Nio, a leading Chinese new energy vehicle startup, signed a framework deal with battery maker CATL on Thursday to develop batteries that can power electric vehicles for up to 15 years, almost double the current national warranty standard.

They are yet to give a production schedule for the new longer-life batteries.

The current national standard, which was announced in 2016, stipulates that power batteries have a warranty of eight years or a mileage of 120,000 kilometers.

That means, from this year on, EV buyers are expected to replace their batteries and the number is to grow sharply as EVs are a serious choice for car buyers.

Statistics show that around 20 million NEVs are estimated to see their batteries' warranty expire from 2025-32.

But batteries are the most expensive components of EVs, which can account for around half of their total cost. A Nio survey shows that a new 96.1 kilowatt-hour battery is priced at more than 236,000 yuan ($32,780).

"You can drive the vehicle when its battery warranty expires, but the mileage will drop dramatically and there might even be safety problems.

"We are long aware that we should solve this problem," said William Li, Nio founder and CEO.

It also partly explains Nio's battery-swap approach, which allows car buyers to buy a vehicle but rent a battery from the company.

Nio has so far built more than 2,300 battery-swap stations and the number is expected to reach 3,310 this year, where its car owners can get their empty battery replaced with a fully charged one in five minutes.

The approach has attracted others. Since late 2023, Nio has partnered with major carmakers including Geely and Changan to draft battery-swap standards and even codevelop such models.

On the same day when it signed the battery development deal with CATL, Nio unveiled its second marque, Onvo, which focuses on family cars.

The first Onvo, which rivals Tesla's Model Y, will make its debut in the third quarter of this year. Deliveries will start in the fourth quarter, said Nio.

Nio delivered 160,038 vehicles in 2023, representing an increase of 30.7 percent from 2022. The company expects to sell up to 33,000 cars in the first quarter, an increase of around 6.3 percent from the same period of 2023.

Li said he is optimistic about the company's sales this year, adding that the arrival of Onvo will help boost its sales and market share in China's NEV market.