掺镧纳米NiO的制备及超大电容性能研究  

Preparation and Supercapacitor Properties of Lanthanum Doped NiO

作　　者：陈野[1] 韩丹丹[1] 张密林[1] 葛鑫[1] 

机构地区：[1]哈尔滨工程大学材料科学与化学工程学院,黑龙江哈尔滨150001

出　　处：《中国稀土学报》2006年第6期691-694,共4页Journal of the Chinese Society of Rare Earths

基　　金：博士点基金资助项目(20050217019)

摘　　要：应用化学共沉淀法制备了掺La的纳米NiO。XRD分析表明,La的掺入不改变NiO的晶体结构,但晶粒尺寸有所减小。利用恒流充放电、循环伏安和交流阻抗等测试方法对La-NiO电极材料在5 mol.L-1KOH溶液中进行电化学性能测试,结果表明,化学掺杂降低了电解液在电极中的扩散阻力,提高了质子扩散能力,增强了电极的可逆性,从而表现了更好的电容性能,并提高了电极的比容量,当掺La的质量分数为5%时,单电极放电比容量可达到277 F.g-1,是纯氧化镍电极的1.98倍。Lanthanum-doped nano-NiO were synthesized by chemical precipitation method. The characterization and performance of samples were studied using X-ray diffraction. The results show that doping lanthanum does not change the crystal structure of NiO, however, the grain size of crystalline was reduced. The electrochemical properties of the electrode materials were measured in the three electrode system. Electrochemical properties of NiO were investigated by using cyclic vohammetry, constant current charge/discharge and AC impedance methods. It can be seen that the chemical doping improves the specific capacitance and the utilization of active materials. When the mass ratio of La is 5%, the composite material presents the best properties. In the 5 mol·L^-1 KOH solution, the maximum discharge specific capacitance is 277 F·g^-1. The result of AC impedance spectrum shows that La doping for NiO can improve the electrochemical reversibility, reducing the resistance of cations transfered between the electrode and electrolyte which makes the electrodes present the better capacitive behavior.

关 键 词：超大电容 氧化镍 镧 掺杂 稀土 

分 类 号：O646[理学—物理化学] TM911[理学—化学]