If you were to make a list of the companies least likely to promote hybrid vehicles, petroleum company ExxonMobil would probably be at the top. But surprise, surprise, the company -- which has had no interest in alternative fuels -- has engineers developing a key component of lithium ion batteries, according to the Wall Street Journal.

ExxonMobil developed a plastic separator film for lithium ion batteries that has been used in cell phones for several years, and now the company wants to enhance the technology for the hybrid vehicle market. The company says its technology can withstand higher temperatures than competitors and is less likely to ignite, one of the key issues that has kept lithium ion batteries from being widely adopted in computers, electronics, and vehicles.

Electric vehicle maker Electrovaya will incorporate ExxonMobil's technology into its upcoming Maya-300 vehicle.

It is unlikely that this represents a significant shift in ExxonMobil's philosophy. Maximizing revenues today and belief in petroleum as THE fuel source will continue to guide their actions. ExxonMobil's focus on immediate shareholder gratification and eschewing of petroleum alternatives has paid off with the company setting the record for corporate profits for four years running.

However, it may signify a realization that there will be a considerable hybrid market, and since ExxonMobil has an applicable technology, it might as well turn it into additional profit. From the company's standpoint at least hybrids derive most of their power from petroleum, so that's better than vehicles running on biodiesel or ethanol.