Bipolar\nBINOL–PIM Cathode for High-Performance\nAluminum Batteries

Given\nthe high abundance of aluminum in the Earth’s crust,\nthe development of aluminum-ion batteries can provide a cost-effective\nsolution for large-scale energy storage. However, the key challenge\nin this field is to identify high-quality cathode materials that enable\neffective insertion/extraction of aluminum complex ions. In this regard,\nwe present a strategy to prepare high-capacity, long-cycling aluminum-ion\nbatteries aluminum–ion batteries (ALBs) cathode materials.\nHigh capacity was achieved by introducing multiple active sites into\na 1,1′-bi-2-naphthol (BINOL) polymer of intrinsic microporosity\ncathode material to realize dual aluminum complex ion adsorption.\nThe cathode had adjustable mesoporous structure that enabled its activation,\nwherein the pore size gradually increased during the insertion/extraction\nof aluminum complex ions, effectively enhancing battery capacity and\ncycling stability. The aluminum-ion battery cathode material achieved\na high capacity of up to 110 mAh/g at a current density of 200 mA/g\nand could withstand over 3000 cycles at a high current density of\n1 A/g. These findings provide a design approach for aluminum-battery\ncathode materials intended for low-cost, large-scale energy storage.