Theoretical Analysis of the Discharge Performance of a NiOOH /  H 2 Cell

Abstract

A mathematical model is presented for the discharge of a NiOOH/H2 cell. This model includes diffusion and migration in the electrolyte phase as well as proton diffusion and ohmic drop across the Solid active material in the porous nickel electrode. A theoretical analysis of the cell performance is presented for different design parameters using this model. It is predicted that proton diffusion in the solid active material is the main factor in limiting the cell voltage and the utilization of the active material. It is also predicted that use of a thick nickel electrode is an effective method for increasing electrode capacity per unit area. This model can be used to predict the two-discharge-plateau behavior of a nickel electrode.

Microstructural tunability of co-continuous bijel-derived electrodes to provide high energy and power densities

“…Each CV curve displays two clear peaks corresponding to the oxidation and reduction of the active material in the reversible reaction Ni(OH) 2 4 NiOOH + H + + e À and indicates that the capacity predominately originates from pseudo-capacitance rather than electronic double-layer capacitance. 25 A similar control experiment was performed on a bare nickel shell, and the resulting faradaic peaks were almost undetectable, conrming that the electrochemical performance predominantly originates from the electrolytically active material alone (ESI Fig. S2 †).…”

Hydrous Nickel Oxide: Redox Switching and the Oxygen Evolution Reaction in Aqueous Alkaline Solution

“…10. MacArthur, 32 Zimmerman and Effa, 33 Weidner and coworkers, 34 and Mao et al 35 have suggested that the charge/discharge process is controlled by the diffusion of protons. We suggest that the latter occurs within the hydrated layer.…”

Study on Electrode Potential of Zinc Nickel Single-Flow Battery during Charge

“…The maximum concentration of protons can be calculated by ρ avg /M Ni(OH) 2 [17], where the average density of active material ρ avg = 3.55 g/cm 3 [18], M Ni(OH) 2 represents the relative molecular mass of Ni(OH) 2 , and Ni(OH) 2 is a proton conducting solid electrolyte. The proton concentration in the nickel oxide electrode is related to the state of charge of the positive electrode, which can be calculated by the following formula [14]:…”

“…Due to the production process, and the doping composition and content of nickel oxide electrodes are different, the equilibrium potential of nickel oxide electrodes varies widely [19,20]. Mao et al [17] gave the equilibrium potential for a NiOOH electrode, as shown the following:…”

“…where c represents the concentration of potassium hydroxide, f ± is the molar activity coefficient of electrolyte, which can be calculated by the following formula [17]: …”