La掺杂NiO电极非对称电化学电容器的研究

Research on asymmetric electrochemical capacitor with lanthanum-doped NiO electrode

采用化学共沉淀法制备了La掺杂NiO非对称电化学电容器的电极材料。通过X射线衍射技术(XRD)对复合电极材料的组成和结构进行了分析;采用循环伏安法、恒流充放电法和交流阻抗法对其电化学性能进行了研究,结果表明:La的掺杂改善了NiO电极材料的充放电可逆性,降低了电极的内阻。这是由于La的引入在NiO晶格中形成缺陷,从而提高了材料的电导率和电极的电化学性能。当n(La):n(NiO+La)=0.04时,La掺杂NiO电极在2 mol/L KOH溶液中,在400 mA/g大电流密度下放电,比电容高达128 F/g。

Lanthanum doped NiO composite electrode material was prepared by chemical co-deposition method. The component and structure of the electrode matedal was analyzed by XRD; the electrochemical properties was investigated by cyclic voltammetry （CV）, constant current charge-discharge and electrochemical impedance spectroscopy （EIS）. The results show that lanthanum doping improves the charge-discharge reversibility of NiO electrode material and reduces the internal resistance of the electrode. This is because lanthanum doping produces imperfections in the NiO lattice, which improves the electrical conductivity and the electrochemical activity of the electrode. When n（La） ： n（NiO＋ La）=0.04, the specific capacitance of the lanthanum doped NiO electrode at the large current density 400 mA/g in 2 mol/L KOH solution reaches 128 F/g.