Jay Narayan: 'Material defects can be a nuisance, but if you engineer them correctly you can make them an advantage.'

According to a news release, a new study conducted by researchers at North Carolina State University and the U.S. Department of Energy's Oak Ridge National Laboratory has revealed a groundbreaking technique that can improve the performance of lithium-ion batteries,

This study shows that microscopic flaws in battery materials may be created with extremely short pulses from a high-powered laser, resulting to improved performance. Nanosecond pulsed laser annealing is a method that uses the same kind of laser that is used in contemporary eye surgery.

"Material defects can be a nuisance, but if you engineer them correctly you can make them an advantage," Jay Narayan, corresponding author of the research publication and the John C. Fan Family Distinguished Chair in Materials Science at N.C. State, said.

The study's authors zeroed in on graphite because it's such a common component of lithium-ion batteries' positive electrodes, or anodes. Graphite was tested by being exposed to batches of 10 and 80 pulses, and the consequent changes in current capacity were examined. 

Portable electronics and electric vehicles have made extensive use of lithium-ion batteries. However, with more enhancements, their potential impact could reach even further. These batteries are essential to the development of renewable energy sources like wind and solar power, and they hold the key to a transportation revolution.

When using the optimum number of pulses (about 10), the current capacity was found to increase by 20% using the nanosecond pulsed laser annealing method. 

Narayan stressed the significance of flaws in batteries to enhance their efficiency. This method resulted in the formation of vacancies, which increased the battery's current capacity by serving as entry and exit points for lithium ions. However, issues might arise when faults are excessive, such as when lithium metal forms and causes fires. 

Narayan suggests that nanosecond pulse laser annealing be available to manufacturers for use in creating both anodes and cathodes. Within a microsecond, the therapy can be completed, making this a practical and efficient option.

Using the same laser approach, the researchers also examined cathode materials, finding improved cathode performance. To make stronger and longer-lasting batteries without resorting to costly materials like cobalt, Narayan and researchers at the University of Texas at Austin are working on this issue right now. 

Distinguished professor of biological engineering at N.C. State, Roger Narayan, and first author and N.C. State graduate student, Nayna Khosla, co-authored the paper published in Carbon. 

Xiao-Guang Sun and M. Parans Paranthaman, both of Oak Ridge National Laboratory, are also credited as co-authors in the work. The U.S. Department of Energy and the National Science Foundation both contributed to this study.