沉淀法制备Na_(0.7)MnO_(2.05)及其水基超级电容器性能测试

Na_(0.7)MnO_(2.05) via Chemical Precipitation Synthesis as an Electrode Material for Aqueous Na-ion Supercapacitors

以Mn(NO_3)_2和NaOH为原料,采用沉淀法合成了用作超级电容器电极材料Na_(0.7)MnO_(2.05).扫描电子显微镜(SEM)观察结果表明所制备样品呈层状板块形貌.电化学测试结果表明,Na_(0.7)MnO_(2.05)是一种性能比较优良的超级电容器电极材料.在1mol·L^(-1) Na_2SO_4电解质溶液中,0~1V的电压范围内,充放电电流密度为200mA·g^(-1)时,比容量高达201F·g^(-1),库伦效率接近100%.

Sodium manganese oxides Na0.7MnO2.05 for supercapacitor electrode material was synthesized using Mn （NO3） 2 and NaOH via chemical precipitation method. The X-ray diffraction （XRD） and scanning electron microscopy （SEM） shows that the obtained Na0.7 Mn02.05 is single-phased with layered structure. The electrochemical performance was characterized by cyclic voltammetry （CV） , impedance measurements and galvanostatic charge-discharge tests in symmetric Na-ion supercapaci-tors with 1 mol ·L^-1 Na2 S04 solution as electrolyte. The Na0.7MnO2.05 material shows a high specific capacity of about 201 F ·g^-1 at a current density of 200 mA·g^-1 and a high coulombic efficiency approaching 100% , except the initial 50 cycles.