Energy Grant Will Advance Development of Lithium-Ion Batteries

Mechanical engineering professor Xiangbo “Henry” Meng has received a $750,000 grant from the U.S. Department of Energy to reconstruct a clean, anti-oxidative surface of high-capacity NMC811 cathodes for lithium-ion batteries used in battery-powered electric vehicles.

By addressing daunting problems related to the performance of NMC811, a lithium nickel manganese cobalt oxide, the research will improve the energy density, lifetime and efficiency of lithium-ion batteries, while also reducing their cost.

Xiangbo “Henry” Meng

“The high nickel content makes NMC811 particularly vulnerable with performance degradation and safety risk in applications,” said Xiangbo Meng, associate professor of mechanical engineering. “To address these issues, surface modification remains an important safety strategy and has proven effective. We are the first to discover that sulfides as surface coatings can play some unique roles in addressing NMC811 issues. Our work will hopefully deliver technical solutions while advancing our understanding of the electrochemistry .”

The high nickel content makes NMC811 cost-effective but challenging for commercialization due to residual lithium compounds on the surface, structural instability, metal dissolution, microcracking and oxygen release. These can cause battery gassing, electrode degradation and other serious performance issues.

Meng specializes in a precise, thin-film technique called atomic layer deposition to coat NMC811 electrodes. Atomic layer deposition enables the coatings to be applied layer by layer at the atomic level. Meng can fine-tune the interface of NMC811 electrodes with a series of novel, sub-nano to nanoscale sulfide coatings to achieve the best battery performance.

Preliminary studies demonstrated that sulfide coatings, via atomic layer deposition, removed residual lithium compounds to form a clean surface and improved electrode stability. The coatings also consumed released oxygen to protect electrolytes from decomposition and acted as an interfacial layer to prevent microcracking and metal dissolution.

For this project, Meng will collaborate with researchers from Argonne National Laboratory and Brookhaven National Laboratory. They will use electron microscopies and synchrotron-based techniques to investigate the underlying mechanisms of sulfide coatings of NMC811.