Free-standing WS2-MWCNTs hybrid paper integrated with polyaniline for high-performance flexible supercapacitor

As two-dimensional layered nanomaterials, the tungsten disulfide (WS2) nanosheets can be used as building blocks of paper-like electrodes for high-performance FSs. However, poor conductivity and mechanical property of WS2 nanosheets (NSs) paper greatly hinders their capacitance and/or rate performance. To solve these problems, we fabricated the WS2-multiwalled carbon nanotubes (MWCNTs)/polyaniline (PANI) composite papers based on liquid exfoliation and electrochemical deposition for high-performance flexible supercapacitors. The WS2-MWCNTs/PANI with conductive PANI chains linked WS2 NSs and MWCNTs takes the advantages of high-electronic double-layer capacitance originated from the internal surface areas of MWCNTs and effective pseudocapacitance generated by exfoliated WS2 NSs and PANI. Electrochemical studies showed that the gravimetric-specific capacitance of WS2-MWCNTs/PANI can reach ~760.1 F/g at a current density of 1 A/g. A symmetric flexible solid-state supercapacitor was also assembled and studied. The WS2-MWCNTs/PANI-assembled FS device also has an excellent area specific capacitance of 1158.7 mF/cm2 at a current density of 0.5 mA/cm2 together with a high-capacity retention of ~82.5% after 2000 cycles.