Low-Cost Rechargeable Battery Using Pencil Graphite as Ion Intercalation / De-Intercalation Electrode

Abstract

Remarkable improvement in utilizing renewable energy has pioneered to a critical demand for the large-scale energy storage system considering cost, safety and environmental aspect. Zn/Al-ion batteries are eco-friendly and advantageous over acid or alkali-based batteries as it is possible to utilize Zn metal as the negative electrode in aqueous medium. Here a Zn/Al-ion battery is developed using Pencil graphite, coated with graphene by cyclic voltammetry (CV), as the positive electrode and Zn metal as the negative electrode in an aqueous AlCl3/Zn(CH3COO)2 (0.5/0.5M) electrolyte. The Zn/Al-ion cell shows average discharge voltage plateaus around 1.0 V which offers a specific cathode capacity of ~54.1 mAh g−1 at a constant current density of 55 mA g−1 and exhibits capacity retention of more than ~95.8% over 100 cycles without any formation of dendrite at the negative electrode (Zn). Reversible Al3+ or [Al(H2O)6]3+ ion intercalation/de-intercalation storage process involving graphene coated pencil graphite (positive electrode) during charge-discharge cycling is proposed on the basis of CV, Electrochemical impedance spectroscopy (EIS), Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX) analysis.