Abstract:

Nanoparticle assembled 3D Co₃O₄ micro-flower anode materials were prepared by soft template method (surfactant cetyltrimethylammonium bromide,CTAB) combined with subsequent air atmosphere heat treatment. The synthesized sample was characterized and analyzed by employing X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), cyclic voltammetry (CV), galvanostatic charge/discharge test and electrochemical impedance spectroscopy (EIS). The unique micro-flowers structure endows the prepared Co₃O₄ anode with excellent lithium storage properties. The reversible specific capacity of about 920 mA·h·g^-1 can be achieved at the current density of 100 mA·g^-1. The synthesized electrode displays almost no capacity decay over 200 cycles with the specific capacity of 757 mA·h·g^-1 at the current density of 500 mA·g^-1. The high current cycling performance test gives the specific capacity of 476 mA·h·g^-1 even at 2 A·g^-1. The simple, effective, and low-cost preparation process of high-performance micro-flower structure transition metal oxide anode materials in this paper will greatly accelerate the practical application of conversion-type electrode materials.

Key words: Co₃O₄, micro-flower structure, nanoparticles, anode, chemical reaction, electrochemistry, lithium-ion batteries

摘要：

通过软模板法(表面活性剂十六烷基三甲基溴化铵,CTAB)结合后续空气气氛热处理制备出纳米颗粒组装三维Co₃O₄微米花负极材料。研究中采用X射线衍射分析(XRD)、场发射扫描电子显微镜(FESEM)、循环伏安测试(CV)、恒流充放电测试以及交流阻抗测试(EIS)对合成样品进行表征分析。研究结果显示，Co₃O₄微米花材料独特的结构优势赋予其优良的电化学性能，在100 mA·g^-1电流密度下电极具备约920 mA·h·g^-1的循环可逆比容量；在500 mA·g^-1电流密度下循环200次后的循环可逆比容量为757 mA·h·g^-1，容量几乎无衰减。大电流循环性能测试显示，所制备电极即使在2 A·g^-1电流密度下依旧具有476 mA·h·g^-1的循环可逆比容量。简易、有效且低成本化的高性能微米花结构过渡金属氧化物负极材料制备工艺将大大加速转换型电极材料的实际有效应用。

关键词: 四氧化三钴, 微米花结构, 纳米粒子, 负极, 化学反应, 电化学, 锂离子电池