Advance in next-generation lithium metal batteries

A Washington State University research team has developed a way to address a major safety issue with lithium metal batteries -- an innovation that could make high-energy batteries more viable for next-generation energy storage.

The researchers used a formulation for their batteries that led to the formation of a unique, protective layer around their lithium anode, protecting the batteries from degradation and allowing them to work longer under typical conditions.

While lithium-ion batteries work by passing lithium ions between a graphite anode and a lithium cobalt oxide cathode, the anode in a lithium-metal battery is made of the high-energy lithium metal.

"If we can directly use lithium metal, we can improve the energy density of batteries dramatically," Song said.

While the advantages of lithium metal have been known for decades, researchers have never been able to make them work safely.

They added two additives to the liquid electrolytes that are typically explored in next-generation lithium batteries.

The two additives worked synergistically and formed a protective layer on the lithium metal surface that was dense, conductive, and robust enough to suppress the growth of dendrites while allowing good cycling stability, Song said.