Matsumoto Naoyuki, Oshima Azusa, Yumura Motoo, Hata Kenji, Futaba Don N
National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
Nanoscale Res Lett. 2020 Oct 2;15(1):195. doi: 10.1186/s11671-020-03408-8.
We report an approach to fabricate high conductivity graphite sheets based on a heat-and-current treatment of filtrated, exfoliated graphite flakes. This treatment combines heating (~ 900 °C) and in-plane electrical current flow (550 A·cm) to improve electrical conductivity through the reduction of crystalline defects. This process was shown to require only a 1-min treatment time, which resulted in a 2.1-fold increase in electrical conductivity (from 1088 ± 72 to 2275 ± 50 S·cm). Structural characterization by Raman spectroscopy and X-ray diffraction indicated that the improvement electrical conductivity originated from a 30-fold improvement in the crystallinity (Raman G/D ratio increase from 2.8 to 85.3) with no other observable structural transformations. Significantly, this treatment was found to act uniformly across a macroscopic (10 mm) sheet surface indicating it is on the development of applications, such as electrodes for energy generation and storage and electromagnetic shielding, as well as on the potential for the development of large-scale treatment technologies.
我们报道了一种基于对过滤后的片状膨胀石墨进行热电流处理来制备高导电性石墨片的方法。这种处理结合了加热（约900°C）和面内电流（550 A·cm），通过减少晶体缺陷来提高电导率。该过程显示仅需1分钟的处理时间，就能使电导率提高2.1倍（从1088±72提高到2275±50 S·cm）。拉曼光谱和X射线衍射的结构表征表明，电导率的提高源于结晶度提高了30倍（拉曼G/D比从2.8增加到85.3），且没有其他可观察到的结构转变。值得注意的是，发现这种处理在宏观（10毫米）的片材表面上均匀起作用，这表明它在诸如能量产生和存储电极以及电磁屏蔽等应用开发方面，以及大规模处理技术的开发潜力方面都具有应用前景。
