离子电池在概念上如何工作:在理想化的电极中结合的热力学
Sam H Finkelstein1, Marco Ricci2,3, Tom Bötticher4
1Department of Chemistry, Brandeis University, Waltham, MA 02453, USA. srohr@brandeis.edu.
Physical chemistry chemical physics : PCCP
|September 10, 2024
概括
离子在电池放电期间由于更强的结合而移动到正极,释放出大量的能量. 这个不可逆转的过程解释了电池的运行和能量释放,需要高电压来充电.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 热力学是一种热力学.
背景情况:
- 离子电池 (LIB) 依赖于离子和电子在电极之间的运动.
- 了解这种运动背后的热力学驱动力对于解释电池功能至关重要.
- 现有的模型往往忽略了电极材料内结合的能量细节.
研究的目的:
- 为了热力学解释在LIB放电期间离子自发的,释放能量的运动.
- 分析阳极和阴极之间结合的能量差异.
- 为了将电极材料的特性与电池电压相关联.
主要方法:
- 使用两相LiFePO4/FePO4正极 (阴极) 的放电LIB的热力学分析.
- 电极材料之间的凝聚性能量差异的计算.
- 与原子的化学潜力相关的凝聚性能量差异.
主要成果:
- 在正极中,离子的结合比在负极 (阳极) 中更强.
- 向阴极的移动是一个能量下坡,不可逆转的过程,释放大约320kJmol-1.
- 电池电压与阴极中的过渡金属的电离能相关,来自凝聚力的能量组件.
结论:
- 在正极中的较强的结合是放电期间能量释放的主要驱动因素.
- 电子充当中间体,它们的能量作用对于解释放电热力学并非必不可少.
- 这种热力学框架准确地根据电极材料凝聚力的能量预测电池电压,适用于双相和单相阴极.
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