Although sodium-sulphur (Na-S) batteries have existed for more than half a century, they have been an inferior alternative and their widespread use has been limited by low energy capacity and short life cycles.Using a simple pyrolysis process and carbon-based electrodes to improve the reactivity of sulphur and the reversibility of reactions between sulphur and sodium, the researchers’ battery has shaken off its formerly sluggish reputation, exhibiting super-high capacity and ultra-long life at room temperature.The researchers say the Na-S battery is also a more energy dense and less toxic alternative to lithium-ion batteries, which, while used extensively in electronic devices and for energy storage, are expensive to manufacture and recycle.This is a significant breakthrough for renewable energy development which, although reduces costs in the long term, has had several financial barriers to entry,” said lead researcher Dr Zhao.“Storage solutions that are manufactured using plentiful resources like sodium – which can be processed from sea water – also have the potential to guarantee greater energy security more broadly and allow more countries to join the shift towards decarbonisation.”The lab-scale batteries (cion batteries) have been successfully fabricated and tested in the University of Sydney’s chemical engineering facility."