Nanosponge-Based Composite Gel Polymer Electrolyte for Safer Li-O₂ Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-oxygen (Li-O2) batteries offer high theoretical energy density but suffer from poor cycling stability and safety concerns.
• Key issues include lithium dendrite formation, organic liquid electrolyte instability, and oxygen crossover.

Purpose of the Study:

• To develop a novel composite gel polymer electrolyte to address the limitations of Li-O2 batteries.
• To improve the safety and cycling stability of Li-O2 battery systems.

Main Methods:

• A composite gel polymer electrolyte was synthesized using a highly cross-linked polymer matrix, a dextrin-based nanosponge, and a liquid electrolyte.
• The electrolyte was prepared via thermally activated, one-pot free radical polymerization.
• The material was tested in a Li-O2 cell with a lithium metal anode and a commercial gas diffusion layer cathode.

Main Results:

• The composite gel polymer electrolyte effectively limited lithium dendrite nucleation and growth due to its cross-linked structure.
• The nanosponge component suppressed oxygen crossover and prevented crystalline domain formation, ensuring good ionic conductivity.
• The tested cell demonstrated a capacity of 5.05 mAh cm-2 with improved reversibility upon cycling compared to liquid electrolyte cells.

Conclusions:

• The proposed composite gel polymer electrolyte offers a promising solution for enhancing the safety and performance of Li-O2 batteries.
• This advanced electrolyte design contributes to overcoming critical challenges for practical Li-O2 battery applications.