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

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) (PE-DOT: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 degrees for 5000 cycles in aqueous and solid-state electrolytes, respectively.

Automated summary

The study introduces a polymer into the precursor to inhibit the self-assembly of MoS2 nanosheets, forming a MoS2/PEDOT:PSS hydrogel in the hydrothermal process, which can be used to prepare free-standing flexible films or for 3D printing. The resulting MP film displays excellent electrochemical performance and high capacitance retention rates after bending cycles in various electrolytes.