Pencil‐Drawing Graphite Nanosheets: A Simple and Effective Cathode for High‐Capacity Aluminum Batteries

Commercial graphite, as an attractive cathode material, has been extensively applied in rechargeable aluminum batteries. However, low capacity and complex cathode preparation procedures limit its further development. Herein, graphite nanosheets as cathode of aluminum battery have been prepared by a novel pencil-drawing strategy, which shows superior capacity of 96 mAh g^-1 and excellent stability with almost 100% capacity retention after 2000 cycles at a current density of 0.5 A g^-1 . By increasing charge-discharge current density to 2 A g^-1 , the battery also exhibits a high capacity of 72 mAh g^-1 and retains 90% after 6000 cycles. Furthermore, a stage 3 anion intercalation/deintercalation mechanism has been proposed according to in situ X-ray diffraction and ex situ characterization techniques. This work provides a controllable method for developing a graphite nanosheets cathode with a simplified process and contributes to the development of other kinds of energy storage devices.