STUTTGART: Mercedes-Benz plans to jointly develop solid-state battery technology for future e-cars with US company Factorial Energy and French-Italian carmaker Stellantis.

Mercedes will contribute a "high double-digit million dollar amount" to the project, the company announced today.

In solid-state batteries, charges aren't transported through a liquid carrier material, allowing lighter battery cells, which increases the potential range of the vehicles.

Higher energy density and faster charging are also possible.

In the summer, the Stuttgart-based company signalled a fundamental shift towards electric vehicles.

The company wants 50 per cent of new sales to comprise fully electric or plug-in cars within four years.

It said then that it wants to go fully electric by the end of the decade - wherever "market conditions allow."