Electrochemically Activated Expanded Graphite with Tailor-Made Pores for Magnesium-Organocation Hybrid Batteries

Persisting limitations of lithium-ion batteries (LIBs) in terms of safety, energy and power density, natural resources, and the price call for expeditious research to develop the "beyond Li-ion" technologies. In this regard, magnesium-organocation hybrid batteries (MOHB) hold the potential to address the above issues associated with LIBs by utilizing abundant and inexpensive elements of magnesium and carbon for the anode and cathode, respectively. Moreover, magnesium metal anode is highly energy-dense yet less susceptible to the dendrite formation, enabling safer operation compared to lithium metal anodes. In this study, we targeted to increase the capacity and rate capability of porous carbon cathode of MOHB by generating tailor-made pores, which were provided by the interlayer accommodation of solvated organic cations with controlled sizes during the electrochemical activation of expanded graphite. Our electrochemically activated expanded graphite can be used as an efficient cathode in MOHB with enhanced kinetics, specific capacitance, and cycle life.