One-Pot Hydrothermal Synthesis of Solution-Processable MoS₂/PEDOT:PSS Composites for High-Performance Supercapacitors

Abstract

It is challenging to hydrothermally synthesize solution-processable MoS₂, as the strong van der Waals force between MoS₂ nanosheets induces self-assembly of agglomerates. Here, we introduce poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) into the precursor to impede aggregate formation in the hydrothermal process. A hybrid MoS₂/PEDOT:PSS (MP) hydrogel is formed due to the electrostatic interactions between the negatively charged MoS₂ and positively charged PEDOT chains. This hydrogel can be easily dispersed in water for subsequent solution processing such as vacuum filtration to form free-standing flexible films or extrusion 3D printing to create novel patterns. The MP film with a fracture strength of 18.59 MPa displays excellent electrochemical performance in both aqueous Na₂SO₄ electrolyte (474 mF cm^-2) and solid-state PVA-H₃PO₄ electrolyte (360 mF cm^-2). Flexibility and robustness can be evidenced by high capacitance retention rates of 94 and 89% after being repeatedly bent to 180° for 5000 cycles in aqueous and solid-state electrolytes, respectively.