Michigan-based battery company Our Next Energy (ONE), in partnership with BMW, has showcased the impressive long-range capabilities of its dual-chemistry technology. The company reports that an iX equipped with this hardware achieved an impressive range of 608.1 miles (978.6 km) on the WLTP test cycle.

That’s approximately 75 percent more than the standard iX, which gets up to 348 miles (560 km) of range, according to the European testing standard. In fact, it’s nearly on par with the impressive distance covered by the highly aerodynamic Mercedes EQXX concept during its initial record-breaking range test (although it has since surpassed that range).

The BMW crossover managed to achieve that impressive distance thanks to ONE’s Gemini dual-chemistry battery technology. As the name suggests, it combines safe lithium iron phosphate cells for shorter trips, with high-density anode-free cells for longer drives.

Read: Michigan Startup Will Supply BMW With Dual-Chemistry Batteries For iX Prototype

ONE claims that this combination creates the longest-range EV battery pack for its size. At the same time, it uses 20 percent less graphite and 60 percent less nickel and cobalt than lithium-ion cells, creating a more sustainable battery, all of which will be important for consumers.

“Electric vehicles will achieve mass adoption when they offer enough range that people will feel comfortable having an EV as their only vehicle,” said Mujeeb Ijaz, CEO & founder of ONE. “The Gemini battery has proven it can double the range of EVs and break down the biggest barrier to electrification.”

Now that ONE has proven that its technology is effective, it is looking to refine the batteries to prepare them for commercialization. It plans to improve the efficiency of the DC-to-DC converter that helps unite the two battery cell chemistries, and to develop enhanced control algorithms to optimize the use of the range-extender cells.

“The 600+ miles achieved by the BMW iX equipped with Gemini is an impressive demonstration,” said Jürgen Hildinger, BMW Group New Technologies Head of High Voltage Storage. “We enjoy working with the team at ONE and look forward to take the next steps together.”