German automaker Daimler (DAIGn.DE) and industrial gases maker Linde (LING.DE) pledged to build 20 hydrogen fuelling stations in Germany in coming years to boost support networks for eco-friendly cars.

Fuel-cell cars compete with purely electric and hybrid vehicles in a race to attract environmentally-conscious drivers, emitting only water vapor and heat.

Daimler plans to substantially raise its offerings of fuel-cells cars from 2017.

Each company will this year start investing 10 million euros ($13 million) to build 10 hydrogen fuelling stations and plan to set up a combined total of 13 through the end of 2015, both companies said in a joint statement on Wednesday.

Germany currently has 16 hydrogen fuelling stations in operation, including the first from Daimler and Linde, which started operating on Sept. 29 in Berlin.

Fuel-cell cars can run five times longer than battery-powered vehicles and fill a tank 10 times as fast. But the high costs have prevented a commercial breakthrough until now. Just a few hundred demo models are on the road, mostly in Japan, California, Germany and Scandinavia.

"We are considerably improving the conditions for successfully marketing fuel-cell cars," said Andreas Opfermann, Linde's head of clean energy and innovation management.

Stuttgart-based Daimler joined forces with Ford (F.N) and Nissan (7201.T) in 2013 to jointly develop a powertrain blueprint for the hydrogen-powered cars.