Phosphide-Enhanced Hierarchical NiMoO₄ Composite in Binder-Free Ni-Electrodes for High-Capacity Aqueous Rechargeable NiZn Batteries

Abstract

A growth strategy is described where a multidimensional P(Ni, Fe) nanoarray electrode is fabricated by phosphiding NiMoO 4 nanoflakes modified with a Ni-based Prussian blue analogue induced by in situ self-sacrificial formation. The generated electrode exhibits a specific capacity of 501.8 mAh g −1 at 1 A g −1 , owing to the unique overlapping cross-stacked network structure with increased surface-and interface-active sites and enhanced conductivity. This is about 2 times larger than those of the NiMoO 4 (200.2 mAh g −1 ) and NiMoO 4 /Ni-Prussian blue analogue (NiMoO 4 /Ni-PBA) (217.3 mAh g −1 ) electrodes. The battery cell assembled with the obtained P(Ni, Fe) nanoarray electrode and a Zn plate as the counter electrode shows a high energy density of 962.6 Wh kg −1 at a power density of 870 W kg −1 . This demonstrates the potential of NiMoO 4 -based materials for NiZn battery applications and gives insight into the design of electrode materials by controlling the surface/interface in next-generation high-performing NiZn batteries.