Report: Honda and Saitec develop practical Mg-ion battery with vanadium oxide cathode; commercialization by 2018
The Nikkei, citing unnamed sources, reports that R&D organization Saitec (Saitama Industrial Technology Center) and Honda Motor have developed a practical magnesium-ion rechargeable battery and hope to commercialize it. Saitec reportedly led the development; Honda R&D assessed the technology’s viability. The two are slated to announce the battery next month.
Because magnesium is divalent, it can displace double the charge per ion (i.e., Mg2+ rather than Li+). As an element, magnesium is much more abundant than lithium, and more stable. Magnesium-ion batteries theoretically could offer good electrochemical performance, while being safer and less expensive than Li-ion batteries. Toyota has been looking into Mg-ion systems for a number of years (earlier post). However, Mg-ion batteries have suffered from a number of limitations, resulting in rapid degradation of performance.
According to the report, the developers use vanadium oxide in the cathode, making it easier for ions to move between it and the magnesium-based anode. The vanadium oxide allows for more charges without deterioration, the sources said. For safety, the team added an organic substance that lowers the risk of magnesium catching fire.
In a 2014 paper (Inamoto et al.), Saitec researchers had reported using a vanadium pentoxide xerogel containing sulfur (S-V2O5 gel) as a cathode for Mg-ion batteries. Charge-discharge tests of that system revealed a specific capacity of 450 mAh g-1, and cyclic voltammetry was almost perfectly stabilized after the second cycle.
According to the Nikkei’s source, the prototype magnesium-ion battery performs as well as a Li-ion counterpart in terms of life and safety. The developers are now working with a number of battery makers to come up with a way to mass produce the battery.
According to the Nikkei, the developers expect to first commercialize the technology in smartphones and other portable devices.
Inamoto, Masashi; Kurihara, Hideki; Yajima, Tatsuhiko (2014) “Electrode Performance of Sulfur-Doped Vanadium Pentoxide Gel Prepared by Microwave Irradiation for Rechargeable Magnesium Batteries” Current Physical Chemistry, Volume 4, Number 3, pp. 238-243(6) doi: 10.2174/1877946805666150311234806