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 NiMoO4 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 NiMoO4 (200.2 mAh g–1) and NiMoO4/Ni-Prussian blue analogue (NiMoO4/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 NiMoO4-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.