The South Korean companies are two of the world's biggest producers of the lithium-ion batteries that power humanity's growing pile of phones, laptops, and electric cars. Audi previously used battery cells from Sanyo and Panasonic to power its "e-tron" plug-in hybrid electric cars.

"This will allow us to supply a technological solution that makes electric cars even more attractive for our customers," says Dr. Bernd Martens, a member of the board of management of Audi's procurement division.

The three companies have revealed little beyond the existence of the partnership, and it's unclear exactly how it will work with even basic questions like whether both companies provide batteries, or if one will be ousted down the line, unanswered. All Audi had to say is it's planning to build a whole lot more EVs, so it's time to forge strong relationships with battery suppliers.