A phosphorene-graphene hybrid material as a high-capacity anode for sodium-ion batteries

作者：Sun, Jie; Lee, Hyun-Wook; Pasta, Mauro; Yuan, Hongtao; Zheng, Guangyuan; Sun, Yongming; Li, Yuzhang; Cui, Yi^*

来源：Nature Nanotechnology, 2015, 10(11): 980-U184.

DOI：10.1038/NNANO.2015.194

• SOLID-ELECTROLYTE INTERPHASE
• BLACK PHOSPHORUS
• RECHARGEABLE BATTERIES
• NEGATIVE ELECTRODE
• LITHIUM-ION
• COMPOSITE
• INSERTION
• GRAPHITE
• STORAGE
• RAMAN

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.

• 出版日期2015-11