Synthesis of nickel selenide/manganese selenide@cobalt sulfide heterostructure with superior stability for supercapacitors
Liu Wan, Ge Ye, Yan Zhang, Jian Chen, Cheng Du, Mingjiang Xie
Abstract
Transition metal selenides (TMSs) are emerging battery-type materials for supercapacitors (SCs) because of their high theoretical capacities and excellent intrinsic conductivity. Nevertheless, the slow kinetics and inferior cycling stability restrict their practical applications. In this investigation, a novel heterostructure consisting of NiSe/MnSe nanospheres and CoS nanosheets anchored on a carbon paper (CP) skeleton is fabricated by a rational two-step electrodeposition approach. The interaction and cooperation between NiSe/MnSe and CoS not only boosts the electroactivity and electrical conductivity but also enhances the ion transportation rate and structural stability. The as-obtained NiSe/MnSe@CoS electrode achieves an increased specific capacity (884.0C/g/0.62C cm −2 at 1 A/g), improved rate property (74.8 % at 20 A/g), and enhanced cyclic performance (85.4 % over 10,000cycles) when compared to pure NiSe/MnSe and CoS electrodes. Moreover, the constructed hybrid supercapacitor (HSC) delivers a maximal energy density of 65.8 Wh kg −1 under a power density of 1212.3 W kg −1 and outstanding long-cycle durability with 93.3 % capacity retention after 20,000cycles at 20 A/g. This research proposes a simple and sound strategy for realizing breakthroughs of TMSs-based electrode materials for HSC with high energy density and superior cyclic stability.