Sulfonated PVDF-HFP and SiO₂ based quasi-solid-state composite electrolyte for Lithium-oxygen batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-oxygen (Li-O2) batteries offer high energy density but face challenges like electrolyte instability and dendrite growth.
• Existing liquid electrolytes limit battery performance and safety due to issues like the shuttle effect and poor structural integrity.

Purpose of the Study:

• To develop a composite quasi-solid-state electrolyte (QSE) for enhanced Li-O2 battery performance and safety.
• To investigate the role of sulfonated poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and silicon dioxide (SiO2) nanofillers in improving electrolyte properties.

Main Methods:

• Fabrication of a composite QSE by integrating sulfonated PVDF-HFP with SiO2 nanofillers.
• Characterization of the QSE's ionic conductivity, lithium transference number, and electrochemical stability window.
• Evaluation of Li-O2 cell performance, including cycle life and post-cycling analysis of electrode stability.

Main Results:

• The developed QSE exhibits an ionic conductivity of 1.29 mS cm-1 and an electrochemical stability window of 5.2 V.
• Li-O2 cells utilizing the QSE achieved a cycle life of 191 cycles under restricted capacity conditions, outperforming liquid electrolyte cells.
• Post-cycling analysis confirmed suppressed lithium dendrite growth and anode pulverization, indicating a stable solid electrolyte interphase.

Conclusions:

• The hybrid polymer-ceramic QSE design effectively addresses key limitations in Li-O2 batteries, enhancing safety and longevity.
• This QSE technology shows significant promise for the practical realization of high-energy-density Li-O2 batteries.
• The findings support the viability of QSEs for next-generation energy storage applications.