Exxon Mobil Corp. believes it has found an answer to a problem that has bedeviled the auto industry in recent years: using rechargeable lithium-ion batteries, like those found in cell phones and laptops, to power cars and trucks.

This weekend, at a conference in Anaheim, Calif., Exxon Mobil will unveil a super-thin plastic sheeting the company says can improve the power, safety and reliability of lithium-ion batteries for use in automobiles.

Exxon Mobil considers the film a breakthrough because it allows battery makers to build smaller and cheaper battery systems — removing key obstacles that have kept automakers from building hybrid and electric vehicles on a wide scale.

Separator films are membranes that keep the battery's positive and negative fields, which are wrapped in a jelly-roll configuration, from touching.

Exxon Mobil developed its film with Japanese affiliate Tonen Chemical. Invented in research labs at Exxon Mobil's Baytown complex, the film is the first to squeeze multiple layers of plastic into a single white sheet the width of a human hair.

The added layers enable the batteries to run at higher temperatures — and produce more power — while still protecting them from overheating, company officials said. It also incorporates features that cause it to shut down if there is a short circuit in the battery.

Exxon Mobil sees the separator film technology as more than just a chance to green up its image. Company officials said there is a legitimate business motive for pursuing the technology.

"Clearly, hybrid and electric vehicles are going to play a role in the future, and we want to be a part of that," Harris said.