Commercial launch of cheaper Mg-ion battery planned for 2018
Honda and The Saitama Industrial Technology Center (Saitec) plan to launch a magnesium-ion (Mg-ion) rechargeable battery in 2018 for portable devices including smartphones. Cheaper and more stable than lithium, magnesium can also displace twice the charge per ion, however, developers have previously been discouraged by its fast degradation rate; hence, the Saitec developers have used vanadium oxide in its cathode to ensure more charges without deterioration.
The Saitama Industrial Technology Center (Saitec), in partnership with Honda, has developed a practical magnesium-ion rechargeable battery, according to Nikkei Asian Review. The two will officially announce their battery next month, and hope to commercialize it by 2018, at first in smartphones and other portable devices.

Masashi Inamoto and colleagues describe the new battery in “Electrode Performance of Sulfur-Doped Vanadium Pentoxide Gel Prepared by Microwave Irradiation for Rechargeable Magnesium Batteries,” published in Current Physical Chemistry.

Because magnesium is divalent, it can displace double the charge per ion (i.e., Mg2+ rather than Li+). As an element, magnesium is more abundant than lithium, more stable, and far cheaper.

Toyota and others have been looking into Mg-ion batteries for years, but performance tends to degrade rapidly. The Saitec developers used vanadium oxide in the cathode, making it easier for ions to move between it and the magnesium-based anode, and allowing for more charges without deterioration. For safety, the team added an organic substance that lowers the risk of the magnesium catching fire.

Source: Nikkei Asian Review via Green Car Congress