原位氧化法制备Zn-Ni氢氧化物纳米片及其电荷存储特性研究

通过简单、低成本的化学浴沉积法在泡沫镍上原位生成了Zn-Ni 氢氧化物(Zn-Ni double hydroxides)纳米片。SEM观察结果表明, Zn-Ni 氢氧化物纳米片均匀附着在泡沫镍表面, 形成均一的多孔纳米片阵列层。此外, 还有大量的Zn-Ni 氢氧化物纳米片聚集成多孔团聚体, 分布于泡沫镍骨架的空隙处, 从而获得较高的活性物质负载量(4.27 mg/cm²)。CV、CP和电化学阻抗测试表明, Zn-Ni 氢氧化物纳米片在2 mol/L KOH电解液中充放电电流密度1 A/g时, 比电容为746.2 F/g(面积电容为3.18 F/cm²); 3000次充放电循环后, 仍保持70.9%的初始比电容。

Capacitive Performance of Zn-Ni Hydroxide Nano-sheet Arrays on Nickel Foams via a Mild Chemical-bath Deposition Process

Zn-Ni hydroxide nano-sheets were successfully deposited on nickel foams through a mild, cost-effective chemical bath method. SEM observation shows that these interconnected nano-sheets form a uniform marray layer and completely cover the surface of nickel foam. At the same time, additional homogeneously-precipitated hydroxide nano-sheets locate in the skeleton voids of nickel foams as aggregated porous clumps, resulting in a relatively high mass-loading of 4.27 mg/cm². Afterwards, the electrochemical capacitive behaviors of this binder-free electrode were investigated by cyclic voltammetry, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy. It is found that the Zn-Ni hydroxide electrode exhibits a specific capacitance of 746.2 F/g (areal capacitance of 3.18 F/cm²) at a current density of 1 A/g in 2 mol/L KOH electrolyte. Meanwhile, the Zn-Ni hydroxide electrode also shows a decent long-life cycling stability, retaining 70.9% of the initial capacitance after 3000 charge-discharge cycles.