Dr. Yu's research interest mainly focuses on the graphite anode for lithium ion batteries. His specific research areas are:
Solving initial capacity loss issue due to the formation of SEI layer on graphite anode
Exploring graphite exfoliation phenomenon due to the solvent co-intercalation with lithium ions
Elucidating Li ion transport mechanism in SEI layer
Improving sluggish kinetics of graphite for better rate & low temperature performance
The transport of lithium ions in the solid electrolyte interphase (SEI) has been previously accepted to proceed two steps: a fast pore diffusion through the outer, porous organic layer followed by a slow knock-off or vacancy diffusion in the inner, dense inorganic layer. Herein, a new one-step pore diffusion without the second slow step has been revealed with discrete inorganic particles in inner SEI layer. These results strongly suggest that the SEI structure on the transport kinetics of Li ions is much less significant thant previously accepted.
[1] Energy Environmental Science, 2023, 16, 5904
Graphite anode has limited compatibility with most of the electrolyte solvents since those solvent molecules tend to co-intercalate into the graphite layer along with lithium insertion and results in the layer exfoliation. We proposed a electrolyte with nanoscale anion network ordering which reduces the interactions between graphite particles and solvent molecules to stabilize the graphite in electrolyte. Our finding highlight the importance of the electrolyte nanostructures in the graphite stability.
[2] ACS Energy Letters, 2024, 9, 5002-5011
We have designed a flow cell to preforming SEI layer on graphite particle surface to compensate the irreversible lithium los due to the formation of the solid electrolyte interphase. The direct Li compensation of freestanding graphite powders is intrinsically different from those cathode or anode prelithiation strategies, which makes it easy to meet the indutrial scale-up requirements and enables a complete solution to solve the initial capacity loss issue.
[3] Carbon, 2022, 196, 589-595
