SK Innovation, the holding company of energy-related business at SK Group, announced Thursday it would expand its electric vehicle battery cell plant, in Seosan, South Chungcheong Province.

“When the facility expansion is completed in the third quarter of the year, the plant will be able to produce enough battery cells to power 40,000 EVs per year, up from the current 30,000 EVs,” the company said in a press release.

The facility expansion was expected as the company secured an order from Mercedes-Benz to supply EV battery cells last month. Mercedes-Benz electric cars, powered by SK Innovation’s battery cells, will come out in 2017.

“The plant has already reached full-capacity, operating 24 hours,” said Kim Hong-dae, who leads the EV battery cell business at SK Innovation, adding that the company had a seven-year backlog.

SK Innovation is a latecomer in the market, compared with two domestic rivals -- LG Chem and Samsung SDI, but its EV battery cell business is growing rapidly.

According to the company data, SK supplied battery cells for 20,000 EVs last year. The supply volume will increase to 30,000 units this year in line with the growth of electric vehicles.

Currently, the company supplies its battery cells for Kia’s Soul EVs and electric cars manufactured by Beijing Automotive Industry Holdings.

By Seo Jee-yeon (jyseo@heraldcorp.com)