Self-decorated Cu_2-xSe nanosheets as anode materials for Li ion batteries and electrochemical hydrogen storage

Hierarchical self-decorated Cu_2-xSe nanosheets were synthesized through a facile solvothermal route in a binary solution of ethylene glycol and distilled water in the absence of a template. The X-ray diffraction (XRD), scanning electron microscope (SEM), and high-resolution transmission electron microscopy (HRTEM) analyses identified that the as-prepared Cu_2-xSe nanosheets were single-crystalline decorated by Cu_2-xSe nanodots. Based on the time-dependence experiment, the reaction and growth process was discussed in detail. Furthermore, the electrochemistry Li and hydrogen storage properties of the hierarchical self-decorated Cu_2-xSe nanosheets were measured. This hierarchical self-decorated Cu_2-xSe nanosheet showed a good cycle and rate performance, indicating its potential application as an anode material for lithium ion batteries. The good cycle and rate performance may be attributed to the unique hierarchical morphology which can buffer the volume change to some degree during the discharging/charging process.