Synthesis of Hierarchical V2O5?Hydrate Composite Micronanostructures as Cathode Materials for Aqueous Zinc- ion Batteries with Good Performance

摘要

It is important to discover novel electrode materials and optimize the performance of existing cathode materials for aqueous zinc-ion batteries. Here, two V2O5·3H2O composites are achieved via a facile hydrothermal route. One is flake-like V2O5·3H2O built up with multiple platelets with surface defects in parallel or normal positions, and the other is V2O5·3H2O composite microflowers built up with multilayered microplatelets in a radial position without surface defects. Both can be used as cathode materials for aqueous zinc-ion batteries. The former showed higher discharge capacity and better rate performance. The electrode of V2O5·3H2O flakes exhibits stable discharge capacity at current densities of 50, 100, 250, 500, 750, 1000, 1500 and 50 mAg-1 . The capacity retention is 90.3% after 80 cycles from 237.2 mAhg-1 to 214.1 mAhg-1 . While V2O5·3H2O microflowers do not exhibit stable discharge capacity at current densities of 50, 100, 250, 500, 750, 1000, 1500 and 50 mAg-1 . The capacity retention is 47.96% after 80 cycles from 223.9 mAhg-1 to 107.4 mAhg-1 . The difference in cycling performance can be ascribed to surface defects and different compositions.