Efficient Design of Electrode Materials for Next-generation Sodium-Sulfur Batteries

Room-temperature sodium-sulfur batteries (RT-NaSBs) offer a promising solution for sustainable, high-capacity energy storage. Using sodium and sulfur, abundant, low-cost, and environmentally friendly, RT-NaSBs deliver very high theoretical energy density, making them attractive alternatives to lithium-ion batteries, particularly for large-scale renewable energy storage and electric mobility. However, practical deployment faces major challenges: rapid capacity fade, dissolution and shuttling of soluble sodium polysulfides, sluggish redox kinetics, and electrode instability. Overcoming these barriers is critical to unlocking their potential. This project addresses these challenges by developing a novel catalyst-free heterostructure combining two-dimensional molybdenum disulfide (MoS₂) with the low-cost electride C12A7:e⁻. The composite works synergistically to confine polysulfides, enhance electron transport, and accelerate sulfur redox reactions, thereby improving cycle life, conductivity, and overall performance. The research pursues three objectives: (i) evaluate MoS₂/C12A7:e⁻ for suppressing polysulfide shuttling through strong chemical immobilization; (ii) investigate how the heterostructure facilitates sulfur reduction reactions and rapid sodium-ion diffusion; and (iii) establish scalable design principles for cathode additives that combine conductivity, confinement, and fast kinetics. Atomic-scale simulations using density functional theory (DFT), coupled with experimental validation, will elucidate interfacial interactions, reaction pathways, and electron transport mechanisms.

This work aims to deliver durable, high-energy-density RT-NaSBs suitable for grid-scale renewable energy storage, electric vehicles, and portable electronics. By employing earth-abundant, low-cost materials in a scalable, environmentally responsible design, the project offers a practical, cost-effective pathway toward next-generation storage. Expected outcomes include fundamental design principles for advanced cathodes, a platform adaptable to other metal–sulfur batteries, and strengthened international collaboration. The project directly supports UNE’s renewable energy priority, enhancing regional resilience in New England and advancing Australia’s leadership in sustainable, high-performance storage technologies.

Funder: UNE Internal Funding Scheme for Early Career Researchers (ECRs) and Mid-Career Researchers (MCRs)
Awarded amount: A$7,500.00

Funder: United Arab Emirates University (In-Kind)
Estimated value: A$15,000.00