Safety-Enhanced Polymer Electrolytes for Sodium Batteries: Recent Progress and Perspectives

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium batteries (SBs) are gaining attention due to sodium's abundance and low cost.
• Conventional liquid electrolytes in SBs pose safety risks (flammability, leakage) and lead to performance degradation via side reactions and sodium dendrites.
• Polymer electrolytes are emerging as a promising solution to overcome these limitations.

Purpose of the Study:

• To review polymer electrolytes for advanced sodium batteries.
• To highlight the advantages of polymer electrolytes in addressing SB challenges.
• To define the requirements for ideal polymer electrolytes and discuss recent progress.

Main Methods:

• Summarization of polymer electrolytes based on various polymers including ethoxylated units, P(VDF-HFP), PMMA, PAN, PVP, single-ion conductors, and polysaccharides.
• Analysis of the inherent benefits of polymer electrolytes for SBs.
• Discussion of recent advancements and future perspectives.

Main Results:

• Polymer electrolytes demonstrate inherent safety, suppress sodium dendrite formation, and reduce electrolyte decomposition.
• Various polymer chemistries show promise for enhancing sodium battery performance.
• Key requirements for ideal polymer electrolytes in SBs have been outlined.

Conclusions:

• Polymer electrolytes are a viable and advantageous alternative to liquid electrolytes for safer and more efficient sodium batteries.
• Further research into polymer electrolyte development is crucial for resolving fundamental and practical challenges in advanced SBs.
• This review provides insights into the current state and future directions for polymer electrolytes in sodium battery technology.