Silicon that is less expensive and that causes less green house gas to produce. A technology that brings more flexibility and requires a substantially smaller investment to install and operate than the old technology.
I don’t think Musk is in love with the Chinese that much to leave this kind of opportunity to his competitors. Considering that they do not need silicon only for their batteries, but also for the aluminum alloy they use to cast the frame of their cars, I believe that 5 cad per share is still too low, even with the fumed silica division spun out.