While lithium-ion batteries have experienced steady improvements, a lot of research has gone into new chemistries that provide a much larger leap in performance. Some of that work has focused on materials like silicon or sulfur that can potentially store far more lithium than existing electrode materials. But other options get rid of electrode materials entirely. These include lithium-air and lithium-metal batteries.

All of these have faced issues with stability, with batteries based on the technology having a short life span compared to existing lithium-ion batteries (though batteries with some silicon are already in use). But on Thursday, a company is announcing that a lithium-metal battery it has in development has reached a stability that’s competitive with existing lithium-ion batteries, retaining 80 percent of its initial capacity out to nearly 700 charge/discharge cycles—and that this has been validated by an outside testing lab.