Speaker
Description
Core-shell architectures have emerged as an effective strategy to enhance structural stability, regulate oxygen redox, and improve lithium-ion transport in lithium-rich layered oxide cathodes. This is due to the ability of the shell to act as a protective barrier that suppresses oxygen loss and mitigates surface degradation, while simultaneously facilitating lithium diffusion and stabilising the electrode-electrolyte interface. These advantages make core-shell design particularly attractive for addressing the limitations of lithium-rich materials such as Li2MnO3, which suffers from voltage decay, irreversible capacity loss, sluggish lithium diffusion, and structural degradation at high voltages. In this study, a Li2MnO3-Li0.69MnO2 core-shell system is investigated using large-scale molecular dynamics simulations with the DL_POLY package under canonical (NVT) conditions with a Nosé-Hoover thermostat. The temperature-dependent behaviour of Li2MnO3 and Li0.69MnO2 nanospheres is first analysed to establish a baseline for lithium diffusion and structural stability, followed by evaluation of the integrated core-shell system with varying shell thickness and interface distance. Results show that Li2MnO3 undergoes significant oxygen loss and enhanced lithium diffusion with increasing temperature, while Li0.69MnO2 exhibits reduced oxygen release but notable lithium loss. The 3 Å core-shell configuration maintains structural stability across temperatures (300 K – 1500 K), with radial distribution function analysis indicating moderate disorder at elevated temperatures. Enhanced lithium diffusion in the shell and thermal expansion trends suggest that the design effectively balances stability and ionic mobility, making it a promising cathode architecture.
| Apply for student award at which level: | PhD |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |