LONDON (Reuters) - French company Blue Solutions plans to build a gigafactory in eastern France costing about 2 billion euros ($2.17 billion) to produce a new solid-state battery it has produced that has a 20-minute charging time, its CEO said.

Solid-state batteries are seen as the "holy grail" of batteries for electric vehicles, promising longer driving ranges and shorter charging times than traditional lithium-ion packs, but technical hurdles have held back large scale commercialisation.

Blue Solutions, a unit of French conglomerate Bollore, already produces solid-state batteries for Daimler electric buses.

Its new smaller battery for cars with a 20-minute charging time aims to have a range of 1,000 km (621 miles) and tests have shown energy density 30%-40% higher than the top lithium-ion cells, Chief Executive Richard Bouveret told Reuters.

The company is also holding talks on more deals after signing one with BMW last year to develop a battery for EVs, he said.

Blue Solutions' planned gigafactory would be located in eastern France, close to both French and German automakers, and start production in 2030, Bouveret said in an interview.

In contrast to typical sprawling battery gigafactories, it would consist of modular towers with a smaller footprint and would have capacity of 25 gigawatt hours (GWh).

In January, a source told Reuters the French company was in talks with German auto giant Volkswagen about adapting a battery for cars. Both Blue Solutions and VW have declined to confirm the discussions.

Blue Solutions aims to have six joint development agreements (JDAs) signed by the end of 2024, including with at least one more automaker, Bouveret said.

The company last year signed a memorandum of understanding with contract electronics maker Foxconn to develop batteries for electric two-wheeled vehicles.

Bouveret said Blue Solutions is open to working with rival battery makers to speed commercialisation of its battery design.

"We are pragmatic. We want to bring our solid-state battery to the market very quickly," he said.

"For that to happen, we may offer a licence for our technology to another battery manufacturer to scale up our chemistry in their own gigafactory."

He declined to identify the companies with whom Blue Solutions was holding talks on JDAs.

The company plans to seek more than 100 million euros as part of a first financing round in the second half of this year to help develop the new battery, Bouveret said.

Blue Solutions is seeking partners that can also bring other expertise, including carmakers, industrial firms and miners of battery component lithium.

The company has a pilot factory near its headquarters in Brittany, where it will produce prototypes of its new battery and ship an "A sample" by the end of the year to select potential customers and a third party testing firm.

Shipping prototypes is a key development for battery makers, showing they are confident of their technology.

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(Reporting by Eric Onstad; Editing by Susan Fenton)

By Eric Onstad