Re ECF Project: 2014-57

Project Title: Printable ionic-gel electrolyte for highly durable dye sensitized solar cells (DSSC)

Applicant: Dr. Tony Shien-Ping FENG, Department of Mechanical Engineering, The University of Hong Kong

Total Approved Grant: $489,000 (ECF & WWGF: 50/50)

Duration: 1/4/2015 to 31/3/2017

Project Status/Remarks: Completed

As a promising alternative for next generation of renewable green energy, dye-sensitized solar cells (DSSCs) have attracted great attention due to their low cost, environmental friendliness, simple fabrication, great potential of miniaturization and portability, as well as the recent high power conversion efficiency. However, the long-time stability of DSSCs remains a road block for their widespread use. This project aims to develop a clay-like ionic-gel electrolyte paste to improve the long term stability of DSSCs. The amount and type of inorganic nano-powders adding into ionic electrolyte will be studied to improve the conductance of electrolyte. Different surface treatments for nano-powders to make a homogeneous dispersion will be investigated. The fundamental conductive behaviour at interface between nanoparticles and gel will be modelled and discussed. The printing process will be developed for this printable ionic-gel electrolyte.

Summary of the Findings/Outcomes:
In this project, the research team successfully synthesized non-volatile ionic pastes as quasi-solid electrolyte for dye-sensitized solar cells (DSSCs) by adding different nanoparticles (NPs) TiO2, ZrO2 and SiO in varied content. The DSSCs with the electrolyte were fabricated by screen-printing method. The addition of the NPs to electrolyte provides the enhanced performance for DSSCs, as compared to the DSSCs with conventional ionic liquid electrolyte. The addition of NPs into NVIP electrolyte improves the electrical conductivity and light scattering. The DSSCs with 10 wt% TiO2 added NVIP exhibited 4.55% of photovoltaic conversion efficiency (PCE) and DSSCs with 2.5 wt% SiO2 added NVIP exhibited 3.92% of PCE. Due to the infiltration of electrolyte within porous TiO2 photoanode, the performance of DSSCs was further improved. The DSSCs with 10 wt% TiO2 added NVIP exhibited 5.15% of PCE after 350h and the ones with 2.5 wt% SiO2 added NVIP exhibited 5% of PCE after 200h. After 2000h, more than 80% of the initial performance was kept due to the long-term stable electrolyte. Different types of DSSCs modules were demonstrated to the public through HKU Information Day 2016-17 and six journals have been published.