Self-assembled molybdenum disulfide nanoflowers regulated by lithium sulfate for high performance supercapacitors

Abstract

Recently, molybdenum disulfide (MoS₂) has been extensively investigated as a promising pseudocapacitor electrode material. However, MoS₂ usually exhibits inferior rate capability and cyclability, which restrain its practical application in energy storage. In this work, MoS₂ nanoflowers regulated by Li₂SO₄ (L-MoS₂) are successfully fabricated via intercalating solvated Li ions. Via appropriate intercalation of Li₂SO₄, MoS₂ nanosheets could self-assemble to form L-MoS₂ nanoflowers with an interlayer spacing of 0.65 nm. Due to the large specific surface area (23.7 m² g⁻¹) and high 1T phase content (77.5%), L-MoS₂ as supercapacitor electrode delivers a maximum specific capacitance of 356.7 F g⁻¹ at 1 A g⁻¹ and maintains 49.8% of capacitance retention at 20 A g⁻¹. Moreover, the assembled L-MoS₂ symmetric supercapacitor (SSC) device displays an energy density of 6.5 W h kg⁻¹ and 79.6% of capacitance retention after 3000 cycles.