Premium electric car brand Zeekr, which is owned by China’s largest privately owned automaker Geely Holding Group, has unveiled a new lithium iron phosphate (LFP) battery cell and pack that supports ultra-fast charging.

Developed entirely in-house, the new LFP battery is said to add 310 miles of range in 15 minutes, thanks in part to an 800V electrical system. Zeekr claims the charging performance of the new batteries “outperforms many competitors” even at low temperatures in winter.

The new battery tech will be made at a Geely-owned battery plant in the province of Zhejiang and will make its debut on the Zeekr 007 sedan. The new EV will launch in China on December 27, with deliveries to follow in January 2024.

The Zeekr 007 features a 75.6-kilowatt-hour LFP battery pack that enables a range of 427 miles on China’s CLTC cycle. Zeekr’s in-house developed pack is manufactured by Quzhou Jidian EV Tech, a wholly owned subsidiary of Geely Holding Group.

LFP batteries typically have lower energy density compared with nickel-manganese-cobalt (NMC) batteries at the cell level. To address that, Zeekr engineers designed the battery pack for the new LFP battery to achieve high energy density at the pack level.

Thanks to the use of newly developed materials and simplified structural design, the volume utilization of the new battery pack reaches 83.7 percent according to Zeekr; the automaker claims that’s higher than what many global competitors have achieved with LFP batteries.

Zeekr claims that the increased energy density does not compromise safety, as the packs have passed six strict safety tests including nail penetration conducted by China’s National Motor Vehicle Quality Inspection and Testing Center.

Up until now, Zeekr has used CATL-supplied nickel-manganese-cobalt batteries on the 001 crossover and 009 minivan. Zeekr has become the latest Chinese company to launch this type of battery in the world’s largest EV market with the goal of reducing dependence on external suppliers for batteries.

In August, CATL also announced a fast-charging LFP battery capable of adding 248 miles of range after just 10 minutes of charge. The Shenxing battery will enable up to 434 miles of range on China’s CLTC cycle, the company said.