Apple has been coping with "tight" supplies of lithium ion batteries, according to the Wall Street Journal. A representative from the company is said to have recently contacted the US offices of Kureha, a Japanese company which controls 70 percent of the marketshare for a polymer called polyvinylidene fluoride (PVDF), used as a binder in lithium ion batteries. The only Kureha factory which produces PVDF is based in Iwaki, and was forced to shut down on March 11th after being hit by that day's 9.0 earthquake.
