Integrated Electrochemical Energy Storage and Photovoltaic Device with a Gel Electrolyte

摘要

Integrating both electrochemical solar cells (harvesting energy) and supercapacitors (energy storage) into a singledevice is unquestionably one of the great challenges nowadays. There has been an extended research in the designand construction of integrated solar energy harvesting and storage systems that can simultaneously capture and storevarious forms of energies from nature. Here, we successfully designed, fabricated and characterized a compact andmonolithically photoelectrochemical device combining a polyvinyl alcohol (PVA)/hydrochloric acid (HCl)- basedgel electrolyte, multi-walled carbon nanotube (MWCNTs), and fluorine doped tin oxide (FTO) as counter andworking electrodes, respectively. The combination device can act either as an independent solar cell, asupercapacitor, or as a solar cell/supercapacitor device. In this structure, energy harvesting takes place only at theworking electrode (WE) that made of a thin film composite of a conducting polymer (i.e. Polyaniline, PANI) andsynthetic dyes materials that coat on the FTO surface by electrochemical deposition technique. The energy storageoccurs in both WE and counter electrode (CE) that made of (MWCNTs) in addition to the gel electrolyte materials.Different synthetic dyes have been used such as Methylene Blue (MB), Methyl Orange (MO), and Prussian Blue(PB). Among them, MB has shown the strongest photoelectrochemical reaction in HCl-PVA gel electrolyte. Thecyclic voltammetry was used to show the effect of PANI/synthetic dyes on the cell, and impedance spectroscopydemonstrated the effect of surface modification of MWCNTs on the performance of the CE.