Sb2S3 Nanoparticles Anchored or Encapsulated by the Sulfur-Doped Carbon Sheet for High-Performance Supercapacitors.

ABSTRACT

The specific capacitance and energy density of antimony trisulfide (Sb2S3)@carbon supercapacitors (SCs) have been limited and are in need of significant improvement. In this work, Sb2S3 nanoparticles were selectively encapsulated or anchored in a sulfur-doped carbon (S-carbon) sheet depending on the use of microwave-assisted synthesis. The microwave-triggered Sb2S3 nanoparticle growth resulted in core-shell hierarchical spherical particles of uniform diameter assembled with Sb2S3 as the core and an encapsulated S-carbon layer as the shell (Sb2S3-M@S-C). Without the microwave mediation, the other nanostructure was found to comprise fine Sb2S3 nanoparticles widely anchored in the S-carbon sheet (Sb2S3-P@S-C). Structural and morphological analyses confirmed the presence of encapsulated and anchored Sb2S3 nanoparticles in the carbon. These two materials exhibited higher specific capacitance values of 1179 (0 to +1.0 V) and 1380 F·g-1 (-0.8 to 0 V) at a current density of 1 A·g-1, respectively, than those previously reported for Sb2S3 nanomaterials in considerable SCs. Furthermore, both materials exhibited outstanding reversible capacitance and cycle stability when used as SC electrodes while retaining over 98% of the capacitance after 10 000 cycles, which indicates their long-term stability. Furthermore, a hybrid Sb2S3-M@S-C/Sb2S3-P@S-C device was designed, which delivers a remarkable energy density of 49 W·h·kg-1 at a power density of 2.5 kW·kg-1 with long-term cycle stability (94% over 10 000 cycles) and is comparable to SCs in the recent literature. Finally, a light-emitting diode (LED) panel comprising 32 LEDs was powered using three pencil-type hybrid SCs in series.