Chinese automaker Nio is partnering with battery supplier CATL for research into longer-life EV batteries, including for use with Nio’s battery-swapping service.

The two companies “will jointly carry out discussions, make technological breakthroughs and innovation, and promote product applications,” according to a Nio press release, with CATL developing batteries with longer service lives for future Nio models.

Nio expects the shorter lifespan of batteries compared to the vehicles they power to become a bigger issue in the coming years. Given an average battery warranty of 8 years, Nio estimates that the battery warranties of nearly 20 million EVs will run out or will have run out between 2025 and 2032.

In the meantime, Nio claims to have extended the useful lives of its swappable batteries to the point where they can be expected to retain 80% capacity after 12 years. The company claims to have opened over 2,300 swapping stations in China and Europe, conducting over 40 million battery swaps to date. Recently Volvo and Polestar parent Geely signed up for battery swapping with Nio.

Nio battery station

It’s not the only company to be talking about battery longevity. Just last week Samsung put a 20-year battery on its development roadmap. Nio isn’t saying when its longer-life batteries will appear, but in the meantime it has rolled out a semi-solid-state battery that prioritizes range. A 150-kwh version yielded 650 miles of range in a real-world demonstration drive of a Nio ET7sedan last year.

CATL used to be a cell supplier, but in recent years it’s stepped into some of the surrounding tech, and begun promoting cell-to-pack construction as an alternative to current battery packs.