Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors
Two-Dimensional Vanadium Carbide (MXene) as Positive Electrode for Sodium-Ion Capacitors
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DOI：
10.1021/acs.jpclett.5b00868
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发表时间：
2015-06-18
影响因子：
5.7
通讯作者：
Simon, Patrice
中科院分区：
文献类型：
--
作者：
Dall'Agnese, Yohan;Taberna, Pierre-Louis;Simon, Patrice
离子电容器通过将阳离子以比电池更快的速率嵌入电极中并且在更大的电势窗口内存储能量。与电化学双层电容器相比，这些装置达到更高的能量密度。锂离子电容器已经商业化生产，但钠离子电容器的发展受到缺乏允许钠离子快速嵌入的材料的阻碍。在这里，我们研究了来自MXene家族的2D碳化钒V2 C的电化学行为。我们通过XRD研究了Na嵌入的机理，并在0.2 mV/s下获得了接近100 F/g的电容。我们用硬碳作为负极组装了全电池，硬碳是用于Na离子电池的已知阳极材料，并且在最大电池电压为3.5V的情况下实现了50 mAh/g的容量。
Ion capacitors store energy through intercalation of cations into an electrode at a faster rate than in batteries and within a larger potential window. These devices reach a higher energy density compared to electrochemical double layer capacitor. Li-ion capacitors are already produced commercially, but the development of Na-ion capacitors is hindered by lack of materials that would allow fast intercalation of Na-ions. Here we investigated the electrochemical behavior of 2D vanadium carbide, V2C, from the MXene family. We investigated the mechanism of Na intercalation by XRD and achieved capacitance of similar to 100 F/g at 0.2 mV/s. We assembled a full cell with hard carbon as negative electrode, a known anode material for Na ion batteries, and achieved capacity of 50 mAh/g with a maximum cell voltage of 3.5 V.