Suppr超能文献

面外离子输运使氮化多孔石墨成为锂和钠离子电池有前途的高速率阳极。

Out-of-plane ion transport makes nitrogenated holey graphite a promising high-rate anode for both Li and Na ion batteries.

机构信息

Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.

Beijing Advanced Innovation Center for Materials Genome Engineering, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China.

出版信息

Nanoscale. 2019 Oct 28;11(40):18758-18768. doi: 10.1039/c9nr06011a. Epub 2019 Oct 8.

Abstract

The search for suitable anodes with good performance is a key challenge for rechargeable Li- and Na-ion batteries (LIBs and NIBs). In this work, we adopt first-principles calculations and ab initio molecular dynamics simulations to investigate the ion transport mechanism and potential of CN stoichiometric nitrogenated holey graphite (CN-NHG) as a promising anode material for LIBs and NIBs. Although huge in-plane diffusion barriers for both Li and Na ions restrict the application of the CN-NHG monolayer as an effective anode, Li and Na ions are found to exhibit facile out-of-plane ion transport in the most stable layered AD stacking CN-NHG. The fully lithiated and sodiated cases of LiCN and NaCN show reversible specific capacities up to 587 mA h g and 353 mA h g, low chemical potentials of 0.12 V and 0.25 V, and small volume expansions of 7.16% and 13.54%, respectively. Meanwhile, the out-of-plane collective diffusion reduces Li/Na collective migration barriers to 0.23 eV and 0.18 eV. These findings suggest that AD stacking CN-NHG, with metallic properties after lithiation and sodiation processes, high specific capacity, low open circuit voltage, small volume expansion, and low collective migration barriers, has the potential to serve as a promising high-rate anode material for LIBs and NIBs with large energy density and power density. The calculations reveal that the novel out-of-plane diffusion behaviour plays a crucial role in Li/Na ion transport in holey layered materials.

摘要

寻找具有良好性能的合适阳极是可充电锂离子和钠离子电池(LIBs 和 NIBs)的关键挑战。在这项工作中,我们采用第一性原理计算和从头分子动力学模拟来研究 CN 化学计量氮掺杂多孔石墨(CN-NHG)作为 LIBs 和 NIBs 有前途的阳极材料的离子传输机制和潜力。尽管 Li 和 Na 离子在平面内的扩散势垒巨大,限制了 CN-NHG 单层作为有效阳极的应用,但我们发现 Li 和 Na 离子在最稳定的层状 AD 堆叠 CN-NHG 中表现出易于进行面外离子输运。LiCN 和 NaCN 的完全锂化和钠化情况显示出高达 587 mA h g 和 353 mA h g 的可逆比容量、0.12 V 和 0.25 V 的低化学势以及 7.16%和 13.54%的小体积膨胀。同时,面外集体扩散将 Li/Na 集体迁移势垒降低至 0.23 eV 和 0.18 eV。这些发现表明,AD 堆叠的 CN-NHG 在锂化和钠化过程后具有金属性质、高比容量、低开路电压、小体积膨胀和低集体迁移势垒,具有作为具有高能量密度和功率密度的 LIBs 和 NIBs 的有前途的高倍率阳极材料的潜力。计算表明,新型面外扩散行为在孔状层状材料中的 Li/Na 离子输运中起着至关重要的作用。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验