Electrochemical Formation and Behavior of Silver and Lead Chlorides as Potential Cathodes for Rechargeable Magnesium Seawater Battery

Abstract

The rapid increase in global energy consumption, along with the depletion of fossil fuels and ongoing climate change require higher efficiency and more reliable electrochemical power sources based on the current rechargeable batteries and supercapacitors. [1] Among the state-of-the-art lithiumion, secondary cells are the most widely used electrochemical energy storage devices in various fields, due to the high energy density of the cell. [2] However, the cost-ineffectiveness and time-consuming extraction process of Li systems are the main reasons why researchers are looking for alternatives. Even rather old, the seawater-activated primary battery that has been discovered in 1978. [3], is becoming a hot topic among the scientific community. Magnesium seawater activated batteries rely on magnesium alloy as the anode material, while among different cathode materials, silver chloride (AgCl) and lead chloride (PbCl2) are most widely applied. [4] In this work, we presented a novel method of electrochemical synthesis of silver chloride (AgCl) and lead chloride (PbCl2) electrodes using the galvanostatic charge/discharge techniques and we investigated the characteristics of possible rechargeable magnesium seawater-activated cells. For the possible rechargeable aqueous-based magnesium alloy AZ63 |3.5% NaCl | Ag|AgCl cell in the current range of 0.4-2.9 A g-1 the specific capacity in the range of 192-140 Ah kg-1 , the energy of 285-199 Wh kg-1 , and power of 575 to 4135 W kg-1 , and for AZ63 |3.5% NaCl | Pb|PbCl2 in the current range of to 0.4-3.44 A g-1 the specific capacity in the range of 127-83.6 Ah kg-1, the energy of 130-84 Wh kg-1 and power of 481 to 3463 W kg-1 are obtained.