Journal Article

Stable Ultrahigh Specific Capacitance of NiO Nanorod Arrays

Zhiyi Lu Zheng Chang Junfeng Liu Xiaoming Sun

2011

Overview

Previously reported examples of electrochemical pseudocapacitors based on cheap metal oxides have suffered from the need to compromise between specific capacitance, rate capacitance, and reversibility. Here we show that NiO nanorod arrays on Ni foam have a combination of ultrahigh specific capacitance （2018 F/g at 2.27 A/g）, high power density （1536 F/g at 22.7 A/g）, and good cycling stability （only 8% of capacitance was lost in the first 100 cycles with no further change in the subsequent 400 cycles）. This resulted in an improvement in the reversible capacitance record for NiO by 50% or more, reaching 80% of the theoretical value, and demonstrated that a three-dimensional regular porous array structure can afford all of these virtues in a supercapacitor. The excellent performance can be attributed to the slim （〈 20 nm） rod morphology, high crystallinity, regularly aligned array structure and strong bonding of the nanorods to the metallic Ni substrate, as revealed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and X-ray diffraction （XRD）.

• Publisher: Tsinghua Press,Tsinghua University Press
• Subject: Arrays / Atomic/Molecular Structure and Spectra / Biomedicine / Biotechnology / Capacitance / Chemistry and Materials Science / Condensed Matter Physics / Density / Electrochemistry / Electrolytes / Fourier transforms / Materials Science / Metal oxides / Morphology / Nanocomposites / Nanomaterials / Nanostructure / Nanotechnology / Nickel / NiO / Research Article / Scanning electron microscopy / Single crystals / Temperature / Transmission electron microscopy / X-ray diffraction / 循环稳定性 / 扫描电子显微镜 / 纳米棒 / 金属氧化物 / 阵列结构 / 高功率密度 / 高比容