Speaker
Description
Spinel LiMn2O4 is a promising cathode material for lithium-ion batteries due to its low cost and three-dimensional lithium diffusion pathways. However, its application is limited by irreversible capacity loss and structural degradation associated with manganese migration, which are linked to structural instability and disrupted lithium transport. Prelithiation compensates for initial lithium loss, while Li2MnO3 surface modification enhances structural stability by suppressing manganese migration. Despite these strategies, the capacity of LiMn2O4 remains lower than that of layered oxides, highlighting the need to simultaneously address structural stability and lithium transport. Molecular dynamics simulations were used to investigate the combined but distinct roles of prelithiation and a Li_xMn2O4@Li2MnO3 core-shell system during stepwise delithiation (x = 2.0 → 1.2). The Li2MnO3 shell preserves MnO6 coordination and suppresses MnO5 formation across all temperatures up to 1200 K, while maintaining a stable core-shell interface with minimal atomic rearrangement. Coordination number and radial distribution analyses show reduced local distortion compared to the pristine spinel across all lithium concentrations. Lithium diffusion remains high (4.54 × 10^-7 cm2 s^-1 at 300 K) and increases with temperature, with consistently higher diffusion coefficients than the pristine spinel at elevated temperatures. No diffusion bottlenecks are observed at the interface, confirming continuous lithium pathways across the core-shell structure. These results demonstrate that the Li2MnO3 shell stabilizes the structure without compromising lithium transport, thereby mitigating manganese migration.
| Apply for student award at which level: | MSc |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |