China Nonferrous Metallurgy

Current aluminum electrolysis processes face challenges such as high temperatures， high energy consumption， and high emissions. Research has explored aluminum electrolysis in ionic liquids， but these methods suffer from complex synthesis processes and high costs. The aluminum trichloridephenyltrimethylammonium chloride-toluene （AlCl₃-TMPAC-TL） ionic liquid is low-cost， has wide electrochemical windows， and exhibits good solubility. However， its conductivity is relatively low， whereas toluene （TL） can significantly enhance the conductivity of the ionic liquid. This study employs an aluminum trichloridephenyltrimethylammonium chloride-toluene （AlCl₃-TMPAC-TL） ionic liquid as the electrolyte and a copper sheet as the substrate. Aluminum alloy electrolysis was conducted using a constant current method at 80℃ . The influence of toluene content （volume fractions：0%，20%，35%， and 50%） on aluminum electrolysis was systematically investigated. The results demonstrate that increasing temperature and toluene content significantly enhances the electrolyte’s conductivity while decreasing its viscosity. Cyclic voltammetry test showed that the presence of toluene in the electrolyte significantly accelerated the reduction and oxidation reactions of aluminum. Electrolysis experiments indicated that pure aluminum can be obtained by electrolysis of aluminum alloy from AlCl₃- TMPAC-TL ionic liquid. The presence of toluene in electrolyte improved the cathodic current efficiency and reduced the direct energy consumption. With the increase of toluene content in electrolyte， the product morphology evolved from irregular micron-scale flakes to cedar-like structure and then transitioned to micron blocks. Furthermore， toluene promotes preferential growth of aluminum along the （111） and （200） crystal planes.