While the title of the article mentions cobalt, graphite is also mentioned.

I've cut and pasted the info. Please read the whole article, which is dated April 2/14. I sure hope that the Zen management has contacted Telsa.

Tesla Motors spokesperson Liz Jarvis-Shean confirmed to Mining Weekly Online that the innovative company had taken a strategic approach with a view to developing the closest supply chain possible

“One of the key reasons is to more completely consider the total environmental impact of the supply chain while significantly reducing battery cost. Our goal is to build batteries with the lowest environmental impact possible and that necessitates looking at where the raw materials come from and how much impact there was in mining, processing and transporting them,” Jarvis-Shean said

Despite Tesla’s Jarvis-Shean declining comment as to whether the company believed there were enough potential new mines for graphite, cobalt etcetera coming on stream in North America to feed its factory’s future demand, she did concede that Tesla was beginning to plan and work closely with mining companies to align capacity and timing

She added that Tesla is excited to continue building relationships with mining and materials companies

http://www.miningweekly.com/article/tesla-motors-planned-gigafactory-causing-a-buzz-in-the-cobalt-world-2014-04-02