Rechargeable aluminium organic batteries

Since aluminium is one of the most widely available elements in Earth's crust, developing rechargeable aluminium batteries offers an ideal opportunity to deliver cells with high energy-to-price ratios. Nevertheless, finding appropriate host electrodes for insertion of aluminium (complex) ions remains a fundamental challenge. Here, we demonstrate a strategy for designing active materials for rechargeable aluminium batteries. This strategy entails the use of redox-active triangular phenanthrenequinone-based macrocycles, which form layered superstructures resulting in the reversible insertion and extraction of a cationic aluminium complex. This architecture exhibits an outstanding electrochemical performance with a reversible capacity of 110 mA h g(-1) along with a superior cyclability of up to 5,000 cycles. Furthermore, electrodes composed of these macrocycles blended with graphite flakes result in higher specific capacity, electronic conductivity and areal loading. These findings constitute a major advance in the design of rechargeable aluminium batteries and represent a good starting point for addressing affordable large-scale energy storage.