Electrodepositing amorphous molybdenum oxides for aqueous NH₄⁺ storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Developing high-performance anode materials is crucial for advancing aqueous ammonium-ion batteries (AAIBs).
• Current anode options for AAIBs are limited, hindering battery performance.

Purpose of the Study:

• To fabricate amorphous molybdenum oxide (MoO) materials for AAIBs.
• To investigate the ammonium (NH₄⁺) storage performance of MoO anodes.
• To understand the factors controlling NH₄⁺ storage in MoO.

Main Methods:

• Fabrication of amorphous molybdenum oxide (MoO).
• Electrochemical testing of MoO as an anode material in AAIBs.
• Analysis of material properties, including valence state of Mo and Mo-O-H content.

Main Results:

• The optimized amorphous MoO electrode achieved high gravimetric capacity (175 mA h g^-1) and areal capacity (1.30 mA h cm^-2).
• Performance surpassed existing state-of-the-art anode materials for AAIBs.
• Valence state of Mo and Mo-O-H content were identified as key factors influencing NH₄⁺ storage.

Conclusions:

• Amorphous MoO is a promising anode material for high-performance AAIBs.
• Understanding the role of Mo valence and Mo-O-H content enables rational design of MoO-based energy storage materials.
• This work provides new insights for developing advanced AAIBs.