Effects of Small Molecule Interlayer Engineering in Vanadium Oxide for Zinc Ion Battery

Vanadium oxide has great potential in the development of battery technology. However, there are several key flaws, such as low rate performance and poor cyclic stability, that require urgent attention for such material. In view of these challenges, this work proposes a strategy to optimize the interlayer spacing of vanadium oxide framework so as to improve its electrochemical performance. In this work, vanadium-oxide is modified with small molecules as molecular pillars, and through this method the as-prepared NH₄V₄O₁₀ is able to exhibit a larger interlayer spacing of 9.6 Å. This expanded interlayer spacing is particularly advantageous as it allows host material to accommodate more Zn²⁺ and to facilitate their migration. The as-assembled Zn//NH₄V₄O₁₀ (denoted as NVO) is able to deliver a capacity of 430 mAh g⁻¹ at current density of 1 A g⁻¹. A good cyclic retention of 85 % is achieved for Zn//NVO after deep cycling for 2000 cycles at 1 A g⁻¹. Thus, based on the collective results, introducing small molecules into the interlayer spacing could be an advantageous strategy in improving the performance of the electrode effectively.