Hydrogenated NiO Nanoblock Architecture for High Performance Pseudocapacitor

• Published in: ACS applied materials & interfaces 2014-04, Vol.6 (7), p.4684-4692
• Main Authors: Singh, Ashutosh K, Sarkar, Debasish, Khan, Gobinda Gopal, Mandal, Kalyan
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/am404995h

Supercapacitor electrodes are fabricated with the self-organized 3D architecture of NiO and hydrogenated NiO (H-NiO) nano-blocks (NBs) grown by the facile electrodeposition and high temperature annealing of the Ni foil on Cu substrate. The unique architecture of H-NiO NBs electrode exhibits excellent cycling stability (only 5.3% loss of its initial specific capacitance after 3000 cycles at current density of 1.1 A g–1) along with the high specific and areal capacitance of ∼1272 F g–1 and 371.8 mF cm–2, respectively at scan rate of 5 mV s–1 compared with the pure NiO NBs electrode (∼ 865 F g–1 and 208.2 mF cm–2, respectively at scan rate of 5 mV s–1). H-NiO NBs electrode also exhibits excellent rate capability; nearly 61% specific capacity retention has been observed when the current density increases from 1.11 to 111.11 A g–1. This electrode offers excellent energy density of 13.51 Wh kg–1 and power density of 19.44 kW kg–1 even at a high current density of 111.11 A g–1. The superior pseudocapacitive performance of the H-NiO NBs electrode is because of the high electron and ion conductivity of the active material because of the incorporation of hydroxyl groups on the surface of NiO NBs.