Aluminium ion batteries (AIBs) are regarded to be one of the most promising alternatives for next-generation batteries thanks to the abundant reserves, low cost, and lightweight of aluminium anode. Like other electrochemical energy storage systems, the electrochemical performances of AIBs intimately depend on the properties of electrolytes and electrode materials. In this project, we will explore new cathode materials for AIBs and investigate the fundamental energy storage mechanisms via various ex-situ/in-situ measurements.