Ultra-high-performance aluminum-based hybrid supercapacitors prepared for nitrogen-doped micro-mesoporous carbon sphere

Aluminum-based devices are promising candidates for the next generation of energy storage due to the advantages of high energy density, high safety, and low cost. The aluminum ion batteries (AIBs) are based on the electrochemical intercalation/deintercalation reactions against the electrodes, but the selection of the cathode is limited to the present. The cathode reactions of cation-type AIBs are plagued by the poor kinetics of solid-state diffusion from high charge density of Al3+ and anion-type AIBs show poor capacity due to the intercalation of large-sized chloroaluminate (AlCl4−) active ions into the cathode. Here, we deliberately adopted a hybrid capacitor-battery mechanism and employed a nitrogen-doped micro-mesoporous carbon sphere of a high specific area as the cathode and aluminum as the anode to construct an aluminum-based energy storage device. After optimization, it exhibits an excellent discharge capacity of 224 mA h g−1 at a current density of 300 mA g−1, and exceptional cycling performance with a discharge capacity as high as 114 mA h g−1 at 10 A g−1 after 35000 cycles. The ultra-high-performance aluminum-based hybrid supercapacitor (Al-HSC) may lead to a new direction for the development of aluminum-based energy storage devices. [Display omitted] •Nitrogen-doped micro-mesoporous carbon sphere (NCS) electrode is constructed.•NSC was first applied to the aluminum-based hybrid supercapacitor (Al-HSC).•The high specific surface area of NCS guarantees high-capacity AlCl4− storage.•NCS exhibits superior performance among existing cathode materials.