China’s Contemporary Amperex Technology (CATL), the world’s largest producer of electric vehicle batteries, has unveiled an upgraded battery that promises an even longer range than rival BYD’s cutting-edge technology.

The first was an upgraded version of its Shenxing battery designed to add more range when fast charging. CATL said the battery can now offer 520 kilometers (323 miles) of range from just five minutes of charging time — a marked improvement over BYD’s promise to add 400km (249 miles) of range in the same amount of time.

At a press event reminiscent of a high-profile car launch, China's leading battery maker CATL detailed innovations that could bring electric cars closer to price and