There are many materials considered to function as the medium for the energy storage. Especially air storage as a technology with long tradition gets heavenly debated recently driven by spectacular start-ups like lightsail. Furthermore hydrogen is a classic under the storage media as well as elevated water and weights.

The availability of greater computational resources gives rise to new approaches like the Materials Project which could revolutionize battery research. Sodium instead of lithium is a highly interesting approach to avoid availability shortage and reduce the price (especially beneficial for grid energy storage).

Highly advanced materials like carbon nanotubes are another fascinating candidate to improve energy storage technologies.