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

Abstract

Abstract:In this study of zinc nickel single-flow batteries (ZNB), the ion concentration of the convection area and the electrode surface of the battery runner were investigated first. Then, the relationships between the electrode over-potential (or equilibrium potential) and the charge time were studied. This was based on the electrochemical reaction rate equation and the equilibrium potential equation, from which a mathematical model of the stack voltage (as affected by the internal parameters of the battery) was obtained. By comparison with experimental data, it was determined that the relative error of the simulated stack voltage of a 300 Ah battery was restricted to <0.62% while charging under the condition of 100 A constant-current charging. This shows that the mathematical model can accurately describe the dynamic characteristics of the battery stack voltage, and is very accurate for predicting the stack voltage of the battery during charging under 100 A constant-current charging conditions.

Equivalent Circuit Model Construction and Dynamic Flow Optimization Based on Zinc–Nickel Single-Flow Battery

“…In Equation 12, R is the hydraulic resistance of the stack, and its value can be seen in the previous research work of our group [33]. The formula for calculating P stack is shown in Equation (13).Considering the pump efficiency, the total mechanical loss of the battery system can be defined as Equation 14.…”

“…is the average voltage drop caused by the self-discharge during charge and discharge, which is 3.65 mV and 6.9 mV, respectively [33]. Based on the above-mentioned calculations in Equations (18)-(21) for the potential of the zinc-nickel single-flow battery stack, combined with the range of concentration of each substance in Table 2, the battery potential can be further expressed by SOC as Equation 22, where E 0 is 1.705 V. Under different operating conditions, the terminal voltage is affected by internal loss and self-discharge.…”

“…The terminal voltage is estimated by Equation (23), where "±" indicates the charging process and the discharging process. E self -discharge is the average voltage drop caused by the self-discharge during charge and discharge, which is 3.65 mV and 6.9 mV, respectively [33]. Figure 6.…”

The characteristics and performance of hybrid redox flow batteries with zinc negative electrodes for energy storage

“…The effect of temperature over this cell was also studied [257], showing that moderately high temperatures were beneficial for its performance. For example, at a current density of 80 mA cm -2 , the overall energy efficiency increased from 53.0% at 0 o C to 70.1% at 40 o C. More recently, Yao et al [261] have studied the electrode potential of this battery, while Wang [262] proposed an alternative Zn-Ni flow cell where the cathode is a Ni(OH)2 electrode coated with a O2 reduction catalyst.…”

Flow measurement inside a zinc-nickel flow cell battery using FBG based sensor system

“…In light of meeting the above challenges with zinc-nickel batteries and the importance of having such batteries deployed in a number of applications, there is a need to develop a suitable monitoring method which can provide useful information on electrolyte flow changes due to dendrite formation inside the flow cell. To date, a manual approach, using visual inspection has been the only effective technique used to examine the condition of a battery, looking at dendrite formationhowever this technique is both costly and not very accurate 5 . In this work, the use of a Fibre Bragg Grating (FBG)-based technique is proposed, creating sensors to detect both internal flow changes and the flow distribution inside the cell, through the variation in strain that accompanies such flow changes.…”