Defect engineering on VO2(B) nanoleaves/graphene oxide for the high performance of cathodes of zinc-ion batteries with a wide temperature range

Designing cathodes with long service life, remarkable rate capability and all-climate workable is crucial to improve the performance of aqueous zinc-ion batteries (AZIBs). Herein, we constructed a vanadium dioxide/ graphene oxide (VO2(B)/GO) sample that combines VO2 with GO through hydrothermal route and can simultaneously provide rate capability. VO2(B)/GO is rich in oxygen vacancies, which weakens the electrostatic force, and GO prevents vanadium oxidation. Density functional theory (DFT) calculations elucidate oxygen vacancies can offer more storage sites with increased reaction kinetics. The electrode exhibited a high reversible capacity of 423 mAh g-1 at 0.5 A g-1 and preserved long-life cycling properties at 15 A g-1. The presence of oxygen vacancies and GO can contribute to the excellent performance and prevent the structure of VO2 from collapsing during cycling. We successfully lit up commercial light-emitting diode (LED) lights with a VO2(B)/GO electrode. In addition, VO2(B)/GO exhibits excellent performance in all-climate conditions (-15-60 degrees C). This combinatorial design strategy provides a broadly applicable approach for durability and all-climate workable batteries.

Automated summary

In this study, a vanadium dioxide/ graphene oxide (VO2(B)/GO) sample was constructed through hydrothermal route, which exhibited remarkable rate capability. The presence of oxygen vacancies in VO2(B)/GO weakened the electrostatic force, while GO prevented vanadium oxidation. The electrode showed a high reversible capacity of 423 mAh g-1 at 0.5 A g-1 and maintained long-life cycling properties at 15 A g-1. The combination of oxygen vacancies and GO contributed to excellent performance and prevented the collapse of VO2 structure during cycling. VO2(B)/GO also exhibited excellent performance in all-climate conditions (-15-60 degrees C).