A high performance SnO2/C nanocomposite cathode for aluminum-ion batteriesElectronic supplementary information (ESI) available. See DOI: 10.1039/c8ta11132d

Rechargeable aluminum-ion batteries have been researched extensively due to their attractive features, such as the abundant aluminum resources and high capacity resulting from the three-electron redox properties. Herein, a porous carbon supported SnO 2 nanocomposite is reported as a cathode material for AIBs. The resultant cell exhibits a high discharge specific capacity of 370 mA h g −1 (with an initial value of 434 mA h g −1 ) at 50 mA g −1 . In the cycling performance, the cell retains a stabilized discharge capacity of 72 mA h g −1 after 20 000 cycles with a coulombic efficiency of ∼100% under an ultrahigh current density of 2 A g −1 . Owing to the well-defined nanostructure, side reactions and pulverization of active particles can be prevented. The results indicate that the SnO 2 /C nanocomposite is a favorable cathode material for AIBs and opens up a new opportunity for the design of high-performance AIBs. A novel SnO 2 /C AIB with high discharge capacity and long cycle life is achieved.