Lithium-ion batteries are popular for powering electric vehicles at the moment. However, they're too expensive for long-term grid-scale energy storage systems. Further, lithium is getting increasingly difficult to come by. Lithium is indeed advantageous for its high energy density and being paired with renewable energy sources to allow grid-level energy storage. Nonetheless, lithium carbonate costs have reached an all-time high. Pandemic-related supply-chain delays, the Russia-Ukraine conflict, and increased demand from corporations all contribute to the escalating price. Furthermore, because of the huge environmental costs and the possibility of human rights breaches, many countries are unwilling to approve lithium mining.
A research comes at the right time as governments and industries worldwide scramble to find options for storing energy to power the clean energy transition. New study suggests ambient temperature solid-state sodium-sulfur battery technology as a viable alternative to lithium-based battery technology. The finding may contribute greatly to the Next-Generation Batteries Market as it provides grid-level energy storage systems.
The research group discovered a homogenous glassy electrolyte that allows for reversible sodium plating and stripping at higher current densities than before. They found a new type of oxysulfide glass electrolyte that might meet all of these criteria simultaneously. The electrolytes were built at room temperature using a high-energy ball milling technique.
The oxysulfide glass has a specific microstructure, resulting in a perfectly homogeneous glass structure. The solid electrolyte generates self-passivating interphase at the interface between sodium metal and the electrolyte. This is required for reversible plating and stripping sodium.
The team used a sulphide electrolyte to accomplish stable plating, and stripping of sodium metal has proven difficult. The research disproved this belief by demonstrating the highest critical current density among all Na-ion conducting sulfide-based solid electrolytes. Further, they also demonstrated the ability to produce high-performance sodium-sulfur batteries at room temperature.
The innovative structural and compositional design methodologies outlined in this paper set a new standard for creating safe, low-cost, energy-dense, and long-life solid-state sodium batteries.