不同NiCO2O4晶体形貌对其超电容性能的影响

Influence of Different Morphologies on the Supercapacitive Performance of NiCo2O4 Particles

采用一步溶剂热法制备出尖晶石型NiCO2O4样品.该方法一次成型,反应后不需再次煅烧,简单易操作,可实现大批量合成.采用Raman、XRD、FT-IR和SEM对其进行表征,并采用循环伏安(CV)、恒电流充放电(GCD)及交流阻抗(EIS)对其电化学性能进行分析,探索反应时间对NiCO2O4晶体的形貌和超电容性能的影响.结果表明:在120℃下反应12 h时,得到的NiCO2O4晶体为微纳米球形结构,其具有良好的电化学性能,且可逆性较好.在0.5 A/g时,放电比电容达504.58 F/g,经过1000次循环,其放电比电容保持率约为82%.

One-step solvothermal method is employed to synthesize spinel-type NiCo2O4 electrode materials with various microstructures.The synthesis method is facile and efficient,and the final samples can be directly obtained without the subsequent calcination process,which is feasible to realize the large-scale fabrication.The composition and microstructures of NiCo2O4 are investigated by Raman,XRD,FT-IR and FE-SEM,and electrochemical performance is studied by cyclic voltammetry(CV),galvanostatic charge and discharge(GCD)and electrochemical impedance spectroscopy(EIS).It turns out that reaction time of the solvothermal has effect on the microstructure and electrochemical properties of NiCo2O4.NiCo2O4 microspheres can be obtained when the solvothermal reaction is at 120℃for 12 h.Moreover,the NiCo2O4 microspheres have superior reversibility.The specific capacitance of 504.58 F/g is obatined at a current density of 0.5 A/g.Additionally,the NiCo2O4 microspheres deliver an outstanding cycling stability with about 82%of the capacitance retention after 1000 GCD cycles.