Rod-shaped Cu1.81Te as a novel cathode material for aluminum-ion batteries

Abstract

Aluminum-ion batteries (AIBs) are supposed to be one of the energy storage systems with great potentialities on account of their high safety, low cost and high theoretical volumetric capacity. Herein, we report a novel rod-shaped Cu_1.81Te cathode material for AIBs. At 40 mA g⁻¹, the initial discharge capacity can reach 144 mA h g⁻¹. The diffusion coefficient of Al³⁺ calculated by the galvanostatic intermittent titration technique (GITT) and cyclic voltammetry (CV) tests at different scan rates is larger than that in sulfides, indicating that telluride has faster kinetics. The results of ex situ X-ray photoelectron spectroscopy (XPS), ex situ X-ray diffraction (XRD) and ²⁷Al nuclear magnetic resonance (NMR) prove that the mechanism of the charging and discharging processes is the reversible intercalation and deintercalation of Al³⁺, which is very important for the subsequent researchers to understand and investigate the mechanism of the Al/Cu_1.81Te battery. This work also proves that telluride can also be used as a cathode material for aluminum storage.