The boom in phones, laptops and other personal devices over the last few decades has been made possible by the lithium-ion (Li-ion) battery, but as climate change demands more powerful batteries for electric vehicles and grid-scale renewable storage, lithium-ion technology might not be enough. Lithium-metal batteries (LMBs) have theoretical capacities an order of magnitude greater than lithium-ion, but a more literal boom has stymied research for decades.