| 球磨辅助高温固相法制备Li1.0Na0.2Ni0.13Co0.13Mn0.54O2正极材料及其性能 |
| Synthesis and Properties of Cathode Material Li1.0Na0.2Ni0.13Co0.13Mn0.54O2 Prepared by Ball-Milling Assist High Temperature Solid State Method |
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| 摘要: 以乙酸盐(乙酸锂、乙酸钠、乙酸钴、乙酸镍、乙酸锰等)为原材料,采用球磨辅助高温固相法制备Li1.0Na0.2Ni0.13Co0.13Mn0.54O2正极材料。借助XRD、SEM等表征材料的结构和形貌,利用循环伏安、恒流充放电、交流阻抗等方法研究材料的电化学性能。结果表明,钠的掺杂导致颗粒表面光滑度降低,形成Na0.77MnO2.05新相。0.05C活化过程中,掺钠样品和未掺钠样品首次放电比容量分别为258.4mAh·g-1和215.8mAh·g-1,库伦效率分别为75.2%和72.8%;2C放电比容量分别为116.3mAh·g-1和106.2mAh·g-1。研究发现,掺钠可减小首次充放电过程的不可逆容量,提高容量保持率;改善倍率性能与容量恢复特性;降低SEI膜阻抗和电荷转移阻抗;掺钠后样品首次循环就可以基本完成Li2MnO3组分向稳定结构的转化,而未掺杂的样品需要两次循环才能逐步完成该过程;XPS结果表明,掺钠样品中Ni2+、Co3+、Mn4+所占比例明显提高,改善了样品的稳定性和电化学性能;循环200次后的XRD结果表明掺钠与未掺钠材料在脱嵌锂反应中的相变化过程基本一致,良好有序的层状结构遭到破坏是循环过程中容量衰减的主要原因。 |
| 关键词: 锂离子电池 Li1.0Na0.2Ni0.13Co0.13Mn0.54O2 球磨 掺钠 |
| 基金项目: 国家自然科学基金面上项目(No.21471135)资助。 |
| Abstract: The cathode material Li1.0Na0.2Ni0.13Co0.13Mn0.54O2 was synthesized by ball-milling assist high temperature solid state method with acetate (lithium acetate, sodium acetate, cobaltous acetate, nickel acetate, manganese acetate) as raw materials. The structure, morphology were characterized by XRD, SEM. The electrochemical properties were investigated by cyclic voltammetry, charge-discharge, and electrochemical impedance spectroscopy. The results showed that doped sodium causes the surface smoothness reduced and the formation of new phase Na0.77MnO2.05. The initial charge and discharge capacities are 258.4 mAh·g-1 and 215.8 mAh·g-1 of the sample doped sodium and bank, respectively, with the initial coulombic efficiencies of 75.2% and 72.8% at a rate of 0.05C; their discharge capacity was 116.3 mAh·g-1 and 106.2 mAh·g-1 at a rate of 2C. Sodium doped can reduce the irreversible capacity in the initial charge/discharge cycle, improve the discharge specific capacity retention, improve the rate performance and capacity recovery features, reduce the SEIfilm impedance and charge transfer impedance. The sample doping sodium can basically complete the transformation of the Li2MnO3 to the stable structure at the first cycle, however, the bank sample need two cycles to complete the transformation process. The XPSresult showed that the proportion of Ni2+, Co3+, Mn4+ increased significantly after sodium doped which can improve the stability and the electrochemical properties of the sample. The XRDresults after 200 cycles showed that the sample doping sodium and the bank have a basically consistent phase change in the reaction of insertion/deinsertion of lithium ion and the damage of good layered structure leads to poor cycling stability. |
| Keywords: lithium ion battery Li1.0Na0.2Ni0.13Co0.13Mn0.54O2 ball milling sodium-doped |
| 投稿时间：2015-12-30 修订日期：2016-04-25 |
| 摘要点击次数: 1682 |
| 全文下载次数: 1887 |
| 王力臻,易祖良,张林森,方华,王诗文.球磨辅助高温固相法制备Li1.0Na0.2Ni0.13Co0.13Mn0.54O2正极材料及其性能[J].无机化学学报,2016,32(6):1009-1018. |
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