Perspectives on Nickel Hydroxide Electrodes Suitable for Rechargeable Batteries: Electrolytic vs. Chemical Synthesis Routes

Abstract

A significant amount of work on electrochemical energy storage focuses mainly on current lithium-ion systems with the key markets being portable and transportation applications. There is a great demand for storing higher capacity (mAh/g) and energy density (Wh/kg) of the electrode material for electronic and vehicle applications. However, for stationary applications, where weight is not as critical, nickel-metal hydride (Mi-MH) technologies can be considered with tolerance to deep discharge conditions. Nickel hydroxide has gained importance as it is used as the positive electrode in nickel-metal hydride and other rechargeable batteries such as Ni-Fe and Ni-Cd systems. Nickel hydroxide is manufactured industrially by chemical methods under controlled conditions. However, the electrochemical route is relatively better than the chemical counterpart. In the electrochemical route, a well-regulated OH− is generated at the cathode forming nickel hydroxide (Ni(OH)2) through controlling and optimizing the current density. It produces nickel hydroxide of better purity with an appropriate particle size, well-oriented morphology, structure, et cetera, and this approach is found to be environmentally friendly. The structures of the nickel hydroxide and its production technologies are presented. The mechanisms of product formation in both chemical and electrochemical preparation of nickel hydroxide have been presented along with the feasibility of producing pure nickel hydroxide in this review. An advanced Ni(OH)2-polymer embedded electrode has been reported in the literature but may not be suitable for scalable electrochemical methods. To the best of our knowledge, no such insights on the Ni(OH)2 synthesis route for battery applications has been presented in the literature.

Potential Application of Ionic Liquids for Electrodeposition of the Material Targets for Production of Diagnostic Radioisotopes

“…Choline chlorine-based ionic liquids are extensively examined in context of their application as a medium for nickel electroplating. In 2010 Florea et al [71] Urea as a source of ammonia has been used in the precipitation of nickel hydroxide, Ni(OH) 2, Equation (3) [76].…”

“…8 of 26 Ash B. et al reported that pure α-Ni(OH) 2 has been synthesized in various concentration of urea and at elevated temperatures [76].…”

“…Urea as a source of ammonia has been used in the precipitation of nickel hydroxide, Ni(OH) 2, Equation (3) [ 76 ]. …”

“…Interface Anal. ; published by Wiley Interscience, 2010].Urea as a source of ammonia has been used in the precipitation of nickel hydroxide, Ni(OH)2, Equation (3)[76].NH − CO − NH + NiSO + 3H O → Ni(OH) ↓ + (NH ) • SO + CO(3)Ash B. et al reported that pure α-Ni(OH)2 has been synthesized in various concentration of urea and at elevated temperatures[76].A significant impact of water content on the morphology of Ni layers was reported by Du et al[77].Figure 2presents the micrographs of Ni deposits obtained from the solutions with various concentration of water. An increases of water in the electroplating bath resulted in a decrease in…”

A study of the possibility of conducting selective laser processing of thin composite electrochromic Ni(OH)2-PVA films

“…Nickel hydroxide, as a component of various electrochemical devices, is one of the intensively studied substances [1]. The options for its obtaining and processing are varied since they allow varying its properties in a wide range [2].…”