Lithium metal electrode batteries

Reversible lithium metal electrode has potential to almost double the energy density of lithium-ion batteries and lower the cost to $100 per kilowatt hour.

Researchers identified critical parameters against which to assess progress and provided a summary of published efforts.

Using lithium (less than 30 microns) rather than thick lithium foils for numerous reasons, including the ability to detect soft shorts.

If the lithium metal electrode can be proven to cycle in small research cells using the four parameters identified here, with material and processing costs consistent with the cost target at scale, additional challenges and opportunities will be evident. A dense lithium foil cycled with high per-cycle utilization is required and will result in significant volume changes in large-format cells; the resulting stresses and shape change may limit cycling and have deleterious side effects. Lithium metal electrodes with minimal volume change, or novel types of large-format cells or packs containing them, are possible solutions. Determining the safety and rate capability of large-format cells, especially after extended cycling and in charge at low temperatures, will be another priority. In terms of manufacturing, lithium metal technologies that integrate easily into existing lithium-ion production lines will achieve the most rapid growth. The need to address these challenges is motivated by the definitive shift towards an electrified future, and the fact that high-energy rechargeable batteries are perhaps the single most important enabler for that transformation to be widely successful.