由石墨导电添加剂启动的混乱岩盐阴极的增强电化学性能
Shripad Patil1,2, Krishna Prasad Koirala3, Matthew J Crafton4,5
1Bredesen Center for Interdisciplinary Research and Education, University of Tennessee Knoxville, Knoxville, Tennessee 37996, United States.
ACS applied materials & interfaces
|August 11, 2023
概括
降低没有的离子干扰岩盐 (DRX) 阴极中的碳含量是更好的离子电池的关键. 石墨添加剂通过创建保护性涂层和稳定的导电网络,显著提高性能.
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
- 储能 储能 储能 储能 储能 储能
背景情况:
- 无离子无序岩盐 (DRX) 阴极为下一代离子电池提供了高的理论容量.
- 对于DRX阴极,通常需要高碳含量 (高达30%重量%),这会对能量密度产生负面影响.
- 了解碳的作用对于优化DRX阴极性能和减少碳负载至关重要.
研究的目的:
- 为了研究碳微观结构和负载 (10-20重量%) 对DRX阴极性能的影响.
- 确定减少电极碳含量的途径,同时保持或提高电池性能.
- 阐明 DRX 阴极在不同碳添加剂的性能变化背后的机制.
主要方法:
- 制造DRX阴极 (Li1.2Mn0.5Ti0.3O1.9F0.1) 使用不同碳添加剂 (石墨,C65,黑) 在10-20%重量负载下.
- 电化学测试包括循环性能和速率能力评估.
- 使用一套工具来分析电极微观结构和表面性质的材料表征.
主要成果:
- 采用常规无序碳 (C65, ketjenblack) 的DRX阴极由于不稳定的接口而显示出快速的容量衰减.
- 使用10 wt%石墨的电极表现出优越的循环性能 (∼260 mA h/g,50个循环后85%的保留) 和速率能力 (∼135 mA h/g在1000 mA/g).
- 加上石墨导致了均的表面涂层和均的分散,增强了电子导电性和稳定性.
结论:
- 石墨在DRX阴极中的优越性能归因于保护性表面涂层和强大的导电网络.
- 使用石墨将碳含量降低到10%的重量是提高DRX阴极能量密度和稳定的可行策略.
- 建议通过替代石墨涂层方法进行进一步优化,以提高DRX阴极性能.
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