General Motors Co is “almost there” on developing an electric vehicle battery that will last one million miles, a top executive said on Tuesday

The automaker also is working on next-generation batteries even more advanced than the new Ultium battery that it unveiled in March, according to GM Executive Vice President Doug Parks, who was speaking at an online investor conference.

He did not specify a timeline for the introduction of the million-mile battery but said “multiple teams” at GM are working on such advances as zero-cobalt electrodes, solid-state electrolytes and ultra-fast charging.

Current electric vehicle batteries typically last 100,000 to 200,000 miles.

Reuters reported exclusively in early May that Tesla, in partnership with Chinese battery maker CATL, plans to introduce its own million-mile battery later this year or early next.

CATL provides battery cells to other vehicle manufacturers and has supply agreements in China with GM and its local partner SAIC Motor.

GM unveiled its Ultium advanced battery system in March. On Tuesday, it said its $2.3 billion battery production joint venture in Ohio with Korean partner LG Chem will be called Ultium Cells LLC.

GM and LG Chem are pursuing a variety of ways to reduce battery costs, Adam Kwiatkowski, executive chief engineer of GM’s electric propulsion systems, told another online investor conference on Tuesday.

The partners are investigating such initiatives as investing in mines, hedging metals prices and partnering with metals refiners, he said.

GM Chief Executive Mary Barra reiterated earlier this year that the automaker intends to sell 1 million electric vehicles a year in 2025 in the United States and China.