Na2Mn(SO4)2·4H2O和Na2Ni(SO4)2·10H2O的结构和热性能,RSC Advances

当前位置： X-MOL 学术 › RSC Adv. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Na2Mn(SO4)2·4H2O和Na2Ni(SO4)2·10H2O的结构和热性能
RSC Advances ( IF 3.9 ) Pub Date : 2020-3-11 , DOI: 10.1039/d0ra00301h
Hamdi Ben Yahia ₁ , Alaa Alkhateeb ₁ , Rachid Essehli ₂

Affiliation

标题化合物通过湿化学途径制备，它们的晶体结构由单晶 X 射线衍射数据确定。Na ₂ Mn(SO ₄ ) ₂ ·4H ₂ O 结晶具有单斜对称性，空间群P 2 ₁ / c，a = 5.5415(2), b = 8.3447(3), c = 11.2281(3) Å, β = 100.172(1)°, V = 511.05(3) Å ³和Z = 2. Na ₂ Ni(SO ₄ ) ₂ ·10H ₂O 也以单斜对称、空间群P 2 ₁ / c结晶，a = 12.5050(8), b = 6.4812(4), c = 10.0210(6) Å, β = 106.138(2)°, V = 780.17 (8) Å ³和Z = 2。Na ₂ Mn(SO ₄ ) ₂ ·4H ₂ O 是勃洛狄特族化合物的新成员，而Na ₂ Ni(SO ₄ ) ₂ ·10H ₂ O 与Na 同构₂ Mg(SO ₄ ) ₂ ·10H₂ O. Na₂ Mn(SO₄ )₂ ·4H₂ O的结构是由[Mn(SO₄ )₂ (H₂ O)₄ ]²⁻结构单元通过适度的O-H⋯O氢键连接而成的钠原子占据沿a轴的大隧道，锰原子位于反转中心，而Na₂ Ni(SO₄ )₂ ·10H₂ O的结构由[Ni(H₂ O)₆ ]²⁺和 [Na₂ (SO₄ )₂ (H₂ O)₄ ]^2-层。这些平行于 (100) 平面的层通过适度的 O-H⋯O 氢键相互连接。热重分析和粉末 X 射线衍射分析表明，只有镍相几乎是纯的。在 300 °C 以上的温度下，所有水分子蒸发，结构相变由P 2₁ / c -Na₂ Ni(SO₄ )₂ ·10H₂ O 转变为C 2/ c -Na₂ Ni(SO₄ )观察到_{2 个。}C 2/c -Na ₂ Ni(SO ₄ ) ₂比Na ₂ Fe(SO ₄ ) ₂热稳定性更高，因此如果开发出稳定的高压电解液，它将适合作为钠离子电池的正极。

"点击查看英文标题和摘要"

Structural and thermal properties of Na2Mn(SO4)2·4H2O and Na2Ni(SO4)2·10H2O

The title compounds were prepared via a wet chemistry route and their crystal structures were determined from single crystal X-ray diffraction data. Na₂Mn(SO₄)₂·4H₂O crystallizes with a monoclinic symmetry, space group P2₁/c, with a = 5.5415(2), b = 8.3447(3), c = 11.2281(3) Å, β = 100.172(1)°, V = 511.05(3) Å³ and Z = 2. Na₂Ni(SO₄)₂·10H₂O also crystallizes with a monoclinic symmetry, space group P2₁/c, with a = 12.5050(8), b = 6.4812(4), c = 10.0210(6) Å, β = 106.138(2)°, V = 780.17(8) Å³ and Z = 2. Na₂Mn(SO₄)₂·4H₂O is a new member of the blödite family of compounds, whereas Na₂Ni(SO₄)₂·10H₂O is isostructural with Na₂Mg(SO₄)₂·10H₂O. The structure of Na₂Mn(SO₄)₂·4H₂O is built up of [Mn(SO₄)₂(H₂O)₄]²⁻ building blocks connected through moderate O–H⋯O hydrogen bonds with the sodium atoms occupying the large tunnels along the a axis and the manganese atom lying on an inversion center, whereas the structure of Na₂Ni(SO₄)₂·10H₂O is built up of [Ni(H₂O)₆]²⁺ and [Na₂(SO₄)₂(H₂O)₄]²⁻ layers. These layers which are parallel to the (100) plane are interconnected through moderate O–H⋯O hydrogen bonds. The thermal gravimetric- and the powder X-ray diffraction-analyzes showed that only the nickel phase was almost pure. At a temperature above 300 °C, all the water molecules evaporated and a structural phase transition from P2₁/c-Na₂Ni(SO₄)₂·10H₂O to C2/c-Na₂Ni(SO₄)₂ was observed. C2/c-Na₂Ni(SO₄)₂ is thermally more stable than Na₂Fe(SO₄)₂ and therefore it would be suitable as the positive electrode for sodium ion batteries if a stable electrolyte at high voltage is developed.

更新日期：2020-03-11

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南