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在Li(4+x) Ti(5) O(12) 旋转中的尺寸效应
W J H Borghols1, M Wagemaker, U Lafont
1Department of Radiation, Radionuclides and Reactors, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands.
Journal of the American Chemical Society
|November 19, 2009
概括
研究纳米化酸 (Li4+x) Ti5O12) 揭示了最佳的粒子大小平衡高容量与稳定性. 接近表面的影响会影响的储存,但过度储存会导致不可逆转的容量损失,影响电池性能.
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
- 固态化学 固态化学
背景情况:
- 纳米化电极材料由于增加了表面积,因此提供了增强的电化学性能.
- 酸 (Li4+x) Ti5O12) 是离子电池的一个有前途的阳极材料,因为它具有零应变特性.
- 纳米材料的表面效应可以显著影响它们的电化学行为和长期稳定性.
研究的目的:
- 为了研究纳米尺寸Li{4+x) Ti{5O}{12) spinel的电化学行为和结构性质.
- 了解粒子大小,近地表面储存和容量保留之间的关系.
- 阐明纳米尺寸Li{4+x) Ti{5) O{12}中曲线电压配置的起源及其对纳米插入材料的影响.
主要方法:
- 电化学 (放电) 试验,以评估容量和循环稳定性.
- 中子衍射分析结构变化和离子占用率.
- 分析电压配置和容量衰减作为粒子大小的函数.
主要成果:
- 纳米化Li(4+x) Ti(5) O(12) 在近表面区域具有更高的离子占用率和容量.
- 过度的近地储存导致不可逆转的容量损失,可能是由于表面重建或机械故障.
- 纳米尺寸Li{4+x) Ti{5}O{12) 的曲线电压概况归因于近表面区域的多样化的结构环境和氧化还原潜力,而不是应变.
结论:
- 对于纳米尺寸的Li{4+x) Ti{5}O{12) 存在一个最佳的粒子大小,以最大限度地提高容量,同时减轻不可逆转的损失.
- {4+x) Ti{5}O{12}的独特的零应变特征需要基于表面环境的解释其观察到的电压特征异常.
- 这些发现为设计稳定和高性能纳米插入材料提供了深入的见解,用于先进的储能应用.
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