Electrodeposited polyethylenedioxythiophene with infiltrated gel electrolyte interface: a close contest of an all-solid-state supercapacitor with its liquid-state counterpart

Abstract

We report the design of an all-solid-state supercapacitor, which has charge storage characteristics closely matching that of its liquid-state counterpart even under extreme temperature and humidity conditions. The prototype is made by electro-depositing polyethylenedioxythiophene (PEDOT) onto the individual carbon fibers of a porous carbon substrate followed by intercalating the matrix with polyvinyl alcohol-sulphuric acid (PVA-H2SO4) gel electrolyte. The electrodeposited layer of PEDOT maintained a flower-like growth pattern along the threads of each carbon fiber. This morphology and the alignment of PEDOT led to an enhanced surface area and electrical conductivity, and the pores in the system enabled effective intercalation of the polymer-gel electrolyte. Thus, the established electrode-electrolyte interface nearly mimics that of its counterpart based on the liquid electrolyte. Consequently, the solid device attained very low internal resistance (1.1 Ω cm(-2)) and a high specific capacitance (181 F g(-1)) for PEDOT at a discharge current density of 0.5 A g(-1). Even with a high areal capacitance of 836 mF cm(-2) and volumetric capacitance of 28 F cm(-3), the solid device retained a mass-specific capacitance of 111 F g(-1) for PEDOT. This is in close agreement with the value displayed by the corresponding liquid-state system (112 F g(-1)), which was fabricated by replacing the gel electrolyte with 0.5 M H2SO4. The device also showed excellent charge-discharge stability for 12 000 cycles at 5 A g(-1). The performance of the device was consistent even under wide-ranging humidity (30-80%) and temperature (-10 to 80 °C) conditions. Finally, a device fabricated by increasing the electrode area four times was used to light an LED, which validated the scalability of the process.

One-Pot Hydrothermal Synthesis of Novel Cu-MnS with PVP Cabbage-Like Nanostructures for High-Performance Supercapacitors

“…In this study, nickel foam was used as a substrate that exhibits good electrical conductivity and a 3D hierarchical structure with open macropores that allow prompt ion and electron transfer. (Figure 4b), which might have emerged during the hydrothermal cooling process due to a divergence in the coefficient of thermal expansion [30]. These wrinkled nanotubes can serve as nucleation sites for the growth of Cu-MnS with PVP nanostructures as well as allow the uniform distribution of Cu and PVP.…”

Novel scalable synthesis of highly conducting and robust PEDOT paper for a high performance flexible solid supercapacitor

“…Capacitance properties are found to improve linearly with increasing the PEDOT layer (28 mF cm -2 to 115 mF cm -2 ) in the paper as expected due to the progressively reduced sheet resistance (Figure 5d). We believe that, apart from the high conductivity of PEDOT (> 375 S cm -1 ), the porous structure of PEDOT as found in the TEM images also helps in maintaining the high capacitance by achieving high electrode-electrolyte interface during the intercalation of the polymer gel electrolyte 62,63 . By considering the weight of the cellulose paper into account, the capacitance of the electrode has been calculated as 20 F g -1 .…”

“…For flexible solid-state-supercapacitor, PVA-H 2 SO 4 gel electrolyte was used as the electrolyte, which was prepared by following our previous reports 62,63 . PVA-H 2 SO 4 coated onto PEDOT-p using roll coating procedure.…”

A Biodegradable Gel Electrolyte for Use in High-Performance Flexible Supercapacitors

“…The cohesive features of solid systems with liquid-like transport properties, would provide a plausible configuration because of their advantages including a high degree of flexibility, semisolid characteristics as well as high ionic conductivity. 4,5,8 Conventional ion gel systems such as PVA−H 3 PO 4 , PVA−H 2 SO 4 , PVA−LiCl, PAN−PEG−LiClO 4 , and P(VDF−HFP)−EMIMBF 4 have been reported. 9,13−16 These polymer-ionic liquid combinations show mechanical deformability and performance-oriented properties with a low probability of safety problems, owing to methods used in their fabrication.…”