Strongly coupled tungsten oxide/carbide heterogeneous hybrid for ultrastable aqueous rocking-chair zinc-ion batteries

Aqueous Zinc-ion batteries (ZIBs) are recognized as the most pivotal competitor of lithium-ion batteries due to their abundant reserves, remarkable safety and affordable cost. However, the uncontrollable dendritic growth and extremely low utilization (<5%) of zinc metal anode severely limit the practicality and energy density of ZIBs. Herein, a novel rocking-chair ZIBs with excellent cycling stability and high energy density is developed via employing tungsten oxide/carbide (WO3/WC) layered heterogeneous hybrid with strong-coupling effect as the intercalated anode and MnO2/graphite cathode. Benefiting from the favorable interface energy and electronic coupling with prominent charge-transfer between WO3 and WC, the WO3/WC//Zn batteries deliver admirable capacity of 164 mAh g(-1) under 0.1 A g(-1) with suitable Zn2+ intercalated potential of 0.43 V (vs. Zn2+/Zn), long-term cyclability with 90.2% after 1000 cycles under 1 A g(-1), and reversible Zn2+ intercalation behavior. Consequently, the assembled WO3/WC parallel to MnO2/graphite rocking-chair ZIBs offer excellent capacity of 69 mAh g(-1) at 0.1 A g(-1), impressive cyclic stability (100% after 10,000 cycles) and exceptional energy density of 85 Wh kg(-1), suppressing most of reported rocking-chair ZIBs. Therefore, this research provides a novel insight for designing safe and high-efficient ZIBs.

Automated summary

A novel rocking-chair ZIBs with excellent cycling stability and high energy density is developed by employing tungsten oxide/carbide (WO3/WC) layered heterogeneous hybrid as the intercalated anode and MnO2/graphite cathode. The batteries deliver admirable capacity and long-term cyclability, offering excellent capacity, cyclic stability, and energy density. This research provides a novel insight for designing safe and high-efficient ZIBs.