• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nanotechnology >Atomic-scale constituting stable interface for improved LiNi0.6Mn0.2Co0.2O2 cathodes of lithium-ion batteries
【24h】

Atomic-scale constituting stable interface for improved LiNi0.6Mn0.2Co0.2O2 cathodes of lithium-ion batteries

机译：构成稳定界面的原子尺度，用于改进的LINI0.6MN0.2CO0.2O2202020.2O2锂离子电池阴极

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Ascribed to their higher capacity and lower cost compared to conventional LiCoO2, the Ni-rich layered LiNi0.6Mn0.2Co0.2O2 (NMC622) is now considered as one promising cathode for lithium-ion batteries (LIBs). However, it still suffers from some evident performance degradation, especially under high cutoff voltages (i.e., >4.3 V versus Li/Li+). The performance degradation typically is exhibited as capacity fading and voltage drop, mainly originating from an instable interface between the NMC622 and electrolyte as well as the evolution of the NMC structure. To improve the interfacial and structural stability of NMC cathodes, herein we deposited an ultrathin layer of Al2O3 coatings (<5 nm) conformally over NMC622 composite electrodes directly using atomic layer deposition (ALD). It was found that, under different upper cutoff voltages (4.3, 4.5, and 4.7 V), the ALD Al2O3 coatings enable enhanced performance of NMC622 cathodes with better cyclability and higher capacity. Particularly, the beneficial effects of the ALD Al2O3 coatings are more remarkable at higher upper cutoff voltages (4.5 and 4.7 V). Furthermore, the ALD coatings can significantly improve the rate capability of NMC622. To this end, we utilized a suite of characterization tools and performed a series of electrochemical tests to clarify the effects of the ALD Al2O3 coatings. This study revealed that the beneficial effects of the Al2O3 ALD coatings are multiple: (i) serving as an artificial layer of solid electrolyte interphase to mitigate undesirable interfacial reactions; (ii) acting as a physical barrier to inhibit metal dissolution of NMC; and (iii) forming a reinforced networked overcoating to boost the mechanical integrity of NMC cathodes. This study is favorable for designing high-performance NMC cathodes.
机译：与传统的LiCoO2相比，由于其容量更高，成本更低，富镍层状LiN0。6Mn0。2Co0。2O2（NMC622）目前被认为是一种很有前途的锂离子电池阴极。然而，它仍然存在一些明显的性能退化，尤其是在高截止电压下（即大于4.3 V与Li/Li+）。性能退化通常表现为容量衰减和电压降，主要源于NMC622和电解质之间的不稳定界面以及NMC结构的演变。为了提高NMC阴极的界面稳定性和结构稳定性，本文采用原子层沉积法（ALD）在NMC622复合电极上共形沉积了一层超薄的Al2O3涂层（<5nm）。研究发现，在不同的上限截止电压（4.3、4.5和4.7 V）下，ALD Al2O3涂层能够增强NMC622阴极的性能，具有更好的循环性和更高的容量。特别是，在较高的截止电压（4.5和4.7 V）下，ALD Al2O3涂层的有益效果更为显著。此外，ALD涂层可以显著提高NMC622的速率性能。为此，我们使用了一套表征工具，并进行了一系列电化学测试，以澄清ALD Al2O3涂层的影响。这项研究表明，Al2O3-ALD涂层的有益效果是多方面的：（i）充当固体电解质界面的人工层，以减轻不良的界面反应；（ii）作为物理屏障，抑制NMC的金属溶解；以及（iii）形成强化网络涂层，以提高NMC阴极的机械完整性。本研究有利于设计高性能的NMC阴极。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号