Synthesis of polythiophene/graphite composites and their enhanced electrochemical performance for aluminum ion batteries

Abstract

Polythiophene/graphite composites were successfully prepared by a simple method of chemical oxidation and mechanical ball-milling and used as cathode materials for rechargeable aluminum ion batteries. AlCl₃ and [EMIm]Cl are used as electrolytes, and aluminum metal is used as the anode material. The morphologies and microstructures of the products were analyzed using field emission scanning electron microscopy. The energy storage mechanism was studied by X-ray photoelectron spectroscopy analysis. As cathode materials for rechargeable aluminum ion batteries, the polythiophene/graphite composites exhibit excellent electrochemical performance. When the mass ratio of polythiophene to graphite is 1 : 1, the electrode exhibits a very high discharge capacity of 152.5 mA h g⁻¹ at a current density of 500 mA g⁻¹ and 113 mA h g⁻¹ at a current density of 1 A g⁻¹. Even at very high current densities of 2 A g⁻¹ and 5 A g⁻¹, the polythiophene/graphite composites still exhibit discharge capacities of 85.7 mA h g⁻¹ and 75.5 mA h g⁻¹ over 500 cycles.