Electrochemical Response of 3D-Printed Free-Standing Reduced Graphene Oxide Electrode for Sodium Ion Batteries Using a Three-Electrode Glass Cell

Abstract

Graphene and its derivatives have been widely used to develop novel materials with applications in energy storage. Among them, reduced graphene oxide has shown great potential for more efficient storage of Na ions and is a current target in the design of electrodes for environmentally friendly Na ion batteries. The search for more sustainable and versatile manufacturing processes also motivates research into additive manufacturing electrodes. Here, the electrochemical responses of porous 3D-printed free-standing log-type structures fabricated using direct ink writing (DIW) with a graphene oxide (GO) gel ink are investigated after thermal reduction in a three-electrode cell configuration. The structures delivered capacities in the range of 50–80 mAh g−1 and showed high stability for more than 100 cycles. The reaction with the electrolyte/solvent system, which caused an initial capacity drop, was evidenced by the nucleation of various Na carbonates and Na2O. The incorporation of Na into the filaments of the structure was verified with transmission electron microscopy and Raman spectroscopy. This work is a proof of concept that structured reduced GO electrodes for Na ion batteries can be achieved from a simple, aqueous GO ink through DIW and that there is scope for improving their performance and capacity.

Production of Sulphur-Doped Graphene Oxide as an Anode Material for Na-Ion Batteries

“…First, a few cycles were necessary for activation process of the reaction between SGO and Na + to stabilize the electrochemical system. 87 Secondly, the less reversible reaction between O and Na. 88 Third, the formation of the Solid Electrolyte Interphase (SEI) layer accompanied with electrolyte decomposition.…”

“…88 Third, the formation of the Solid Electrolyte Interphase (SEI) layer accompanied with electrolyte decomposition. 21,87 The formation of SEI layer during the first cycle of the charge and discharge process is because Fermi level of the anode material is higher than the LUMO (lowest unoccupied molecular orbit) of the electrolyte. Consequently, the electrolyte undergoes spontaneous dissolution into an SEI characterized by the presence of both organic and inorganic insoluble components.…”