Shuttle suppression in room temperature sodium-sulfur batteries using ion selective polymer membranes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sodium-sulfur batteries are promising for large-scale energy storage due to their high theoretical energy density.
• Conventional separators in sodium-sulfur batteries face challenges like polysulfide shuttle and poor ion selectivity.
• Developing advanced separators is crucial for improving the performance and cycle life of these batteries.

Purpose of the Study:

• To investigate the efficacy of a novel sodiated Nafion-coated polypropylene separator for room temperature sodium-sulfur batteries.
• To evaluate the impact of this new separator on battery capacity and cycling stability.
• To demonstrate an improved cation selectivity for enhanced battery performance.

Main Methods:

• Fabrication of a composite separator using a sodiated Nafion coating on a porous polypropylene backbone.
• Assembly of room temperature sodium-sulfur battery cells utilizing the novel separator.
• Electrochemical testing, including capacity measurements and cycling performance evaluation over 20 cycles.

Main Results:

• The sodiated Nafion separator demonstrated effective cation selectivity, mitigating polysulfide crossover.
• Battery cells equipped with the new separator exhibited a 75% enhancement in capacity after 20 cycles.
• The specific capacity reached 350 mA h g(sulfur)(-1) at the end of the cycling test, indicating improved performance.

Conclusions:

• The sodiated Nafion-coated polypropylene separator is a viable alternative for enhancing room temperature sodium-sulfur battery performance.
• This separator design effectively addresses key challenges in sodium-sulfur battery technology, leading to significant capacity retention.
• The study highlights the potential of tailored ion-selective membranes for next-generation battery applications.