Exxon’s battery wiz Pat Brant focuses on making lithium-ion batteries viable for vehicles

Closing the economic gap between 5-pound laptops and 5,000-pound trucks



Pat Brant has a problem.

Or rather, we all have a problem, and Brant is one of the people trying to solve it.

The problem is that electric cars and plug-in hybrids, which could play a key role in reducing greenhouse gas emissions, require batteries that are powerful and long-lasting, but also lightweight, compact and not too expensive.

Lithium-ion batteries—the kind used in cell phones and laptop computers—are seen as the best bet for now. But designing a battery for a 5,000-pound vehicle is quite different than designing a battery for a 5-pound laptop.

Enter Brant, one of three chief scientists at ExxonMobil Chemical.

For the last five years, Brant has been working to develop components for lithium-ion batteries to help the batteries meet the new performance demands placed on them. Specifically, Brant and his team are tailoring polymers to improve the thin separator films that separate the batteries’ anodes and cathodes.

Like a dam on a river

“It basically acts a lot like a dam on a river,” Brant explained in an interview. “It helps you to store energy and then release that energy and use it as you need it.”

The films, which are about the width of a human hair, separate the two electrodes while allowing ions to pass through as the battery is used and as it recharges. If the separator fails, the battery can short-circuit or overheat.

The powerful lithium-ion batteries made for cars will have to perform in ways other batteries don’t, Brant explained. They’ll have to withstand a certain amount of vibration, for instance, and they’ll have to last for many years.

“The batteries are getting larger and tackling bigger jobs,” he said. “Demands on all of the components in the battery—not just the separators—become greater.”

Getting involved

Brant earned a PhD in chemistry from the University of Arizona. He worked as a post-doc at Purdue University and later got a fellowship at the Naval Research Lab in Washington, D.C., where he had his first exposure to polymers.

He started working at Exxon in 1981, before the company merged with Mobil. There he focused on polyolefins, a family of plastics that includes polypropylene and polyethylene.

He learned about the technologies involved, but also the market drivers and other factors that affect how materials are developed, he said. “I’ve had … what you’d say is a priceless education inside the company, something you just can’t get outside.”

In 2005, Brant traveled to Japan and visited with a team working on battery separator films. Shortly after, he was part of that team.

Works closely with Tokyo’s Toten

Brant, who is now 59, works at a facility near Houston, Texas, helping design new plastics to be used as separator films. ExxonMobil Chemical works in collaboration with its affiliate Tonen Chemical, which is based in Tokyo.

“We work very close together, sort of hand in glove,” Brant said.

As a chief scientist, Brant himself spends less time in a lab than he used to. Instead, he spends a lot of time communicating with others.

“There’s a big opportunity to work together to lever off each other’s strengths,” he said.

In late 2007, ExxonMobil announced that ExxonMobil and Tonen Chemical had developed a separator film to meet the additional demands required by vehicle applications. The film, comprised of multiple layers of different plastics, provides better protection if the battery overheats and ultimately allows for more efficient batteries, according to ExxonMobil.

The Canadian battery maker Electrovaya used ExxonMobil’s new separator films in lithium-ion batteries made for the Maya300 low-speed electric vehicle.

A young, exciting technology

Brant stresses that lithium-ion battery technology is still new. Eighteen years ago, there were virtually no lithium-ion batteries, he said.

“It’s a very young technology, still a very exciting technology to be involved in, with so many possible major applications.”

In addition to powering vehicles, lithium-ion batteries could help utilities increase reliability without building new power plants and help bring about the development of intermittent energy sources such as wind and solar.

(The American battery maker A123 Systems recently helped develop a 12-megawatt frequency regulation and spinning reserve project in Chile using lithium-ion technology.)

Might take longer for viability

That said, Brant thinks battery costs will have to come down before vehicles charged from the grid will make real headway in the market.

When asked about President Obama’s goal of having a million plug-in hybrid vehicles on the road by 2015, Brant said he thought it might take a few more years than that.

“It’s going to take probably some sort of subsidy to see them through,” he added.

Brant himself has yet to jump on the electric vehicle bandwagon. He drives a Volkswagen Jetta with a standard gasoline engine. “Personally, I’m a bit of a trailing-edge technology (guy),” he said. “I tend to look for a high degree of viability.”

Improving the viability of electric cars may seem like an unlikely goal for a company that depends on the continued demand for oil and gas. But to anyone who questions Exxon Mobil’s commitment to the technology, Brant has a ready response.

“I think the basic answer is simply that we have recognized—and I think others have too—that all forms of energy, if they’re economical, if they’re efficient, are going to be necessary going forward,” he said.

Brant’s goal, at least for now, is making batteries economical.

“One of the most important messages that I could offer anybody is look for the big challenges; then look for ways to solve them,” Brant said. A career in science, he added, can be a great way to turn those challenges into opportunities.

For more information

ExxonMobil Chemical Co.
A123 Systems project in Chile

Contact Stefan Milkowski at smilkowski@greeningofoil.com