Development of a water based process for stable conversion cathodes on the basis of FeF3
Development of a water based process for stable conversion cathodes on the basis of FeF3
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DOI：
10.1016/j.jpowsour.2016.02.080
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发表时间：
2016-05
影响因子：
9.2
通讯作者：
A. Pohl;M. Faraz;A. Schröder;M. Baunach;W. Schabel;A. Guda;V. Shapovalov;A. Soldatov;V. Chakravadhanula;C. Kübel;R. Witte;H. Hahn;T. Diemant;R. Behm;H. Emerich;M. Fichtner
中科院分区：
文献类型：
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作者：
A. Pohl;M. Faraz;A. Schröder;M. Baunach;W. Schabel;A. Guda;V. Shapovalov;A. Soldatov;V. Chakravadhanula;C. Kübel;R. Witte;H. Hahn;T. Diemant;R. Behm;H. Emerich;M. Fichtner
以氧化石墨烯为前驱体，采用球磨法制备了FeF 3纳米粒子，并以其为前驱体，发展了一种简便的水基合成HTB-FeF 3/rGO和r-FeF 3/rGO复合材料的方法。HTB-FeF 3/rGO电极在环境空气中浇铸，并且压延电极在1.3-4.3 V范围内100次循环后显示出470 Wh kg-1（210 mA h g-1，12 mA g-1）的稳定比能量，具有非常小的容量衰减。良好的循环稳定性归因于FeF 3纳米颗粒与还原氧化石墨烯碳周围的紧密接触。结合原位XRD、XAS和非原位穆斯堡尔谱，我们发现HTB-FeF 3/rGO复合材料在放电过程中Li快速嵌入HTB-FeF 3结构的隧道中，tox= 0.92 Li。Li嵌入之后，HTB-LixFeF 3在低于2.0V下缓慢转化为LiF和Fe纳米颗粒。在充电过程中，LiF和Fe相缓慢转变为非晶FeF 2和FeF 3相，HTB-FeF 3骨架结构没有重新形成。在55 °C的高温下，获得了780 Wh kg− 1的高得多的比能量。
A facile water based synthesis method for HTB-FeF3/rGO andr-FeF3/rGO composites was developed using FeF3nanoparticles prepared by ball-milling and aqueous graphene oxide precursor. Electrodes of HTB-FeF3/rGO were cast in ambient air and the calendered electrode shows a stable specific energy of 470 Wh kg−1(210 mA h g−1, 12 mA g−1) after 100 cycles in the range 1.3–4.3 V with very little capacity fading. The good cycle stability is attributed to the intimate contact of FeF3nanoparticles with reduced graphene oxide carbon surrounding. Using a combination of in situ XRD, XAS and ex situ Mössbauer spectroscopy, we show that during discharge of HTB-FeF3/rGO composite Li is intercalated fast into the tunnels of the HTB-FeF3structure up tox= 0.92 Li. The Li intercalation is followed by slow conversion of HTB-LixFeF3to LiF and Fe nanoparticles below 2.0 V. During charge, the LiF and Fe phases are slowly transformed to amorphous FeF2and FeF3phases without reformation of the HTB-FeF3framework structure. At an elevated temperature of 55 °C a much higher specific energy of 780 Wh kg−1was obtained.