Novel Insight into Rechargeable Aluminum Batteries with Promising Selenium Sulfide@Carbon Nanofibers Cathode

Due to the unique electronic structure of aluminum ions (Al3+) with strong Coulombic interaction and complex bonding situation (simultaneously covalent/ionic bonds), traditional electrodes, mismatching with the bonding orbital of Al3+, usually exhibit slow kinetic process with inferior rechargeable aluminum batteries (RABs) performance. Herein, to break the confinement of the interaction mismatch between Al3+ and the electrode, a previously unexplored Se2.9S5.1-based cathode with sufficient valence electronic energy overlap with Al3+ and easily accessible structure is potentially developed. Through this new strategy, Se2.9S5.1 encapsulated in multichannel carbon nanofibers with free-standing structure exhibits a high capacity of 606 mAh g(-1) at 50 mA g(-1), high rate-capacity (211 mAh g(-1) at 2.0 A g(-1)), robust stability (187 mAh g(-1) at 0.5 A g(-1) after 3,000 cycles), and enhanced flexibility. Simultaneously, in/ex-situ characterizations also reveal the unexplored mechanism of SexSy in RABs.

Automated summary

Due to the unique electronic structure of aluminum ions (Al3+), traditional electrodes usually exhibit slow kinetic process and inferior rechargeable aluminum batteries (RABs) performance. To solve this problem, a Se2.9S5.1-based cathode with sufficient valence electronic energy overlap with Al3+ and easily accessible structure is developed. This cathode exhibits high capacity, high rate-capacity, robust stability, and enhanced flexibility, and the mechanism of SexSy in RABs is also explored.