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The intelligent construction of electrode nanostructures with unique morphologies is of admirable importance for increasing the energy storage capacity of highly efficient supercapacitor devices. In this study, the negative electrode material Bi2O3/Bi2Se3 nanoflower (Bi2O3/Bi2Se3 NFs) hybrid was first fabricated via a simple one-step solvothermal approach; due to the favorable conductivity of Bi2Se3, high theoretical capacity of Bi2O3 and their distinctive nanostructures, the achieved Bi2O3/Bi2Se3 NFs exhibited the maximum specific capacity of 132.7 mA h g−1 (∼531 F g−1) at 1 A g−1 and the superior rate capability of 113.8 mA h g−1 (∼455 F g−1) at 10 A g−1. Moreover, the positive electrode material NiCoSe2/Ni0.85Se nanoparticles (NiCoSe2/Ni0.85Se NPs) obtained by an electrodeposition method delivered the high specific capacity of 248.4 mA h g−1 (∼1788 F g−1) at 1 A g−1 as well as the appealing rate property of ∼84% capacity retention when the current density was increased by 100 times (i.e., 100 A g−1). More significantly, it was found that the assembled Bi2O3/Bi2Se3 NFs//NiCoSe2/Ni0.85Se NP asymmetric aqueous battery (AAB) device achieved the extraordinary energy density of 88.4 W h kg−1 at the power density of 2.4 kW kg−1 along with a durable lifespan (maintaining the capacity retention of up to 91.5% even after 10 000 cycles). Consequently, the design strategy and novel perspectives reported herein not only hold extensive promise for expanding the preparation techniques of morphology-controlled composites with robust electrochemical properties but also promote the practical applications of newly emerging metal selenides in next-generation aqueous batteries. [ABSTRACT FROM AUTHOR]

In this paper, the N-doped graphene nanotubes (N-GNTs) are used as the scaffolds to grow α-Fe 2 O 3 nanoparticles (NPs) and Ni(OH) 2 nanosheets arrays (NAs)/Co 0.85 Se 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-Fe 2 O 3 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/Co 0.85 Se 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. • The two advanced hybrid electrode materials were prepared respectively. • The electrodes show ultrahigh specific capacity and good rate performance. • An alkaline rechargeable battery with the two electrodes was successfully assembled. • The device can present high energy density and outstanding cycling performance. [ABSTRACT FROM AUTHOR]