负热膨胀和氧-氧化电化学
Bao Qiu1,2, Yuhuan Zhou1, Haoyan Liang1
1Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Ningbo, China.
Nature
|April 16, 2025
概括
氧减氧 (OR) 活性物质由于乱序过渡而表现出负热膨胀. 电化学方法可以恢复结构完整性, 为这些先进材料提供电压衰变的解决方案.
科学领域:
- 材料科学
- 电化学
- 固态物理
背景情况:
- 材料中的结构障碍会影响热力学和电化学性质.
- 氧化减氧 (OR) 电化学增强容量,但可以降低可逆性并诱导疾病.
- 传统的热膨胀模型 (格鲁尼森关系) 可能不适用于OR材料,因为它具有动态的乱序过渡.
研究的目的:
- 研究手术室活性材料的热膨胀行为.
- 探索混乱-秩序转换和热膨胀之间的联系.
- 建立设计可调节的热膨胀材料的框架,包括零热膨胀.
主要方法:
- 对OR活性物质的实验性表征.
- 热膨胀系数的分析
- 电化学循环诱导和逆转结构障碍
- 在电化学过程中进行材料修复.
主要成果:
- 在OR材料中发现了显著的负热膨胀 (-14.4 ((2) × 10−6 °C−1),这归因于热驱动的乱序过渡.
- 证明OR行为调制精确地控制热膨胀.
- 通过电化学驱动力成功恢复结构混乱,通过调整切断电压实现近100%的结构恢复.
结论:
- 热驱动的乱序过渡是OR材料负热膨胀的原因.
- 电化学控制OR行为允许精确调整热膨胀.
- 运行电化学过程可以恢复OR活性材料,减轻电压衰减并提供材料寿命的途径.
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