Tetramethyl Succinonitrile as a Solid Plasticizer in a Poly(ethylene oxide)₈ -LiI-I₂ Solid Polymer Electrolyte

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Dye-sensitized solar cells (DSSCs) present a viable alternative to silicon-based photovoltaics.
• Fast ion-conducting solid polymer electrolytes are crucial for DSSC performance, especially in arid climates like the Gulf countries.
• Existing electrolytes face challenges in conductivity and stability under specific environmental conditions.

Purpose of the Study:

• To develop and characterize a novel solid polymer electrolyte for dye-sensitized solar cells (DSSCs).
• To investigate the potential of a poly(ethylene oxide)-tetramethyl succinonitrile blend as a solid polymer electrolyte matrix.
• To evaluate the performance enhancement of DSSCs utilizing the newly synthesized LiI-I2 solid polymer electrolyte.

Main Methods:

• Synthesis of a LiI-I2 solid polymer electrolyte using a blend of poly(ethylene oxide) and tetramethyl succinonitrile.
• Characterization of the electrolyte's properties including ionic conductivity, phase transitions, and ion transport mechanisms using techniques like Fourier-transform infrared spectroscopy, X-ray diffractometry, and differential scanning calorimetry.
• Fabrication and performance testing of DSSCs with the novel electrolyte and comparison against a control DSSC.

Main Results:

• The synthesized polymer electrolyte exhibits an electrical conductivity greater than 10^-4 S cm^-1 at room temperature.
• Tetramethyl succinonitrile acts as a plasticizer, promoting an amorphous phase in the polymer electrolyte, evidenced by spectroscopic and thermal analyses.
• DSSCs incorporating the new electrolyte demonstrated a significant improvement in short-circuit current density (≈661%) and overall cell efficiency (≈3.5%).

Conclusions:

• The poly(ethylene oxide)-tetramethyl succinonitrile blend is a promising material for developing high-performance solid polymer electrolytes for DSSCs.
• The enhanced ionic conductivity and amorphous nature of the electrolyte facilitate efficient ion transport, leading to substantial performance gains.
• This novel electrolyte offers a potential solution for robust and efficient dye-sensitized solar cell applications, particularly in challenging environmental conditions.