Engineering ultrahigh-specific-capacity α-Fe2O3 nanoparticles and Ni(OH)2/Co0.85Se nanostructures separately anchored on N-doped graphene nanotubes toward alkaline rechargeable battery

Abstract In this paper, the N-doped graphene nanotubes (N-GNTs) are used as the scaffolds to grow α-Fe2O3 nanoparticles (NPs) and Ni(OH)2 nanosheets arrays (NAs)/Co0.85Se nanoparticles (NPs) respectively, which are directly acted as hybrid negative and positive electrodes for alkaline rechargeable battery (ARB). The synergistic merits from the supporters and active materials enable the N-GNTs@ α-Fe2O3 NPs to deliver an ultrahigh specific capacity of 309 mAh g−1 at 1 A g−1, and good rate performance. By paring with the N-GNTs@ Ni(OH)2 NAs/Co0.85Se NPs (268 mAh g−1 at 1 A g−1), an ARB configuration is assembled. Contributed by the particular electrode architectures, the device displays a high energy density of 78.8 Wh kg−1 at 2.47 kW kg−1 and robust cycling life (91.3% retention of the initial specific capacity over 10,000 cycles). This strategy reported here opens up a new avenue to construct unique hybrid electrodes and maximizes their superiority, which leads to the ultrahigh capacity for the fabrication of next-generation energy storage devices.