A Hierarchical SnO 2 @Ni 6 MnO 8 Composite for High-Capacity Lithium-Ion Batteries.

Semiconductor-based composites are potential anodes for Li-ion batteries, owing to their high theoretical capacity and low cost. However, low stability induced by large volumetric change in cycling restricts the applications of such composites. Here, a hierarchical SnO@NiMnO composite comprising NiMnO nanoflakes growing on the surface of a three-dimensional (3D) SnO is developed by a hydrothermal synthesis method, achieving good electrochemical performance as a Li-ion battery anode. The composite provides spaces to buffer volume expansion, its hierarchical profile benefits the fast transport of Li ions and electrons, and the NiMnO coating on SnO improves conductivity. Compared to SnO, the NiMnO coating significantly enhances the discharge capacity and stability. The SnO@NiMnO anode displays 1030 mAh g at 0.1 A g and exhibits 800 mAh g under 0.5 A g, along with high Coulombic efficiency of 95%. Furthermore, stable rate performance can be achieved, indicating promising applications.