Engineering of MoSe2 decorated Ni/Co selenide complex hollow arrayed structures with dense heterointerfaces for high-performance aqueous alkaline Zn batteries

Abstract

The development of advanced Ni/Co-based cathode electrodes for aqueous alkaline Zn batteries (AZBs) is highly desirable, but still remains a challenging task. Herein, we rationally design and synthesize the unique MoSe2 decorated Ni/Co selenide complex hollow arrayed structures (CH-MNCS) with dense heterointerfaces supported on nickel foam (NF) through a metal–organic framework-engaged strategy, in which heterostructured CoSe/MoSe2 hollow nanocages are uniformly assembled on heterostructured NiSex/MoSe2 nanotubes. Benefiting from the apparent morphological, structural and compositional advantages, aqueous AZBs based on the NF/CH-MNCS binder-free cathode exhibit high areal capacity and energy density of 1.42 mAh cm−2 and 2.45 mWh cm−2 at a current density of 2 mA cm−2, respectively, as well as decent rate capability and long cycling stability. Furthermore, density functional theoretical calculations further confirm the presence of heterointerfaces can not only enhance the electrical conductivity but also facilitate the adsorption of OH− ions in the electrolyte. More importantly, the quasi-solid-state NF/CH-MNCS//Zn batteries are also assembled to demonstrate the potential for practical applications. This work may provide a new perspective to construct heterostructured transition metal selenide complex hollow structures on conductive substrate for aqueous AZBs and other energy storage devices.