Zinc-air batteries are a promising technology for large-scale electricity storage. However, their practical deployment has been hindered by some issues related to corrosion and passivation of the zinc anode in an alkaline electrolyte. In this work, anionic surfactant sodium dodecyl sulfate (SDS) and nonionic surfactant Pluronic F-127 (P127) are examined their applicability to enhance the battery performances. Pristine zinc granules in 7 M KOH, pristine zinc granules in 0–8 mM SDS/7 M KOH, pristine zinc granules in 0–1000 ppm P127/7 M KOH, and SDS coated zinc granules in 7 M KOH were examined. Cyclic voltammograms, potentiodynamic polarization, and electrochemical impedance spectroscopy confirmed that using 0.2 mM SDS or 100 ppm P127 effectively suppressed the anode corrosion and passivation. Nevertheless, direct coating SDS on the zinc anode showed adverse effects because the thick layer of SDS coating acted as a passivating film and blocked the removal of the anode oxidation product from the zinc surface. Furthermore, the performances of the zinc-air flow batteries were studied. Galvanostatic discharge results indicated that the improvement of discharge capacity and energy density could be sought by the introduction of the surfactants to the KOH electrolyte. The enhancement of specific discharge capacity for 30% and 24% was observed in the electrolyte containing 100 ppm P127 and 0.2 mM SDS, respectively.

This work aims at analyzing an integrated system of a zinc-air flow battery with a zinc electrolyzer for energy storage application. For efficient utilization of inherently intermittent renewable energy sources, safe and cost-effective energy storage systems are required. A zinc-air flow battery integrated with a zinc electrolyzer shows great promise as an electricity storage system due to its high specific energy density at low cost. A mathematical model of the system was developed. The model was implemented in MATLAB and validated against experimental results. The validation of the model was verified by the agreement between the simulation and experimental polarization characteristic. The behavior and performance of the system were then examined as a function of different operating parameters: the flow rate of the electrolyte, the initial concentration of potassium hydroxide (KOH) and the initial concentration of zincate ion. These parameters significantly affected the performance of the system. The influence of the hydrogen evolution reaction (HER) on the performance of the system was investigated and discussed as it significantly affected the coulombic efficiencies of both the zinc-air flow battery and the zinc electrolyzer. Optimal KOH concentration was found to be about 6-7 M. Whilst increased KOH concentration enhanced the discharge energy of the battery, it also increased HER of both the battery and the electrolyzer. However, higher initial concentration of zincate ion reduced HER and improved the coulombic efficiency of the system. Besides, a higher flow rate of electrolyte enhanced the performance of the system especially at a high charge/discharge current by maintaining the concentration of active species in the cell. Nevertheless, the battery suffered from a higher rate of HER at a high flow rate. It was noted that the model-based analysis provided better insight into the behavioral characteristics of the system leading to an improved design and operation of the integrated system of zinc-air flow battery with the zinc electrolyzer.

Zinc-air batteries (ZABs) are considered a promising energy storage system. A model-based analysis is one of the effective approaches for the study of ZABs. This technique, however, requires reliable discharge data as regards parameter estimation and model validation. This work, therefore, provides the data required for the modeling and simulation of ZABs. Each set of data includes working time, cell voltage, current, capacity, power, energy, and temperature. The data can be divided into three categories: discharge profiles at different constant currents, dynamic behavior at different step changes of discharge current, and dynamic behavior at different random step changes of discharge current. Constant current discharge profile data focus on the evolution of voltage through time. The data of step changes emphasize the dynamic behavior of voltage responding to the change of discharge current. Besides, the data of random step changes are similar to the data of step changes, but the patterns of step changes are random. Such data support the modeling of a zinc-air battery for both theoretical and empirical approaches.

In this work, transparent thin film zinc-manganese dioxide (Zn-MnO 2 ) batteries were fabricated using an inexpensive screen-printing technique. Both electrodes were fabricated as micro-electrode arrays with feature size of 50 μm, which are below resolution of human eyes. Thus, the electrodes appeared transparent. Moreover, a transparent alkaline polymer gel electrolyte (PGE) film prepared by polymerization of acrylate, potassium hydroxide and water was used as a quasi-solid-state electrolyte. The PGE film functioned as both an electrolyte and an insulator/separator. Three patterns of the micro-electrodes with different percentages of opening area (75%, 80% and 85%) were investigated. The open-circuit voltages of the batteries fabricated were 1.25 V. Ohmic loss zones were 0.1-2.0 mA.cm −2 . The battery with an opening area of 80% provided an average transparency of 90% without significantly affecting battery performance. Moreover, energy density of the battery could be further increased by increasing the thickness of the electrodes. By increasing the thickness of the micro-electrodes upto 80 μm, energy density of the battery was significantly enhanced without loosing its transparency.

The formation of dendritic zinc during recharge is a critical issue hindering the widespread application of rechargeable zinc-air batteries. Here, we demonstrate that the dendritic growth of zinc can be effectively suppressed using Carbopol gel electrolyte. This work investigates the effects of the concentration of Carbopol (0-3.5 wt.%) on polarization characteristic and a discharge/recharge profile of the batteries. Moreover, the morphology of the zinc anodes and their electrochemical parameters were examined as a function of cycling. The gel electrolyte significantly changes the anode/electrolyte interface and affects the nucleation and growth of zinc, resulting in effective inhibition of zinc dendrites. Therefore, cyclability of the batteries was considerably enhanced. However, increasing the concentration of Carbopol leaded to increasing the internal resistance of the batteries but a reduction in resistance at the electrode/electrolyte interface.

Due to the increasing trend of using renewable energy, the development of an energy storage system (ESS) attracts great research interest. A zinc–air battery (ZAB) is a promising ESS due to its high capacity, low cost and high potential to support circular economy principles. However, despite ZABs' technological advancements, a generic dynamic model for a ZAB, which is a key component for effective battery management and monitoring, is still lacking. ZABs show nonlinear behaviour where the steady-state gain is strongly dependent on operating conditions. The present study aims to develop a dynamic model, being capable of predicting the nonlinear dynamic behaviour of a refuellable ZAB, using a linear parameter-varying (LPV) technique. The LPV model is constructed from a family of linear time-invariant models, where the discharge current level is used as a scheduling parameter. The developed LPV model is benchmarked against linear and nonlinear model counterparts. Herein, the LPV model performs remarkably well in capturing the nonlinear behaviour of a ZAB. It significantly outperforms the linear model. Overall, the LPV approach provides a systematic way to construct a robust dynamic model which well represents the nonlinear behaviour of a ZAB.

No abstract

No abstract