Applications of Porous Co(OH)2 and Ni(OH)2 Nanotube Electrodes in Supercapacitors

• Main Authors: Song, Cheng-Zhao, 宋承兆
• Other Authors: Chen, Jin-Ming
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/41580259528102639746

碩士 === 國立交通大學 === 材料科學與工程學系所 === 105 === Large-area 3D supercapacitor electrodes were fabricated with a facile electrochemical deposition method which co-deposited of Ni-Cu layer, then selectively etching Cu from Ni-Cu layer to complete nickel nanotube on the selected substrates. Further cathodic depositon of Co(OH)2 or Ni(OH)2 hydroxide particles on the as-prepared nanoporous substrates, respectively. High-performance 3D porous supercapacitor electrodes had been synthesized. This research was divided into three parts: Part I: Two 3D porous structures, sucker-like nanoporous (SNP) and nanotube arrays (NTA) grew on nickel foam were used to enhanced the electrochemical performances of Co(OH)2-based supercapacitor electrodes. Both Co-SNP and Co-NTA electrodes were tested with cyclic voltammetry (CV) and galvanic charge-discharge (GCD) methods in 1M KOH aqueous electrolyte. The Co-SNP and Co-NTA electrodes exhibited specific capacitance of 2900 F/g and 2500 F/g at 1 A/g in a three electrode cell, respectively. Part II: Carbon fiber were used to synthesized a high-performance flexible Ni(OH)2-based electrodes. Large-area modified method were also used on carbon fiber substrate, which grew a flexible nanoporous (FNP) structures on the surface. The Ni-FNP electrodes were measured in 1M KOH aqueous electrolyte and exhibited a specific capacitance of 2000 F/g at 10 A/g in a three electrode cell. Both supercapacitor electrodes in part I and part II were analyzed with scanning electron microscope (SEM, SU-8010), transmission electron microscope (TEM, JEOL-JEM3000F) and energy dispersive spectroscope (EDS). The crystal structure, investigation of oxidation state, and the variation of the oxidation state during charge-discharge cycles in these electrodes were measured by X-ray diffraction (XRD) techniques at BL01C2, X-ray photoemission spectroscopy (XPS) at BL20A, and in-situ X-ray absorption spectroscopy (XAS) at BL01C1 and BL17C1 in National Synchrotron Radiation Research Center (NSRRC), respectively. Part III: Asymmetric supercapacitors (ASCs) were built with Ni(OH)2//Co(OH)2 electrodes and measured with CV and GCD in 1M KOH aqueous and solid-state electrolytes, respectively. The devices were tested in 1 M KOH electrolyte and displayed a voltage range of 1.6 V. Finally, the Ni(OH)2 and Co(OH)2 electrodes combined with base solid-state electrolyte to form a flexible solid-state asymmetric supercapacitor devices. This flexible device also performed a voltage range of 1.6 V and tested with bending and twisting experiments. Moreover, the device has remarkable cycle stability of only 5% loss after 10000 cycles. A red LED could be powered with the devices in series more than 1 minute.