In a lithium-ion battery, the cathode is a lithium metal oxide while the anode is graphite. Researchers are currently looking for ways to replace graphite with lithium metal as the anode to boost the battery’s energy density.
Since the packing density of lithium atoms is the highest in its metallic form, batteries that use metallic lithium anodes can pack more energy per weight or volume than graphite-based anodes, Rensselaer explains. However, lithium metal anodes are plagued by ‘dendrite’ build-up that takes place over repeated cycles of charging and discharging.
Dendrites are protrusions that emanate out of the lithium metal surface and often, grow long enough to create a short circuit between the electrodes, leading to a fire hazard.
Rensselaer says it has discovered a way to use internal battery heat to diffuse the dendrites into a smooth layer. “We have found that lithium metal dendrites can be healed in situ
