Georgia Institute of Technology Materials Science and Engineering

Committee Members:

Prof. Gleb Yushin, Advisor, MSE

Prof. Faisal Alamgir, MSE

Prof. Ting Zhu, ME/MSE

Prof. Seungwoo Lee, ME

Prof. Alexander Alexeev, ME

“Enhancing Ion Transport in Thick Li-ion Battery Electrodes by Pore Engineering”

Abstract:

Development of lithium-ion batteries (LIBs) had been instrumental for the broad use of sophisticated mobile electronic devices. Nowadays LIBs have also become the very foundation of electric vehicles (EV) and energy storage systems (ESS) for electric grid due to LIBs' unprecedented combination of high volumetric energy and power densities, reliable operation, and relatively low cost. However, as the conventional LIB materials reach their performance limits, further improvements in LIB performance and reduction in LIB costs need to come either from novel materials development or from improved LIB manufacturing. In the latter case, increasing areal electrode capacity loadings from 3-4 mAh/cm2 to 5-7 mAh/cm2 or higher values without significant sacrifices in the volumetric electrode capacity or charge rates becomes critical for volumetric energy density improvement beyond 600-700 Wh/L, gravimetric energy density improvements beyond 250 Wh/L and meaningful cost savings, which are critically important for the broad adoption of renewable energy technologies.  Unfortunately, higher areal capacities and thus thicker or dense electrodes may slow down the transport of ions during charge and discharge, thereby reducing rate performance and capacity utilization in realistic operating conditions, increasing cell resistance and ultimately shortening LIB cycle life. 

For my Ph.D. project I propose to alter the distribution of pores in the conventionally produced high-capacity loading LIB electrodes by both micro-mechanical means and laser-induced post-treatments and systematically study the impact of pore modifications on the average electrodes' tortuosity and electrochemical properties. The new fundamental knowledge to be gained in the proposed study will help to establish guiding principles for the advanced fabrication techniques to fine-tune the size, shape, and distribution of pores within electrodes. As a result, LIB manufacturers should be able to dramatically accelerate ion transport and enable fast charging, while simultaneously increasing LIB energy density and reducing LIB fabrication costs.