Electrodepositing amorphous molybdenum oxides for aqueous NH4+ storage.

The limited choice of anode materials always challenges the development of high performance aqueous ammonium-ion batteries (AAIBs). Herein, we fabricate amorphous molybdenum oxide (MoOx) materials and study the NH4+ storage performances. The results indicate that the optimized electrode exhibits high gravimetric/areal capacities of 175 mA h g-1/1.30 mA h cm-2, outperforming state-of-the-art anode materials for AAIBs. Our findings indicate that the valence state of Mo and the Mo-O-H content in MoOx synergistically control the NH4+ storage performances, offering new understanding for rational design of MoOx materials for energy storage applications.