An amorphous tin-based nanohybrid for ultra-stable sodium storage

The natural abundance of sodium resources makes sodium-ion batteries a potential and promising alternative to lithium ion battery technology for large-scale energy storage application. However, the long-term stability of sodium ion batteries is largely hindered by the widely employed crystalline electrode materials, for example tin-based compounds, because of their structural degradation and pulverization during cycling. Herein, an ultra-stable sodium ion battery anode material by rationally manipulating a crystalline tin-based compound into an amorphous structure is reported for the first time. Typically, a phosphorus-containing monomer is polymerized on tin oxide quantum dots dispersed on graphene oxide nanosheets, further mediating the formation of a stable and amorphous tin-based hybrid at elevated temperatures. The robust cyclability and structural stability are well demonstrated by performance evaluation and ex situ characterization. The unique structural design proposed here may open up new avenues for developing advanced metal oxide anode materials for sodium ion batteries.