http://www.electrovaya.com/pdf/IN/2008/IN20080311.pdf

This archived PDF at the Electrovaya website was originally from Wall Street Journal has already shed some lights last year.

Key points: Exxon is not keen on biofuel but is bullish on the hybrid market... There are competing technologies out there such as Polypore International and Asahi Kasei Chemicals so first to market is crucial and Exxon has done it with Electrovaya... the trick is to drive down the price of the separtor-film while maintaining the safety features and Ford seems to think Exxon can pull it off with its deep pocket... so Ford might be interested in Exxon's technology or at least Ford is watching this technology to unfold