Portable High Voltage Integrated Harvesting-Storage Device Employing Dye-Sensitized Solar Module and All-Solid-State Electrochemical Double Layer Capacitor.

Alberto Scalia,Timo Jacob,Andrea Lamberti,Alberto Varzi,Stefano Passerini

doi:10.3389/fchem.2018.00443

Abstract

A dye-sensitized solar module (DSSM) and a high voltage all-solid-state electrochemical double layer capacitor (EDLC) are, for the first time, implemented in a compact Harvesting-Storage (HS) device. Conductive glass is employed as current collecting substrate for both DSSM and EDLC, leading to a robust and portable final structure. The photovoltaic section is constituted by a 4 series cells W-type module, while in the storage section an EDLC employing an ionic liquid-based polymeric electrolyte (a mixture of polyethylene oxide and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, PEO-Pyr14TFSI) and activated carbon electrodes is used. The solid state EDLC is first characterized individually to determine its electrochemical performance before successfully proving the integration with the DSSM. The harvesting-storage properties of the integrated photo-capacitor are evaluated through photo-charge and subsequent discharge protocols performed at two different discharge currents, showing that in this configuration the EDLC unit can be effectively charged up to 2.45 V.

Highlights

Fossil fuels are the worldwide most employed energy source
VM is the maximum voltage reached during the galvanostatic charge-discharge (GCD) (2.5 V), V is the electrochemical double layer capacitor (EDLC) voltage, i is the imposed discharge constant current, ti.d is the initial discharge time, tf.d is the final discharge time, and EEDLC is the EDLC energy evaluated during discharge phase
The CA value of 0.16 F was calculated, namely providing a normalized capacitance of 9 mF·cm−2. Such a polymer electrolyte-based EDLC offers a capacitance value almost four times higher than that of the liquid electrolyte EDLC proposed by Chien et al (2015), which is one of the very few examples of photo-capacitor with a PV section composed by a module instead of a single solar cell

Summary

Introduction

Fossil fuels are the worldwide most employed energy source. In the past, their relative abundance has promoted their use in several contexts: automotive, residential heating, industry, power plants, etc. The increasing level of pollution, poor air quality and global warming caused by their excessive employment is forcing the international community to shift toward greener and renewable alternatives, such as photovoltaic (PV) power generation (Gonçalves et al, 2008; El Chaar et al, 2011; Parida et al, 2011). In the emerging PV technology framework, different technologies have been proposed.

Methods

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Conclusion