In situ topotactic synthesis of a porous network Zn2Ti3O8 platelike nanoarchitecture and its long-term cycle performance for a LIB anode

Abstract

This paper introduces the in situ topotactic synthesis of a porous network Zn₂Ti₃O₈ platelike nanoarchitecture via using layered H_1.07Ti_1.73O₄·H₂O (HTO) as the precursor. The introduction of H₂O₂ in the interlayer of HTO leads to access of more Zn²⁺ ions into the interlayers and the formation of the Zn²⁺ ion-exchanged product with a Zn/Ti molar ratio of 1.07 : 1.73 during ion exchange. This ion-exchanged product is in situ topotactically transformed into a Zn₂Ti₃O₈ nanoarchitecture after heat-treatment, and the [110]-crystal-axis of the Zn₂Ti₃O₈ nanoarchitecture is vertical to the basal plane of the 2D nanoarchitecture. The H₂O₂ molecule within the ion-exchanged product decomposes and escapes due to heat-treatment, resulting in the formation of a porous network structure similar to a sponge. The pore size is about 10–20 nm. Moreover, the electrochemical investigation indicates that such a porous network Zn₂Ti₃O₈ nanoarchitecture as a Li-ion battery anode has a reversible capacity of 423 mA h g⁻¹ during the 100th cycle at a current density of 100 mA g⁻¹. It is wondrous that at a current density of 1 Ag⁻¹ during 1000 cycles, its reversible capacity still remains at 408 mA h g⁻¹.