Could solid-state batteries power long range EVs?

The future of mobility will be largely electrical, powered by fast charging, safe, and compact batteries. Today’s rechargeable Li-ion batteries have some room for improvement, but not enough to allow vehicles sufficient range and autonomy.

Imec’s researchers are working on a next generation of batteries, replacing the wet electrolyte with a solid, in order to increase the energy density of the cell.

Recently, imec developed a solid nanocomposite electrolyte with an exceptionally high conductivity of up to 10mS/cm and with a potential to increase this even further. With this new electrolyte, imec has now made a prototype battery.

The electrolyte was applied into the battery cell as a liquid precursor, and solidified afterwards. The prototype battery achieved a volumetric energy density of 200Wh/liter at a charging speed of 0,5C (2 hours).

“Our results show that we can make solid-state batteries that have the potential to reach the capabilities of wet batteries, and this using manufacturing processes similar to those for wet batteries,” said Philippe Vereecken, Principal Scientist and Program Manager at imec.

“But unlike wet-batteries, our solid-state batteries will be compatible with metallic lithium anodes with a target of 1,000Wh/liter at a charging speed of 2C (half an hour). This, together with their longer lifetime and improved safety, makes them a promising compact battery technology for tomorrow’s long range vehicles.”

To further improve the battery performance, imec is looking into combining nanoparticle electrodes with its solid nanocomposite electrolyte. Imec uses ultra-thin coatings as so-called buffer layers to control the interface between the active electrode and electrolyte.

This technology can also be used to improve the performance of standard liquid cells and even for all-solid-state batteries with pressed and sintered inorganic electrolytes.

Bringing battery technology to fruition and transfer it to the market will require the involvement and commitment of the world’s major material suppliers and battery producers. Therefore, imec performs its battery R&D as a collaborative programme for open innovation to which it invites all interested parties.