Defect-free soft carbon as cathode material for Al-ion batteries

Al-ion batteries are proposed as promising energy storage candidates for beyond Li-ion technology due to the higher natural earth of Al metal. Recently, various graphite and graphene cathodes for Al-ion batteries have been studied in this regard, but their costs are not satisfactory. In this study, a novel cathode for Al-ion batteries is prepared by graphitizing inexpensive soft carbon materials (mesocarbon microspheres and petroleum coke) at 2800 °C. The charge and discharge process is showcased here for graphitized petroleum coke, which has a storage capacity of 77.7 mAh g −1 with two high discharge voltage (~ 2.25 and 1.80 V), higher than graphitized mesocarbon microspheres (51 mAh g −1 ). It also has excellent cycle stability and no reduction in specific capacity after 1000 cycles. Affordable cost of the graphitized petroleum coke cathode makes Al-ion battery more promising for large-scale chemical energy storage.