Army scientists energize battery research

Kang Xu, an Army Research Laboratory scientist, is one of the inventors responsible for a 30-percent increase in energy density in lithium batteries.

ADELPHI, Md. — Army scientists are squeezing more power from batteries by developing new methods and materials with incredible results.

“Our battery group has recently developed some new materials that could potentially increase the energy density of batteries by 30 percent,” said Cynthia Lundgren, electrochemical branch chief at the U.S. Army Research Laboratory.

This small group of scientists work on energy and power solutions for America’s Soldiers.

“This 30 percent is actually quite a big deal. Typically improvements range about one percent a year with a few step changes,” Lundgren said.

For years, researchers studied how batteries work. They looked at how each component reacts with another. At high voltages batteries are extremely energetic systems.

“There has never been a battery, a single cell, that operated at five volts,” Lundgren explained. “Through our understanding of that interface, we were able to design an additive that you add into the electrolyte that is somewhat of a sacrificial agent. It preferentially reacts with the electrode and forms a stable interface. Now the battery is able to operate at five volts.”

Scientists are calling the additive a major step forward. Since Army researchers Kang Xu and Arthur Cresce designed the substance two years ago, the lab has filed patent applications.

“This is what you would call a quantum leap,” Cresce said. “We’ve gone from circling around a certain type of four-volt energy for quite a while. All of a sudden a whole new class of batteries and voltages are open to us. The door is open that was closed before.”

Army research has the potential to reduce battery weight and allow Soldiers to carry more ammunition or water.

“Our goal is to make things easier for the Soldier,” Lundgren said. “This research started because of the Army’s unique needs. There is a huge investment in batteries.”

In the future, Lundgren hopes they just don’t make better materials, but rather design new types of energy devices undreamt of today.

“We’re looking at designing systems to allow for ubiquitous energy — energy anywhere for the Soldier using indigenous sources,” Lundgren said. “Some of our new programs are looking at how we may make fuel out of water. For instance, can we split water and make hydrogen to be used as fuel in a fuel cell or small engine?”

Lundgren said future advances will occur with the right resources.

“The laboratory gives us really good resources, but our highest value resource is our scientists,” she said. “We have an exceptional group of scientists here. We’ve been able to retain them. They have been sought after by many people. But, they’re ability to do good research here, research that can make a difference has allowed us to attract and retain really top talent.”