Scientists Working Toward Better Batteries

Mar 09, 2006
From left, Daniel Fischer, Won-Sub Yoon, James McBreen, and Xiao-Qing Yang.
From left, Daniel Fischer, Won-Sub Yoon, James McBreen, and Xiao-Qing Yang.

As more and more people rely on cell phones, laptop computers, personal organizers, and even hybrid electric-gas vehicles, scientists are working to develop rechargeable batteries that are ever smaller, cheaper, lighter, safer, and longer-lasting.

At the National Synchrotron Light Source, a collaboration of scientists is deeply involved in this effort. They are investigating a group of promising new materials for use in lithium-ion batteries, the most common type of battery found in portable electronics and the most promising type for hybrid cars.

Lithium-ion batteries work by shuttling positively charged lithium ions between the “cathode” (the battery’s positive terminal) and “anode” (the negative terminal). As the battery is charged, lithium ions are forced out of the cathode and moved into to the anode through the “electrolyte,” the solution inside the battery. When the battery is in use, the process reverses. The scientists are studying a group of new cathode compounds consisting of the elements lithium, cobalt, nickel, manganese, and oxygen.

“Despite the wide use of lithium-ion batteries, there have been very few studies on exactly how the cathode material behaves in the charging process,” said the study’s lead researcher, Brookhaven chemist Won-Sub Yoon. “How are the oxygen atoms involved? What is the relationship between the oxygen atoms and the other metal atoms in the compound? To design a better cathode material, and thus a better battery, these questions must be answered. An in-depth understanding of these problems will provide a road map for the development of these new materials.”

Using various x-ray techniques, Yoon and his colleagues have done just that. They discovered that as lithium ions leave the cathode material during the charging process, changes occur on the manganese and cobalt atoms that are quite different from those that occur on the nickel atoms. Specifically, the manganese and cobalt atoms do not lose electrons as the lithium ions are removed, while the nickel atoms, in contrast, do lose electrons. The group also learned more about how the cathode material compensates for the positive charge it loses as the lithium ions move to the anode. They found that empty regions with positive charge, called “holes,” are created in the cathode. In addition, their x-ray data show just where these holes are located: within the electron orbitals of oxygen atoms that are bound to cobalt atoms.

Gathering these details on the cathode’s electronic behavior is an important step in lithium-ion battery research. This new knowledge will help the material become a common component of a new series of better lithium-ion batteries. More detailed information on this research can be found in the group’s scientific paper, which is published in the December 14, 2005, edition of the Journal of the American Chemical Society.

The other scientists involved in this research are Kyung Yoon Chung, Xiao-Qing Yang, and James McBreen (BNL Chemistry Department); Mahalingam Balasubramanian (Argonne National Laboratory); Clare Grey (Stony Brook University); and Daniel Fischer (National Institute of Standards and Technology).

Source: BNL, by Laura Mgrdichian

Explore further: Car hacking: The security threat facing our vehicles

add to favorites email to friend print save as pdf

Related Stories

NREL bolsters batteries with nanotubes

Jul 01, 2014

Researchers at the Energy Department's National Renewable Energy Laboratory (NREL) are turning to extremely tiny tubes and rods to boost power and durability in lithium-ion batteries, the energy sources for ...

Team bolsters batteries with nanotubes

Jun 17, 2014

Researchers at the Energy Department's National Renewable Energy Laboratory (NREL) are turning to extremely tiny tubes and rods to boost power and durability in lithium-ion batteries, the energy sources for ...

A nanoscale glimpse of batteries in action

Sep 13, 2013

Lithium–oxygen (Li–O2) batteries are a new type of experimental battery that electric car manufacturers are hoping will address the issue of limited driving range. Unlike the lithium-ion batteries used ...

Recommended for you

Facebook dressed down over 'real names' policy

4 hours ago

Facebook says it temporarily restored hundreds of deleted profiles of self-described drag queens and others, but declined to change a policy requiring account holders to use their real names rather than drag names such as ...

Apple iOS 8 software bug affects health apps

5 hours ago

A bug in Apple's new iOS 8 software for mobile devices is prompting the company to withhold apps that use a highly touted feature for keeping track of fitness and health data.

Yelp to pay US fine for child privacy violation

11 hours ago

Online ratings operator Yelp agreed to pay $450,000 to settle US charges that it illegally collected data on children, in violation of privacy laws, officials said Wednesday.

User comments : 0