On the charge-discharge behaviors of magnesium electrode 2011-39-7237
Recently, high energy density battery attracts public attention
with the application to power source of electric vehicle and
electric energy storage system in solar and wind generation.
Magnesium electrode has large theoretical capacity as much as 3839
mAh cm-1. Besides, magnesium compounds are abundant in the
earth's crust and most of them are nontoxic. Therefore,
rechargeable magnesium battery, whose negative electrode reaction
is magnesium deposition / dissolution, is one of the most expected
candidates.
However, rechargeable magnesium deposition and dissolution is
not achieved in most electrolytes. Magnesium has extensively high
reactivity, leading the formation of surface films in the
electrolytes. These films cannot conduct magnesium ion and inhibit
magnesium deposition and dissolution reactions. So far, reversible
magnesium deposition and dissolution can be achieved only in RMgX
(R = alkyl or aryl, X = halogen), Mg(BR4)2 or Mg(AlCl2RR')2 /
ether solutions [1,2,3]. In these solutions, magnesium is thought not to be
covered with surface films. However, since these solutions have
limitation for the battery electrolyte, due to their thermal and
chemical instability, studies for more proper electrolytes are
needed.
In this work, we focused on the electrolyte consisting of
magnesium bromide and 2-methyltetrahydrofuran (2-MeTHF), which were
composed of Grignard reagents. The electrochemical behavior of
platinum electrode in the solution and the analysis of deposits
were studied in detail.
