Researchers at the University of Sydney claimed to have developed a new, low-cost sodium-sulfur battery with four times the energy capacity of lithium-ion batteries. The success of the technology could significantly reduce the cost of transitioning to a decarbonized economy.

The new battery has been designed to provide a high-performing solution for large-scale renewable energy storage systems while reducing operational costs.

The research involved contributions from researchers at Chongqing University, the University of Adelaide, the University of Wollongong, the Chinese Academy of Sciences in Beijing, and the University of Science and Technology China.

Lead author Shenlong Zhao, from the School of Chemical and Biomolecular Engineering, University of Sydney, said, “This is a significant breakthrough for renewable energy development which, although it reduces costs in the long term, has had several financial barriers to entry.”

Sodium-Sulfur Battery

The battery was constructed using sodium-sulfur (Na-S), a type of molten salt that can be processed from seawater, which costs much less to produce than lithium-ion.

The widespread use of sodium sulfur has been limited because of its low energy capacity and short life cycles.

The team noted that using a simple pyrolysis process and carbon-based electrodes could improve the reactivity of sulfur and the reversibility of reactions between sulfur and sodium.

The researchers said this could, in turn, enable the battery to get rid of its formerly sluggish reputation and exhibit high capacity and long life at room temperature.

The Na-S battery is claimed to be a more energy-dense and less toxic alternative to lithium-ion batteries, which is both expensive to manufacture and recycle.

The lead author noted that storage solutions that are manufactured using plentiful resources like sodium have the potential to guarantee greater energy security and allow more countries to join the shift toward decarbonization.

The lab-scale batteries have been successfully fabricated and tested in the University of Sydney’s chemical engineering facility.

The research was funded by the Australian Research Council, the National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities, and the Ministry of Science and Technology China.

A BNEF report recently found that after declining steadily since 2010, average prices for lithium-ion battery packs across all sectors have risen to $151/kWh in 2022, a 7% rise from the year before.

In July, scientists at the Indian Institute of Technology (IIT), Kharagpur, used nanomaterials to develop sodium-ion (Na-ion) batteries and supercapacitors that can be integrated into e-cycles for rapid charging.