使用密度函数理论的LiNiO2,LiCoO2和LiMnO2的热力学特性
Lucas Tosin Paese1, Philippe Zeller1, Sylvie Chatain1
1Université Paris-Saclay, CEA, Service de Recherche en Corrosion et Comportement des Matériaux, 91191, Gif-sur-Yvette, France. lucas.tosinpaese@cea.fr.
Physical chemistry chemical physics : PCCP
|July 24, 2023
概括
这项研究使用DFT计算了氧化,氧化和氧化的形成能量. 结果显示LiCoO2和LiMnO2的协议很好,但强调LiNiO2的差异,建议进一步研究.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 固态物理 固态物理
背景情况:
- 过渡金属氧化物是可充电电池的重要阴极材料.
- 准确的热力学数据对于理解材料的稳定性和性能至关重要.
- 对于一些氧化物 (如LiNiO2) 的实验数据很少,需要进行理论研究.
研究的目的:
- 使用DFT计算LiCoO2,LiNiO2和LiMnO2的形成能量和度.
- 评估这些材料的各种交换相关函数的准确性.
- 调查晶体学扭曲和振动贡献对热力学性能的影响.
主要方法:
- 使用密度函数理论 (DFT) 的计算.
- 赫斯循环与DFT一起用于能源计算.
- 固体 (PBEsol) 功能的PBE被确定为最准确的.
- 为了包括振动效应,使用了和准的近似值.
主要成果:
- 对于LiCoO2,LiNiO2,正方体LiMnO2和方体LiMnO2.2,0K的形成度被确定.
- 计算的形成能量与LiCoO2 (1.6kJ/mol差异) 和LiMnO2 (0.01kJ/mol差异) 的实验数据有很好的一致.
- 一个显著的差异 (大约. 对LiNiO2观察到24kJ/mol),这促使进一步调查.
- 对LiCoO2的热容量计算与实验值非常相匹配 (300 K时的差异为3.3%),而LiNiO2显示出更大的差异 (300 K时的差异为17%).
- 计算了o-LiMnO2的新热容量数据.
结论:
- 该PBEsol功能为LiCoO2和LiMnO2.2提供了准确的形成能量.
- 该研究强调,由于存在重大差异,需要对LiNiO2的热力学特性进行实验测量.
- 振动贡献和结晶学扭曲在这些材料的能量特性中发挥着作用.
- 计算的热力学和结构数据为电池材料开发提供了宝贵的见解.
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