Ion exchange for synthesis of porous CuxO/SnO2/ZnSnO3 microboxes as a high-performance lithium-ion battery anode

Abstract

Binary Sn-based metal oxides are potential anode materials for lithium ion batteries (LIBs). However, they suffer from large volume expansion during the discharge/charge process, leading to poor cycling performance. In this work, a multicomponent Cu_xO/SnO₂/ZnSnO₃ composite with a porous structure was prepared by employing ZnSn(OH)₆ microcubes as precursors with the ion exchange method. Under high temperature, Cu²⁺ can exchange with partial Zn²⁺ in ZnSn(OH)₆ to form CuSn(OH)₆ microboxes. Then, through an annealing process, the porous Cu_xO/SnO₂/ZnSnO₃ composite was obtained, which also retained the box morphology. The Cu_xO/SnO₂/ZnSnO₃ microboxes can deliver an improved capacity of 615 mA h g⁻¹ due to the porous structure, which may enhance the transportation of Li⁺ and electrons. The ion exchange method for obtaining porous binary metal oxide nanomaterials can be used for fabricating other metal oxide composites in many areas such as LIBs, catalysts, etc.