Experimental lithium-metal battery delivers 700 Wh/kg and works in extreme cold

Crystal ball: The next leap in battery innovation may arrive not from a new electrode material but from a redesigned electrolyte. A team of researchers has created a monofluorinated hydrofluorocarbon solvent system that pushes lithium-metal pouch cells to energy densities exceeding 700 Wh/kg at room temperature, and around 400 Wh/kg even at temperatures as low as -50 °C. Their findings, published in Nature, point to potential applications in electric vehicles, aerospace, and grid storage operating in extreme climates.

Unlike much of the news in the energy storage field, which often focuses on cathode breakthroughs, this study zeroes in on the chemistry of electrolytes – the medium that shuttles lithium ions between electrodes.

The electrolyte's solvent molecules determine how easily those ions move, how fast the battery can charge, and whether it survives wide temperature swings.

Traditionally, scientists have relied on solvents that contain oxygen or nitrogen ligands, which ...