通过热驱动的再分配在和丰富的层级阴极材料中的表面对散装合
Shaofeng Li1,2, Sang-Jun Lee1, Xuelong Wang3,4
1Stanford Synchrotron Radiation Lightsource , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States.
Journal of the American Chemical Society
|July 10, 2019
概括
轻微升高的温度会触发富含和 (LMR) 阴极材料的氧化还原合. 这项研究揭示了LMR材料中氧离子和过渡金属之间的热驱动电荷转移.
科学领域:
- 材料科学
- 电化学
- 能量储存
背景情况:
- 富含和 (LMR) 的分层阴极材料由于过渡金属和氧离子的联接氧化还原活性而具有高容量和能量密度.
- 在环境温度下,LMR阴极的电化学氧化还原演变得到了充分研究.
- 在非电化学条件下,对LMR阴极行为的热效应在很大程度上仍未被探索.
研究的目的:
- 在轻微升高的温度 (高达~100°C) 中研究带电Li1.2Ni0.15Co0.1Mn0.55O2 (LMR) 材料中的热驱动的氧化还原合效应.
- 在没有电化学驱动力的情况下,受温度扰动影响的表面与散装氧化还原相互作用的理解.
主要方法:
- 对带电的Li1.2Ni0.15Co0.1Mn0.55O2材料进行系统研究.
- 应用温和的热应力 (高达~100°C) 来诱导表面与散装的氧化还原合.
- 对氧离子和过渡金属离子之间的电荷转移机制的分析.
主要成果:
- 在~100°C的LMR材料中,第一次观察大量氧离子和表面过渡金属离子之间的电荷转移.
- 这种电荷转移归因于离子的热驱动再分配.
- 在轻微的热扰动下,在深度脱的LMR材料中证明动态的非平衡状态.
结论:
- 轻微升高的温度可以在LMR阴极材料中诱导显著的氧化还原活性,独立于电化学循环.
- 这些发现强调了在实际应用中考虑LMR材料的热稳定性的重要性.
- 了解这些热驱动过程对于优化先进电池技术的性能和安全至关重要.
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