Magnesium flow battery

Non-aqueous magnesium batteries have emerged as an attractive alternative among “post-lithium-ion batteries” largely due to the intrinsic properties of the magnesium (Mg) negative electrode. Supplementary Table 1 summarizes the physical and electrochemical properties of the Mg negative electrode and other metal negative electrodes.

Magnesium seawater–activated batteries are primary batteries that generate reactions using seawater as an electrolyte.

By contrast, the issues of self-corrosion and chunk effect are inevitable and, therefore, are major issues hindering the broad utilization of aqueous magnesium batteries. Basically, Mg anode efficiency is below 50% when discharging in a commonly used electrolyte (e.g. 3.5 wt% NaCl solution) under a low current density (e.g. 1 mA cm –2) .

Developing novel cathode structures and efficient bifunctional catalysts is crucial for increasing the discharge voltage and enhancing battery power also a key factor in determining whether magnesium–air batteries can replace lithium batteries as mainstream next–generation energy storage devices.

Mizrahi, O. et al. Electrolyte solutions with a wide electrochemical window for recharge magnesium batteries. J. Electrochem. Soc. 155, A103–A109 (2008). Doe, R. E. et al. Novel, electrolyte solutions comprising fully inorganic salts with high anodic stability for rechargeable magnesium batteries.

During the operation of magnesium–air batteries, the anode metal magnesium undergoes an electrochemical oxidation reaction, loses electrons, and reaches the three–phase junction of the air electrode through an external circuit, reacting with oxygen and water to generate hydroxide ions.