The utilization of vanadium from spent catalysts for preparation of layered K0.51V2O5 as aqueous-based potassium ion cathodes

The accumulation of spent selective catalytic reduction (SCR) catalysts has resulted in a huge loss of metal resources. Among them, regenerating vanadium (V) from spent SCR catalysts for the preparation of energy storage materials represent a promising direction. Herein, we proposed a wet method to recover V and further synthesized layered materials (K_0.51V₂O₅) as cathodes for aqueous-based potassium ion batteries. To help better improve the electrochemical performance, (potassium chloride (KCl) and potassium trifluoromethanesulfonate (KOTf)) were employed as the electrolytes. As results, the cells could deliver a high specific capacity of 109.7 mAh g⁻¹ in 3 M KOTf electrolyte, which is far beyond than those in KCl electrolytes. Furthermore, the molecular dynamic simulations and spectroscopic analysis indicated that strong cation anion interactions could be observed in concentrated KOTf electrolytes, which could weaken water molecule hydrogen bonds and contribute to the formation of salt derived solid electrolyte interphase.