Boosting Zinc-Ion Storage Capability by Effectively Suppressing Vanadium Dissolution Based on Robust Layered Barium Vanadate.

Vanadium-based compounds with an open framework structure have become the subject of much recent investigation into aqueous zinc-ion batteries (AZIBs) due to high specific capacity. However, there are some issues with vanadium dissolution from a cathode framework as well as the generation of byproducts during discharge that should not be ignored, which could cause severe capacity deterioration and inadequate cycle life. Herein, we report several barium vanadate nanobelt cathodes constructed of two sorts of architectures, i.e., Ba1.2V6O16·3H2O and BaV6O16·3H2O (V3O8-type) and BaxV2O5·nH2O (V2O5-type), which are controllably synthesized by tuning the amount of barium precursor. Benefiting from the robust architecture, layered BaxV3O8-type nanobelts (Ba1.2V6O16·3H2O) exhibit superior rate capability and long-term cyclability owing to fast zinc-ion kinetics, enabled by efficiently suppressing cathode dissolution as well as greatly eliminating the generation of byproduct Zn4SO4(OH)6·xH2O, which provides a reasonable strategy to engineer cathode materials with robust architectures to improve the electrochemical performance of AZIBs.