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 advan-tages 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.