Volkswagen Group on Wednesday announced it is investing a further $200 million in QuantumScape, bringing its total investment in the Silicon Valley-based battery startup to over $300 million.

QuantumScape was founded in 2010 by Jagdeep Singh and counts venture capital firms Kleiner Perkins Caufield and Lightspeed Management as additional key investors.

The company is developing solid-state batteries, a technology that has the potential to deliver much greater range and shorter charge times for electric cars than currently possible.

VW has been collaborating with QuantumScape since 2012 and in 2018 established a joint venture whose aim is to commercialize solid-state batteries by 2025. Plans for the establishment of a pilot plant will be finalized later this year.

As the name suggests, solid-state batteries use a solid electrolyte instead of the liquids or gels that most electric car batteries use today. The result is that they are less prone to overheating or fire; are much denser, meaning less weight and higher capacity; and they're also better for fast charging.

VW has previously said a solid-state battery similar in size to a current lithium-ion battery could deliver a range comparable to a conventional gasoline-powered car. We're talking close to 500 miles on a single charge. The highest range at present is the 402 miles of the 2020 Tesla Model S Long Range Plus.

VW is making moves to become a major player in the battery space, which makes sense as it is currently committed to having 75 battery-electric models across its portfolio of brands by 2029. The automaker already has supply deals with established battery suppliers, including CATL which just announced a battery that will last 16 years and more than 1.2 million miles. And, through a joint venture with Swedish battery startup Northvolt, VW has also just started construction of a second battery plant in Europe.

“We are securing our global supply base with efficient producers, gradually building up manufacturing capacities and driving the development of cutting-edge solid-state battery technology,” Frank Blome, head of battery cell business at VW, said in a statement.