Co_(3)O_(4)@NC的制备及其电化学性能

Preparation and Electrochemical Properties of Co_(3)O_(4)@NC

过渡金属氧化物是一种超级电容器电极材料。采用共沉淀法制备了立方体Co类普鲁士蓝(Co-PBA)纳米材料,先将Co-PBA在氮气中进行退火,PBA衍生为掺氮的碳纳米盒,得到产物Co@NC,再在空气中250℃下退火,得到Co_(3)O_(4)@NC纳米复合材料。Co-PBA材料的微观结构为盒状并均匀分布,平均尺寸约为500 nm。在三电极体系下测试其电化学性能,循环伏安(CV)测试结果显示在不同电流密度下曲线具有相似的形状,拥有良好的对称性,说明该材料制备的电极在充放电时的可逆性较好。Co_(3)O_(4)@NC复合材料在电流密度1 A/g时的比电容为1000.02 F/g,在电流密度5 A/g下充放电2500次后电容保持率为97.29%,保持了良好的循环稳定性。实验结果表明,Co_(3)O_(4)@NC复合材料是一种很有前途的超级电容器电极材料。

Transition metal oxide is a kind of electrode material for supercapacitors.The cubic Co Prussian blue analogue(Co-PBA)nano-materials were prepared by coprecipitation method.Co-PBA was first annealed in nitrogen,and PBA was derived into a nitrogen-doped nano carbon box to obtain the product Co@NC.Then it was annealed at 250℃in air to obtain Co_(3)O_(4)@NC nanocomposite.The microstructure of Co-PBA material is in the shape of nanoboxes and uniformly distributed,with an average size of about 500 nm.The electrochemical properties were tested in a three electrode system.And the cyclic voltammetry(CV)test results show that the curves have similar shapes under different current densities and have good symmetry,indicating that the electrode prepared by the material has good reversibility during charging and discharging.The specific capacitance of the Co_(3)O_(4)@NC nanocomposite is 1000.02 F/g at a current density of 1 A/g,and the capacitance retention rate is 97.29%after 2500 chargedischarges at a current density of 5 A/g,which maintains a good cycle stability.The results show that Co_(3)O_(4)@NC composite is a promising electrode material for supercapacitors.