…there’s been a major development in the field of lightweight and highway-capable batteries. Related to my previous post on battery longevity, a major source of lithium-cell degradation has been uncovered.
Chemical systems age by various means. In the case of lithium cells, the charge carriers (ions of lithium) are mobile, which is why they’re charge carriers. Unfortunately, these numerous, tiny particles aren’t 100% controllable on long timescales (any more than consumer-grade gas tanks can keep gasoline or diesel for timescales of years).
One research group has now found a key process for that degradation. Cells have copper parts to act as conductors at various places. Shrikant Nagpure at Ohio State University found this copper has been unintentionally and undesirably absorbing lithium ions. Ions tied up at any one place can’t be charge carriers over the cell as needed. The National Institute of Standards and Technology (NIST) confirmed this, with sophisticated measurement.
The next step is then to keep ions from getting trapped, and thus produce long-lived batteries. Either a barrier layer could be found, or a better copper substitute, or a process for copper regeneration. Hmmm, a cell conductor. That might be something like… graphite!