Anisotropic Growth of Al-Intercalated Vanadate by Tuning Surface Hydrophilicity for High-Rate Zn Ion Storage

Aqueous zinc ion battery (ZIB) cathodes with high rate performance are still lacking due to the sluggish kinetics of Zn2+ insertion. Here, preferential two dimensional (2D) spreading surface is constructed on conductive carbon paper supports by disclosing hierarchical porous structures. The unique surface hydrophilicity enables anisotropic growth of layered Al-intercalated vanadate nanobelts with high-aspect ratios. As a cathode of ZIB, the pre-intercalated vanadate nanobelts with a large interlayer spacing (1.38 nm) exhibit high specific capacities and excellent rate performance (534 and 221 mA h g-1 at 1 and 20 A g-1, respectively). Moreover, chemically resistant HfO2 layers have been applied by atomic layer deposition to prevent effectively the cathode from degradation, leading to an outstanding cycling stability (88% retention at 1000 cycle). The anisotropic growth of 2D electrode materials by tuning the surface hydrophilicity provides an effective pathway for designing improved electrode materials for various energy storage technologies.