2D graphitic carbon nitride as the efficient cathode material for the non-aqueous rechargeable iron-ion battery under an ambient environment

We fabricated non-aqueous rechargeable iron ion batteries under ambient conditions (without an inert atmosphere or glovebox) using two-dimensional (2D) graphitic-carbon nitride (g-C3N4) as the low-cost active cathode material, synthesized using the one-step simple polymerization route. Mild Steel (MS) is an anode with a non-aqueous solvent-based tetra-ethylene glycol dimethyl ether electrolyte. Galvanostatic charging-discharging (GCD) characteristics are measured at various current densities. A specific capacity of 130 mAh g−1 is observed at 40 mA g−1 current density, and more than 50% of capacity retention is recorded over 100 cycles. RIIBs are also evaluated at a higher current density of 400 mA g−1 (3C rate- 20 min for one cycle), showing 60 mAh g−1 with an excellent rate capability for more than 240 cycles. The impedance is carried out to analyze the onset of interface layer resistance during cycling. Using the stack of the seven rechargeable coin cells, we demonstrated the lightening of the “IITJ” pattern based on white light emitting diodes (LEDs). Thus, 2D-graphitic C3N4 can be used as an efficient cathode material for safer and more reliable rechargeability with non-aqueous electrolytes-based RIIBs, exhibiting potential for next-generation energy storage devices for various small/large-scale applications.