Architecting Hollow MnS / CNT Hybrid Composites for Ultra‐High Performance Asymmetric Supercapacitors

ABSTRACT

The development of high‐performance supercapacitors has accelerated interest in advanced materials with enhanced energy density, power output, and long cycle life. Among emerging architectures, hollow structures are particularly attractive due to their very high active surface area, rich redox‐active sites, and ability to buffer volume changes during charge/discharge process. In this work, we report the synthesis of hollow MnS/carbon nanotube (MnS/CNT) composites via a one‐pot hydrothermal synthesis. The integration of MnS having multiple redox states and high capacitance with conductive CNTs enables a synergistic architecture that enhances ion/electron transport and structural robustness. The resulting hollow MnS/CNT composite demonstrates a 3.15‐fold improvement in specific capacitance (1225 F g ⁻¹ at 5 A g ⁻¹ ) compared to pristine MnS (388.5 F g ⁻¹ ). An asymmetric supercapacitor fabricated with MnS/CNT as cathode and activated carbon as anode exhibits a high energy density of 41.34 Wh kg ⁻¹ at a power density of 3825.8 W kg ⁻¹ , and sustains 13.02 Wh kg ⁻¹ at a power density of 18027.69 W kg ⁻¹ . The asymmetric supercapacitor device also achieves 83% capacitance retention after 5000 cycles, confirming excellent electrochemical stability. The observed superior electrochemical performance is ascribed to the hollow MnS framework, which facilitates ion diffusion and accommodates structural stress, and the CNT network, which ensures efficient charge transport. This work highlights a scalable strategy for designing high‐efficiency electrode materials and positions hollow MnS/CNT composites as promising candidates for next‐generation electrochemical energy storage systems.