Schmitz Alexa, Schütte Kai, Ilievski Vesko, Barthel Juri, Burk Laura, Mülhaupt Rolf, Yue Junpei, Smarsly Bernd, Janiak Christoph
Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, 40204 Düsseldorf, Germany.
Gemeinschaftslabor für Elektronenmikroskopie RWTH-Aachen, Ernst Ruska-Centrum für Mikroskopie und Spektroskopie mit Elektronen, D-52425 Jülich, Germany.
Beilstein J Nanotechnol. 2017 Nov 22;8:2474-2483. doi: 10.3762/bjnano.8.247. eCollection 2017.
Metal-fluoride nanoparticles, (MF -NPs) with M = Fe, Co, Pr, Eu, supported on different types of thermally reduced graphite oxide (TRGO) were obtained by microwave-assisted thermal decomposition of transition-metal amidinates, (M{MeC[N(iPr)]} ) or [M(AMD) ] with M = Fe(II), Co(II), Pr(III), and tris(2,2,6,6-tetramethyl-3,5-heptanedionato)europium, Eu(dpm), in the presence of TRGO in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF]). The crystalline phases of the metal fluorides synthesized in [BMIm][BF] were identified by powder X-ray diffraction (PXRD) to be MF for M = Fe, Co and MF for M = Eu, Pr. The diameters and size distributions of MF @TRGO were from (6 ± 2) to (102 ± 41) nm. Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) were used for further characterization of the MF -NPs. Electrochemical investigations of the FeF-NPs@TRGO as cathode material for lithium-ion batteries were evaluated by galvanostatic charge/discharge profiles. The results indicate that the FeF-NPs@TRGO as cathode material can present a specific capacity of 500 mAh/g at a current density of 50 mA/g, including a significant interfacial charge storage contribution. The obtained nanomaterials show a good rate capacity as well (220 mAh/g and 130 mAh/g) at a current density of 200 and 500 mA/g, respectively.
通过在离子液体1-丁基-3-甲基咪唑四氟硼酸盐（[BMIm][BF₄]）中，在热还原氧化石墨烯（TRGO）存在的情况下，对过渡金属脒基化合物（M{MeC[N(iPr)]₂} 或 [M(AMD)₃]，其中M = Fe(II)、Co(II)、Pr(III)）以及三（2,2,6,6-四甲基-3,5-庚二酮）铕（Eu(dpm)）进行微波辅助热分解，获得了负载在不同类型热还原氧化石墨烯（TRGO）上的金属氟化物纳米颗粒（MFₓ-NPs，其中M = Fe、Co、Pr、Eu）。通过粉末X射线衍射（PXRD）确定在[BMIm][BF₄]中合成的金属氟化物的晶相，对于M = Fe、Co为MF₂，对于M = Eu、Pr为MF₃。MFₓ@TRGO的直径和尺寸分布为(6 ± 2)至(102 ± 41) nm。能量色散X射线光谱（EDX）和X射线光电子能谱（XPS）用于对MFₓ-NPs进行进一步表征。通过恒电流充放电曲线评估了FeF₂-NPs@TRGO作为锂离子电池阴极材料的电化学性能。结果表明，FeF₂-NPs@TRGO作为阴极材料在电流密度为50 mA/g时可呈现500 mAh/g的比容量，包括显著的界面电荷存储贡献。所获得的纳米材料在电流密度分别为200和500 mA/g时也显示出良好的倍率性能（分别为220 mAh/g和130 mAh/g）。
