The world is closely looking developments in battery technology to achieve the common goal of net-zero emissions by 2050. In order to further the objective, lower prices, more capacity, and the best possible use of finite natural resources are expected to be crucial factors.
Researchers from the University of Sydney have developed a sodium-sulfur battery that greatly outperforms lithium-ion cells in terms of capacity, assisting in the achievement of the aim. The cost of manufacturing the battery is also significantly lower.
The need for alternatives
Dr. Shenlong Zhao of the University’s School of Chemical and Biomolecular Engineering led the research, which used a molten salt mixture of constituent materials extracted from seawater, which significantly reduced the cost.
Following a series of downward revisions in the average price of lithium-ion batteries, growing raw material costs and inflation resulted in a 7% increase in 2022 to $151/kWh.
“Our sodium battery has the potential to significantly lower prices while offering four times the storage capacity. “This is a big accomplishment for renewable energy production, which, although lowering long-term costs, has had multiple financial hurdles to entrance,” stated Dr. Zhao in a press statement.
How scientists achieved the result
The concept of sodium-sulfur (Na-S) cells has been around for over 50 years but has remained impractical mainly due to their low energy capacity and short lifespan. The researchers have now used a ‘simple pyrolysis process and carbon-based electrodes to improve the reactivity of sulfur and the reversibility of reactions between sulfur & sodium’. This resulted in dramatically increased capacity and longevity at room temperature.
When compared to lithium-ion batteries, which are commonly used in electronic devices and for energy storage, Na-S cells are less toxic and more energy dense, making them easier to recycle and more cost effective to produce.
Throughout the battery’s development, the team had numerous use-case scenarios in mind, with the goal of delivering a viable alternative for “large renewable energy storage systems, such as electricity grids, while dramatically reducing operational costs.”
Such technology has the “potential to ensure improved energy security more generally and allow more countries to join towards decarbonization.”
At the University’s chemical engineering centre, the team built and tested the technology using lab-scale batteries. The next stage is to commercialise the technology employed in the Ah-level pouch cells on a big scale.
Their findings were published in Advanced Materials.