Pillaring Effect of K Ion Anchoring for Stable V₂O₅‐Based Zinc‐Ion Battery Cathodes

Abstract

Abstract Aqueous zinc‐ion batteries (ZIBs) have attracted widespread attention due to their advantages in safety and environmental benignity. However, achieving a cathode material with stable electrochemical performance for such a system remains an ongoing challenge. Herein, a K 0.5 V 2 O 5 cathode has been designed and synthesized by intercalating of K + into V 2 O 5 , thus constructing a stable crystal structure by forming chemical bonds between V 2 O 5 layers. The successful intercalation of K + has been confirmed by a series of experimental tests and Vienna Ab‐initio Simulation Package simulation. These layer‐interlinking chemical bonds act as “pillars” to strongly hold the V 2 O 5 layers together and protect them from dissolution. Furthermore, the K 0.5 V 2 O 5 electrode also exhibits excellent durability (about 150 mA h g −1 at 5 A g −1 after 3000 cycles). More impressively, even after standing for three days in the solution of 3 M ZnSO 4 electrolyte, the K 0.5 V 2 O 5 electrode still maintains a high capacity of 92.2 mA h g −1 after 150 cycles, demonstrating its outstanding stability and tolerance in such aqueous electrolyte.