Electrochemical Behaviors of Aluminum Anode in Ionic Liquid Electrolyte for Al-ion Battery

초록

As the environmental issues about exhaustion and the combustion gas of fossil fuel are becoming a global problems, there are many attempts to develop renewable energy systems such as solar cell, fuel cell which can save and use energy efficiently. Li-ion battery has been applied for the storage of energy produced by renewable energy sources for load leveling. However, Li-ion battery has low energy density to apply middle or large-sized energy storage devices and the depletion of lithium resources became an important issue with the rapid increase in demand of lithium and safety issues due to the large reactivity of lithium. Therefore, new secondary battery system with high energy density and safety needs to be developed and aluminum metal is recently suggested to be a new anode material. Aluminum is abundant in earth crest and high energy density with 1.06kWh/kg(Li-ion battery : 0.406kWh/kg). Furthermore, three electrons reaction has a possibility to realize a high capacity ? reaction system. In this work, aluminum-ion battery system was built with aluminum anode and aluminum chloride molten ionic liquid electrolyte, AlCl3 ? [EMIm]Cl. Manganese oxide cathode was used as a cathode. Electrochemical behaviors of aluminum anode were investigated with cyclic voltammetry and electrochemical impedance spectroscopy. In order to study the electrochemical stability of Al anode surface in electrolyte, Al surface was modified with electropolishing and selective dissolution of aluminum and the microscopic surface morphology changes was observed with SEM. Additionally, swagelok type of the cell was prepared and the effect of electrolyte composition on charge-discharge behaviors of rechargeable Al-ion battery was investigated.