Advances in rechargeable magnesium batteries employing graphene-based materials

Rechargeable magnesium batteries (RMBs) can play an important role in the ongoing transition towards renewable and green forms of energy. Over the past two decades, this technology has seen great improvements in terms of capacity, stability, rate capability, operating voltage, etc. Moreover, high inherent safety and availability of materials for magnesium-based batteries are clear advantages over lithium-based energy storage devices. However, RMB technology still poses significant challenges, such as low intercalation rates with common positive electrode materials or the incompatibility of electrolytes with Mg metal anodes, leading to formation of a passive layer, which can render the devices inoperable. These problems can be overcome by improving battery materials or designing new compounds for electrodes and electrolytes, and by mitigating the undesired interactions between battery components. Graphene has been in the focus for energy materials research since its discovery and is intensely studied in battery research for composite materials to enhance electrochemical characteristics as well as to increase mechanical stability of electrode materials. In this review, we give an overview of recently developed rechargeable Mg batteries employing graphene and graphene-based materials to improve cathodes, anodes and other aspects of these devices, in order to produce more capable and viable RMBs.