Effects Of Environmental Factors On The Anode And Cathode Performance Of Al/Air Seawater Batteries

With the growing shortage of fossil energy and the increasingly seriousenvironmental pollution, human urgently requires the development of new energy.Seawater batteries as a new energy technology have been extensive concern. Theperformances of seawater batteries are affected by many factors, for example, theelectrode material and electrolyte. Seawater environment is so extremely complex andchangeable that the effects on the performances of seawater batteries are intricate.Therefore, it is of vital importance for exploitation of high performance seawaterbattery and development of seawater battery industry to study the effects of theseawater environmental factors on the performances of the seawater batteries. In thispaper, the aluminum-air seawater battery was selected as the research object. Weexamined the impact of concentration of sodium chloride, temperature, and pH ofseawater on the anode and cathode performance of aluminum-air seawater battery.The highlights in this paper are summarized as follows:1. Aluminum alloy anode was obtained from ingots of pure Al, pure Zn, pure In,pure Cd by melting. Air electrode was prepared by pressing “catalyst layer/copperscreen” together.2. The effects of concentration, temperature and pH of simulated seawater on theelectrochemical performances of aluminum alloy were studied by polarization curve,electrochemical impedance spectroscopy (EIS) and galvanostatic polarization curve.Experimental results showed that the anticorrosion performance of aluminum alloydecreased then increased and the discharge performance enhanced with theconcentration increased. With the temperature increased, the anticorrosion performance of aluminum alloy increased. The aluminum alloy presented an excellentdischarge performance at40℃. The anticorrosion performance of aluminum alloywas worse in acid and alkaline simulated seawater, but the aluminum alloy presenteda better discharge performance.3. The effects of concentration, temperature and pH of simulated seawater on theelectrochemical performances of air electrode were investigated using polarizationcurve and galvanostatic polarization curve, respectively. It was found that airelectrode exhibited lower polarization and more positive stable discharge potentialand showed the best discharge performance in3.5%NaCl simulated seawater. Thepolarization of air electrode increased with the temperature increased. At40℃，airelectrode exhibited excellent discharge performance. Air electrode presented lowerpolarization and relative positive stable discharge potential at pH11, which indicatedair electrode had better discharge performance.4. The electrochemical performances of anode and cathode of aluminum-airseawater battery were studied with pH value of seawater increased. The resultsobtained indicated that increasing the pH of seawater led to a higher corrosionsensitivity of the aluminum alloy. The stable discharge potentials significantly wereshifted to positive direction. The polarization of air electrode was getting smaller andstable discharge potential gradually increased with the pH increased.