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• Activated carbon nanotubes (ACNTs) possess plentiful active sites. • ACNTs as conductive support to deposit NiS and alleviate particles agglomeration. • The nanostructured NiS/ACNTs composite possesses outstanding performances. • The effects of electrolyte concentration on the NiS/ACNTs electrode are studied. • The NiS/ACNTs//AC ASCs delivers high energy density and power density. [Display omitted] Hexagonal nickel sulfide is extensively studied and used for supercapacitors due to its high theoretical specific capacitance (1060 F g−1), simple synthesis craft and low cost. However, the poor electrical conductivity and easy agglomeration severely restrict its practical application. Herein, we design the composite materials of the nickel sulfide nanoparticles and activated carbon nanotubes (NiS/ACNTs) with plentiful active group by hydrothermal method and subsequent annealing treatment, thus effectively inhibiting the agglomeration of NiS nanoparticles and producing good supercapacitor behaviors. Benefiting from the superiority of composite structure, the NiS/ACNTs hybrid electrode delivers a high specific capacitance of 1266 F g−1 at a current density of 1.0 A g−1 and sustains a capacitance value of 1028 F g−1 at 10 A g−1 (81% of initial specific capacitance). Moreover, the asymmetric supercapacitors (ASCs) with NiS/ACNTs cathode and activated carbon (AC) anode exhibit a high energy density of 36.0 Wh kg−1 at a power density of 806 W kg−1 and a good capacitance retention of 83% after 2000 cycles at 2.0 A g−1. Therefore, the combination of the battery-type materials and carbon materials will a significant exploration to solve particle agglomeration and develop the high electrochemical performance ASCs. [ABSTRACT FROM AUTHOR]

• Polypyrrole coating is utilized for polysulfides immobilization. • Lithium sulfide is wrapped inside cathode from exposure. • Activation barrier and polysulfides shuttle are greatly suppressed. • Electrochemical performances of as-prepared cells are promoted. The significantly-high theoretical energy density and eco-sustainability of lithium sulfur batteries (LSBs) arouses a rapid surge of interest in recent years. However, some key issues of cathode, for instance, the polysulfides confinement, low ion/electrons transfer and etc., hinder the practical utilization of LSBs. Herein, such issues could be carefully handled by using the conductive polypyrrole as polysulfides wrapper. The polypyrrole with pyrrole rings can efficiently confine polysulfides inside cathode for redox. Meanwhile, the conductive polypyrrole with delocalized π-electron cloud can facilitate electrons transfer. Besides, the addition of carbon nanotube (CNT) and oxidized graphene (GO) can enhance the conductivity of cathode material. As a result, the Li 2 S/CNT/GO/PPy cathode delivers a cycling capacity of 525 mAh g−1 with a low-capacity decay rate of 0.065 % cycle−1 after 400 cycles. Therefore, the lithium-sulfur battery with Li 2 S-based and PPy-wrapped cathode could reasonably be counted as a potential alternative of long-cycling Li-ion cells. [Display omitted] [ABSTRACT FROM AUTHOR]