Composites of cerium-doped vanadium oxide nanoparticles and nitrogen-doped carbon constructed by simultaneous electrodeposition for aqueous zinc-ion storage

Novel electrode materials with high specific capacity and cycling stability for aqueous zinc ion storage are desirable. A simultaneous electrodeposition method is developed to construct Ce-doped vanadium oxide / poly( o -methoxyaniline) composites on carbon cloth (CC). After thermal treatment, Ce-doped vanadium oxide @ nitrogen-doped carbon composites (Ce-VO@NC/CC) are obtained. The Ce-VO@NC films are poorly crystallized, with oxide nanoparticles around 10 nm in size embedded in NC. The introduction of Ce ions tunes the morphology of the deposits and induces electron interaction. Using three-electrode test in 2 M ZnSO 4 , the Ce-VO@NC/CC exhibits an excellent specific capacity of 347.2 mAh g −1 at 1 A g −1 galvanostatic charging-discharging current density, and outstanding cycling stability, with 90.3 % of its initial capacity maintained after 5000 cycles at 10 A g −1 . In comparison, the VO@NC/CC exhibits 270.8 mAh g −1 at 1 A g −1 , and 73.0 % capacity retention after 5000 cycles, inferior to the Ce-VO@NC/CC. Both diffusion-controlled and surface-capacitive processes contribute to the stored charge. Ex-situ characterizations indicate that both Zn 2+ and H + participate in the charge storage process, along with the redox of metal centers and nitrogen in the NC layer. A two electrode device is constructed using Ce-VO@NC/CC, Zn foil and 2 M ZnSO 4 . The device can deliver a specific energy density of 151.4 Wh kg −1 at the power density of 500 W kg −1 . • One-step electrodeposition to composite Ce-doped VO x with PoMA • 347.2 mAh g −1 and 90.3 % retention (5000 cycles) are achieved in 2 M ZnSO 4 . • Charge storage involves H + and Zn 2+ de/intercalation. • Ce-doping alters the morphology and introduce electron interaction. • Achievement of top-tier energy density (151.4 Wh kg −1 )