Construction of sodium-poor and oxygen defect-rich vanadium oxide nanobelts for high-performance aqueous zinc-ion batteries

Although the enhancement of the zinc storage performance of layered vanadium oxides can be realized by the ionic pre-intercalation strategy, it also occupies a large number of active sites and thus fails to release the full potential of vanadium oxides. Here, vanadium oxide nanobelts with sodium-poor and oxygen defect-rich were constructed by regulating the content of pre-embedded sodium ions to strike a balance between pre-embedded ions and structural stability. The introduction of trace sodium ions not only increases the spacing of vanadium oxide layers but also occupies as few active sites as possible, which provides the possibility of massive storage, rapid diffusion and stabilization of the host structure for zinc ions. Moreover, the abundant oxygen defects transform the ion transport pathway from two-dimensional to three-dimensional, which greatly improves the ion transport rate in the host phase. Due to these advantages, the synthesized vanadium oxide nanobelts exhibit remarkable electrochemical properties, and this work provides a new idea for the design of structurally stable layered vanadium oxides with excellent properties.