Development and characterization of Al–Ni and nanographite electrodes for energy storage

Development new batteries is a research thrust to meet the global demand for storage energy. An aluminum (Al)-ion battery, similar to a lithium (Li)-ion battery, but with a lower manufacturing cost, was investigated, modifying the aluminum foil with nickel (Ni) coating to act as an anode, and graphite coated with nanographite powder acting as a cathode. The base electrolyte aluminum chloride (AlCl₃) was modified by using additives, namely sodium chloride (NaCl), indium (III) chloride (InCl₃) and mercury (II) chloride (HgCl₂). The developed electrodes were electrochemically characterized by cyclic voltammetry, chronoamperometry and potentiodynamic polarization, while the constituents and morphology were examined by X-ray diffraction and electron microscopy. It was found that the nanographite powder produced a higher current density and more energy compared to the solid graphite electrode. The aluminum–nickel electrode acted as a more efficient electrode compared to the pure aluminum one, giving a much higher current during electro-oxidation. The effect of electrolyte additives such as sodium chloride, indium (III) chloride and mercury (II) chloride made the polarization resistance lower and the current higher. An electrolyte composition of 0·075 M aluminum chloride + 2 M sodium chloride + 4 M indium (III) chloride + 5 M mercury (II) chloride produced the highest current density and energy.