Optimizing the Spin States of Mesoporous Co3O4 Nanorods through Vanadium Doping for Long-Lasting and Flexible Rechargeable Zn-Air Batteries

High-performance rechargeable Zn-air batteries with long-life stability are highly desirable for the power application in electric vehicles and portable electronics for their great balance in capacity and safety. The key component of the Zn-air batteries is the bifunctional oxygen electrocatalyst that requires high intrinsic reversibility and durability. Spinel Co3O4 emerges as a promising nonprecious-metal catalyst for oxygen catalysis but limited by the inefficient catalytic performance with an undesirable e(g)(0) configuration of Co3+ ions at the octahedral sites. Herein, a mesoporous vanadium-doped Co3O4 (V-Co3O4) electrocatalyst is developed, with an optimized e(g) occupancy of 1.010. By optimizing the spin states of Co3O4 through V-doping, V-Co3O4 exhibits a great bifunctional property that even outperforms Pt-IrO2. As a demonstration, both a liquid-state rechargeable Zn-air battery and an all-solid-state flexible cable-type Zn-air battery are fabricated using the V-Co3O4 electrocatalysts, offering a promising power source for the next-generation electronics.

Automated summary

The vanadium-doped Co3O4 (V-Co3O4) electrocatalyst shows enhanced oxygen electrocatalysis efficiency by optimizing the spin states, demonstrating superior bifunctional properties. Zinc-air batteries fabricated with V-Co3O4 electrocatalysts offer a promising power source for next-generation electronics.