Advancement of technology towards high-performance non-aqueous aluminum-ion batteries

Al-ion batteries (AIBs) have been identified as one of the most hopeful energy storage systems after Li-ion batteries on account for the ultrahigh volumetric capacity, high safety and low cost from the rich abundance of Al. Nonetheless, some inevitable shortcomings, such as the formation of passive oxide film, hydrogen side reactions and anode corrosion, finally limit the large-scale application of aqueous AIBs. The nonaqueous AIBs have been considered as one of most hopeful alternatives for high-powered electrochemical energy storage devices. Nonetheless, various technical and scientific obstacles should be resolved because nonaqueous AIBs are still nascent. Some significant efforts have aimed to resolve these issues towards large-scale applications, and some important advancement has been made. In the present review, we mainly intended to offer an overview of non-aqueous AIBs systems, and we comprehensively reviewed the recent research advancement of the cathode materials, anode materials electrolyte and collectors as well as the fundamental understanding of the functional mechanisms. In addition, we have also analyzed several technical challenges and summarized the strategies used for overcoming the challenges in improving the electrochemical properties, including morphology control, surface engineering, doping and construction of composite electrodes as well as the charge storage mechanisms of the materials with different crystal structures. At last, future research orientation and development prospect of the AIBs are proposed.