...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Materials Chemistry, A. Materials for energy and sustainability >Honeycomb-like porous iron fluoride hybrid nanostructures: excellent Li-storage properties and investigation of the multi-electron reversible conversion reaction mechanism
【24h】

Honeycomb-like porous iron fluoride hybrid nanostructures: excellent Li-storage properties and investigation of the multi-electron reversible conversion reaction mechanism

机译：蜂窝状多孔氟化铁杂化纳米结构：优异的锂存储性能和多电子可逆转化反应机理的研究

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

Iron fluoride cathodes with good specific energy/power performance can hardly operate durably at room temperature due to poor conductivity and sluggish kinetics. Fabricating novel hybrid nanostructures is a promising approach to obtain a fast diffusion and transport process. In this study, a porous honeycomb-like iron fluoride hybrid composite comprising iron fluoride nanocrystals (similar to 1-4 nm) encapsulated in separate carbon nests constructed by multi-scale pores (similar to 1-100 nm) was fabricated through a combination of room-temperature fluorination and a mild annealing process for the first time. The iron fluoride topochemically evolved from a smaller iron oxide nanocrystal precursor (similar to 2-3 nm) is closely engineered with carbon creases nested in carbon microbubbles (CMBs) which exhibit a three dimensional (3D) porous honeycomb-like network structure. As a cathode material for lithium-ion batteries (LIBs), the hybrid electrode delivers a large capacity of nearly 500 mA h g(-1) at 20 mA g(-1) (normalized to the composite, i.e. the capacity is calculated based on the total mass of the composite). Meanwhile, a durable cyclability of more than 500 cycles and a large rate of 10 A g(-1) were also realized at room temperature. The impressive specific energy/power performance (1100 W h kg(-1)/224 W kg(-1)) which is superior to that of today's Li-ion batteries (similar to 380 W h kg(-1)/similar to 80 W kg(-1)) reveals the efficiency of the novel hybrid nanostructure in speeding up the kinetics without sacrificing the storage capability. Direct insights into the lithiation process reveal that iron fluoride firstly undergoes a mild amorphization process, and then crystallizes as g-Fe nanocrystals after in-depth lithiation; during the de-lithiation process, g-Fe firstly becomes amorphous due to the injection of fluorine, and subsequently evolves into double-salt-like LixFeFy nanocrystals for further fluorine enriching. Reversible conversion between C-Fe-0/LiF and T-FeF2, like LixFe3+Fy with a 3 mole electron transfer, lasts for more than 100 cycles without any obvious re-distribution of the active materials.
机译：具有良好的比能量/功率性能的氟化铁阴极在室温下几乎不能持久地工作，这是由于导电性差和动力学迟缓。制备新颖的杂化纳米结构是获得快速扩散和传输过程的有前途的方法。在这项研究中，通过组合以下方法制造了多孔蜂窝状氟化铁杂化复合材料，该复合材料包含封装在由多尺度孔（类似于1-100 nm）构造的单独碳巢中的氟化铁纳米晶体（类似于1-4 nm）。首次实现了室温氟化和温和退火工艺。从较小的氧化铁纳米晶体前体（类似于2-3 nm）拓扑化学演化出的氟化铁与嵌套在碳微泡（CMB）中的碳折痕紧密工程化，碳微泡表现出三维（3D）多孔蜂窝状网络结构。作为锂离子电池（LIB）的正极材料，混合电极在20 mA g（-1）时可提供近500 mA hg（-1）的大容量（对复合材料进行归一化，即，该容量基于复合材料的总质量）。同时，在室温下也实现了超过500次循环的持久循环能力和10 A g（-1）的大比率。令人印象深刻的比能量/功率性能（1100 W h kg（-1）/ 224 W kg（-1））优于当今的锂离子电池（约380 W h kg（-1）/相似80 W kg（-1））揭示了新型杂化纳米结构在不牺牲储存能力的情况下加快动力学的效率。对锂化过程的直接见解表明，氟化铁首先经历了温和的非晶化过程，然后在深入的锂化之后结晶为g-Fe纳米晶体。在去锂化过程中，g-Fe首先由于注入氟而变成非晶态，然后演变成双盐状LixFeFy纳米晶体，以进一步富集氟。 C-Fe-0 / LiF和T-FeF2之间的可逆转化（例如具有3摩尔电子转移的LixFe3 + Fy）可持续100多个循环，而活性材料没有任何明显的重新分布。

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