Amorphous Bimetallic Co3Sn2 Nanoalloys Are Better Than Crystalline Counterparts for Sodium Storage

作者：Zhu Jian; Deng Da^*

来源：Journal of Physical Chemistry C, 2015, 119(37): 21323-21328.

DOI：10.1021/acs.jpcc.5b05232

Sodium-ion batteries are considered as a promising alternative to replace the existing lithium-ion batteries for energy storage due to the benefits of low cost and safety. However, it is still challenging to develop suitable electrode materials for reversible storage of sodium. Metal anodes have high capacity for sodium storage but suffer the issue of poor cyclability due to pulverization caused by large volume variation and electrode disintegration. To address this issue, amorphous bimetallic active inactive nanoalloy Co-Sn with Sn acting as a high capacity active compound and Co acting as a conductive inactive matrix has been explored here. We demonstrated that amorphous nanoalloys exhibited superior electrochemical performances as compared to the low-crystalline and crystalline counterpart nanoalloys as negative electrode materials for sodium-ion batteries. The degree of crystallinity has negative effects on electrochemical performances. The improved performance of amorphous nanoalloys could be attributed to the easy accessibility for sodium ions, strain accommodation, and defect sites to host sodium ions.

• 出版日期2015-9-17