Binder-free coaxially grown V6O13 nanobelts on carbon cloth as cathodes for highly reversible aqueous zinc ion batteries

For stable, high-capacity aqueous zinc ion batteries (AZIBs), layered metal oxides, especially with multivalent metal ions, are promising active materials (cathodes) with high operating voltages. However, when uses in batteries prepared with conventional electrode fabrication methods, these materials suffer from low electrical conductivity and high active material detachment from the current collector, leading to poor electrochemical performance. Here, we present the synthesis of ultrathin V6O13 nanobelts containing multiple valences (V4+ and V5+) grown coaxially on carbon cloth (CC) using a hydrothermal method for the first time. The ultrathin V6O13 integrated into CC shows advantages such as fast electron transfer between the active material and current collector, low active material detachment, and short diffusion length in metal ion insertion-extraction. In AZIBs, V6O13@CC displays promising reversible galvanostatic charge-discharge capacity retention during cycling with excellent rate capability. An initial specific capacity of 227 mAh g−1 is obtained at 9 A g−1 and nearly 99% is retained after 1000 cycles. This stable reversible capacity is attributed to enhanced electrical conductivity and low active material detachment from the current collector (carbon cloth). This report discusses the hydrothermal preparation of a flexible cathode on CC that is promising for high-performance aqueous metal ion batteries.