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||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.