A research group in the US has taken a significant step forward with this technology, coming up with a design for a long-lasting lithium metal battery that remains functional for a record-breaking number of charging cycles.The idea behind these types of batteries is to swap out the graphite used in the anode component for pure lithium metal, which can hold as much as 10 times the energy. Described as a dream material by some researchers, lithium metal is seen as key to helping us break through a key bottleneck in energy storage, but scientists have struggled with longevity issues with the versions developed so far failing quickly during use.