Olchowka Jacob, Nguyen Long H B, Petit Emmanuel, Camacho Paula Sanz, Masquelier Christian, Carlier Dany, Croguennec Laurence
CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB UMR 5026, F-33600, Pessac, France.
RS2E, Réseau Français sur le Stockage Electrochimique de l'Energie, FR CNRS 3459, F-80039 Amiens Cedex 1, France.
Inorg Chem. 2020 Dec 7;59(23):17282-17290. doi: 10.1021/acs.inorgchem.0c02546. Epub 2020 Nov 13.
Polyanionic NaV(PO)FO has been successfully prepared for the first time by ionothermal reaction in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI) ionic liquid. Its structure and elemental stoichiometry are confirmed by X-ray diffraction, NMR spectroscopy, and ICP-OES, respectively. Furthermore, the scanning electron microscopy reveals that the as-obtained material possesses an original platelet-like morphology. A topochemical reaction mechanism is proposed to explain the formation of the 3D framework of NaV(PO)FO from layered compound α-VOPO·2HO. Galvanostatic electrochemical tests indicate a modification of the desodiation and sodiation mechanism of the as-prepared NaV(PO)FO compared to those synthesized by conventional solid-state approaches. Furthermore, the electrochemical performance of NaV(PO)FO obtained at different cycling rates is also discussed.
通过在1-乙基-3-甲基咪唑双（三氟甲基磺酰）亚胺（EMIM TFSI）离子液体中进行离子热反应，首次成功制备了聚阴离子型NaV(PO)FO。分别通过X射线衍射、核磁共振光谱和电感耦合等离子体发射光谱法确定了其结构和元素化学计量比。此外，扫描电子显微镜显示，所获得的材料具有原始的片状形态。提出了一种拓扑化学反应机理来解释由层状化合物α-VOPO·2HO形成NaV(PO)FO的三维骨架。恒电流电化学测试表明，与通过传统固态方法合成的材料相比，所制备的NaV(PO)FO的脱钠和钠化机理有所改变。此外，还讨论了在不同循环速率下获得的NaV(PO)FO的电化学性能。
