Chinese researchers develop high-voltage sodium-sulfur battery that could challenge lithium batteries

A Chinese research team reports a lab-scale high-voltage sodium‑sulfur battery that exceeded 2,000 Wh/kg in early tests and endured about 1,400 charge-discharge cycles; the design uses sulfur, sodium, aluminum and a chlorine-based electrolyte.

A research team in China has reported a new sodium‑sulfur battery design tested at laboratory scale. The cell combines a pure sulfur cathode, an aluminum foil anode, sodium ions, and a chlorine‑based electrolyte. In early tests the team reported very high energy density and long shelf life. The publication is being discussed because the design uses inexpensive materials and may change cost assumptions for large-scale storage. Key findings: - The reported cell architecture uses sulfur at the cathode and aluminum foil as the anode, with an electrolyte containing aluminum chloride, sodium salts and chlorine. - Early laboratory measurements reportedly exceeded 2,000 watt‑hours per kilogram for energy density (based on the weight of active materials). - Test cells endured about 1,400 charge‑discharge cycles before significant capacity loss was observed. - After more than a year of storage in the lab, the cells were reported to retain about 95 percent of their charge. - The researchers estimated a raw‑material cost near $5 per kilowatt‑hour based on active material prices, and noted the electrolyte is corrosive and presents handling challenges. Summary: The reported design shows high energy density and notable durability in laboratory tests, and the team highlighted very low raw‑material cost estimates based on active materials. The researchers also reported that the chlorine‑rich electrolyte is corrosive and that these results come from lab cells rather than fully packaged commercial units, so engineering scale‑up and safety work remain important next steps.