Development of Performance Enhancement Technology for Lithium Secondary Batteries Processed by Laser

GIST Professors Kim Hyung-jin and Jung Sung-ho Research Team Successfully Improves Battery Capacity and Output Simultaneously

[Asia Economy Reporter Kim Bong-su] A processing method that can further enhance the performance of lithium secondary batteries has been developed.

The research team of Professor Kim Hyung-jin from the School of Energy Convergence and Professor Jung Sung-ho from the Department of Mechanical Engineering at Gwangju Institute of Science and Technology (GIST) announced on the 26th that they succeeded in simultaneously improving the capacity and output of various lithium secondary battery electrodes such as lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP), and graphite by processing them with a femtosecond laser.

A femtosecond laser (1 femtosecond = one quadrillionth of a second) is a laser with an extremely short pulse width of several tens of femtoseconds per pulse, enabling microfabrication of several micrometers with almost no thermal effect.

In lithium secondary batteries, the structural characteristics according to the thickness and porosity of the electrode greatly affect battery performance. While thickening the electrode by stacking more active material or densification through strong compression processes can improve energy density, the output density rapidly decreases due to structural limitations unfavorable to ion conductivity.

In other words, capacity and output in batteries have a trade-off relationship, and the thickness and porosity of the electrode, which have the greatest impact on performance, are optimized and applied within a limited range.

In previous research, the team demonstrated the effect of laser processing by three-dimensionally structuring electrodes thicker (100?700 μm thickness) and denser (26% porosity) than commercial electrode levels through laser processing, thereby widening and shortening the lithium-ion diffusion path from the electrode surface to the current collector, significantly improving both energy density and power density.

In this study, to apply laser processing technology to mass production, the team analyzed the correlation between various processing conditions (processing depth, spacing, etc.) and changes in battery performance, proposing laser processing design conditions considering the operating environment and performance according to the usage of lithium secondary batteries. In particular, they intuitively analyzed the laser processing effect by visualizing the lithium-ion distribution inside the electrode using laser-induced breakdown spectroscopy (LIBS).

Professor Kim Hyung-jin said, “The core of this study is establishing the main design conditions for laser processing of lithium secondary battery electrodes and visualizing the distribution of lithium ions inside the electrode during charge and discharge using laser analysis technology.” He added, “It is possible to design beyond the limitations of existing electrode specifications through laser microfabrication processes, and by simultaneously improving energy density and power density, we hope to contribute to a revolutionary performance enhancement of lithium secondary batteries.”

The results of this study were published online on the 22nd of last month in the international journal in the field of applied chemistry, the Journal of Energy Chemistry.

This content was produced with the assistance of AI translation services.