A novel dual-graphite aluminum-ion battery

Advanced rechargeable batteries with long cycle life, high safety and low cost through multiple electrochemically reversible reactions are practically attractive. Recently, aluminum-ion batteries have attracted extraordinary attention owing to their unique advantages, such as low cost, low flammability and high stability. Herein, we firstly introduce a reversible dual-graphite intercalation chemistry with simultaneous deposition of Al³⁺ and intercalation of AlCl₄^- in graphitic materials for a new aluminum-ion battery based on an ionic liquid electrolyte. This novel dual-graphite aluminum-ion battery (DGAB) shows excellent cycling life with a stable discharge capacity of ~70 mA h g⁻¹ at 20 mA g⁻¹, a superior cycling coulombic efficiency (98.5%) and great rate capability, retaining ~70 mA h g⁻¹ over 600 continuous cycles. In addition, the battery offers a high discharge voltage approaching 2.1 V (vs. Al³⁺/Al). This work paves ways for further developing aluminum-ion batteries for the wide range of energy storage applications.