Template sacrificial controlled synthesis of hierarchical nanoporous carbon@NiCo 2 S 4 microspheres for high‐performance hybrid supercapacitors

Abstract Binary transition metal sulfides are hotly investigated in advanced energy storage devices because of their ultra‐high reversible capacity. Nevertheless, the unsatisfied rate capability and cycling stability still hinder their practical application. Herein, hierarchical nanoporous carbon@NiCo 2 S 4 (HNCMs@NCS) composites with core–shell flower‐like structures were prepared by in situ growing of NiCo 2 S 4 nanosheets on HNCMs through a hydrothermal‐assisted template sacrificial method. Benefiting from a synergistic effect between the NiCo 2 S 4 shell with high specific capacity and the HNCMs with unique porous structure, the synthesized flower‐like HNCMs@NCS composites exhibit extraordinary electrochemical performances, including a high capacity of 346.9 mAh·g −1 at 1 A·g −1 , superb rate property with 86.4% initial capacity at 30 A·g −1 and predominant cycle stability with 81.2% capacity retention after 5000 cycles. Furthermore, the resulting HNCMs@NCS cathode was coupled with the chemical‐activated HNCMs (AHNCMs) anode to construct a hybrid supercapacitor device. The as‐fabricated device exhibits superior energy density (49.9 Wh·kg −1 at 802 W·kg −1 ) and ultra‐high power density (24 kW·kg −1 at 29.5 Wh·kg −1 ). This fascinating result further demonstrates the tremendous prospect of the synthesized HNCMs@NCS composites as high‐performance supercapacitor electrode materials.