Sulfur-Vacancy-Enriched Borophene@MoS2 Heterostructures for High-Performance Supercapacitors

Borophene has attracted significant research attention in the field of energy storage owing to its unique structure, impressive electronic conductivity, and tunable surface chemistry. However, interlayer restacking and stability issues impede their scalability for use in electrochemical devices. To overcome this limitation, herein, a unique sulfur-vacancy-enriched 2D borophene/3D MoS2 nanoflower-based heterostructure was synthesized. The high density of sulfur vacancies, along with abundant edge-enriched active sites, facilitates fast ion transport and swift reaction kinetics, while the synergistic interactions within the heterostructure maximize the electroactive surface area to develop highly efficient symmetric supercapacitor (SC) devices. The optimized BM-3-based symmetric SC device exhibited a specific capacitance of 319.58 F g-1, an energy density of 53.70 Wh kg-1, and a power density of 550 W kg-1 at a current density of 1 Ag-1 within the potential window of 1.1 V and exhibited outstanding cycling stability with 91.01% capacitance retention after 6000 cycles. Meanwhile, the asymmetric capacitor showed a high specific capacitance of 217.58 F g-1 with a high energy density of 87.33 Wh kg-1 and a power density of 850 W kg-1 at a 1 Ag-1 current density.