Highly efficient dye‐sensitized solar cells: A comparative study with two different system of solvent‐free binary room‐temperature ionic liquid‐based electrolytes

Abstract

In this work, novel redox electrolytes based on poly (ethylene oxide) (PEO) were prepared using binary ionic liquid 1‐methyl‐3‐propylimidazolium iodide (MPII) with 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) or 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIMBF4) to reduce the high viscosity of MPII. The addition of low viscosity ionic liquids is to overcome the low mass transportation of redox mediator faced by the single ionic liquid. Therefore, different ratios of ionic liquids were added, and their effect on the electrical properties of the ionic liquid‐based gel polymer electrolytes (GPE) was observed. It was confirmed that all the system dominant by ions rather than electron. The binary ionic liquid system containing 37.5 wt.% of BMIMBF4 showed the highest ionic conductivity of 24.2 mS cm−1. Fourier‐transform infrared and X‐ray diffraction studies confirmed that complexation occurred between all materials. The combination of two alkyl side chain length has enhanced the efficiency of the DSSC with short‐circuit current density (JSC) of 26.81 mA cm−1, open‐circuit voltage (VOC) of 0.67 V, fill factor of 44.5% and photovoltaic conversion efficiency (η) of 7.8%. This work has provided valuable insight for further stability of binary ionic liquid‐based GPE compared to single ionic liquid electrolytes.

Fabrication of Gelatin-Derived Gel Electrolyte Using Deep Eutectic Solvents through In Situ Derivatization and Crosslinking Strategy for Supercapacitors and Flexible Sensors

“…6 In general, most gel electrolytes have low mechanical strength and tensile capacity, and mechanical properties often cannot be combined with ionic conductivity. 7,8 Therefore, the preparation of gel electrolytes with integrated properties remains a great challenge.…”

“…An ideal electrolyte for flexible and wearable electrochemical energy devices is anticipated to meet the requirements of multiple properties including high ionic conductivity, enough mechanical strength, wide electrochemical window, good thermal stability, and other attractive features, such as self-healing properties . In general, most gel electrolytes have low mechanical strength and tensile capacity, and mechanical properties often cannot be combined with ionic conductivity. , Therefore, the preparation of gel electrolytes with integrated properties remains a great challenge.…”

Influence of Cation Size and Polarity on Charge Transport in Ionic Liquid Based Electrolytes

“…Imidazolium-based ionic liquids have been widely used as electrolyte components for lithium-ion batteries, [18,19] DSSCs, [20,21] supercapacitors [22,23] and field effect transistors [24,25] due to their low viscosity, [26,27] high conductivity, [28,29] non-flammability [30] and ease of functionalization through the available 1,3-positions. Regarding the conductivity of the ILs, it has been reported that oxygen atoms on the side chains of cation provide relatively higher conductivity values compared to the ones with the same length of n-alkyl chains due to ion-ion and van der Waals interactions.…”

Ionic Liquids Based Cocktails as a Composite Redox Electrolyte for Natural Dye-Sensitized Solar Cells

“…To obtain a high cell efficiency, an organic solvent must be incorporated into the formulation of the electrolyte [19]- [21]. According to recent studies [22], the ionic liquid compounds that are incorporated in DSSCs can be used to obtain high efficiency. C4 to C10 alkyl chains will form compounds with ionic liquids (ILs) characteristics, while compounds with longer alkyl chains than that will form liquid crystals [23].…”