Botryoidalis hollow Zn₂SnO₄ boxes@graphene as anode materials for advanced lithium-ion batteries

Hollow Zn₂SnO₄@graphene (GN) composites are synthesized after the calcined process of precursor ZnSn(OH)₆@GO, which are prepared by a simple co-precipitation and alkali etching method. The hollow boxes are supported by the flexible graphene sheets and the sheets stack on each other to form the botryoidalis Zn₂SnO₄@GN composites. Compared with solid (hollow) Zn₂SnO₄ cubes (boxes), hollow Zn₂SnO₄@GN composites show an enhanced electrochemical performance (752.9 mA h g^-1 at a current density of 300 mA g^-1 after 45 cycles) and high rate capability. The volume expansion and contraction of Zn₂SnO₄ can be effectively buffered by the two strategies, hollow inner and flexible GN. With rational and delicate design, this kind of composites may be potential anode materials for lithium-ion batteries.