High performance δ-Bi2O3 nanosheets transformed Bi2S3 nanoflakes interconnected nanosheets as negative electrode for supercapacitor applications

[Display omitted] •Bismuth oxide (δ-Bi2O3) with high specific capacitance has emerged as a promising negative electrode material for supercapacitors.•δ -Bi2O3 nanosheets followed by hydrothermal route.•δ-Bi2O3 nanosheets electrode has only reached to 474 F g−1 for 1 A g−1 with poor retention of 46%. Progress of negative electrode for supercapacitors (SCs) is most important topic of the recent advanced technological era for the next generation energy storage devices and applications. Bismuth oxide (δ-Bi2O3) with high specific capacitance has emerged as a promising negative electrode material for SCs. Herein, a facile two-step synthesis strategy has been proposed to fabricate Bi2S3 nanoflakes interconnected nanosheets electrode by the conversion of electro-deposited as-prepared δ-Bi2O3 nanosheets followed by hydrothermal route. From the comparison study, it is concluded that Bi2S3 nanoflakes interconnected nanosheets exhibit ultrahigh specific capacitance (565 F g−1 at 1 A g−1) and exceptional cycling stability (∼98% retention after 2000 cycles) as a negative electrode material. Meanwhile, δ-Bi2O3 nanosheets electrode has only reached to 474 F g−1 at 1 A g−1 with poor retention of ∼46%. The improved and better performance of Bi2S3 nanoflakes interconnected nanosheets electrode is attributed to high conductivity due to sulfurization. The current fabrication strategy would provide valuable insights to prepare Bi-based nano-materials for high-performance energy storage technologies and beyond.