中国物理B ›› 2022, Vol. 31 ›› Issue (9): 98202-098202.doi: 10.1088/1674-1056/ac6863
Configurational entropy-induced phase transition in spinel LiMn2O4
Wei Hu(胡伟)1,2, Wen-Wei Luo(罗文崴)1, Mu-Sheng Wu(吴木生)1, Bo Xu(徐波)1, and Chu-Ying Ouyang(欧阳楚英)1,†
- 1 Department of Physics, Laboratory of Computational Materials Physics, Jiangxi Normal University, Nanchang 330022, China;
2 School of Ecology and Environment, Yuzhang Normal University, Nanchang 330103, China
Configurational entropy-induced phase transition in spinel LiMn2O4
Wei Hu(胡伟)1,2, Wen-Wei Luo(罗文崴)1, Mu-Sheng Wu(吴木生)1, Bo Xu(徐波)1, and Chu-Ying Ouyang(欧阳楚英)1,†
- 1 Department of Physics, Laboratory of Computational Materials Physics, Jiangxi Normal University, Nanchang 330022, China;
2 School of Ecology and Environment, Yuzhang Normal University, Nanchang 330103, China
摘要： The spinel-type LiMn$_{2}$O$_{4}$ is a promising candidate as cathode material for rechargeable Li-ion batteries due to its good thermal stability and safety. Experimentally, it is observed that in this compound there occur the structural phase transitions from cubic ($Fd\bar{3}m)$ to tetragonal ($I4_{1}/{amd}$) phase at slightly below room temperature. To understand the phase transition mechanism, we compare the Gibbs free energy between cubic phase and tetragonal phase by including the configurational entropy. Our results show that the configurational entropy contributes substantially to the stability of the cubic phase at room temperature due to the disordered Mn$^{3+}$/Mn$^{4+}$ distribution as well as the orientation of the Jahn-Teller elongation of the Mn$^{3+}$O$_{6}$ octahedron in the the spinel phase. Meanwhile, the phase transition temperature is predicted to be 267.8 K, which is comparable to the experimentally observed temperature. These results serve as a good complement to the experimental study, and are beneficial to the improving of the electrochemical performance of LiMn$_{2}$O$_{4}$ cathode.
中图分类号: (Lithium-ion batteries)
- 82.47.Aa