锂离子电池正极材料Li_(1.2)Mn_(0.54-x)Ni_(0.13)Co_(0.13)Zr_xO_2的制备及电化学性能  

Preparation and Electrochemical Performances of Li_(1.2)Mn_(0.54-x)Ni_(0.13)Co_(0.13)Zr_xO_2 Cathode Materials for Lithium-Ion Batteries

作　　者：任祥忠[1] 刘涛[1] 孙灵娜[1] 张培新[1] 

机构地区：[1]深圳大学化学与化工学院,广东深圳518060

出　　处：《物理化学学报》2014年第9期1641-1649,共9页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21000174);深圳市战略新兴产业发展基金(JCYJ20120613163733279;JCYJ20130329113849606)资助项目~~

摘　　要：为了改善富锂锰基正极材料Li1.2Mn0.54Ni0.13Co0.13O2的循环性能,采用燃烧法合成了正极材料Li1.2Mn0.54-xNi0.13Co0.13ZrxO2(x=0.00,0.01,0.02,0.03,0.06).通过X射线衍射(XRD)和扫描电镜(SEM)对其结构与形貌进行了表征,利用恒电流充放电测试,循环伏安(CV)及电化学交流阻抗谱(EIS)技术对其电化学性能进行测试.结果表明,Li1.2Mn0.54-xNi0.13Co0.13ZrxO2(x=0.00,0.01,0.02,0.03,0.06)正极材料均具有α-NaFeO2型层状结构;在室温,2.0-4.8 V电压范围,以0.1C和1.0C(充放电电流以1.0C=180 mA·g-1计算)倍率充放电进行测试,样品Li1.2Mn0.52Ni0.13Co0.13Zr0.02O2的首次放电比容量分别为280.3和206.4 mAh·g-1.其中,在1.0C倍率下,100次循环后容量保持率由原来的73.2%提高到88.9%;以5.0C倍率充放电进行测试,经50次循环后,掺杂正极材料的放电比容量为76.5 mAh·g-1,而未掺杂材料仅有15.0 mAh·g-1.在50、25和-10°C,2.0C倍率条件下,掺杂正极材料的电化学性能均得到有效改善,其中,在-10°C经过50次循环后正极材料Li1.2Mn0.52Ni0.13Co0.13Zr0.02O2比未掺杂的正极材料相比,其放电比容量提高了61.1%.To improve the cycling performance of lithium-rich cathode materials, Li1.2Mn0.54Ni0.13Co0.13ZrxO2 and Li1.2Mn0.54-xNi0.13Co0.13ZrxO2 （x=0.00, 0.01, 0.02, 0.03, and 0.06） were synthesized by a combustion method. The structure and morphology were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The electrochemical performances were examined by cyclic voltammetry （CV）, electrochemical AC impedance spectroscopy, and galvanostatic charge-discharge cycling. The results indicate that all of the doped samples have a layer of α-NaFeO2. When charged and discharged at 0.1 C and 1.0C （1.0C=180 mA·g^-1） in the voltage range of 2.0-4.8 V, the initial discharge capacities of Li1.2Mn0.52Ni0.13Co0.13ZrxO2 were 280.3 and 206.4 mAh·g^-1, respectively. Moreover, the capacity retention after 50 cycles improved from 73.2% to 88.9% at 1.0C at room temperature. Meanwhile, this system delivered a higher discharge capacity of 76.5 mAh ·g^-1 than that of the bare materials （15 mAh·g^-1） at 5.0C after 50 cycles. Electrochemical performances of the doped samples were improved at a 2.0C rate at different temperatures （50, 25, and -10 ℃）. Furthermore, compared with the undoped material, the specific discharge capacity increased by 61.1% at -10 ℃ after 50 cycles.

关 键 词：燃烧法 锂离子电池 正极材料 富锂材料 掺杂 

分 类 号：TM912[电气工程—电力电子与电力传动]