BEIJING/SHANGHAI, March 5 (Reuters) - Chinese carmaker BYD's chairman Wang Chuanfu on Thursday launched the second-generation of the Blade Battery, with what he says is a "disruptive" charging speed in extremely cold environments.

The launch comes as the electric vehicle maker seeks to regain momentum in an increasingly competitive domestic market after a recent sales downturn.

The new Blade Battery can be charged from 20% to 97% in less than 12 minutes in temperatures as low as minus 20 degrees Celsius, enabling a driving range of 777 kilometres (483 miles), Wang told an event from the company's headquarters in Shenzhen.

The batteries also are designed with higher energy density enabling a driving range of more than 1,000 km for BYD's luxury Denza Z9GT and Yangwang U7 models, Wang said, adding the batteries had also passed safety tests exceeding China's new national standards.

BYD also aims to expand its "Flash Charging" network to 20,000 stations by the end of 2026, including 2,000 on highways. The company had built more than 4,000 stations as of March 5.