A phosphorene-graphene hybrid material as a high-capacity anode for sodium-ion batteries
A phosphorene-graphene hybrid material as a high-capacity anode for sodium-ion batteries
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DOI：
10.1038/nnano.2015.194
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发表时间：
2015-11-01
影响因子：
38.3
通讯作者：
Cui, Yi
中科院分区：
文献类型：
--
作者：
Sun, Jie;Lee, Hyun-Wook;Cui, Yi
钠离子电池作为锂离子电池的替代品最近引起了极大的关注，因为钠源不存在锂源可能存在的地缘政治问题。尽管最近关于钠离子电池阴极材料的报告已经证明其性能与锂离子电池相当，但有竞争力的钠离子电池技术的主要科学挑战是开发可行的阳极材料。在这里，我们展示了由夹在石墨烯层之间的几个磷烯层制成的混合材料显示出2的比容量，440 mA h g（-1）（仅使用磷的质量计算）在0.05A g（-1）的电流密度和83%的当在0和1.5V之间操作时100次循环后的容量保持率。使用原位透射电子显微镜和非原位X射线衍射技术，我们通过钠离子沿着磷烯层的x轴嵌入，随后形成Na 3 P合金的双重机理解释了我们的阳极的大容量。石墨烯层在混合材料中的存在用作机械主干和电气高速公路，确保合适的弹性缓冲空间适应磷烯层沿着y和z轴方向的各向异性膨胀，以实现稳定的循环操作。
Sodium-ion batteries have recently attracted significant attention as an alternative to lithium-ion batteries because sodium sources do not present the geopolitical issues that lithium sources might. Although recent reports on cathode materials for sodium-ion batteries have demonstrated performances comparable to their lithium-ion counterparts, the major scientific challenge for a competitive sodium-ion battery technology is to develop viable anode materials. Here we show that a hybrid material made out of a few phosphorene layers sandwiched between graphene layers shows a specific capacity of 2,440 mA h g(-1) (calculated using the mass of phosphorus only) at a current density of 0.05 A g(-1) and an 83% capacity retention after 100 cycles while operating between 0 and 1.5 V. Using in situ transmission electron microscopy and ex situ X-ray diffraction techniques, we explain the large capacity of our anode through a dual mechanism of intercalation of sodium ions along the x axis of the phosphorene layers followed by the formation of a Na3P alloy. The presence of graphene layers in the hybrid material works as a mechanical backbone and an electrical highway, ensuring that a suitable elastic buffer space accommodates the anisotropic expansion of phosphorene layers along the y and z axial directions for stable cycling operation.