2 research outputs found
Mg/O<sub>2</sub> Battery Based on the Magnesium-Aluminum Chloride Complex (MACC) Electrolyte
Mg/O<sub>2</sub> cells employing
a MgCl<sub>2</sub>/AlCl<sub>3</sub>/DME (MACC/DME) electrolyte are
cycled and compared to cells with
modified Grignard electrolytes, showing that performance of magnesium/oxygen
batteries depends strongly on electrolyte composition. Discharge capacity
is far greater for MACC/DME-based cells, while rechargeability in
these systems is severely limited. The Mg/O<sub>2</sub>-MACC/DME discharge
product comprises a mixture of Mg(ClO<sub>4</sub>)<sub>2</sub> and
MgCl<sub>2</sub>, with the latter likely formed from slow decomposition
of the former. The presence of Cl in these compounds suggests that
the electrolyte participates in the cell reaction or reacts readily
with the initial electrochemical products. A rate study suggests that
O<sub>2</sub> diffusion in the electrolyte limits discharge capacities
at higher currents. Formation of an insulating product film on the
positive electrodes of Mg/O<sub>2</sub>-MACC/DME cells following deep
discharge increases cell impedance substantially and likely explains
the poor rechargeability. An additional impedance rise consistent
with film formation on the Mg negative electrode suggests the presence
of detrimental O<sub>2</sub> crossover. Minimizing O<sub>2</sub> crossover
and bypassing charge transfer through the discharge product would
improve battery performance