三明治型纳米多孔镍/氧化镍电极材料的制备及储能特性

Fabrication and Electrochemical Properties of Sandwich-Type Nanoporous Nickel/Nickel Oxide Composite Electrodes

摘要:

设计Ni₄₀Ti₆₀高强韧非晶合金为前驱体在0.25 M HF溶液中“自由脱合金-自然氧化”一步法得到纳米多孔镍/氧化镍(np-Ni/NiO)复合电极材料。对复合电极材料的结构、形貌和储能特性进行探究,结果表明：np-Ni/NiO具有“脱合金层︱非晶芯层︱脱合金层”的三明治型复合结构,层与层之间自然结合,保证了电极材料的柔韧性和结构一体化；脱合金层的厚度与NiO的含量随脱合金时间延长而增加。脱合金2 h的样品其体积比电容可达491.1 F/cm₃,循环6000次后仍可达472 F/cm₃。

Abstract:

Nanoporous Nickel/Nickel Oxide (np-Ni/NiO) composite electrodes were fabricated with a “free dealloying - natural oxidation” method by dealloying a high ductile amorphous Ni₄₀Ti₆₀ precursor alloy in 0.25 M HF solution. The structure, morphologies and electrochemical properties of the composite electrodes were studied by XRD, SEM and Electrochemical measurements. The results indicate that the np-Ni/NiO composites exhibit a sandwich-type structure with "dealloyed layer︱amorphous alloy core︱dealloyed layer ". Due to the good connection between layers, the electrode material performs an excellent flexibility and structural integration. The thickness of the dealloyed layer and the content of NiO increase with extending the dealloying time. The volume capacitance of np-Ni/NiO by dealloying Ni₄₀Ti₆₀ ribbons in 0.25 M HF for 2 h can reach to 491.1 F/cm₃ at a discharge current density of 0.5 A/cm₃. After 6000 cycles, the volume capacitance remains at 472 F/cm₃, indicating an excellent cycle stability of np-Ni/NiO composite electrodes.