| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Materials for Energy Conversion and Storage VI
|
| Presentation Title |
Stress-enhanced Reaction Non-uniformity in Lithium Intercalation Compounds |
| Author(s) |
Kaiqi Yang, Youtian Zhang, Fan Wang, Ming Tang |
| On-Site Speaker (Planned) |
Ming Tang |
| Abstract Scope |
During battery cycling, reaction inhomogeneity occurs in battery electrodes across a wide range of length scales. It is a major contributor to the capacity under-utilization and degradation of battery electrodes. Here we present a theoretical prediction that coherency stress arising during charge/discharge can destabilize lithium intercalation front and result in non-uniform reaction at the particle level. This is an intrinsic reaction instability mechanism determined by materials properties, which cannot be eliminated by improving electrical wiring and mass transport kinetics in the electrodes. Using LiFePO4 as a case study, our simulation satisfactorily explains operando observation of phase evolution in single crystalline electrode particle and unequivocally confirms the role of stress in triggering inhomogeneous delithiation behavior. In LiFePO4 secondary particles, our modeling predicts that the incompatibility in lattice expansion between randomly oriented primary particles further increases the reaction non-uniformity. The predicted phase transition pathway agrees well with synchrotron-based transmission X-ray microscopic study. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |