Rational design of bi-phase CaV2O6/NaV6O15 cathode materials for long-life aqueous zinc batteries

Vanadium-based compounds with various crystal structures are highly promising cathode materials for aqueous zinc-based batteries. However, their further development is limited due to the low electrical conductivity, slow zinc ion diffusion, and weak structural stability. It is a feasible strategy to resolve above mentioned issues through surface modification. Herein, we design bi-phase coexisting CaV2O6/NaV6O15 nanobelt structures with abundant interfaces, which provide more reactive sites than single-phase ones. The samples as the electrode materials deliver a specific capacity of 312 mAh g(-1) at 5 A g(-1) after 2000 cycles. They still keep a capacity of 231 mAh g(-1) at 10 A g(-1) with a cycle life of 6500 times.

Automated summary

Vanadium-based compounds with bi-phase coexisting CaV2O6/NaV6O15 nanobelt structures show enhanced electrical conductivity, improved zinc ion diffusion, and stronger structural stability, making them promising cathode materials for aqueous zinc-based batteries. The electrode materials deliver a specific capacity of 312 mAh g(-1) at 5 A g(-1) after 2000 cycles, and still maintain a capacity of 231 mAh g(-1) at 10 A g(-1) with a cycle life of 6500 times.