When it comes to electric-car batteries, Nissan is no longer going its own way.

The company that launched the first modern, mass-market all-electric car has sold its electric-car battery subsidiary, Automotive Energy Supply Corporation (AESC) to Envision Group, a Chinese renewable energy company. The two firms announced the deal on Friday.

"With this strategic acquisition and collaboration, we aim to expand our activities via investment into the new company to realize the value of (Internet of Things) technology for smart transportation, (Vehicle-to-Grid), and smart city solutions," said Envision CEO Lei Zhang in a statement.

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Alone among major automakers, Nissan had stuck to developing its own batteries for electric cars in-house. since the 1990s.

The batteries it used in early versions of the Nissan Leaf had durability problems, losing range after as little as a year in some cases. Nissan was also the only major automaker that used air-cooled battery packs.

Other automakers turned to suppliers such as Panasonic and Korean conglomerate LG Chem to supply batteries for their electric cars and used liquid cooling in their battery packs. Tesla has a joint venture with Panasonic to develop battery cells for its electric cars. LG Chem supplies batteries to General Motors, Volvo, Hyundai, Kia, and other automakers.

Nissan improved its batteries, but a study showed that the larger 30-kwh batteries in 2016 Leafs had even higher rates of degradation than earlier 24-kwh batteries.

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For its latest 40-kwh batteries, Nissan developed a new nickel-manganese spinel cell that is designed in part to reduce capacity loss.

Nissan plans to introduce a new, longer-range Leaf e-Plus for 2019 that will use 60-kwh batteries supplied by LG Chem.

The sale of AESC includes Nissan's battery manufacturing facility in Smyrna, Tennessee, as well as facilities in England and Japan. The battery plants are expected to remain in operation as Envision works to develop new batteries and technology for connected electric cars and vehicle-to-grid integration.