Unlocking the potential of commercial carbon nanofibers as free-standing cathodes for flexible aluminum ion batteries

Rechargeable aluminum-ion batteries (AIBs) are one of the most attractive next-generation energy storage technologies. Here, we report new edge-rich graphitic nanoribbon interconnected nanocup stacks as positive electrodes for AIBs by cleaving commercial carbon nanofibers. AIBs with an exceptionally high rate capacity (above 95 mA h g−1 at a high current density of 50 A g−1) and high energy density (214 W h kg−1) are achieved. Moreover, the binder-free and freestanding electrode presents a negligible capacity decay after 20 000 cycles at a current density of 10 A g−1. This report highlights the potential of a new practical carbon-based positive electrode for scalable and flexible AIBs.