在中度脱时,丰富的层状氧化物中存在大量的氧气损失和化学膨胀
Peter M Csernica1, Kit McColl2, Grace M Busse1
1Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA.
Nature materials
|October 17, 2024
概括
离子电池中的氧气损失即使在中度脱时也会发生,这挑战了以前的假设. 这项研究强调了日历衰老在理解分层氧化物电极中氧气不稳定的关键作用.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 电池技术 电池技术
背景情况:
- 层状氧化物电极对于离子电池至关重要.
- 脱过程中的氧气损失是主要的降解机制.
- 人们对氧气损失的确切机制仍然不太了解.
研究的目的:
- 为了研究Li1.18-xNi0.21Mn0.53Co0.08O2-δ电极中的氧气非静电测量.
- 了解含量与氧气损失之间的关系.
- 探索长期开放电路电压阶段对氧气稳定性的影响.
主要方法:
- 使用循环协议,扩展开放电路电压在各种电荷状态下保持.
- 作为脱的函数的量化氧气损失.
- 测量化学膨胀系数与氧气非静态度相关.
主要成果:
- 即使在中度脱水平下,也观察到大量的氧气损失.
- 在100小时的休息后,在不同的切断潜力下记录了特定的氧气损失量 (2.57.6毫升O2/g).
- 发现了显著的化学膨胀系数,超过已知缺氧材料的化学膨胀系数.
结论:
- 氧气的不稳定性是这些层层的氧化物电极的内在特性,即使在中间电位.
- 深度脱不是氧气损失的先决条件.
- 日历老化是评估电池材料中氧气稳定的关键因素.
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