Scientists at the US Department of Energy’s National Renewable Energy Laboratory (NREL) say they have discovered a new approach for developing a rechargeable non-aqueous magnesium-metal battery.
In a proof-of-concept paper published in the journal Nature Chemistry, the research team said they have pioneered a method to enable the reversible chemistry of magnesium metal in the noncorrosive carbonate-based electrolytes and tested the concept in a prototype cell.
NREL said the technology “possesses potential advantages over lithium-ion batteries— notably, higher energy density, greater stability, and lower cost”.
“This finding will provide a new avenue for magnesium battery design,” said Seoung-Bum Son, first author of the paper, entitled An Artificial Interphase Enables Reversible Magnesium Chemistry in Carbonate Electrolytes.
Corresponding author of the paper, Chunmei Ban, said: “The dominant lithium-ion battery technology is approaching the maximum amount of energy that can be stored per volume, so there is an urgent need to explore new battery chemistries that can provide more energy at a lower cost.”
According to the research team, magnesium batteries theoretically contain almost twice as much energy per volume as lithium-ion batteries. However, the team said previous research found chemical reactions of the conventional carbonate electrolyte created a barrier on the surface of magnesium that prevented the battery from recharging.
“The magnesium ions could flow in a reverse direction through a highly corrosive liquid electrolyte, but that barred the possibility of a successful high-voltage magnesium battery,” the NREL team said.
In seeking to overcome these roadblocks, the researchers developed an artificial solid-electrolyte interphase from polyacrylonitrile and magnesium-ion salt that protected the surface of the magnesium anode. “This protected anode demonstrated markedly improved performance,” the team said.