A research team led by Dr. Minah Lee at the Energy Storage Research Center of the Korea Advanced Institute of Science and Technology (KIST) has made a significant breakthrough in the development of magnesium batteries.
This breakthrough involves a chemical activation strategy for magnesium metal that allows for the efficient operation of magnesium batteries in commonly used electrolytes, free of corrosive additives. The findings of this groundbreaking research have been published in the esteemed journal ACS Nano.
The Significance of Magnesium Batteries
As the demand for lithium-ion batteries continues to skyrocket due to the rapid growth of the electric vehicle and energy storage system (ESS) markets, concerns have arisen about the stability of the supply chain for raw materials such as lithium and cobalt. In response to this challenge, researchers have been actively exploring next-generation secondary batteries. Among these alternatives, magnesium-based batteries have attracted attention due to the abundance of magnesium in the Earth’s crust.
Magnesium secondary batteries offer the potential for high energy density, thanks to the utilization of Mg2+ as a divalent ion instead of monovalent alkali metal ions like lithium. The use of magnesium metal as an anode, with a volumetric capacity approximately 1.9 times higher than that of lithium metal, allows for the highest energy density achievable in secondary batteries.
Challenges in Commercializing Magnesium Batteries
Despite the numerous advantages of magnesium batteries, their efficient charging and discharging have posed significant challenges. Magnesium’s reactivity with electrolytes has hindered the commercialization of these batteries. However, the KIST research team has successfully developed a technology that enables highly efficient charge and discharge reactions of magnesium metal, thus opening up the possibility of commercializing magnesium secondary batteries.
Revolutionary Electrolyte Approach
Unlike previous studies that relied on corrosive electrolytes to facilitate charging and discharging of magnesium, the KIST researchers utilized a common electrolyte with a composition similar to commercially available electrolytes. This innovative approach not only enables the use of high-voltage electrodes but also minimizes corrosion of battery components. By synthesizing an artificial protective layer on the magnesium surface using a novel composition based on magnesium alkyl halide oligomers, the researchers achieved remarkable results.
The team employed a simple process that involved dipping the magnesium metal, intended for use as the anode, into a reactive alkyl halide solution prior to cell assembly. By selecting a specific reaction solvent, they facilitated the formation of nanostructures on the magnesium surface. These nanostructures, in turn, enhanced the dissolution and deposition of magnesium, effectively suppressing unwanted reactions with electrolytes and maximizing the reaction area.
Groundbreaking Results and Implications
The application of this technology resulted in a remarkable reduction in overpotential, decreasing from over 2 V to less than 0.2 V during the charging and discharging of magnesium metal in a common electrolyte without corrosive additives. Moreover, the Coulombic efficiency, previously less than 10%, was increased to over 99.5%. The KIST team demonstrated stable charging and discharging of activated magnesium metal for over 990 cycles, showcasing the potential of magnesium rechargeable batteries to operate in conventional, mass-produced electrolytes.
Dr. Minah Lee of KIST expressed the significance of this work, stating, “This research provides a new direction for magnesium secondary battery research, which has traditionally relied on corrosive electrolytes hindering the formation of interfacial layers on magnesium metal surfaces. It enhances the possibility of low-cost, high-energy-density magnesium secondary batteries based on common electrolytes that are suitable for energy storage systems (ESS).”
The breakthrough achieved by Dr. Minah Lee’s research team at KIST represents a significant advancement in the field of magnesium battery technology. Their chemical activation strategy for magnesium metal enables the efficient operation of magnesium batteries in commonly used electrolytes, free from corrosive additives. By successfully overcoming the challenges associated with the reactivity of magnesium with electrolytes, this research opens up new possibilities for the commercialization of magnesium secondary batteries.
With their higher energy density and the potential for mass production using readily available materials, magnesium batteries could revolutionize the electric vehicle and energy storage industries. The findings of this study bring us one step closer to a future with low-cost, high-energy-density magnesium secondary batteries that can contribute to the development of sustainable energy storage systems.
reference link :https://pubs.acs.org/doi/full/10.1021/acsnano.2c08672