Tesla's Gigafactory Comes Into Focus

Among the potential other manufacturing partners that Navigant Research expects to be chosen are a cathode material supplier (such as Nippon Denko or Umicore Umicore), a graphite supplier (Northern Graphite, Alabama Graphite), an electrolyte manufacturer (Ube, Sumitomo, or Nichia), and a separator manufacturer (Celgard, Ube, or Toray). Other materials needed for the batteries, such as lithium carbonate, copper foil, and aluminum casings, will probably be made offsite and delivered by rail.

http://www.forbes.com/sites/pikeresearch/2014/08/01/teslas-gigafactory-comes-into-focus/