高等学校化学学报 ›› 2025, Vol. 46 ›› Issue (3): 20240449.doi: 10.7503/cjcu20240449

• 材料化学 • 上一篇    下一篇

镁在Zr-Ti-Mg-Ni-Mn-V-Fe高熵合金中的原子占位及对储氢性能的影响

陈治中, 尹福虎, 胡泊涛, 斯庭智()   

  1. 安徽工业大学材料科学与工程学院,马鞍山 243002
  • 收稿日期:2024-09-27 出版日期:2025-03-10 发布日期:2024-12-14
  • 通讯作者: 斯庭智 E-mail:tzsiahut@163.com
  • 基金资助:
    安徽省高校自然科学研究重大项目(KJ2020ZD26)

Atomic Occupation of Mg in Zr-Ti-Mg-Ni-Mn-V-Fe High-entropy Alloy and Its Effect on Hydrogen Storage Property

CHEN Zhizhong, YIN Fuhu, HU Botao, SI Tingzhi()   

  1. School of Materials Science and Engineering,Anhui University of Technology,Maanshan 243002,China
  • Received:2024-09-27 Online:2025-03-10 Published:2024-12-14
  • Contact: SI Tingzhi E-mail:tzsiahut@163.com
  • Supported by:
    the Key Natural Science Research Foundation of Education Department of Anhui Province, China(KJ2020ZD26)

摘要:

通过Mg的添加, 设计制备了3种A原子过计量的AB2型Zr0.85Ti0.15Mg x Ni1.20Mn0.56V0.12Fe0.12(x=0.20, 0.25, 0.30)高熵合金, 探究了Mg添加量及其原子占位对储氢性能的影响. 结果表明, 所有合金均为C15 Laves单相结构, 当x从0.20增至0.30时, 合金的储氢量由0.35%(质量分数)显著提升至1.03%; 合金具有优良的热力学性能, 其中, Mg0.30合金的放氢焓变(ΔHd)仅为28.93 kJ/mol; Mg0.30合金的放电容量为167.0 mA·h/g, 30次充放电循环后容量保持率为80.9%, 展现了较好的电化学储氢性能. Rietveld全谱拟合结果揭示, Mg原子既占据Laves相A原子的8a位置, 又占据B原子的16d位置; 随着x的增加, 8a位置的占位因子(g)保持恒定, 而16d位置的g增加. 这一结果不仅导致合金四面体间隙的增大, 还促进了对氢强亲和力的四面体间隙的形成, 从而显著提高了合金的储氢能力.

关键词: 高熵合金, Laves相, 原子占位, 储氢性能, 四面体间隙

Abstract:

In this study, A atom overstoichiometric AB2-type high-entropy alloys of the composition Zr0.85Ti0.15Mg x Ni1.20Mn0.56V0.120Fe0.12x=0.20, 0.25, 0.30) were designed and synthesized by adding magnesium(Mg). The impact of Mg atomic occupation on the hydrogen storage properties was investigated. The results showed that all the alloys formed a single C15 Laves phase. Notably, the hydrogen storage capacity increased significantly, from 0.35%(mass fraction) for the alloy with x=0.20 to 1.03% for the alloy with x=0.30. The alloys also exhibited excellent thermodynamic properties, with the Mg0.30 alloy achieving a low hydrogen desorption enthalpy(ΔHd=28.93 kJ/mol). Furthermore, the Mg0.30 alloy demonstrated good electrochemical performance, with a discharge capacity of 167.0 mA·h/g and a capacity retention of 80.9% after 30 charge-discharge cycles. X-ray diffraction(XRD) Rietveld refinement revealed that Mg atoms occupy the 8a and 16d sites in the Laves phase. As x increased, the occupation factor(g) at the 8a site remained constant, while g at the 16d site increased, leading to an expansion of the tetrahedral volume in the alloys. This structural change promoted the formation of tetrahedral interstitials with a strong affinity for hydrogen, which significantly enhanced the hydrogen storage capacity.

Key words: High-entropy alloy, Laves phase, Atomic occupation, Hydrogen storage property, Tetrahedral interstitial

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