動(dòng)力學(xué)參數(shù)進(jìn)行表征。結(jié)果表明：當(dāng)摻雜量x=0.05時(shí)，Mg2+、Al3+摻雜的正極材料在2.8~4.3 V、0.1C下的首次放電比容量分別為139.2、151.6 mA∙h/g，20次循環(huán)后的容量保持率分別為98.8%和96.7%；摻雜Mg2+或Al3+均能提高LiNi1/3Co1/3Mn1/3O2的交換電流密度和鋰離子擴(kuò)散系數(shù)。結(jié)合實(shí)驗(yàn)結(jié)果和摻雜離子的離子半徑和化學(xué)穩(wěn)定性，解釋了摻雜離子在LiNi1/3Co1/3Mn1/3O2晶格中的占位及其在充放電過(guò)程中的作用。
關(guān)鍵字: 鋰離子電池；正極材料；層狀LiNi1/3Co1/3Mn1/3O2；摻雜；改性；電化學(xué)性能
cathode materials with doping multiple components
（1. Institute of Biomaterial, College of Science, South China Agricultural University, Guangzhou 510642, China;
2. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Layered LiNi1/3Co1/3Mn1/3−xMxO2 (M= Mg, Al, Cr) cathode materials for lithium-ion battery were synthesized by co-precipitation method. The structures, morphologies, electrochemical properties and kinetic parameters of the LiNi1/3Co1/3Mn1/3−xMxO2 cathode materials were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), charge/discharge tests and electrochemical impedance spectroscopy (EIS). The results show that the LiNi1/3Co1/3Mn1/3−xMxO2 cathode materials (M=Mg2+, Al3+; x=0.05) exhibit initial capacity of 139.2 and 151.6 mA∙h/g in the voltage range of 2.8−4.3 V, and at 0.1C rate, the capacities retain 98.8% and 96.7% after 20 cycles, respectively. Mg2+ or Al3+ doping can enhance the exchange current density and diffusion coefficient of LiNi1/3Co1/3Mn1/3−xMxO2 materials. Based on the ionic radius and chemical stability of doped metal ions, the occupation in the structure and the role of the doped metal ions during charge-discharge cycling were discussed.
Key words: lithium-ion battery; cathode materials; layered LiNi1/3Co1/3Mn1/3O2; doping; modification; electrochemical properties
